Are MM6501's Bi-ampable?

[arun1963]

A friend of mine, who lives a different city has just bought a pair of MM6501, a Genesis 4x50w rms amp, the Pioneer deh p-7150 HU, a SR 124dvc and the pdx monoblock.

She wants to know if she can bi-amp the 6501's of the 4ch genesis amp. The xover of 6501 has all the binding points on one side, but there are only 6 points. Hence one line in and two lines out (one to the mid bass and one to the tweet). Hence the 6501's would not be bi-ampable right?

[abraves4410]

it would need to have 2 seperate inputs hence 8 pts to be biampable

so in short, the mm6501s arent biamp capable

[audiobliss]

If it's a set of component speakers, then yes, it's biampable. However, they may not be easily biampable.

As you noted, the crossovers only have one set of inputs, so you can biamp that way. However, if you utilized a crossover in your head unit (didn't look that one up, so I don't know if it has one; probably not judging from the model number) or if you ran an aftermarket one and went active, you can biamp.

[MacLeod]

That sucks. The Momo 6.5's had a bi-ampable crossover. Looks like theyre getting cheap.

You can still bi-amp tho. Run the tweeters thru the passive crossover off the amps front channels then run the rears full range off the rear channels. Thats the way I ran my beloved MM6's and even my trusty MMC690's several years ago and had very good results.

[Toxis]

getting cheap? Why make the mid line biampable? Just save that feature for the TOTL.

If you get line level crossover, you can go active and biamp any component set. Just more work to get them to sound right. The SR components are biampable through the crossovers just making it easier to do so.

[arun1963]

That sucks. The Momo 6.5's had a bi-ampable crossover. Looks like theyre getting cheap.

Yes, that was one of the really nice things about the momo's xover. The MM's are supposed to be a slight upgrade to the momo's, so I figured they would keep the best parts of the momos and tweak the weaknesses. But obviously not. I pushed my friend to buy the MM's over Rainbows (her first choice) partly based on bi-amp capability.

You can still bi-amp tho. Run the tweeters thru the passive crossover off the amps front channels then run the rears full range off the rear channels. Thats the way I ran my beloved MM6's and even my trusty MMC690's several years ago and had very good results.

Thanks that sounds like a good solution. The MM mids would play the 20-60hz and 4Khz+ range as well? The HU she has bought does not have BP/LP for the mids, so it would be full range like u mentioned. Tks you just saved my **s.

If it's a set of component speakers, then yes, it's biampable. However, they may not be easily biampable.

As you noted, the crossovers only have one set of inputs, so you can biamp that way. However, if you utilized a crossover in your head unit (didn't look that one up, so I don't know if it has one; probably not judging from the model number) or if you ran an aftermarket one and went active, you can biamp.

I had suggested that she buy the pioneer p-80rs so that she could go active down the line and it would give her ability to BP the mids and a whole lot of other tuning features. She bought the HU last and the model was her choice. Basically she got fed up of me spending her money for her. :D

getting cheap? Why make the mid line biampable? Just save that feature for the TOTL.

If you get line level crossover, you can go active and biamp any component set. Just more work to get them to sound right. The SR components are biampable through the crossovers just making it easier to do so.

Just from my perspective, I love Polk because I get incrdible VFM with all polk products. On sq, my momo's are at par with rainbows that cost 2 times what the momos cost me. The momo's blow away the rainbows that are priced competitively. The usp is that polk offers features/sq in their mid line what other established brands offer in a higher line. Thats VFM and I think thats why polk has customer loyalty. Its just a feature I thought they would carry over to the MM series.

Thanks a ton for all your help mac, audiobliss & toxis.

BTW just wondering if anyone here heard of Genesis amps? Its a top end brit company that does a lot of research work. I got a free trial for 2 days some weeks back and I have to admit that the sound was something special. I love my pa 500.4 and have no plans to upgrade that, but the Genesis is in a different league. They are also frightfully expensive. The 4x50watts costs upward of a $1K. If any of you'll get a chance just hear these amps.

