Polk MM6501/651s. Why can't I get them to sound good? Do I need an amp?

blacksharpiemar

Hello all.

First of all, I'd like to say I've had the MM set (6501s front/651 back) speakers installed in my car for approximately two months now. Much to my dismay I've been completely unable to get satisfying SQ out of them. I have a set of Yamaha Studio Monitors (Which offer a relatively flat response) at home and when I step into the car I've been completely disappointed. :frown: The lows distort easily, the mids are not well pronounced, the highs seem unbalanced, and if I had to sum up of the voicing of the speakers in one word, it would be "SHALLOW".

I'm currently running them off of my Pioneer AVH-3200 BT unit and would like to give these speakers one more chance before I give up on them entirely. I was considering amping them, and as such, was wondering which AMP you recommend. My budget is relatively low, at around $300. If It's not a specific brand, I'd love to know what power rating you recommend I best run these speakers at to help them out. I have a 10" sub in the back of my Toyota Matrix accompanying them. It has an RMS power rating of 500w.

I stopped into a local audio shop and they recommended not running the POLKs on more than 60w/channel. Why would they have recommended this when from what I understand they can handle up to 100w?

Do you guys think an amp is the solution I need? I was even considering looking into an auto-eq unit like the JBL MS-8 if necessary. Unfortunately, when it comes to car audio I know little and I'm desperate to get my car system sounding right. Any and all suggestions would be appreciated.

Please Polk Audio Forums, you're my only hope... :frown:

kawizx9r

An amp should most certainly help.

Another thing, how often do you drive your vehicle? I ask because even though you've had your speakers for 2 months, it's quite possible that they haven't been broken in yet. It took a solid 3+months or so until my Polk subwoofer sounded really good.

As for power, as long as your gains are set properly and you're not abusing your speakers you should be fine with more than 60w/channel. I've got 75+w/channel to EACH driver, not just each side.

I'll let the pro's take over from here. Btw, welcome to CP!

-Freddy

blacksharpiemar

kawizx9r wrote: »

An amp should most certainly help.

Another thing, how often do you drive your vehicle? I ask because even though you've had your speakers for 2 months, it's quite possible that they haven't been broken in yet. It took a solid 3+months or so until my Polk subwoofer sounded really good.

As for power, as long as your gains are set properly and you're not abusing your speakers you should be fine with more than 60w/channel. I've got 75+w/channel to EACH driver, not just each side.

I'll let the pro's take over from here. Btw, welcome to CP!

-Freddy

Thank you for the kind welcome.

The first couple of weeks I had the speakers I went out for approximately ten hour long sessions of HU adjustment/pink noise playback. I drive the car approximately a half hour per weekday and two hours-three hours per weekend (all of which I had the speakers running).

I suppose all of that considered, I've put around 50+ hours on them so far. I noticed within a couple of hours worth of playback the speakers "opened up" considerably from when I first fired them up. Despite this, I'm very much wondering how I can bring the SQ level closer to that very awesome "flat" response you'd get from a set of studio monitors like I have at home. (Clarity/Enhanced Stereo Imaging/Definition/Tonal Balance)

All things considered, I'm not expecting miracles, only the best I can attain with this specific speaker set, which I feel so far I've not reasonably experienced.

arun1963

1. The issue is not with the speakers per se, its with the environment you're listening to them in.

2. If you're running the speakers off HU power, the typical hu would run out of clean power about 1/3 the way on your volume knob. So yes get an amp. 4x75-100watts rms would be fine.

3. If you're looking to reproduce home 2ch sound in your car, ditch the rears for a start and get a hu that has tons of tuning features. Better yet, get a processor. You need the DSP from the hu or processor to correct for all that's wrong in a car. Speakers at different distances from you, hence different arrival times. Speakers on the far side are on axis while the near side ones are nearly 90 deg off axis, hence varying frequency response. This is particularly severe at some frequencies (typically 2-4khz) range where the on axis speaker will be much louder than the off axis one. Reflections is another issue that messes up the sound.

Can you get good sound in a car? Yes, but you need the right equipment and tuning. Speaker placement is also key. Once you install the amp, remember to seal your doors.

blacksharpiemar

arun1963 wrote: »

1. The issue is not with the speakers per se, its with the environment you're listening to them in.

2. If you're running the speakers off HU power, the typical hu would run out of clean power about 1/3 the way on your volume knob. So yes get an amp. 4x75-100watts rms would be fine.

3. If you're looking to reproduce home 2ch sound in your car, ditch the rears for a start and get a hu that has tons of tuning features. Better yet, get a processor. You need the DSP from the hu or processor to correct for all that's wrong in a car. Speakers at different distances from you, hence different arrival times. Speakers on the far side are on axis while the near side ones are nearly 90 deg off axis, hence varying frequency response. This is particularly severe at some frequencies (typically 2-4khz) range where the on axis speaker will be much louder than the off axis one. Reflections is another issue that messes up the sound.

Can you get good sound in a car? Yes, but you need the right equipment and tuning. Speaker placement is also key. Once you install the amp, remember to seal your doors.

Thank you for the suggestion, although I forgot to mention I have also already fully dynamat treated the vehicle.

Vital

MM6501s are rated at 125W rms per side at 2.7Ohms and they aren't bi-ampable so not sure why u're hearing 60W per side or 75W per each driver.
MM651s are 100W per side at 2.7Ohms

This whole 2.7 Ohms is kind of confusing since 99% of the time it's either 2 or 4 Ohms but in your case just about any decent 4-channel 2Ohm stable amp in 90-125W (at 2Ohms) range will work fine. There's nothing wrong with amp pushing a bit more watts then speakers are rated for as well as a bit less watts then speakers are rated for as long as gains are set properly.

