Polk MMC6500 Crossover/EQ Questions

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Hierge
Hierge Posts: 5
edited April 2010 in Car Audio & Electronics
(I posted this in a different forum and it is more appropriately posted here. Mea Culpa. )

System:

Alpine CDA-9835 Head Unit
Soundstream Van Gogh 4 X 125 watt Amp
2 Infinity 200 watt sub systems
2 sets Polk MMC6500 Momo component speakers

Car:

2003 Mustang GT convertible / Had the Mach system previously so tweets are by the front left and right mirrors. Mids are by the ankles in the doors. I had everything professionally installed by Tweeter and I have zero knowledge how they set this system up with crossover settings etc. Rear Momos are right behind the seats in a component setup. Subs are in the trunk on each side.

This car has been sitting in suspended animation parked for four years and I never got the system completely set up on the Alpine side. I have a couple questions and observations on which I sincerely hope to get some feedback. Thank you in advance!

1. The speakers sound fantastic, but the equalization is proving troublesome due to too many parameters and my limited brain. I have the choice on the Alpine to configure an "active crossover" using their online system to do this graphically then download the settings to the head unit. This setting allows me to set up a 3 way or a 2 way crossover on a grid pattern (X Y Axis) with crossover frequency on the X axis and -db on the Y Axis. I can manually set the subs from 50 to 120. My questions are as follows:

A. The Momos have their own crossover and though I did not witness their setup, I am guessing from the very strong tweeters that they are set at Zero not -3 or -6. I am basically looking at a 2 way setup with the Momo crossovers covering the entire tweet/mid components on each channel. Am I correct in thinking this? OR should I use the Alpine to split it's active crossover into 3 zones on the X axis and set the frequency cutoffs of the mid components separately from the tweeter components?

B. I can cut off the Momos on the crossover at any frequency. I am pushing a pretty good bit of clean power through them right now and am not as much worried about clipping or distortion. I am currently using 80, but is there a better rule of thumb here?

2. The Alpine head unit uses a parametric equalizer which is a real pain in the you know where to use. This is also on an XY Axis with frequency on the X axis and DB on the Y axis. There are five sliding points (where you click and hold your mouse dragging them to any point on the XY Axis.) I just want to take the "eek" off the tweets to mellow them out just a smidge. I can adjust the width of the parameters by increments of 1, 1.5, and 3. Is there any common wisdom on parametric equalizer adjustments?

Any help on this would be greatly appreciated. I am just learning here and trying to be accurate in my questions. Thanks.
Post edited by Hierge on

Comments

  • arun1963
    arun1963 Posts: 1,797
    edited April 2010
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    Welcome to CP. That's a fine setup, with great potential. You'll have to put in some effort in setting it up though. Excellent hu with lots of tuning options and the option of going active. Good amp and speakers. Here's what I would do:

    1. Disconnect the rears and bi-amp the front components. Rear speakers add to phase and cancellation issues and would pull your stage back once you have dialed it in.

    2. Take out the passive xovers and run active from your hu. You would set a two way network. One between your sub and mids and the other between your mids and tweets. The momo passive splits the sound between the mid and tweet, too low. Hence, the tweet is playing much lower than it should. When I ran the momos in passive mode, they were at -6db from the crossover. You're right, the stock setting is 0.

    3. Once you've set your network from the hu you can then get down to tuning. You will need to use the time alignment to get the speakers in phase and this will set the foundation of your stage and give you sound from the front. You will need to use the eq to level match the various frequencies. The parametric eq can give you really good results. L/R control on an equaliser is better, but I'd take the parametric 5 band over a normal 5 band graphic eq.

    4. The graphic eq adjusts one frequency, the parametric one adjusts a range of frequencies around the one you select. 1, 1.5 and 3 are the q curves on which you adjust a frequency. The higher the number, the wider the range of frequencies that are raised or pinched around the central frequency that you selected. Think of a bell curve. A q of 1 would give the curve a narrow base while a Q of 3 would give the curve a much wider base, hence more frequencies would be affected.........I know that sounds confusing.

    cheers
  • Hierge
    Hierge Posts: 5
    edited April 2010
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    Thanks arun1963!