[MacLeod]

getting cheap? Why make the mid line biampable? Just save that feature for the TOTL.

Why would you NOT make the mid line speakers biampable? Being able to biamp a speaker makes for better tuning flexibility which generally means better sound. Thats something I would think is important to all speaker lines. Granted the guy who buys the $50 set of coaxials wont care but the MM's are $300 a pop. Chances are, the typical customer who is willing to shell out $300 for a set of speakers is going to be a little more audio savvy and would probably appreciate a bi-ampable crossover. With the $300 price point pretty heavily populated and other competitors like JL Audio's C5 using a pretty customizable crossover I wouldve thought it would be an important feature to keep.

[Toxis]

but other than people who come to these kind of forums for research will never even understand what bi-amping is or why it's a benefit. So again, why add money to the production costs for a feature that really 2-3% of the buyers will use? That's just not good business; especially in this economy. If someone wants to bi-amp them, they can. Just get the right processor. More money in the long run but it'll be better off with more tuning capabilities. I honestly don't think bi-amping through the OEM Crossover will give you much more sound over just running a bigger amp seeing you can't tweak anything other than some tweeter attenuation.

[MacLeod]

Most car audio consumers dont frequent forums and Id wager its a whole lot more than 2% that like to tinker with their stereos. Granted there are a lot of consumers out there that just want some basic speakers dropped in the stock locations so they can have some decent tunes to listen to while they drive to work and the grocery store and they would never think or look twice into bi-amping but then these are the people looking into a $75 set of coaxials, not a quality set of $300+ components.

$300 is a very decent chunk of cash for car audio speakers and I think that anybody willing to shell out 3 bills for a set are not the type that just want some simple drop in gear. These are the ones that care about getting excellent sound quality and are not above doing a little tweaking and tuning and its for these people, who I think make up a large part of the consumer base for $300 speakers, that cool features like a biampable crossover will appeal to.

[Toxis]

Coming from the retail side of things and 10 years of slinging it (dear god, I need a new profession. haha!), Most people looking for nice, clean, powerful speakers will drop $300 on speakers but will have no idea about biamping. I see people all the time looking for a big 4ch amp and some killer comps up front with good coaxes in the back. I have yet to really meet anyone (through work; the internet is a different story obviously) who would want to get an EQ and tune their system without spending $500+ on their front stage. We just got done doing a car for a guy who bought some $250 components for his front stage and his idea of getting better sound up front was to add another set of tweeters. I see that a lot more than people who want to biamp or have any sort of tuning ability. But maybe I'm a bit out of it coming from the home side now days even though my car salesmen say they have never had anyone ask about biamping. And yes, I just went to ask just to prove my point. lol

"Boom, roasted." haha :)

[audiobliss]

Interesting experiences, Toxis. I must say I definitely buck that trend, though.

I walked into my local hifi/car audio store, wanting very much to biamp my front components and forgo rear speakers all together. Ended up paying just $150 for my front components.

[arun1963]

polk is going to the dogs. Need proof?

The MM6501's on the tech section are rated at 2.7 ohm. These are 4 ohm speakers that may be stable at 2.7ohms, but they are not 2.7ohm speakers since you cant feed them a signal at 2.7 ohms, so why advertise this crap. Sounds like some mktg a****** pulled mkt shar figures and decided the way to get mkt share was to out b\s sony explode. Next you know the polk boxes will prodly proclaim speaker power in peak watts.

Why am I pissed? becoz my friend who installed the MM comps w the genisis amp, decided that instead of bi-amping she would just connect left and right comp bridged off the 4ch genesis amp. She figured if they are advertised at 2.7 ohms they will be stable at 2 ohm.......2 days of fun and now the mm's are kaput. Just sent the following msg to polk CS, expecting to be banned very shortly ;)

Appologies all round I don't normally lose my cool like this.

"Why the hell would you advertise the MM6501 at 2.7ohms? WTF is 2.7 ohms and more importantly HTF do you get 2.7ohms to your speaker????????

