Bi-wiring/Bi-amping explained

[steveinaz]

Bi-wiring requires speakers that have "bi-wire" capability, that is 2 sets of binding posts (4 posts total, each speaker). Bi-wire capable speakers can also be "bi-amp'd."

Keeping things simple, bi-wiring allows you to run speaker connections seperately to the high/low sections of your speaker, minimizing the components used in the cross-over network (less is usually better in Audio). Proponents of bi-wiring state that low frequency signals will traverse the bass wires, and high frequency signals will traverse the mid/treble wires, thereby introducing less intermodulation distortion. The debate forever goes on about its "real" effectiveness. I can tell you that I've tried both for over 30 years, and have reverted to a single run of high quality wire. Opponents to bi-wiring claim that you simply end up spending twice as much on speaker cables, and get negligible--if any--improvement.

My opinion? Rather than spending money on less expensive wires so you can afford bi-wiring---spend more money on a very good set of wires and use a single run. Do you need to spend 800 bucks on speaker wire? Hell no. Wire, like everything has a point of diminishing returns. I'm extremely happy with my $280 set of AudioQuest Granites. If your pockets are deep--go for it and bi-wire, just don't sacrifice quality of cable.

Bi-amping is much more effective, but also much more expensive. It requires 2 identical amps (ideally). One amp is used for mid/highs, the other amp for low frequencies. I have bi-amp'd in the past with very nice results--but no longer have 2 amps. Again, IMO its better to spend the bucks on one powerful good quality amp, then to buy 2 so-so amps.

Hope this helps.

Here's my setup for reference:

Parasound HCA-1500A amplifier
Parasound PHP-850 Preamp
Cambridge Audio D500SE CD Player
Athena AS-F2 tower speakers
Audioquest Granite speaker wires (single run)
Audioquest Sidewinder interconnects

[F1nut]

Steve,

Welcome to the forum.

I will have to disagree with your statement that bi-amping requires 2 identical amps. Actually one of the advantages of bi-amping is that one can optimize one amp for the mid/high range and another for the low range. The only thing that must be matched is the gain. In using two different amps with different gain levels, you must have a level adjustment. It is often easier to have identical amps rather than trying to adjust the level.

F1

[steveinaz]

You're right, it can be done with different amps, but note that I said (ideally) above. It can be troublesome to match different amps at times.

[F1nut]

Duely noted. I just wanted to present all the options of bi-amping.

[Tour2ma]

Originally posted by steveinaz
Bi-wiring ... minimizing the components used in the cross-over network Actually it makes no difference at all in the utiization of the cross over network. A bi-wirable speaker has separate entry points to the high and low frequency portions of the crossover. The two portions are in parallel whether you use a single wire run with jumpers, or bi-wire.

The same would be true for the same speaker, if it had only one pair of posts. Effectively the jumper would just be inside the cabinet.

Originally posted by steveinaz
Bi-amping ... One amp is used for mid/highs, the other amp for low frequencies. Well, again, not really. Both amps amplify the full signal, it's just that large portions of the output of each are not of use to the drivers being fed (moreso in the case of the tweeters). There may be some net gain via the external feedback loop, if the amp design can make use of the "unused" signal.

As you infer, bi-amping is often just a means of over coming a power deficiency, and it can be a more economical approach than upgrading to a single, more powerful amp.

As F1 pointed out, effective use can be made of "unequal" amps producing the same gain. There are other characteristics that are worth matching as well, including input sensitivity, slew rate and damping factor. The amount of power difference that can be employed depends on the speaker.

In the case of Polks with tweeters and mid-woofers, the difference can be substantial as there is so little power requirement in the higher frequencies. Certainly a 50% less powerful amp would be adequate, probably a 75% and possibly even a 90%, depending on music and listening levels (but personally, I wouldn't go that low).

However, in a three way design, where most often the posts are split between feeding the tweets/ mid's together and the woofer(s) separately, 50% less to the upper frequencies would be as low as can see going.

Just trying to amplify the discuission here... :D

[dorokusai]

To start the thread with a end all statement was doomed for discussion. I agree there are other aspects that you did not touch on in the starter, as the above statements make clear. In theory, EVERYTHING works, its in application that the wrench or individual becomes a player.

The gain adjustment can also compensate for pre-amp levels and/or "THX" levels that are mismatched, in addition for cross amping brands.

There are alot of variables that affect Bi-Anything, I personally think its just ground level useable. You, the listener/owner, decide.

[steveinaz]

Keep in mind that anyone who is asking the question "what is bi-wiring" is probably new to hi-fi and doesn't have the technical background to understand the theories associated with bi-wiring/bi-amping; this is why my initial thread was kept simple, non-technical and to the point. I could have given the scientific answer--but thats already been done here numerous times, yet everyday someone else aks "what is bi-wirng?" It became obvious to me that the answers they were getting were far too technical.

You misunderstood my statement on bi-amping; of course both amplifiers reproduce the entire signal--what I was saying is that the best approach to bi-amping is to dedicate 1 amp for mid/high and the other amp for low freq's.

Much of this, in my opinion, is voodoo science. I've been deep into hi-fi for 30+ years and have found that bi-wiring improvements are largely "psyhcological" and extremely detremental to your wallet if done correctly. If you want true improvements; use your dollars on a top-notch source component, rather than a double-set of expensive speaker cable. A better source component will reward you with 10 times the improvement that bi-wiring would.

Just ask Thiel, Wilson, Magnepan, Athena, Vandersteen, Dyna Audio and a few other top-shelf speaker manufacturers why they don't support bi-wiring.

My point is this, spend your bucks on good solid quality products first; then experiment with bi-wiring or whatever your wallet can support.

