Will I Be Happy With The MMC6500?

JawKnee

Yeah, I'll definitely be paying close attention to my gains on the amp. I have them set to zero to start off-- it's not installed yet. I assume I'll barely move them beyond that when I'm done tuning the system.

I was a little worried if the amp was too much as well, but I know the manual for the MMC6500s mentioned bi-amping with the Polk C400.4 (another 100x4) so I assume I'll be okay with the Phoenix Gold Xenon 100.4.

JawKnee

neomagus00 wrote:

i would personally set the highpass at ~70 Hz, but that's up to you - anywhere you like it is fine... you'll be running one pair of channels straight into the mids, but the other pair goes through the xover first before going to the tweeter... (just making sure you don't blow your tweets! )

Actually, I believe I run both channels through the crossovers during bi-amping, which is what I'm doing.

So any other input regarding what I set the high and low pass crossovers on my amp?

neomagus00

sorry... ::sheepish look::... i forgot the mmc6500 xovers are biampable... gain walkthrough, if you want it...

JawKnee

neomagus00 wrote:

sorry... ::sheepish look::... i forgot the mmc6500 xovers are biampable... gain walkthrough, if you want it...

Regarding tuning, I've always wondered if the car should be on/engine running for 14 volts?

neomagus00

for setting your maximum gain, that's probably a good idea, yes... for actual tuning, adjusting eq and such, as well as adjusting gains downward from maximum to match the others, the car should be off to get the lowest noise floor possible... i'll have to make sure to add that to the walkthrough...

JawKnee

Any more input regarding the crossover settings on the amp?

ND13

I'm running my MMC6500s with a PG R4.0:2 that has 125 wpc and it does a more than adequate job. It does take about 70 hours or so to properly burn the tweeters in. They tend to be bright at first, then mellow out with burn-in. Other than a few esoteric brands(read $1k up) of components, the only sub $1k components that I've had experience with that can top the MMC6500s for overall performance are the SR6500s. With the SRs you step into another realm.

The Xenon amp is a step above my PG amp, so you should be just fine. Just be careful and tune it correctly.

MacLeod

Noel - youre running yours straight wired tho right? JawKnee is wanting to bi-amp them which would be 100 to each tweeter and 100 to each mid. Thats too much.

Plus, the Xenon amps are quite underrated as they are excellent competition level amps and I guarantee you that 100x4 is easily 130x4 or more so youre talking 260 watts to 120 watt speakers. Im not saying theyll instantly fry just that its going to be way too easy to overload them with that much power. For what its worth, Im still of the opinion you should straight wire them babies.

Also, its not so much the tweeter breaking in as it is the mid. The MM6's were like this too. Had no midbass and were quite thin for the first month then started fleshing out nicely and within 3 months were great! Its that lack of midbass and depth from the newborn mids that make em seem too bright.

JawKnee

MacLeod,

I have always been a little worried if my amp would be too powerful to bi-amp these components. Ultimately, I'll try configuring them each way for now.

My question, what differs between bi-amping the MMC6500s with my Xenon 100.4 vs. the Polk Audio C400.4? Both are rated at 4x100 I believe and I'm sure the C400.4 like the Xenon 100.4, will actually deliver more than 100 watts.

I ask because the manual for the MMC6500s mentions bi-amping with the C400.4 so that makes me feel a little safer in bi-amping with my Xenon. However, I will admit that 200 plus watts to these components does indeed sound "too much".

Manual for MMC6500s: http://www.polkaudio.com/downloads/manuals/car/MOMOSystems_Manual_5250_6500.pdf

Maybe I'll wire them straight and bridge the remaining 2 channels and power a 10" sub or an 8" sub . It's only money right?

audiobliss

Yes, you could use the crossovers and then bridge the rear two channels for a sub. That'd be a cost-effective way of amping fronts and powering a sub.

However, don't be afraid of bi-amping the MMC6500s. In my opinion, you should try it. Like you point out, Polk recommends bi-amping with the C400.4, so it can't be too different. There is most definitely less margin for error and a better chance of smoking your speakers with bi-amping, but as long as you set the gains correctly and use common sense when you're turning up that volume knob, you should be just fine.

And then, since it's only money, you could buy a separate Class D amp for you sub!

JawKnee

audiobliss wrote:

Yes, you could use the crossovers and then bridge the rear two channels for a sub. That'd be a cost-effective way of amping fronts and powering a sub.

However, don't be afraid of bi-amping the MMC6500s. In my opinion, you should try it. Like you point out, Polk recommends bi-amping with the C400.4, so it can't be too different. There is most definitely less margin for error and a better chance of smoking your speakers with bi-amping, but as long as you set the gains correctly and use common sense when you're turning up that volume knob, you should be just fine.

And then, since it's only money, you could buy a separate Class D amp for you sub!

I will definitely try bi-amping first. But back to my original question, how should I set the amp's crossovers if at all?

neomagus00

if you're running through the provided passive xovers, leave the amp's off, and you can control the highpass (60, 80, 100 Hz, whatever) from the HU...

audiobliss

What HU are you using? You might have already said, but if so, I missed it.