These are 4 ohm speakers that may be stable down to 2.7ohms. Since you can't get 2.7ohms to the speakers why the hell would you advertise that? Next your packaging will proudly proclaim peak power ratings.

Sounds like some mktg ass who has no clue about the product or the brand equity is blindly following the mkt share leader ie sony xplode. God forbid!!!!!

Why am I pissed? becoz a friend bought the mm's read your ratings and connected each speaker bridged on 2 ch's of a 4 ch amp. She figured if the speakers were rated at 2.7 ohm they would handle 2 ohms. 2 days into her install....... kaput mm's. She's a newbie its your damn fault. I am a die hard polk fan but the new mgt is just ruining this company. "

[Toxis]

the hilarious part of that post is you blowing up with a very limited understanding of speakers and amplifiers; let alone how they work together. So you're upset that Polk gave you a 2.7 ohm speaker. Well they were honest and told you this so you could get an amp that's capable to give you the correct wattage at 2.7 ohms for this setup. You say that the speakers aren't stable to 2.7 ohms but it's amplifiers that need to be stable to handle an impedence, not a speaker! Now if you really want to get technical, speakers impedence changes depending on the frequency being played at that point but they have a stand still impedence which is a starting point for the impedence curve. So any 4 ohm speaker will dig to 2.7 ohms and honestly can go down to 1 ohm really. But when a speaker's impedence starts around 2.7, it just means they can get to under 1 and most likely under .5 ohms. So really what happened is you hooked up a very nice amp (Genesis) but for what you're doing with it, you have way too much power for the speakers or the amp was clipping causing it distortion (yes Mac, you can say your piece here haha). Either way, you melted the coils because of too much power and you surpassed the thermal handling of the coil. So I ask you, how is it Polk's fault when you are the one who hooked up a system without understanding the scenario? You bridged an amp which typically you don't want to go lower than 4 ohms on a bridged channel and you purposely ran 2.7 ohms. Not Polk's fault... this is all you. Sorry to be the a-hole telling you how it is but you're yelling at the wrong people. Next time, use the same rant but do it in a mirror.

[arun1963]

Tks toxis for your wonderfull summation.

1. Your assumption of my ignorance, is just YOUR assumption.

2. I ran the genisis amp for 2 days trial. The amps birth sheet mentions 4x50w rms at 4ohm and 2x200w rms bridged at 2ohm. There is no way this amp is 4x50. It played louder and much cleaner than my 4x90w @ 4ohm pa500.4. Cleaner watts are louder watts so let's assume the genesis puts out 4x90 realistic watts (btw notice how this company undersells its products check the website). Actual bridged is 2x290watts. Typically class a/b amps work on 65-75% efficiency. Lets assume 75% for the genesis, so the mm's each saw 220 watts rms. Not surprised the vc's fried.

So what started this blunder? What was the root cause? I asked my friend why did she bridge the ch's her answer " You touted polk as a highly reputable company. Hence I assumed if they rated the speaker at 2.7 ohm it would work at 2 ohms and to get 2 ohm I had to bridge the amp ch's
."

Yes I know the speakers can dip down to 1 ohm but that is like a for a nano second, if that is what youre going to consider then you just proved my point that polk will advertise peak power cause that is also for a fraction of a second.

I am sure that all your years in retail would have taught you the basic lesson that you have to customer proof your product both in manufacturing and in sales and mktg. You have to account for the dumb customers. Here we're giving the customer a banana skin to slip on.

[MacLeod]

Yeah dude, your post is just ridiculous. You cant "feed" a 2.7 ohm load to your speakers. Impedance is a measure of resistance. An amp, if unresisted, will make 100% power and quickly burn itself out. The speaker adds resistance and keeps this from happening. A 4 ohm speaker will draw less power from an amp as a 2 ohm speaker would.

Cleaner watts are not louder watts. Good grief.