[HBombToo]

Originally posted by steveinaz


Much of this, in my opinion, is voodoo science. I've been deep into hi-fi for 30+ years and have found that bi-wiring improvements are largely "psyhcological" and extremely detremental to your wallet if done correctly. If you want true improvements; use your dollars on a top-notch source component, rather than a double-set of expensive speaker cable. A better source component will reward you with 10 times the improvement that bi-wiring would.



Agreed in whole and well said.

I would also like to add a quick thought on Bi-Amping.

I agree with the notion that a less powerfull amp can be used for the tweeter side but at your listening levels it must not clip.

Also, the crossover has a certain frequency response and outside of this response will present no load on an amplifier. In short the preamp will see the entire band but as we seperate the high and low pass sections on the speakers and add another amp, each amp will only be loaded for each bandpass section its connected to.

HBomb

[steveinaz]

Originally posted by HBombToo

Also, the crossover has a certain frequency response and outside of this response will present no load on an amplifier. In short the preamp will see the entire band but as we seperate the high and low pass sections on the speakers and add another amp, each amp will only be loaded for each bandpass section its connected to.

HBomb

Precisely! You said it better than I could; thanks for the assist.

[dorokusai]

Sounds good to me :)

[Tour2ma]

steve,

I actually agree with your bi-wire/ bi-amp stance in general. While I have utilized both, I have not heard a night and day difference.

I am honestly not trying to show you up or anything like that. What I was attempting to do was to address a couple statements in your original post that either are not, well.., accurrate or I felt were potentially misleading. For example, the statement that bi-wiring eliminates part of the cross-over. Many think this and it's not the case. What it is, is one of the falicies that the "voodoo" springs from.

Anyway, in that spirit, I must point out that my Maggie 1.5's are bi-wirable, as are many other models. There are other Maggies that are not.

Henry,

Agree with Steve on your bi-amp clarifications. In our many discussions on bi-amping, I had not seen the load issue put quite that way before. Something to reflect on a bit more...

[steveinaz]

That's what forums are for, sharing theories, ideas, etc.

I stand corrected on the cross-over issue, after doing a little research I found that I had fallen prey to a misleading theory...this being the case--it seems to prove my point further that bi-wiring (as I have found) is probably an expensive waste of time. I've tried speakers connected both ways many times through the years and always end up going back to a single run. I think sometimes the "theory" is way more exciting than the actual results experienced.

I doubt seriously that any of us, save a 6 month old audiophile, would be likely to hear the benefits of bi-wiring, and I just can't justify slapping down big bucks on 2 sets of cables.

Great discussion!

[rastaboom]

I can't tell you the difference this made to the sound of my Polk Audio Rti10 tower front speakers ! The benefits should be made more clear in the documentation - it took me a few years to stumble on this forum and others talking about the great sound from bi-amping.

If you have speakers that have 4 posts behind each - two for the bass, two for the midrange/tweeter - and you're only connecting to 2 and using the bridge to feed the other 2, your speakers are most certainly underpowered. I couldn't understand why these not-too-cheap speakers weren't very impressive in my setup. I was using the back surround speakers for a 7.1 sound - but it was a waste. It resulted in underpowered front speakers and too much sound coming from the back and sides....and the back information is just faked information !!

Just recently I changed to 5.1 by setting my Denon AVR-1907 rear-surround amplifiers to bi-amp the front r/l bass. The difference is simply AMAZING !!!

Now I know why these speakers cost so much !

When BluRay and others start putting out a big chunk of their movies in 7.1 - and when the HD channels on TV start doing the same - I will most certainly invest in a 7.1 amp that also supports bi-amping. I simply will never underpower those towers again !!!

[wutadumsn23]

Thanks for your input rasta, and welcome to Club Polk. Having said that, next time feel free to start your own thread, since this one is over 6 years old, lol. Stick around and enjoy our little forum, and get ready to empty your wallet, lol.

-Jeff

[F1nut]

Talk about a blast from the past......anyway...

If you have speakers that have 4 posts behind each - two for the bass, two for the midrange/tweeter - and you're only connecting to 2 and using the bridge to feed the other 2, your speakers are most certainly underpowered.

That comment is far, far from the truth.


It resulted in underpowered front speakers and too much sound coming from the back and sides....

Yep, that's what happens when you don't calibrate the set up. Did you have the fronts set to small or large before and what are they set to now?

[comfortablycurt]

I can't tell you the difference this made to the sound of my Polk Audio Rti10 tower front speakers ! The benefits should be made more clear in the documentation - it took me a few years to stumble on this forum and others talking about the great sound from bi-amping.

If you have speakers that have 4 posts behind each - two for the bass, two for the midrange/tweeter - and you're only connecting to 2 and using the bridge to feed the other 2, your speakers are most certainly underpowered. I couldn't understand why these not-too-cheap speakers weren't very impressive in my setup. I was using the back surround speakers for a 7.1 sound - but it was a waste. It resulted in underpowered front speakers and too much sound coming from the back and sides....and the back information is just faked information !!

Just recently I changed to 5.1 by setting my Denon AVR-1907 rear-surround amplifiers to bi-amp the front r/l bass. The difference is simply AMAZING !!!

Now I know why these speakers cost so much !

When BluRay and others start putting out a big chunk of their movies in 7.1 - and when the HD channels on TV start doing the same - I will most certainly invest in a 7.1 amp that also supports bi-amping. I simply will never underpower those towers again !!!

Well that's a whole lot of bad information...but whatever works for you.

Your speakers are still receiving the exact same amount of power from your AVR. Every channel on your AVR is powered by one common power amplifier, so the speaker is only going to draw as much power as it needs...regardless of how many outputs it's hooked up to.

Bi-wiring with an AVR has zero benefits in my experience. Others have reported improvements though...

[Keiko]

Well that's a whole lot of bad information...but whatever works for you.