    1. It sounds to me like you have taken a great deal of time to set up your system and get it dialed in. I do notice that the rear speakers do pull the stage back, but I paid a pretty penny for them and hate to waste them. My solution would be to just set the balance all the way to the front speakers, dial in the sound stage and use the fader according to my mood. The other issue I have with getting rid of the rear speakers is the mids being at ankle height on the front doors. At least I do get mids (albeit at the cost of soundstage) closer to ear level.

    2. I would have to have this professionally done. Digging out the crossovers and rewiring is something that I am not thrilled at doing right now. I'd also like to hear a change like this prior to having it done. Perhaps I can hear another system in my area that features this setup, or a bunch of people on this forum pile on and convince me to do it without hearing it.

    3. I am getting a cloth measuring tape from the store later today to get the distances set as best as possible. I am going to mark the delay on the left speakers to my left ear and the right to my right ear.

    4. I actually do understand how the parametric equalizer works from your description. Thanks. What is confusing is that it doesn't create a "bell curve" type EQ curve like a graphic EQ. It "pulls" the smooth curve out of form with no smoothing, looking somewhat like a circus tent after you put in a pole. (Best analogy I can come up with.) I am still in the graphic EQ bell cure world so it looks strange for now.

    Thanks for your reply. Can you tell me more about my HU from the standpoint of equalization? There are other options available on the unit itself for USER set EQs, Bass Balancing (whatever that means) and polarization of Subs. I have it set in 180 mode now. The subs sit at opposite corners of the small trunk with woofers facing each other. Are they out of phase now? My guess is yes.
  • arun1963
    arun1963 Posts: 1,797
    edited April 2010
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    Hierge wrote: »
    Thanks arun1963!

    No prob. The name is arun, '63 is just the DOB. Yeah, old geyser :)
    Hierge wrote: »
    I do notice that the rear speakers do pull the stage back, but I paid a pretty penny for them and hate to waste them. My solution would be to just set the balance all the way to the front speakers, dial in the sound stage and use the fader according to my mood. The other issue I have with getting rid of the rear speakers is the mids being at ankle height on the front doors. At least I do get mids (albeit at the cost of soundstage) closer to ear level.

    You can always sell the rears and recover your cost. Put that money towards sound deadening. You can never have enough of this stuff. If you're going after the best possible stage and image and great tonality, rears will only mess things up. I would strongly recommend active. I don't know about the Alpine hu, but with my pio 880, I lose the fader when I'm in active mode.

    Having the mids at ankle height is "MUCH" better than having them higher up on the door. I have mine like 6" below the window and I 'hate' that location. With the mids higher on the doors they are closer to your ears and hence louder with everything they do, reflections in the 1-3khz range are also much more pronounced and getting the balance and leveling right is next to impossible.

    Hierge wrote: »
    2. I would have to have this professionally done. Digging out the crossovers and rewiring is something that I am not thrilled at doing right now. I'd also like to hear a change like this prior to having it done. Perhaps I can hear another system in my area that features this setup, or a bunch of people on this forum pile on and convince me to do it without hearing it.

    Sure, listen to some well tuned active set-ups. With the kind of tuning options you have, active will always be much better. It well worth the time and effort. Just make sure you get it done by a good installer.

    Hierge wrote: »
    3. I am getting a cloth measuring tape from the store later today to get the distances set as best as possible. I am going to mark the delay on the left speakers to my left ear and the right to my right ear.

    Setting time alignment at measured distance is a starting point. You'll have to tweak a bit here to get it right. Remember its not about what it measures but how it sounds. :)
    Hierge wrote: »
    4. I actually do understand how the parametric equalizer works from your description. Thanks. What is confusing is that it doesn't create a "bell curve" type EQ curve like a graphic EQ. It "pulls" the smooth curve out of form with no smoothing, looking somewhat like a circus tent after you put in a pole. (Best analogy I can come up with.) I am still in the graphic EQ bell cure world so it looks strange for now.

    A graphic eq is great if you have independent L/R control. Then you can fine tune each frequency separately for L/R. If its an eq for summed L/R I'd go with the parametric. Don't worry about how the graph looks, how it sounds is more important.
    Hierge wrote: »
    for your reply. Can you tell me more about my HU from the standpoint of equalization? There are other options available on the unit itself for USER set EQs, Bass Balancing (whatever that means) and polarization of Subs. I have it set in 180 mode now. The subs sit at opposite corners of the small trunk with woofers facing each other. Are they out of phase now? My guess is yes.

