This Baby Looks Tight, huh?

[knownalien_]

yummy! (http://www.polkaudio.com/homeaudio/specs/individual/subwoofers/psw1000/)

[McLoki]

Still $1200 for a sub that goes down to 30hz (-3db point). Not near enough for me to trade in my SVS.

Michael

[jdhdiggs]

^^^^ Agreed, it's tuned too high for today's market at that price range

[billbillw]

I bet an SVS PC+ (or PB12+) would walk all over it for a few hundred less out of pocket.

[McLoki]

I bet an SVS PC+ (or PB12+) would walk all over it for a few hundred less out of pocket.
Let alone the SVS PB12-Ultra (http://www.svsubwoofers.com/subs_pb12_ultra.htm) that it is priced against......

[knownalien_]

so the frequency response is down to 20 but you are saying it won't be very loud that low?

[knownalien_]

Let alone the SVS PB12-Ultra (http://www.svsubwoofers.com/subs_pb12_ultra.htm) that it is priced against......


beautiful looking sub.

[audiobliss]

so the frequency response is down to 20 but you are saying it won't be very loud that low?

Exactly. The overall frequency response tells you what frequencies it will produce. The +/-3db frequency range tells you which are audible. You pretty much just ignore the overall rating and go with the +/-3db limits.

And I agree, 30Hz ain't nearly low enough. You can even forget price for a minute. 2 10" woofers. 400 continuous watts. Should be able to go lower than 30Hz.

[jdhdiggs]

so the frequency response is down to 20 but you are saying it won't be very loud that low?

There's nothing garunteeing that it will be loud above that either. Typically Polk seems to do a -3/-10 rating so I'd guess it's 10 dB down at 20 which would actually not be bad for most subs that you'd find at tweeter or CC.

I'm guessing the tuning point is about 26-27 range but the woofs are already straining coming into that range.... I'll take a listen and give it a fair shot.

[knownalien_]

but with two 10" woofers and so much power only effective to 30 hz? It's the same rating as my LSi15's!!

It's gotta be a misprint. They've done that before.

[knownalien_]

even the RTi12's are rated at 30 Hz.

[jdhdiggs]

Let me let you in on a little secret, I'm guessing that this sub is meant more for supplementing the bass rather than replacing the bass produced by a speaker. Most people don't have enough amp to drive the bass sections to full volume so a sub is needed regardless of the speaks.

[Airplay355]

Rti12's have three 7" bass drivers. That's alot of surface area.

8 minutes and I can leave work :) Yippee!!

[knownalien_]

Rti12's have three 7" bass drivers. That's alot of surface area.


reguardless, they are still rated at 30hz (-3db point).

[knownalien_]

Let me let you in on a little secret, I'm guessing that this sub is meant more for supplementing the bass rather than replacing the bass produced by a speaker. Most people don't have enough amp to drive the bass sections to full volume so a sub is needed regardless of the speaks.

that's not a secret. how it will perform is.

[jdhdiggs]

You missed the point... :(

This is/does not appear to be a HT sub, rather one to fill out the lower octives only. That is completley different from a Velo, Rel, SVS, HSU, etc.. which would replace all the bass and perform for HT. This looks to be a music only, close to full range speaker only sub. A match for say the LSi9-15 crowd.

Airplay was giving you a reason as to why the 12's are rated so low. What was your point with your response?

Also, 30 isn't THAT bad, the problem is that DIY, HSU, and SVS make 20Hz easily obtainable in that price range.

[knownalien_]

You missed the point... :(

This is/does not appear to be a HT sub, rather one to fill out the lower octives only. That is completley different from a Velo, Rel, SVS, HSU, etc.. which would replace all the bass and perform for HT. This looks to be a music only, close to full range speaker only sub. A match for say the LSi9-15 crowd.

Airplay was giving you a reason as to why the 12's are rated so low. What was your point with your response?

Also, 30 isn't THAT bad, the problem is that DIY, HSU, and SVS make 20Hz easily obtainable in that price range.
it's no secret because the very fact that it is an LSi compliment means that it is intended for audio (multi channel at that). I am still trying to see what point I missed. In the second place, I am not looking for anything other than a musical sub. If you'd read anything else that I posted you may have noticed that that is my primary enjoyment. Also, I couldn't get the specs on the SVS's.

as for airplay, the speakers have the same rating as the PSW1000 as do my speakers. Do those specs mean the system as a whole or each individual woofer, in which case the PSW1000 would be X2 and the RTi12 would be X3?

the point of my post is the point above which equates -3 db in the 30 range as not so hot.

[McLoki]

Also, I couldn't get the specs on the SVS's.
Here is a quote from SVS for the ultra sub....