Bend over there then, Curt. I'll bi-wire ya. :p

http://i10.photobucket.com/albums/a148/mikeLee1961/pe12.jpg

[wutadumsn23]

Well that's a whole lot of bad information...but whatever works for you.

Your speakers are still receiving the exact same amount of power from your AVR. Every channel on your AVR is powered by one common power amplifier, so the speaker is only going to draw as much power as it needs...regardless of how many outputs it's hooked up to.

Bi-wiring with an AVR has zero benefits in my experience. Others have reported improvements though...

Yup, I am with you on this one Curt.

-Jeff

[Keiko]

Yup, I am with you on this one Curt.

-Jeff

Shuddup Jeff! I got dibs on bi-wiring him first. :mad:

[wutadumsn23]

Doh, man you have all the fun Mike. Besides I am closer, you are way out in the ocean!!

[Keiko]

Doh, man you have all the fun Mike. Besides I am closer, you are way out in the ocean!!

I have cables laid out all through the Pacific. I got this whole planet, bi-wired. :p

[wutadumsn23]

LOL, you kill me Mike. Looks like it's up to you, me, and Curt to poop on threads now with Russ being on hiatus, lol.

[Keiko]

Curt can't talk right now. He's being bi-wired. :eek:

[wutadumsn23]

Yikes. :D

[Keiko]

And I'm not thread crappin' neither. I'm staying on topic. So there! :p

[edbert]

Bi-wiring with an AVR has zero benefits in my experience. Others have reported improvements though...


I would actually disagree to a point. I think it depends on the speakers that you are bi-amping. I have a very modest system in having Monitor 40's as my mains. My AVR is a 7.1 receiver and you can use the two surround back channels as the available option to bi-amp the mains effectively giving you 5.1. I did back to back comparison using the same movie sequence in Borne Identity and u-571. I noticed a fairly significant improvement in the sound going from regular amplification to bi-amping. Granted, I am running a smaller Monitor series speaker and not LSi's, so the difference I hear will be vastly different from someone running a higher end speaker. At the same time, someone used to hearing a higher quality speaker will probably think my setup sounds like piss no matter how you hook it up because they are used to a better speaker with lots of good clean power being fed to it. Overall, this is all very subjective and it really depends on the quality of the components being used and the level of quality a person is used to hearing coming out of their speakers.

EDIT: Alright, so I am apparently still asleep or something, I misread the section that I quoted as saying bi-amping and not bi-wiring. I agree with the bi-wiring because I tried that as well and didn't notice any improvement. The rest of what I said is just my .02 on an issue that wasn't even brought up. Consider it my contribution to the forum for the year.

[cabbiepimpin]

Question: clearly, bi-amping by redirecting the rear surround channels on an AVR is useless since all the channels derive their power from the same amplifier source.

However, does this analysis still pertain to AVRs which purportedly have different/discrete power sources for each channel? I have a Denon AVR1909; I believe the website markets it as having "independent power supplies."

If this is so, then would not bi-amping with the 1909 actually derive a benenfit since each run to each of the front speakers is drawing from a separate power source? Or is this all marketing gimickery?

[steveinaz]

Seeing a post from yourself 6 years ago, is like the first time you heard your voice on a cassette recorder-----you sound like a dork...

LOL

[Cpyder]

If I have two 2-way speakers and two amps, would it be better to just use one amp per speaker and not bi-amp. I feel like using one amp to power the tweeters would basically be a waste of an amp since the tweeters don't need much juice, but the woofers would.

1 amp / 1 speaker

or

bi-amp?

[steveinaz]

I would not bi-amp in that setup.

[anhchungdoan]

Well that's a whole lot of bad information...but whatever works for you.

Your speakers are still receiving the exact same amount of power from your AVR. Every channel on your AVR is powered by one common power amplifier, so the speaker is only going to draw as much power as it needs...regardless of how many outputs it's hooked up to.

Bi-wiring with an AVR has zero benefits in my experience. Others have reported improvements though...

When a person using the passive bi-amp method from the AVR as the poster stated, there is nada, zero better on SQ. The amp will see only 50W instead of 100W go to the hi and the same go to the low frq. and as a result, the amp will have to work harder and draw more current ( higher distortion and running hot= heat issue).

Bob Carver recommended vertical bi-amp for his Sunfire Signature multi channel amp, it may work due to the sound characteristic of the Voltage/Current ouput however the benefit remains to be seen as subjective issue.

Bi-amping with 2 different type of amps or with 2 separated same types of amp will require an active X-over ( NHT/Bryston) but one needs to make sure that the procedure is in compliance with the speakers manufacture's recommendation.

[anhchungdoan]

Question: clearly, bi-amping by redirecting the rear surround channels on an AVR is useless since all the channels derive their power from the same amplifier source.

However, does this analysis still pertain to AVRs which purportedly have different/discrete power sources for each channel? I have a Denon AVR1909; I believe the website markets it as having "independent power supplies."

If this is so, then would not bi-amping with the 1909 actually derive a benenfit since each run to each of the front speakers is drawing from a separate power source? Or is this all marketing gimickery?

You are getting there, brother. I'd rather using bridge mode than passive bi-amp if i need more juice to the FL/FR.

[anhchungdoan]

Bend over there then, Curt. I'll bi-wire ya. :p

http://i10.photobucket.com/albums/a148/mikeLee1961/pe12.jpg


Nice 2 channel amp but I will have to pass. :D

[concealer404]

If I have two 2-way speakers and two amps, would it be better to just use one amp per speaker and not bi-amp. I feel like using one amp to power the tweeters would basically be a waste of an amp since the tweeters don't need much juice, but the woofers would.

1 amp / 1 speaker

or

bi-amp?


Try both ways. See which sounds better. Can't take that long to find out, right?

