Bass on mmc6500 beats MB Quart

ascalon
ascalon Posts: 17
Today, I have a freshly installed pair of mmc6500 components in the front. 2 weeks ago, I had a pair of MB Quart rvf 216 installed in the back as a coaxial mount. I decided on both before listening to them, but I did get a chance to listen to the momos at Fry's before receiving them. I'm not sure if it's because they were installed by different companies but...

Holy ****, the Momos blow mb quart out the water! It's ridiculous how much better their bass response is. Greater frequency range, better handling, and cleaner bass. It's freakin ridiculous because the stated frequency range is a lot more constricted than that of the MB Quart! :mad: That ticks me off. What should I check for on the mb quarts to explain why they have a bad time producing bass below 100hz? Could it be loose connections on the back of the speaker from a poor install? Could both (left and right) speakers be defective?

Or is it that because of the phase plug hole in the middle of the friggin woofer (which is there for a coaxial mount, although it can be mounted as a component) creating an inability for the woofer to produce as much bass as the Momo which has a solid sealed woofer? Is this one of the main differences between a coaxial and component performance, even though both can be used as components?
Post edited by ascalon on

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  • Greg Peters
    Greg Peters Posts: 605
    edited February 2008
    ascalon wrote: »
    Today, I have a freshly installed pair of mmc6500 components in the front. 2 weeks ago, I had a pair of MB Quart rvf 216 installed in the back as a coaxial mount. I decided on both before listening to them, but I did get a chance to listen to the momos at Fry's before receiving them. I'm not sure if it's because they were installed by different companies but...

    Holy ****, the Momos blow mb quart out the water! It's ridiculous how much better their bass response is. Greater frequency range, better handling, and cleaner bass. It's freakin ridiculous because the stated frequency range is a lot more constricted than that of the MB Quart! :mad: That ticks me off. What should I check for on the mb quarts to explain why they have a bad time producing bass below 100hz? Could it be loose connections on the back of the speaker from a poor install? Could both (left and right) speakers be defective?


    Or is it that because of the phase plug hole in the middle of the friggin woofer (which is there for a coaxial mount, although it can be mounted as a component) creating an inability for the woofer to produce as much bass as the Momo which has a solid sealed woofer? Is this one of the main differences between a coaxial and component performance, even though both can be used as components?


    Well let's see...


    MB Quart RVF 216

    Power Handling: 70 - 140 W
    Frequency Response: 38 - 32.000 Hz
    Impedance: 4 Ohms
    Crossover Frequency: 4.200 Hz
    Sensitivity: 86 dB (1W/1m)

    Polk MMC6500

    Overall Frequency Response 43Hz - 25kHz
    Nominal Impedance 4 ohms
    Power Handling (continuous) 125 w
    Power Handling (peak) 250 w
    Efficiency 90 dB
    Crossover 2.6kHz 2nd order High & Low Pass




    A manufacturer's stated frequency response only offers true insight into a speaker's performance capability if they list frequencies with meaningful output from their drivers rather than frequencies reproduced regardless of the volume they are reproduced at. The Momos may well reproduce a 38hz tone if you were to feed them one, but not at an appreciable volume to make it a useable part of the component set's frequency response for typical usage. In this case, Polk has more than likely emphasized useable frequency response over what the mid is actually capable of reproducing in ideal labratory conditions.

    The performance you find from both brands installed in-car will be a function of how well suited the individual speaker is to it's "cabinet" or "infinite baffle". In the case of the Momos, if you have them installed in a door cavity, they'll use the internal volume of that door as a (leaky) cabinet, and will be able to produce more appreciable midbass than the same speaker installed in a simple baffle (in the case of a non-enclosed kick panel, or rear quarter panel trim), while the same speaker installed in a rear deck may see too much volume in it's enclosure (the trunk) and not get the same re-enforcement of the midbass frequencies you'd see in the door install where the volume of the enclosure is closer to manufacturer's spec.