Multiple tuning points allow you the customer to experiment with "lower than low" bass at their leisure. As it is, the PB12-Ultra is tuned stock to 20Hz (with all three ports firing), which will yield strong response to around 15Hz with mid-sized rooms and corner placement. Above this point is where nearly all music and movie bass is centered. It also is the most efficient mode for the PB12-Ultra; with amazing sound pressure level capacity, and incredible accuracy to the source material at all sound pressure levels, low or loud. Want deeper? If you willing to give up a few decibels in SPL capacity above 20Hz (and the PB12-Ultra has more "headroom" than most folks will use), then insert one, or even two port plugs, click over the subsonic filter knob to the corresponding 16Hz or 12Hz position and you are there. Most users would experience strong output to around 15Hz with good placement in a typical room with a 20Hz setup. This is the sort of bass that is just plain scary when done with low distortion. but it's one of the reasons SVS's are so famous! Room size and shape will largely determine how much. Of course for those desirous of impeccable natural wood finishes the Ultra will be worth the price of admission even without more performance.

Michael

[jdhdiggs]

Gotcha! All of the woofers are contributing at the 30 hz. So in the case of 2 drivers, each one by itself is -9db down (-6 dB below it's individual tune point and falling fast) Add the two together (+6) and you get -3 db for the system. This has no voluime associated to it though. My guess is that the long throw dual 10's would go louder than the RTi12's but this is part of the reason why people say thes specs, and frequency response graphs, are almost worthless beyond a very general sense of capabilities.

[HBombToo]

My guess is that the long throw dual 10's would go louder than the RTi12's but this is part of the reason why people say thes specs, and frequency response graphs, are almost worthless beyond a very general sense of capabilities.

I guess shirt waffling and unplanned bowel movements should be added to the SVS spec sheet :D

[jdhdiggs]

Well Henry, if you keep insisting on sittin atop the ports, BM's are expected, along with sever flatulance...

[knownalien_]

but this is part of the reason why people say thes specs, and frequency response graphs, are almost worthless beyond a very general sense of capabilities.
well, that's the jist of it then. say, I have the Avia Guide to home theater DVD. Do you think there are any audio tests which cover the REAL low end?

[PolkThug]

Do you think there are any audio tests which cover the REAL low end?

Fuckin' Eileen!

[knownalien_]

nah, I just checked. nothing.

[McLoki]

well, that's the jist of it then. say, I have the Avia Guide to home theater DVD. Do you think there are any audio tests which cover the REAL low end?
You will certainly find some here. (http://bfdguide.ws/sinewaves/)

Don't forget you have to put in some correction values if you are using a radio shack spl meter to read deep (and some not so deep) bass tones.

Just plot yourself a curve and see how your sub works in your room... :)

Michael

[knownalien_]

^^ thanks!

[michael_w]

You can't judge everything by its specs...

[reeltrouble1]

You can't judge everything by its specs...

+1^^^^

Exactly, Alien is to be applauded. Since he is new and unconditioned to the HSU/SVS subs his thinking is different. He is trying to learn. He is thinking about how it will sound, and likes the looks, well, most would.

Of course specs are important, they establish the baseline expectations and can be used to get an idea of quality.

I have heard the SVS several times supplementing some fine systems with Polk as well as other fine speakers. Musically, there was nothing remarkable. Sure they can go deep and with great power. In a HT system nothing like it.

The lowest frequency on the piano keyboard if at 27.5 hz, rarely used by artists. Bass Guitar is at 41.2 Hz. So if you can go down to 30 hz with power (-3db) your in good shape. As reference, cymbal crashes are at 15 khz, the highest note on the keyboard 4.1 khz and middle C dividing bass from treble at 261.6 hz. Recording engineers really dont like low bass its difficult to work with and do well. Fortunately for us some do.

I am on record as liking my music 2.nada, I have no issue with any of the fine brands of subs members here like and use, if however, I were using the LSI or RTI bookshelf for a musical system I would not readily dismiss the Polk sub based solely on the specs.

RT1

[audiobliss]

Good, informative post.

[knownalien_]

+ Recording engineers really dont like low bass its difficult to work with and do well.


I think the reason, from the acoustic "live" setting, is two-fold (think classical concert where the recordings are made and cleaned up in a studio, which might not be needed)

#1 live performances do not feature the body feeling bass that listeners take for granted. This complicates things a bit because speakers of the past got folk quite used to "boominess." Now we are fooled into thinking that that is a real worl effect. also, live classical performances competes with regular music and the trend has been to NOT engineer flatly, but to emphasize the extremes in rock and rap. In classical music, many would feel cheated if they didn't get loud bass/bass drums.

#2 during the recording of a live classical performances, the mics tend to pic up low level hums which may not be obvious to the recorder (usually wind noise). Ultimately, for audiophiles, their gear is likely to be MUCH better than that in a studio. Thus, they will be able to pick up stuff the engineers missed. Thus it must be difficult to seperate the low level hum from the same pitched not of a member of the orchestra.

#3 every note starts with a fundamental and after that it is all upper partials/harmonics. If you hit the lowest "a" on a piano, your ear will more easily percieve the higher partials with only a hint of the fundamental. It is a strange fact, and it leaves the engineer wondering if he should "enhance" the bass. The higher you go in range, the more the fundamental speaks to us and no enhancement is neeeded. The same can be said of an upright bass being bowed. If not in it's sweet spot, you'll hear more of the partial(s) than the fundamental. Remember that the 2nd partial is the same note an octave higher. An upright bass would have to be triple its size for lower notes to be able to speak as well as its open D.


but that's all acoutsic stuff. Once you stick stuff through an electronic device, all the rules change.