[vc69]

Well that's a whole lot of bad information...but whatever works for you.

Bi-wiring with an AVR has zero benefits in my experience. Others have reported improvements though...

That is an opinion (that I happen to share). However, rastaboom was referring to Bi-amping. Which I also agree is a waste of time with a receiver.

Bi-amping with 2 different type of amps or with 2 separated same types of amp will require an active X-over...

zackly

This thread seems to have a misunderstanding of what bi-amping is.

Bi-amping (or tri/quad) is done (properly) with an active crossover and some serious room analysis/tuning. It sometimes involves a 1/3 octave graphic EQ (in some cases parametric) for each channel, separate low and high cabinets (not always) and a very expensive (accurate) real-time analyzer/mic and a frequency/noise generator for setting it all up. We do it in live concert sound applications all of the time.
It is not anything like bi-wiring and certainly quite different than just hooking up two separate amps and adjusting the levels.

[anhchungdoan]

That is an opinion (that I happen to share). However, rastaboom was referring to Bi-amping. Which I also agree is a waste of time with a receiver.



zackly

This thread seems to have a misunderstanding of what bi-amping is.

Bi-amping (or tri/quad) is done (properly) with an active crossover and some serious room analysis/tuning. It sometimes involves a 1/3 octave graphic EQ (in some cases parametric) for each channel, separate low and high cabinets (not always) and a very expensive (accurate) real-time analyzer/mic and a frequency/noise generator for setting it all up. We do it in live concert sound applications all of the time.
It is not anything like bi-wiring and certainly quite different than just hooking up two separate amps and adjusting the levels.


Please enlighten me about bi-amping. If my pre-amp has only one set of pre-out and I want to use one amp to drive my woofer and another amp to driver my electrostat panel, what is your configuration without an external active cross-over?

[vc69]

Please enlighten me about bi-amping. If my pre-amp has only one set of pre-out and I want to use one amp to drive my woofer and another amp to driver my electrostat panel, what is your configuration without an external active cross-over?
I don't understand your question. You will need a xover. I think you must have misread my post.

[anhchungdoan]

I don't understand your question. You will need a xover. I think you must have misread my post.


I am sorry that I misread your reply to my post.

It can be done without the external cross-over as in case with B &W tech recommended due to their internal cross-over but if it is a case, it 's not a-true bi-amping.

I will recommend a follow-up reading for polk posters who has issues with bi-amping. Please google SOUND.WESTHOST.COM/BIAMP.HTM for more details. Bi-amping is not a simple tweak. Life is a learning process as I am continuing learning everyday. I hope that reading will help to clear up some confusion.

[anhchungdoan]

I may need VC69 help on another issue that I would like some polk posters be aware of, especially the ones who want to tweak their gear.

Besides the hype about the bi-amping from some of the AVR maufactures, please be careful with the XLR hypes from some of the high-price AVR and mid-end pre/amp manufactures.

Their selling point is " we have XLR output ( pre) and XLR input (amp) to lure in some less-informed customer to buy their the hi-price products. Most of these XLR connections are just HYPE. Yes, they look impresssive but these XLR are not true balance output/input at all. They are simply single-ended connections with a XLR adaptor. You will not be benefit at all with these type of balanced connections.

Look at some XLR inout/ouput from Adcom, Rotel, Parasound, Emotiva....products , they are there for nothing but cheap gadgets. Call them up and ask them if their products have true balanced input/ output or not. If they say they are, then simply ask them what is their pins configuration, if they do not have a clear answer then you know the answer.

I know this is not the same topic but it could be a side benefit to some new comers to the audio world. Welcome to the HYPE and buyers beware.

Now I finish my rant. :D

[vc69]

That site definitely covers all of the commonly misunderstood concepts of both bi-wiring and bi-amping.

Good linkage!

http://sound.westhost.com/bi-amp.htm#common-question

[TECHNOKID]

Seeing a post from yourself 6 years ago, is like the first time you heard your voice on a cassette recorder-----you sound like a dork...

LOLOn the opposite, you should feel good about this, we seen the question coming back over and over and I wished people would actually done this through this discussion (which has many good leads to understand the process) instead of starting the process all over and this with so many wrong pointers.


Now, we have to realize there is 2 differents reasons for bi-amping and it seems people confuse the 2;

1. When people speak of improved SQ, power gain isn't necessary the goal and should be used differently in the discussion. Improving the SQ through bi-amping is oriented toward isolating the High and Mid bi means of seperate channels and this should be the true goal for bi-amping.

2. The use of bi-amping through seperate amps with the goal in mind to gain power is achievable but the ideal unless you intend to achieve both power gain and High/Mid isolation otherwise it is preferable to simply use seperate amp with High/Mid jumpered.

3. Then you can talk about benefit of bi-amping through an AVR... The gain would be simple isolation of High/Mid but forget about any power gain improvement and if you do talk about SQ, don't talk power gain!

Looks like most realize the concept of buying AVRs with pre-outs and using seperate amps to achieve either/or/both gain and isolation. Part of the reasonning is also that while using seperate amps what ever power which isn't used from that AVR is the freed for the other channels that are actually hooked-up to the AVR.

Last but NOT the least, when one is talking about power gain, he/she must realize that in order to gain 3db, power must be doubled therefore, the same retoric question about extra power "Should I hear any difference or gain power" by using my AVR to provide extra power to my speakers should be answered once for all. If you want to hear substantial gain power coming out of your speaker, your external amp should provide at least twice as much juice than the original one. Improved SQ does not mean power gain either.

Cheers!
TK

[TECHNOKID]

I may need VC69 help on another issue that I would like some polk posters be aware of, especially the ones who want to tweak their gear.