    As for the hole in the cone to accomodate coaxial mounting, I wouldn't look at it as a design fault limiting midbass- many manufacturers (including Polk, with their SR line) use this design with the cone moving around a fixed phase plug or coaxial post protruding through the middle of the cone.

    It wouldn't be fair to compare the two speaker brands/models without trying them both in the same application- installed in the door. The performance will be as much about the install (and installed location) as it will about the design. Both models you own have a reputation of being "power hungry", in that you'll see the most performance gains powering them toward their upper continuous power ratings. You haven't mentioned how you are powering your speakers, and that too has an effect on performance you'll see once installed.

    The Momos are slightly more efficient than the Quarts at 1 watt/1 meter, but for comparing them with typical amplifier power, the efficiency specs are less indicative of what you can expect in a real-world application. I'm not really surprised that the Momos seem to sound better to you than the MB Quarts- quality of Quart product has fallen off since they first became higher-end contenders, while the Momos have been solid and maybe even improving since their launch. Anyway, glad to hear you are enjoying your new speakers.
  • ascalon
    ascalon Posts: 17
    edited February 2008
    Thank you very much for the thorough response!

    Both speakers are installed in the doors, and the doors/enclosures have pretty much equal space/volume. Only dif is the tweeter on the polks is at the top of the door panel, closer to head level, in the front set. They are powered off a 4 channel, *kicker zx650.4, 120 watts rms x 4 amplifier. High end stuff (I learned my lesson after buying a crap pioneer amplifier with a Best Buy sub package). I've noticed that the HPF on the head unit works far more accurately than with just the amp's HPF, but that's probably the same with most amps. Just wish the gains were noted in voltage instead of meaningless numbers 0-11...

    But like I said, I though the Polk's sounded great off the bat, for bass response. The highs seemed kinda low though. I had set the crossover to -2 or -3 db before they were installed (and I'm assuming the installer didn't change it), so I guess these really aren't as bright as most say they are. I'll wait for them to break in though. As far as the quarts go, I opened up my door panel tonight to check out the install job on them. Aside from the crossover being sloppily laid on the bottom of the door behind the moisture guard lining (an area that I'm guessing could get wet quite easily), everything seems right. I tested the left speaker with some bass heavy music so I could actually LOOK at it while it's doing it's job. It wasn't having nearly as much trouble as usual. My only guess is that the bad bass sounds I hear at high columes either occurs because

    1. The door panel is vibrating in a way that sours the music.
    2. Or somehow my speakers/amp aren't getting enough power when driving more than one speaker, and thus are getting distorted on bass heavy music.

    Number 1 seems more likely to me, I think. With the door panel off, the single speaker was doing almost as well as the Polk for bass frequencies. It may have been door noise rather than the woofer being stressed. I'll do some more testing to find out though.
  • ascalon
    ascalon Posts: 17
    edited February 2008
    Well let's see...


    MB Quart RVF 216

    Power Handling: 70 - 140 W
    Frequency Response: 38 - 32.000 Hz
    Impedance: 4 Ohms
    Crossover Frequency: 4.200 Hz
    Sensitivity: 86 dB (1W/1m)

    Polk MMC6500

    Overall Frequency Response 43Hz - 25kHz
    Nominal Impedance 4 ohms
    Power Handling (continuous) 125 w
    Power Handling (peak) 250 w
    Efficiency 90 dB
    Crossover 2.6kHz 2nd order High & Low Pass




    A manufacturer's stated frequency response only offers true insight into a speaker's performance capability if they list frequencies with meaningful output from their drivers rather than frequencies reproduced regardless of the volume they are reproduced at. The Momos may well reproduce a 38hz tone if you were to feed them one, but not at an appreciable volume to make it a useable part of the component set's frequency response for typical usage. In this case, Polk has more than likely emphasized useable frequency response over what the mid is actually capable of reproducing in ideal labratory conditions.