Now Polks ratings didnt low those speakers - hooking 120 watt speakers up to an amp making OVER 200 watts is what blew them. You guys were worried about the WRONG ratings. If youd looked at the power handling, you would not have bridged them at nearly double their rating limits. This isnt Polks fault.

Now in fairness, it is a little oddball to make a 2.7 ohm speaker.

And Toxis, now run in there and ask those salesmen if they think having a biampable crossover would be a pretty cool selling point. May be the tie breaker for someone considering a $300 set of MM's and a $300 set of Focal Access. Then come back here and admit your defeat! ;)

[arun1963]

why advertise it at 2.7 ohm and have a complete noob interpret it differently? It's also genesis's fault for not rating the equipment properly why would they rate a 4x90w amp as 4x50w. Jeez 220watts rms bridged, that is sick.

"Cleaner watts are not louder watts. Good grief." Just for that, pls explain once and for all why a cleaner signal sounds louder? There is so much back and forth on this topic on the web.

At least I took you'll out of your boring lives and made u'll laugh :D :p

Oh and btw I didnt suggest that she bridge. It was her idea. I only got to know that she did this when she called me today. I guess why I'm really pissed is becoz my best friend who happens to be a woman chewed my ass up over 4 calls today about how the polks sucked and how it was my fault that the speakers burnt and that she should have bought the rainbows in the first place etc etc. Ever been at the wrong end with a woman friend, when u know she's at fault and you try telling her that and she just takes her anger to the next level? Conversation ended when I told her, "Now you sound exactly like the wife", .........click, brrrrr.

I shouldnt have flipped. Tks for the reality check. Have a nice weekend ya'll

[MacLeod]

Ummm....never said a cleaner signal doesnt sound any better. I said its not louder. 120 db is 120 db regardless if its pure distortion or as clean and pure as the wind driven snow.

A cleaner signal sounds better because ITS CLEANER!

[arun1963]

Tks that settles it.
Since ure online its knowledge sucking time :-).

On a toally different tangent, "Is there a big difference between an hu with 24 bit and another with a 16bit dac? Assuming ofcourse that all other capabilities and settings are constant. The point of debate is that all audio cd media (except sacd etc) is 16bit/44.1hz, recorded" So 24bit dac is overkill.

[Toxis]

Tks toxis for your wonderfull summation.

1. Your assumption of my ignorance, is just YOUR assumption.

I don't use the word ingorance as an insult, just a statement. I didn't mean it as "you're a retard." I meant it as "you don't know what you're saying." Not understanding something is the definition of ignorance. The fact you took it insulting is a product of reading words on a screen and not talking to someone to hear their inflections to understand their true meaning.

2. I ran the genisis amp for 2 days trial. The amps birth sheet mentions 4x50w rms at 4ohm and 2x200w rms bridged at 2ohm. There is no way this amp is 4x50. It played louder and much cleaner than my 4x90w @ 4ohm pa500.4. Cleaner watts are louder watts so let's assume the genesis puts out 4x90 realistic watts (btw notice how this company undersells its products check the website). Actual bridged is 2x290watts. Typically class a/b amps work on 65-75% efficiency. Lets assume 75% for the genesis, so the mm's each saw 220 watts rms. Not surprised the vc's fried.

It sounded louder and cleaner because it's heavily underrated. If they call it 50w, that's to play it safe when in reality, it's probably putting out 80-100w/ch. A lot of amps do this. The nicer the amp you get, the more it's underrated. So yes, this is Genesis' problem. But that's a good problem really. Just gain it down so you don't pump so much fuel into the fire and you'll be fine.

So what started this blunder? What was the root cause? I asked my friend why did she bridge the ch's her answer " You touted polk as a highly reputable company. Hence I assumed if they rated the speaker at 2.7 ohm it would work at 2 ohms and to get 2 ohm I had to bridge the amp ch's
."

Yes I know the speakers can dip down to 1 ohm but that is like a for a nano second, if that is what youre going to consider then you just proved my point that polk will advertise peak power cause that is also for a fraction of a second.