Besides the hype about the bi-amping from some of the AVR maufactures, please be careful with the XLR hypes from some of the high-price AVR and mid-end pre/amp manufactures.

Their selling point is " we have XLR output ( pre) and XLR input (amp) to lure in some less-informed customer to buy their the hi-price products. Most of these XLR connections are just HYPE. Yes, they look impresssive but these XLR are not true balance output/input at all. They are simply single-ended connections with a XLR adaptor. You will not be benefit at all with these type of balanced connections.

Look at some XLR inout/ouput from Adcom, Rotel, Parasound, Emotiva....products , they are there for nothing but cheap gadgets. Call them up and ask them if their products have true balanced input/ output or not. If they say they are, then simply ask them what is their pins configuration, if they do not have a clear answer then you know the answer.

I know this is not the same topic but it could be a side benefit to some new comers to the audio world. Welcome to the HYPE and buyers beware.

Now I finish my rant. :DEffectively you should start a different thread with this topic as your comments may divert this discussion totally out of wack. I will not comment any further in order to keep this discussion on track but would love you to start a different discussion with this because I think you might have some mis-conception about the manufacturers/suppliers in thinking they would provide phony technology.

Cheers!
TK

[vc69]

Effectively you should start a different thread with this topic as your comments may divert this discussion totally out of wack. I will not comment any further in order to keep this discussion on track but would love you to start a different discussion with this because I think you might have some mis-conception about the manufacturers/suppliers in thinking they would provide phony technology.

Cheers!
TK

+1
Start another thread.

[anhchungdoan]

On the opposite, you should feel good about this, we seen the question coming back over and over and I wished people would actually done this through this discussion (which has many good leads to understand the process) instead of starting the process all over and this with so many wrong pointers.


Now, we have to realize there is 2 differents reasons for bi-amping and it seems people confuse the 2;

1. When people speak of improved SQ, power gain isn't necessary the goal and should be used differently in the discussion. Improving the SQ through bi-amping is oriented toward isolating the High and Mid bi means of seperate channels and this should be the true goal for bi-amping.

2. The use of bi-amping through seperate amps with the goal in mind to gain power is achievable but the ideal unless you intend to achieve both power gain and High/Mid isolation otherwise it is preferable to simply use seperate amp with High/Mid jumpered.

3. Then you can talk about benefit of bi-amping through an AVR... The gain would be simple isolation of High/Mid but forget about any power gain improvement and if you do talk about SQ, don't talk power gain!

Looks like most realize the concept of buying AVRs with pre-outs and using seperate amps to achieve either/or/both gain and isolation. Part of the reasonning is also that while using seperate amps what ever power which isn't used from that AVR is the freed for the other channels that are actually hooked-up to the AVR.

Last but NOT the least, when one is talking about power gain, he/she must realize that in order to gain 3db, power must be doubled therefore, the same retoric question about extra power "Should I hear any difference or gain power" by using my AVR to provide extra power to my speakers should be answered once for all. If you want to hear substantial gain power coming out of your speaker, your external amp should provide at least twice as much juice than the original one. Improved SQ does not mean power gain either.

Cheers!
TK

Theorically, To gain 3db the power must be double. It 's a simple fact but I aslo like to add that for human ears to really feel the impact of the difference in SPL, it will take some where between 5/10 db. I forgot the name of the study so take it with a grain of salt if you will.

Bi-amping is a nice approach, let say I want my electrostat panel sound like tube but I want tight bass for my woofer. So, tube amp for the Hi and SS amp for the low. That's when tube meets SS and I gain the benefit of both by bi-amping my speakers.

As you say, to gain more power just to buy another external multi-channel amps but the pre-samp section remains the same. If the pre-amp section is "suck" then the amplification part just amplify the" suckness". I agree with you.

[anhchungdoan]

+1
Start another thread.

My bad. Sorry! I probably will one day. Thank you.

[vc69]

IIRC 1 db gain requires double the output power. 3 db increase = noticeable increase in volume.

Am I confused?

[TECHNOKID]

IIRC 1 db gain requires double the output power. 3 db increase = noticeable increase in volume.

Am I confused?Find decibel power gain by entering before and after power:
Not used in sound engineering.

http://www.sengpielaudio.com/calculatorVoltagePower.htm use this calculator and you will notice that every time you double your power the db increases by 3 every time.

You probably confuse it with the volt: Find decibel voltage gain by entering input and output voltage: which doubles when you add an extra volt at the output IE: 1 volt in w/2 volts out = 6db but if you increase the same o/p you will notice that while your o/p power is dubled, your db increase is 3 dbs every additional volts at the o/p.

Cheers!
TK

[vc69]

Ok. But I seem to remember this formula. Somebody please chime in as I am getting old and may be wrong here. :o

Say speaker efficiency is 89db (@1 watt @1 meter)

90 db requires 2 watts
91 db requires 4 watts
92 db requires 8 watts
93 db requires 16 watts
and so forth.

Generally speaking a 3 db gain (in output) is required to "hear" a noticeable increase in volume.


This has certainly strayed off topic. But I wanted to get a consensus. :)

[anhchungdoan]

Here it is. I found the old study. Valid or invalid, it's your call.

1. Imperceptible change : 1db increase
2.Barely perceptible change: 3db increase.
3.Clearly noticeable change: 5db increase.
4.About twice as loud : 10db increase.
5.About 4 times as loud: 20db increase.

*Statistic for the Decible comparison chart were taken from a study by Marshall Chasin M.Sc, Aud(c), FAAA, Centre for Human Performance and Health, Ontario, Canada.

You all have a nice week-end.

[sTiLlLeArNiNg]

*Statistic for the Decible comparison chart were taken from a study by Marshall Chasin M.Sc, Aud(c), FAAA, Centre for Human Performance and Health, Ontario, Canada.