    The performance you find from both brands installed in-car will be a function of how well suited the individual speaker is to it's "cabinet" or "infinite baffle". In the case of the Momos, if you have them installed in a door cavity, they'll use the internal volume of that door as a (leaky) cabinet, and will be able to produce more appreciable midbass than the same speaker installed in a simple baffle (in the case of a non-enclosed kick panel, or rear quarter panel trim), while the same speaker installed in a rear deck may see too much volume in it's enclosure (the trunk) and not get the same re-enforcement of the midbass frequencies you'd see in the door install where the volume of the enclosure is closer to manufacturer's spec.

    As for the hole in the cone to accomodate coaxial mounting, I wouldn't look at it as a design fault limiting midbass- many manufacturers (including Polk, with their SR line) use this design with the cone moving around a fixed phase plug or coaxial post protruding through the middle of the cone.

    It wouldn't be fair to compare the two speaker brands/models without trying them both in the same application- installed in the door. The performance will be as much about the install (and installed location) as it will about the design. Both models you own have a reputation of being "power hungry", in that you'll see the most performance gains powering them toward their upper continuous power ratings. You haven't mentioned how you are powering your speakers, and that too has an effect on performance you'll see once installed.

    The Momos are slightly more efficient than the Quarts at 1 watt/1 meter, but for comparing them with typical amplifier power, the efficiency specs are less indicative of what you can expect in a real-world application. I'm not really surprised that the Momos seem to sound better to you than the MB Quarts- quality of Quart product has fallen off since they first became higher-end contenders, while the Momos have been solid and maybe even improving since their launch. Anyway, glad to hear you are enjoying your new speakers.

    Where did you get the info for the quarts from? Most places I've seen have them listed at 120 watts rms at the most, and 90db sensitivity.
  • Greg Peters
    Greg Peters Posts: 605
    edited February 2008
    ascalon wrote: »
    Where did you get the info for the quarts from? Most places I've seen have them listed at 120 watts rms at the most, and 90db sensitivity.

    I searched with the "Google" and clicked on Quart's own sight, then copied/pasted from specifications listed there ;).
  • ascalon
    ascalon Posts: 17
    edited February 2008
    I searched with the "Google" and clicked on Quart's own sight, then copied/pasted from specifications listed there ;).

    I see. Funny how everyone else has it wrong :p . If they can handle 140 watts, and my amp does 120, I should be able to push the gains on its channel pretty damn high without distortion (although my ears may begin to bleed) of the highs, though much higher than the 12~1 o'clock position on my gain knob makes the bass start distorting for real (though the high still seem loud and clear.

    Darnit, has anyone used a kicker amp that can comment on the gains setting? With my head unit being in the neighborhood of 2 volts, the gains switch should need to be set pretty far right, but that doesn't seem to be the case...
  • 1hawaii50
    1hawaii50 Posts: 26
    edited June 2008
    ascalon wrote: »
    Darnit, has anyone used a kicker amp that can comment on the gains setting? With my head unit being in the neighborhood of 2 volts, the gains switch should need to be set pretty far right, but that doesn't seem to be the case...

    Ascalon,
    I know I'm reviving an old thread, but I was wondering if you ever got this worked out? I just finished an install with a set of MMC6500's in the front doors, and MMC690's in the rear deck of my 07 Altima. I'm powering them via the factory H/U (non-bose), and a Kicker ZX650.4 amp. I'm finding similar issues. I am using a Navone LOC set to full volts, and I get decent volume with my gains turned all of the way down. If I attempt to turn the gains up even 1/4, I get quite a bit of bass distortion. I'm not sure If I should set the HPF on the amp, or where to begin. If you've got any advice, I'd appreciate it.
  • 99_orange_SS
    99_orange_SS Posts: 1
    edited June 2008
    1hawaii50.... I am just wondering if you ever fingured out the issue to your question above? If so what was it?
  • 1hawaii50
    1hawaii50 Posts: 26
    edited June 2008
    Not yet...Unfortunately I tore my lateral meniscus in my left knee while finishing up the install, and I just had surgery 2 days ago. I've got a buddy who is pretty good at setting up systems, but I haven't been able to hook up with him yet with me being "out of commission" at the moment. Hopefully within the next week or so I can get together with him and work on it.