I am sure that all your years in retail would have taught you the basic lesson that you have to customer proof your product both in manufacturing and in sales and mktg. You have to account for the dumb customers. Here we're giving the customer a banana skin to slip on.

The fact that companies have to "consumer proof" their equipment is the reason Sony Xplod and Kenwood claim 1000w out of an amp that couldn't do that under a lightning strike. Consumer proofing products is what hinders some companies from giving equipment all it's got. People know how to abuse the hell out of stuff but rarely know how to use it properly (again, this is speaking to the masses... your friend is a perfect example obviously). I ask you again, how is it Polk's fault that you ran almost double the RMS power to a speaker and it blew in 2 days (obviously not enough time to properly break in the drivers as well)?

And Toxis, now run in there and ask those salesmen if they think having a biampable crossover would be a pretty cool selling point. May be the tie breaker for someone considering a $300 set of MM's and a $300 set of Focal Access. Then come back here and admit your defeat! ;)

I never once said it wasn't a good selling point for a mid line comp set nor did I say it shouldn't be done. I just said for the market share this comp set is geared towards, they typically will never use this feature so why add it for a small percentage of the people who would use it? Why put the money into something your own consumers typically will never understand, let alone use? Gotta think about return investment. It'd be like Sony coming out with a TV for $1000 with all the features of the $2500 model but just the picture is not quite as good. Then the extra jump to the bigger model isn't justified anywhere near as much; thus selling less of the more expensive and more profitable model. Sure Polk is a small company but they design products for profits...

why advertise it at 2.7 ohm and have a complete noob interpret it differently?

If you know what ratings are, they can't be misinterpretted. You were thinking about loads towards an amp and applying it to the speakers. Again, that's the ignorance of the consumer, not the advertising. Polk did you a good deed by telling you the truth of their speakers. Now Infinity made/makes some speakers that they call 4 ohm but in the spec sheet are truly 2 ohm. They say "4 ohm safe" for head units but guess what happens when you put them in a kids car who jams their radio? Well, ask your friend... she experienced it. lol

Lastly, it sounds like she has knowledge of car audio but clearly not enough to do this without help. You should've been there to help her out in the first place but also do some research beforehand to make sure what you're doing is a safe bet.

Then again, blowing up to Polk's CS and on here is clearly not a good idea either and shows your maturity level when you get irate.

[MacLeod]

I never once said it wasn't a good selling point for a mid line comp set nor did I say it shouldn't be done. I just said for the market share this comp set is geared towards, they typically will never use this feature so why add it for a small percentage of the people who would use it? Why put the money into something your own consumers typically will never understand, let alone use?

Ummmm.....ok....let me see if I got this straight. You never said they shouldnt do it.......just that they shouldnt do it?!??!!

Gotta think about return investment. It'd be like Sony coming out with a TV for $1000 with all the features of the $2500 model but just the picture is not quite as good. Then the extra jump to the bigger model isn't justified anywhere near as much; thus selling less of the more expensive and more profitable model. Sure Polk is a small company but they design products for profits...

OK. just checking again but youre saying that if they make the MM crossover biampable........that they would be as good as the SR's???

So if you take a Honda Accord and put some Ferrari style wheels on it, people wouldnt buy Ferraris anymore? Theyd just buy Accords?

You cant fool me! Youre just messing with my head - trying to confuse me. Well Im on to your diabolical scheme and will not be led astray by your tricky logic any longer.

"Is there a big difference between an hu with 24 bit and another with a 16bit dac?

Only if you can hear the grass grow.

[arun1963]

Some objective observations from yesterday:

Then again, blowing up to Polk's CS and on here is clearly not a good idea either and shows your maturity level when you get irate.

Yes. U hit the nail on the head. I know this is an issue and keep a watch on it. The ability to manage yourself when on the threshold of your stress limit and over, is vital.

Appology tendered to cs folks as well.

Thank God vaccation time is comming up.