A Canadian? What the heck do Canadian's know about audio :confused: I mean; we all live in IGLOOs and travel by dogsled? :o

[anhchungdoan]

A Canadian? What the heck do Canadian's know about audio :confused: I mean; we all live in IGLOOs and travel by dogsled? :o


Hey, take it easy on the Canadian! My beautiful lady and my "the one and the only" female pianist and jazz singer, Diana Krall is from where you already know. :D

[TECHNOKID]

A Canadian? What the heck do Canadian's know about audio :confused: I mean; we all live in IGLOOs and travel by dogsled? :oWe Canadians don't know dip $h1t about audio thus the reason for coming out here, right? ;)

[MLZ]

Please correct me as I am not an electrical engineer or electrician, but when researching bi-wiring and looking at the electrical diagram, it appears that all bi-wiring does is move the effective jumper from the speakers to the amplifier.

What I think I see is in non-bi-wired the circuit is amplifier terminal to speaker terminal A to Speaker Terminal B and in bi-wired the circuit is speaker terminal A to amplifier terminal to Speaker Terminal B.

[anhchungdoan]

We Canadians don't know dip $h1t about audio thus the reason for coming out here, right? ;)

Hey! take it easy. Now you guys spoil my week-end. Iggloo and dogsleds? Another attempted shot at another pretty woman from Alaska. I know what you guys are doing. I do not care if she sees Russia from her house, I like pretty woman.

Diana Krall, Jazz singer ( Canadian) & Sarah Palin ( Alaskan) = 2 beautiful components.

[TECHNOKID]

Please correct me as I am not an electrical engineer or electrician, but when researching bi-wiring and looking at the electrical diagram, it appears that all bi-wiring does is move the effective jumper from the speakers to the amplifier.

What I think I see is in non-bi-wired the circuit is amplifier terminal to speaker terminal A to Speaker Terminal B and in bi-wired the circuit is speaker terminal A to amplifier terminal to Speaker Terminal B.You are right, with jumper = split occurs at the speaker while bi-wiring (jumper removed) = split occur at the amplifier not much difference unless you are using extreme lenghts of cable. I can not comment on the remainder of your post as I do not really understand your A/B talk (I guess not seeing the block diagram you are talking about...).

Cheers!
TK

[mufsoman]

FYI, I just recently did a bunch of trials with my set up (see my review of the Tsi500 demos in the "Speaker" section). I originaly had my Rti8's biwired because I was convinced there was an improvement in the sound. After reading a couple of threads about how the little metal jumper bars can be a crappy way to connect the speaker terminals, I tested using single wire with wire jumpers instead....and got what I percieve as the same improved sound. Even went back to the single wire and metal jumpers to compare and got what I percieve as less quality sound. I'm still a newbie and figuring all this out, but could the percieved sound improvement that people say they get from biwiring really be just the improvement of two wires feeding the speaker terminals vs. using a crappy jumper plates??? Just a thought......

[TECHNOKID]

FYI, I just recently did a bunch of trials with my set up (see my review of the Tsi500 demos in the "Speaker" section). I originaly had my Rti8's biwired because I was convinced there was an improvement in the sound. After reading a couple of threads about how the little metal jumper bars can be a crappy way to connect the speaker terminals, I tested using single wire with wire jumpers instead....and got what I percieve as the same improved sound. Even went back to the single wire and metal jumpers to compare and got what I percieve as less quality sound. I'm still a newbie and figuring all this out, but could the percieved sound improvement that people say they get from biwiring really be just the improvement of two wires feeding the speaker terminals vs. using a crappy jumper plates??? Just a thought......Valid point as crappy/good connections goes a long way, maybe this what you actually experienced.

Cheers!
TK

[MLZ]

I can not comment on the remainder of your post as I do not really understand your A/B talk (I guess not seeing the block diagram you are talking about...).

Cheers!
TK

You got it - I guess the example wasn't needed anyway. :o

[vc69]

FYI, I just recently did a bunch of trials with my set up (see my review of the Tsi500 demos in the "Speaker" section). I originaly had my Rti8's biwired because I was convinced there was an improvement in the sound. After reading a couple of threads about how the little metal jumper bars can be a crappy way to connect the speaker terminals, I tested using single wire with wire jumpers instead....and got what I percieve as the same improved sound. Even went back to the single wire and metal jumpers to compare and got what I percieve as less quality sound. I'm still a newbie and figuring all this out, but could the percieved sound improvement that people say they get from biwiring really be just the improvement of two wires feeding the speaker terminals vs. using a crappy jumper plates??? Just a thought......

That is my suspicion. I think that doing away with the plate jumpers and using wire is where the most marked improvement can be had.
As for hi-end and rather expensive bi-wire cables, I am still undecided in my setup. I have some, so I use them. But I don't think they are giving me a justifiable return on investment. I think that may change as I move up to an amp that can reveal those subtleties. I am reserving judgment till then.

[F1nut]

Ok. But I seem to remember this formula. Somebody please chime in as I am getting old and may be wrong here. :o

Say speaker efficiency is 89db (@1 watt @1 meter)

90 db requires 2 watts
91 db requires 4 watts
92 db requires 8 watts
93 db requires 16 watts
and so forth.



No, it would look like this;

89dB - 1 watt
92dB - 2 watts
95dB - 4 watts
98dB - 8 watts
101dB - 16 watts
104dB - 32 watts
107dB - 64 watts
110dB - 132 watts
113dB - 264 watts
116dB - 528 watts

So, for every 3dB increase it takes double the power.

[vc69]

No, it would look like this;

89dB - 1 watt
92dB - 2 watts
95dB - 4 watts
98dB - 8 watts
101dB - 16 watts
104dB - 32 watts
107dB - 64 watts
110dB - 132 watts
113dB - 264 watts
116dB - 528 watts

So, for every 3dB increase it takes double the power.