MacLeod

The difference between the Polk amp and the PG amp is the Polk amp makes a little shy of 90 per channel where the PG puts out 130+. Those extra 40 watts are whats worrying me. If you were using a 50x4 Id absolutely say to bi-amp.

The only real benefit of bi-amping is the extra flexibility in tuning the tweeters output, thats about it. You can still get excellent SQ from straight wiring.

As for crossover points, I would skip the amps x-overs and use the passive Momo x-overs. That way youd know theyre set to the proper frequency. Also those x-overs have a tweeter protection link in there so it will pop before your tweeters do, hopefully.

audiobliss

bi-amp...:D

Besides the flexibility....you can say you're bi-amping!

MacLeod

Yeah and hopefully that will be cool enough that you wont be bothered by those smoking pieces of melted plastic where your tweeters used to be.

audiobliss

...that's why I mentioned gains and commone sense...;)

But I must say, when the pros speak, heed what they say. But I still think you should at least experiment with bi-amping.

JawKnee

Audiobliss, I am using the stock HU :gasp

So does the supplied passive crossovers of the MMC6500s result in the mid running in full range?

ND13

MacLeod wrote:

Noel - youre running yours straight wired tho right? JawKnee is wanting to bi-amp them which would be 100 to each tweeter and 100 to each mid. Thats too much.

Plus, the Xenon amps are quite underrated as they are excellent competition level amps and I guarantee you that 100x4 is easily 130x4 or more so youre talking 260 watts to 120 watt speakers. Im not saying theyll instantly fry just that its going to be way too easy to overload them with that much power. For what its worth, Im still of the opinion you should straight wire them babies.

Also, its not so much the tweeter breaking in as it is the mid. The MM6's were like this too. Had no midbass and were quite thin for the first month then started fleshing out nicely and within 3 months were great! Its that lack of midbass and depth from the newborn mids that make em seem too bright.

That's why I said to tune it correctly. Who says the gains have to be at 100%??? But I do agree that he probably won't get that much benefit from bi-amping them. It is worth a try though, if just for **** and grins.

cam5860

What kind of question is that WILL I BE HAPPY WITH THE MMC6500. People just don't realize how good polkmomo speakers sound. I tell you what you go put any component set you want in for 300 bucks or less and then you put the mmc6500 in and hear the difference. You will say man I didn't realize what i was missing out on. I never new speakers could sound this good.

JawKnee

cam5860 wrote:

What kind of question is that WILL I BE HAPPY WITH THE MMC6500. People just don't realize how good polkmomo speakers sound. I tell you what you go put any component set you want in for 300 bucks or less and then you put the mmc6500 in and hear the difference. You will say man I didn't realize what i was missing out on. I never new speakers could sound this good.

Hmm... I think my question was fine, especially when I stated what I was looking for in my original post. I'm sure the Polk Audio Momo speakers will be awesome as I already have them and I'm anxiously awaiting on completing the installation this weekend. In any event, I asked, "Will I be happy..." because I was trying to see if the MMC6500s would provide me some extra "punch/oomph/bass" over my stock components found in my 2005 S2000.

JawKnee

Yet another question, perhaps a "strange" one.

Does the length of the speaker wire from amp to crossover and crossover to the speakers have to be the exact same on both sides? I never thought about this before, but will mismatching lengths introduce any "timing" issues?

And thanks for answering my question regarding the amp's crossover settings. I assumed bypassing them and feeding an unprocessed signal to the passive crossovers would be best. I'll probably experiment anyways.

neomagus00

no, you could have a mile of wire on one side and eight feet on the other and it wouldn't matter - the signal travels at pretty close to the speed of light ... besides, you'll be much too busy dealing with the massive pathlength difference to worry about much else, timing-wise

and using the passive xovers results in the mid being lowpassed and the tweet being highpassed...

ND13

JawKnee wrote:

Yet another question, perhaps a "strange" one.

Does the length of the speaker wire from amp to crossover and crossover to the speakers have to be the exact same on both sides? I never thought about this before, but will mismatching lengths introduce any "timing" issues?

And thanks for answering my question regarding the amp's crossover settings. I assumed bypassing them and feeding an unprocessed signal to the passive crossovers would be best. I'll probably experiment anyways.

It's always a good idea to make them as equal as you can. With that said, any timing differences would be negligible and in no way audible to human ears, unless we're talking about runs of wire in the hundreds of miles.


Edit- I see Neo answered the question while I was distracted at work .

JawKnee

Thanks guys! Hopefully I can find some time this weekend in between other projects at home to finish my car audio project. I'll be sure to keep everyone posted

MacLeod

Agreed, you could have one wire 50 feet longer than the other and it wouldnt matter.

Light travels at 186,000 a second (!) which means it would take about a zillionth of a nano second for the signal to travel the extra 4 feet. Hell, even if you could hear a delay that small the speakers wouldnt even be able to produce it!

ND13 wrote:

That's why I said to tune it correctly. Who says the gains have to be at 100%???

Thats true bro but even with the gains at zero, a 500 watt amp would still shred a 100 watt speaker. Hell, Im running about 150 to each of my SR's and my gains are set almost on the floor and on some recordings (Pink Floyd "Hey You") they still can bottom out! Having enough power is important but having too much power kills speakers.