Also while we're at Ohms i'm pretty sure your Pioneer's internal amp works with 4Ohms only so you will def hear distortion and maybe even speakers cutting off at high volumes just becuase of that. I know i had it with my Kenwood DNX unit and stock speakers as Kenwood is 4Ohms while stocks were 2.

Your $300 range is fine for a 4-channel amp to power your speakers and yes, amp will def improve quality as well as "loudness" There's LOTS of amps that will work for you, you just need to shop around to see what fits you better. Polk Audio PA500.4 comes to mind btw, take a look at it. The only "bad" thing about it is that it's pretty big in size so make sure to check where you will be installing it if there's enought space.

Another thing to check - i'd imagine your headunit has some (at least) basic tunning options so if you're sending a full range signal to your speakers then bass distortion is obvious as these speakers don't handle low bass frequencies too well, no 6.5'' speaker does. Check you h/u's settings, make sure it only send frequencies above 50-60Hz range to your Polks as anything below that is your subwoofer's job.

tw33ker

I, too, is having the same problem. I just can't power these speakers. I have tons of 6.5" speakers (Pioneer speakers of diff't models, Kenwoods, Mb Quarts, Rockford Fosgate, Infinity Kappa's, you name it...) but these polk audio mm6501's are like the worst speakers i ever had.... I was led to believe all the good reviews -- and because of the good reviews, i bought these speakers believing i had the best component speakers...... I powered em with 60 RMS kenwood and i also powered em with Boston Acoustic 50 rms but they still don't sound good... They sound terrible!!! I am almost giving up!!! I am close to smashing up these speakers... These will be my last Polk Audio car speakers...

If i were to bridge my 4 channel amp, can they take 160 watts RMS per channel???? I have to ask first before i would damage them... I dont know what else to do with these speakers.... i spent so much for something it never sound good...

nguyendot

Power is going to make the biggest difference right now, after that staging.

I'd give them a clean amp and you'll hear a night and day difference.

arun1963

tw33ker wrote: »

I, too, is having the same problem. I just can't power these speakers. I have tons of 6.5" speakers (Pioneer speakers of diff't models, Kenwoods, Mb Quarts, Rockford Fosgate, Infinity Kappa's, you name it...) but these polk audio mm6501's are like the worst speakers i ever had.... I was led to believe all the good reviews -- and because of the good reviews, i bought these speakers believing i had the best component speakers...... I powered em with 60 RMS kenwood and i also powered em with Boston Acoustic 50 rms but they still don't sound good... They sound terrible!!! I am almost giving up!!! I am close to smashing up these speakers... These will be my last Polk Audio car speakers...

If i were to bridge my 4 channel amp, can they take 160 watts RMS per channel???? I have to ask first before i would damage them... I dont know what else to do with these speakers.... i spent so much for something it never sound good...

Can't really help without knowing what you feel is lacking. I'm assuming polarity and connections are good. Just going by the sets you're referencing the MM's against it may be that you're finding the MM's less 'bright'.

More details would help.

tw33ker

I bridged my 4-channel amp (Boston Acoustics GTA-504) and the speakers were supposed to be getting 160watts RMS each (bridged).... The sound was still disappointing. Didn't sound good. I even put baffles on the speaker... It sounded better with the baffles but sound quality is not good .... There is no bass... bass sounds terrible... I finally give up =(

What kind of amp and RMS are you guys running on your MM6501 speakers?

Anyone willing to buy my mm6501's???? i'm very disappointed!!!

Vital

tw33ker wrote: »

Anyone willing to buy my mm6501's???? i'm very disappointed!!!

If it's cheap enought :biggrin:

but yeah, those speakers actually produce great midbass so it has to be something else.... buuuut feel free to pm me your "let me get rid of those pos' price" lol

tw33ker

how many RMS are you guys powering your mm6501 speakers???

I used 16 gauge speaker wire to connect "input" (xover) to amp...

The tweeter has more sound than the mid... The mid can't handle bass.. there was bass distortion...after tweaking my h/u LPF I was able to adjust the bass distortion. But still it never sounded good.... I don't know what else to do. I had done adjustments on my AMP from gains to LPF/HPF, all the settings in my h/u...

I only used my mm6501 speakers for testing... Then i put back my MB Quart speakers... I have only used my POLKS maybe 15 minutes of testing... How much r u willing to buy?

kawizx9r

Have the speakers been properly broken in?.....

Can't expect to hook them up and start blasting right away with them. This goes for any and all new speakers.

tw33ker

it hasnt broken in yet... how many RMS are u guys powering your 6501's???

tw33ker

I'm thinkin about getting the Polk Audio DB651S 6.5" 2-Way Car Speakers <

---

do they sound good? Anyone who has had these speakers? I wanna get rid my mm6501 speakers...

Vital

db coax over mm comps??? u gatta be kidding me.

There is def something wrong witgh install/tunning/break in... It is also possible that speakers themselves are defective in some way offcourse (that's always an option with anything) but it's the last option on the list.

tw33ker

Could be that the speakers are defective.... there's nothing wrong with installation/connections... nothing wrong with the tuning... these speakers are the only ones that never sounded right of all my speaker collection

tw33ker

how many RMS are you guys powering your Polk Audio component speakers? 50 watts? 100 watts? 75????

Vital

Whatever they are rated for. A little less wont make any difference but def not 50W since they are 100-125rms if IIRC