Ok, I was confused.:o

Thanks.

[sTiLlLeArNiNg]

Hey, take it easy on the Canadian! My beautiful lady and my "the one and the only" female pianist and jazz singer, Diana Krall is from where you already know. :D

Hey! take it easy. Now you guys spoil my week-end. Iggloo and dogsleds? Another attempted shot at another pretty woman from Alaska. I know what you guys are doing. I do not care if she sees Russia from her house, I like pretty woman.

Diana Krall, Jazz singer ( Canadian) & Sarah Palin ( Alaskan) = 2 beautiful components.

No worries man! In case you didn't notice TECHNOKID and i are both Canuck's lol :)

We Canadians don't know dip $h1t about audio thus the reason for coming out here, right? ;)

Yup! I'm sTiLlLeArNiNg ;) :D

[Lasareath]

Seeing a post from yourself 6 years ago, is like the first time you heard your voice on a cassette recorder-----you sound like a dork...

LOL


Welcome to Club Polk Steve!


Did you have the fronts set to small or large before and what are they set to now?


I just can't figure out where i set my 1.2's to large on my Adcom GFP-750!!!! ARGH!!!!! :mad:

[anhchungdoan]

Welcome to Club Polk Steve!





I just can't figure out where i set my 1.2's to large on my Adcom GFP-750!!!! ARGH!!!!! :mad:

IMS, I set all my full range speakers @ small/ 80hz for movies. IMHO, if you have a GOOD sub , it works better that way. If your sub does not go down ,say to 20hz you may want to tried both way and see which way sounds better to your ears.

[warlocks1]

Give it a try Sal! I am going to try setting my 1.2tl's to small and crossover at 120 hz. I will let my center handle the low end. :D

[JotGloky73]

from the lack of response I figure that must be a bad idea. Guess Ill start bidding on some expensive, 20 year old wiring harnesses on ebay:

[F1nut]

What are you talking about?

[Krazyz1]

Since this started out a explanation of bi-wiring/bi-amping , here is my scenario. Some speakers you can hear a difference when bi-wired. On my RTiA9's made a big difference. The only way I can describe it is that the music sounds meatier or more robust. Not just my oppinion , others that had heard it before and after agreed.This is the part where I be come un-educated and need some education from people in the know. Does the amplifier read the ohm value still at the rated 8 ohm , or bi-wired does the amp see it as a 4 ohm load?????? I don't know and this is what got me wondering. For sake of argument a ROTEL RB-1090 will support 4 speakers in standard wiring mode , but will only support 2 if bi-wired. Why???????

[sTiLlLeArNiNg]

TBH Krazy i think the biggest improvement come's from removing the stupid jumper bar's that come on all 4 post speaker cabinet's and using speaker wire ;)

I'm currently trying to build some cable's based off of Canare's 4s11 which is a 4 conductor cable, i will be pairing up the lead's on the AMP/AVR side and running each separate lead to the corresponding terminal's on the speaker side. I have pretty much everything i need except for the terminal's which i hope to get ordered this week or early the following week :o

I'm not shure but i think with your Rotel example you would be bi-amping and not just bi-wiring :confused: I would assume that there would be more noticeable gain from bi-amping vs bi-wiring ;)

I still beleive that bi-wiring produce's noticeable improvement's and i beleive those improvement's vary depending on the speaker :cool:

Trying to bi-wire/bi-amp is not very costly IMO (provided you have the 2nd amp for bi-amping) as you can get Canare 4s11 (which is very highly reccomended by many people) usually for $1.19/ft - $1.39/ft and since you are in the state's most companies offer free shipping to lower 48 sate's on order's over $100 :)

[Krazyz1]

I agree with most of what you are saying , but if you go to Rotel home page and go into archive downloads it shows distinctly on the rear panel wiring 4 speakers hooked up 2 strand only and also only 2 speakers wired to it that are bi-wired. I fully understand the difference between the 2. Bi-wiring is removing jumper bars at speaker terminal and running 2 set of speaker wires to amp and the you have 2 + cables on red term. and 2 - wires on black term. Bi-amping is essentially the the same EXCEPT each cable would be connected to seperate amps. If I am in error feel free to correct me. Still no answer on ohm issue that is my biggest curiosity.Because if your speakers are essentially rated 8 ohm and because non stand wiring might make the amp read 4 ohm , I would think that would open the door to over power your speakers since amps have 1 rating @ 8 ohm and 4 ohm almost always higher. That's why the ohm issue is important to me. I don't want to think I am only shoving 200w. because 8 ohm , where in reality I might be running 350w. because I DON'T know if amp reads the load different because of bi-wiring. Someone please clear this up for me. Thank you.

[TECHNOKID]

I agree with most of what you are saying , but if you go to Rotel home page and go into archive downloads it shows distinctly on the rear panel wiring 4 speakers hooked up 2 strand only and also only 2 speakers wired to it that are bi-wired. I fully understand the difference between the 2. Bi-wiring is removing jumper bars at speaker terminal and running 2 set of speaker wires to amp and the you have 2 + cables on red term. and 2 - wires on black term. Bi-amping is essentially the the same EXCEPT each cable would be connected to seperate amps. If I am in error feel free to correct me. Still no answer on ohm issue that is my biggest curiosity.Because if your speakers are essentially rated 8 ohm and because non stand wiring might make the amp read 4 ohm , I would think that would open the door to over power your speakers since amps have 1 rating @ 8 ohm and 4 ohm almost always higher. That's why the ohm issue is important to me. I don't want to think I am only shoving 200w. because 8 ohm , where in reality I might be running 350w. because I DON'T know if amp reads the load different because of bi-wiring. Someone please clear this up for me. Thank you.Your question is not an easy one as speakers are wired differently from brand to brands. IE: many Polk speakers will give you a higher impedance when the jumper are connected since the Xo provides for high impedance input however, when the jumper is/are removed, you will read the 8 ohms impedance at one set of speaker connector/leads while you still read high impedance at the other set. Even without elaborated Xo, you still read only 8 ohms no matter what because there is always some capacitors to isolate drivers from each other in order to avoid impedance drop with drivers connected in parallell (this is also basic Xo principle as the capacitor are chosen to pass specific frequencies while blocking others). Your best bet is to simply use a multimeter to check how your specific speaker reacts when you measure them without the jumpers. Personally, in order to read a change in impedance value when removing the jumpers would lead me to believe the speaker has a piss poor design. As I pointed out, your best bet is to experiment by measuring how your specific speakers react when you do remove the jumper. In fact, my personal opinion is that upgrading your Xo is a much better improvement and investment than wasting time and money on cables in order to bi-amp.