    I don't have much experience with the Alpine decks. Mac's the man with the alpines. As a general rule I prefer using the manual tuning rather than auto / preset anything. I'm not sure about the subs firing at each other. Generally the subs should fire in the same direction to prevent cancellations. Again Mac's a better authority on that. Set at 180 deg yes they would be out of phase with the mids
  • Hierge
    Hierge Posts: 5
    edited April 2010
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    arun1963 wrote: »
    No prob. The name is arun, '63 is just the DOB. Yeah, old geyser :)
    You can always sell the rears and recover your cost. Put that money towards sound deadening. You can never have enough of this stuff. If you're going after the best possible stage and image and great tonality, rears will only mess things up. I would strongly recommend active. I don't know about the Alpine hu, but with my pio 880, I lose the fader when I'm in active mode.

    ARUN, My birthday is in November 1963 so we're both old guys :)

    I have looked into this more and thought about it more since you have changed my thinking. Nobody ever rides with me in this car and the rear speakers are not that important. I went through a bunch of posts on the MMC6500 speakers and people generally do not keep the passive crossovers when they have an Active Crossover on the head unit and the opportunity to biamplify.

    I'd just take the Momos out of the rear channels and put them in another vehicle. They are too good to sell in my opinion.

    I actually paid a heap for sound deadening since the Mustang is such a cheaply made car with crummy doors. I was mad about it at the time since it was a couple hundred bucks, but I had the cash and wanted the system to be primo. Unfortunately, the installer didn't suggest how to set it up like you have, they asked me and did it according to what I told them.

    I bought all these components after extensive research, but knew next to nothing about the HU or Amp. The installer was charging me too much for other things which made me less than happy. So... I guess they wanted rid of me as soon as they could. That's why nothing ever got set up on the HU.

    They did a good job otherwise.

    I need to read up on the amp manual and see what type of wiring they used. I can just run wires to the mids in the door and bi-amplify from there I guess.

    I am not satisfied with the sound yet and know that these Momos can sound a lot better with tweaking. Since I never ride with rear passengers, I think I am convinced to go with the biamp and active crossover. Just need to find a good installer who won't rip me off in the Washington DC area.
  • arun1963
    arun1963 Posts: 1,797
    edited April 2010
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    DSkip wrote: »
    My thought on the sub was that you would want one sub wired out of phase and that would help prevent cancellation. That's something I don't have any experience with, but I THINK I remember seeing that a few places.

    Yup running one out of phase, would help with cancellations. Just not sure what if anything that would do to tonality.
  • arun1963
    arun1963 Posts: 1,797
    edited April 2010
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    Hierge wrote: »
    ARUN, My birthday is in November 1963 so we're both old guys :)

    Funny thing is, when I was 26-28 like most guys here, everyone around me seemed much older. Now that I'm older, everyone around me is much younger. 2/3 of the population here is under 32yrs. Seems like a couple of generations focused only on making babies. ;)

    Hierge wrote: »
    have looked into this more and thought about it more since you have changed my thinking. Nobody ever rides with me in this car and the rear speakers are not that important. I went through a bunch of posts on the MMC6500 speakers and people generally do not keep the passive crossovers when they have an Active Crossover on the head unit and the opportunity to biamplify.

    ++ on going active and not running rears. I ran the momo's for about two and a half years. The last 8 months were active. You can get them sounding very nice with proper tuning.
    Hierge wrote: »
    just take the Momos out of the rear channels and put them in another vehicle. They are too good to sell in my opinion.

    Yup that's another option.
    Hierge wrote: »
    need to read up on the amp manual and see what type of wiring they used. I can just run wires to the mids in the door and bi-amplify from there I guess.

    I am not satisfied with the sound yet and know that these Momos can sound a lot better with tweaking. Since I never ride with rear passengers, I think I am convinced to go with the biamp and active crossover. Just need to find a good installer who won't rip me off in the Washington DC area.

    There's a guy here (bigaudiofanatic) who stays somewhere in Jersey, then there's cody, but he's way down south in Texas :) When you're getting the bi-amping done, I would look at changing the install on the subs. Then you'd get down to the fun part which is tuning.