[audiobliss]

#3 every note starts with a fundamental and after that it is all upper partials/harmonics. If you hit the lowest "a" on a piano, your ear will more easily percieve the higher partials with only a hint of the fundamental.

That is very interesting. Had never heard that before.

[knownalien_]

That is very interesting. Had never heard that before.
sure. go to a piano and you have to bang the heck out of it to be able to "feel" the note. But the same rule applies with the upright bass. A piano would have to be much bigger for the waveforms to be able to use the box of the piano. as it is, the waveform doesn't complete itself until it leaves the piano. did that make sense?

lol

[audiobliss]

Not really, lol. And I've played piano for 7 years.

You're just saying there's not enough area inside the piano for the note to resonate for it to.....what?

lol, sorry; I'm just not following.

[reeltrouble1]

Has to do with the box, length of the strings, power ratio of the action at the hammer strike or bow and so on, thats why Steinway Grands are 12', there are other laws in effect, curvature of the ear, etc., its a very deep topic, loads of info if you do a search. Basically the strings resonate when struck then a wooden soundboard is utilized, crack the soundboard and your well, screwed. Really amazing stuff you can spend years studying it.

RT1

[knownalien_]

^^ well, as you know the wave of a really low frequency is huge compared to a higher note's. When you hit the lowest note on a piano (grand piano) the wave doesn't fully develop until after it leaves the piano leaving the wave to use the room to use as a resonance box. as a contrast, the violin is likely the most perfect acoustic instrument in terms of dynamics. It's dealing with higher frequencies and the resonances all fit within the body itself and can use the body of the violin itself to amplify the note. Play the lowest G string loudly and assuming you don't have a pos fiddle, it WILL carry and you WILL feel it. You feel it because the wood of the violin is resonating sympathetically with the waveform. That acts to amplify. All sound is, recall, is compression and rarefaction from the speakers pov. when the driver comes out it is compressing air to "spell" a waveform. When it drives back towards the speaker it causes a "vacumm" in the air: rarefaction. A violin must deal with sound in a similar way, but it creates the waveform differently.

in essence, the reason that a bigger driver (or combined suface area of many) can more easily reporduce lower notes is the same basic reason why a piano would have to be bigger to reproduce (at volume) the lowest fundamental of a very low note. But in acoustic intruments it is the comprimise that has to be made. No one is going to lug around a piano the size of a 20' X 20' room!

lol


p.s this knowledge is from being a classical musican and also having taken physics acoustic classes. ;)

[McLoki]

It's the wierd digressions like this (the thread started with how an unreleased Polk subwoofer looked remember?) that make this such a cool forum to belong to.

Thanks for the explanation. While much went over my head, it was still very interesting reading...

Michael.

[audiobliss]

Wow. Very interesting stuff, for sure. Thanks for the replies, both of ya!

knownalien - A classical musician and physics acoustic student...wow!

[knownalien_]

the physics was 10 years ago. I'm running on fumes now. :lol

[reeltrouble1]

Very cool KA, there are a very few of us here who do music theory. At PF they were ribbing me about one theory post I did, I get one of those looks, like here he goes again, Teds Random thoughts!!!!

Next up Modal Theory!!!! :D relax j/k

RT1

[knownalien_]

^^ you seem to know your stuff. I can't imagine someone trying to rib you about something.

[knownalien_]

(the thread started with how an unreleased Polk subwoofer looked remember?)



well, to steer the ship right again, I guess you could say that in terms of CLASSICAL music, we really ask a subwoofer to "embellish" what is not heard live. Add to that that we are condencsing a full orchestra into a tiny (avg.) listening room when the performance was in a hall. How is that supposed to translate.

put even more succintly (sp?), subwoofers and classical music do not really mate well in terms of hardcore purity. But hey, Stravinskly wrote fast moving notes in Rite of Spring and damn if we're gonna hear them!!

[jdhdiggs]

Too bad church organ music is out with this sub :(

[reeltrouble1]

Too bad church organ music is out with this sub :(

hehehehe, good one, get your Baroque (sp) groove on. LOL JD.

KA, just hang around and get to know these guys, no topic or needle is left unturned!! :o

[jdhdiggs]

On a serious note the soundhound CD will blow up most subs of this type with church music. A really cool CD if you can find it! Well recorded with a lot of 16Hz notes

[knownalien_]

yeah, there are plenty of organ examples where you get that 16 hz. The Camille Organ Symphony is a big audiophile test. In a church, the low notes DO carry (as many here likely know) but they are basically using the whole main room as a resonance box. And if you have seen the size of the pipes of REAL church organs, then it is showing exactly what I am talking about in terms of size and it's effect on LFE. I think organ music was probably the first "thumpin'" put out there!

lol