Cheers!
TK

[WilliamM2]

Still no answer on ohm issue that is my biggest curiosity.Because if your speakers are essentially rated 8 ohm and because non stand wiring might make the amp read 4 ohm , I would think that would open the door to over power your speakers since amps have 1 rating @ 8 ohm and 4 ohm almost always higher. That's why the ohm issue is important to me.I don't want to think I am only shoving 200w. because 8 ohm , where in reality I might be running 350w. because I DON'T know if amp reads the load different because of bi-wiring. Someone please clear this up for me. Thank you.

Bi-wiring is just moving the jumper from the speaker to the amp terminals. It won't change the load on the amp at all.

[TECHNOKID]

Bi-wiring is just moving the jumper from the speaker to the amp terminals. It won't change the load on the amp at all.Humm, that's an interesting way to put it (and also very easily understood also ;))!

Cheers!
TK

[CoolJazz]

...and to clarify for the record, as established before, using a voltmeter does not tell you the actual impedance value of a speaker at all!

CoolJazz

[TECHNOKID]

...and to clarify for the record, as established before, using a voltmeter does not tell you the actual impedance value of a speaker at all!

CoolJazzUsing a multimeter or ohmeter (not voltmeter) will give you the static/DC impedance of the speaker(s) (read the impedance/resistance of the coil) and this is exactly what is shown in the speaker's specs/user manual. Yes, the dynamic impedance is a different ball game but the static/nominal impedance is always the reference when talking about impedance matching. OK, I went back and I did mention a multimeter (NOT VOLTMETER) which measures resistance and impedance). Multimeter = measures résistance, coils, combination of, the only thing it will not measure is capacitance unless it has the feature to do so and of course this is measure off circuit/line!

For people who do not understand how to measure the DC impedance of a speaker, here it is:

Measuring speaker nominal impedance
If you just want to find out the nominal impedence of the speaker e.g. ist it 4, 8 or 15 ohms then there is a rough & ready way. Just use your multimeter to measure the DC resistance of the voice coil i.e. across the speaker terminals (with nothing else connected) and multiply the answer by 1.3. So if the DC resistance is say 6 ohms then the speaker is nominally 8 ohm impedance. The single most dominant branch of the model is the voice coil DC resistance, Re. It's going to be in series with everything else we will look at (you mentioned "stray capacitance". Yes, there is some, but it's magnitude is absolutely miniscule compared to all other components so it can be ignored). http://www.epanorama.net/documents/audio/speaker_impedance.html

Cheers!

[vc69]

For people who do not understand ... <snip>

Cheers!

Good grief.

The load (impedance) presented by a single speaker does not represent the load presented by a typical home speaker with a crossover network and more than one driver (woofer, mid, tweeter).
also
The impedance of *any* speaker varies according to the frequency(s) and amplitude of the signal being reproduced.

Hence CoolJazz's statement.

[Krazyz1]

LOTS of good info. I will take some variables out and be more specific. I have Polk RTiA9's with jumper bars removed. They are bi-wired and sound " meatier " , more substance. I like the sound improvement. I just didn't know if the amp would now think it is hooked up to a 4 ohm speaker instead of a 8 ohm. Hope I clairified a little more understandable the concern.

[GV#27]

The impedance of *any* speaker varies according to the frequency(s)True that,it is not a pure resitance.

[F1nut]

LOTS of good info. I will take some variables out and be more specific. I have Polk RTiA9's with jumper bars removed. They are bi-wired and sound " meatier " , more substance. I like the sound improvement. I just didn't know if the amp would now think it is hooked up to a 4 ohm speaker instead of a 8 ohm. Hope I clairified a little more understandable the concern.


If you replaced the jumpers with high quality wire, you would get the same result.

Your amp is still seeing a nominal 8 ohm load.

[Krazyz1]

Thanks for the concrete answer

[sTiLlLeArNiNg]

If you replaced the jumpers with high quality wire, you would get the same result.

I don't think it need's to be "high quality" i think pretty much any speaker wire is better than the stock jumper plate's

[dorokusai]

The plates just stink....jumpers are cheap and easy to make.

[WilliamM2]

If that the case, the traces on the crossover circuit board must really stink. And what about the plain metal tabs on the drivers?

[F1nut]

William....please stifle.

[dorokusai]

If that the case, the traces on the crossover circuit board must really stink. And what about the plain metal tabs on the drivers?

I agree.

[sTiLlLeArNiNg]

Trace's on the circuit board should be best grade copper, speaker terminal's ARE questionable. If you like your stock jumper bar's use 'em :) I bet ya if ya peel 'em off and use some speaker wire you would hear a difference too ;)

[TOOLFORLIFEFAN]

I replaced my stock jumpers on my 1.2's and it made a world of difference.

Has anybody ever got inside the cabenets and just wired everything to the bottom post's?