[Toxis]

Mac, I think it would be a good selling point yes but a selling point that would never get used. I honestly believe less than 2% of the buyers would actually biamp their speakers. If I was a salesman still, I'd design systems to do so but knowing the market, I'm gonna say it's not in Polk's interst to add this feature so save the cash.

Now I'm not saying that one feature would make them close to SR quality but that's one less reason foe people to buy the SRs over the MMs. Yes the Srs are better but don't give away all the features foe half the price. I'm looking at it as a marketing angle. Sorry, it's the retail in me speaking.

Please excuse the grammar; I'm on my iPhone.

[Cunningstunter]

Hi I am so glad we found this reference - a mate and I are building my new system for my new car. I am looking at the MM6501s and originally a MM1240 but perhaps now a MM1240DVC instead. . . .the reason for the DVC had something to do with how we wired it all up to match the resistance but again, this is all well above my head.

So whilst I too, being a complete newb, was scratching my head at the whole 2.7ohm thing. . . . .

So what benefits are there running the DVC over the SVC for the subwoofer?
And can anyone post up a few different options as far as amplifiers go?

What I have been offered is a Option Audio OAH500 - 5 channel amp. There was talk of perhaps bridging the 4 channels to 2 for the MM6501s but after reading the above not too sure - I think that's where we had to think about going the DVC route for the Sub?

RMS power at 14.4V (2Ω Load) 130W x 4CH + 500W
RMS power at 14.4V (4Ω Load) 90W x 4CH + 300W
RMS power at 14.4V (4Ω Load Bridged) 260W x 2CH + 500W

Even if we don't bridge them, can we use all 4 channels to greater affect than running only 2? If that's the case a 5 channel amp is probably a waste of time and honestly the above specs confuse a newb like me.....after reading this whole thread through a few times I definately don't want to fry a set of $450 (AUD) speakers!

I also play alot of guitar and listen to a very wide range of music > just don't understand too much about this technical stuff!! Any help/advice MUCH appreciated!!!

[Installer4life]

Why would polk make a 2.7 ohm speaker? I will tell you why. You go to your nearest car audio store, exception Best Buy, to buy some speakers. You play some music that you like at a volume you like and do some A/B comparisons..Most speakers are 4ohm as we can agree. When you switch from "X" brand to Polk and the music plays louder that gets your attention. They do this for that reason. For most people they need to hear a difference. Basically $100.00 speakers sound like $100.00 speakers no matter the manufacture. Polk has just up their presence on the car audio display. They sell themselves. Polks not stupid they know for the most part sales people aren't going to recommend their speakers every thime so they make them jump off the display at the customer. JBL and Infinity have been doing this for years. Why do you think the number one selling coaxial in the US is Infinity Reference. Its not the sound quality..It does help that Best Buy sells it or should I say clerks it.. I went to Genesis's web site and could not find a 4 channel amp that was rated into 2ohms bridged. I have to agree that bridging the amp was a mistake and that the installation of the system is the reason for the blown speakers. Have your friend take it to a professional next time. One nice thing that came out of this is that now you know a watt is not a watt and amplifiers make a big difference in sound quality. The Genesis brand amp is far superior to the Polk Audio brand. I can attest to this because I have worked with both of them. If you want to hear a really nice amp at a reasonable price you should audition a ZED AUDIO brand amp.

[Coolbinu]

A friend of mine, who lives a different city has just bought a pair of MM6501, a Genesis 4x50w rms amp, the Pioneer deh p-7150 HU, a SR 124dvc and the pdx monoblock.

She wants to know if she can bi-amp the 6501's of the 4ch genesis amp. The xover of 6501 has all the binding points on one side, but there are only 6 points. Hence one line in and two lines out (one to the mid bass and one to the tweet). Hence the 6501's would not be bi-ampable right?

any component speaker set is bi-amp capable.. only thing is that we should alter some wiring in the crossover network. you can consult an electronics technician to do it for you.. or else if you want i can help you with the wiring diagram.