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Polk Audio MM651

Quote: "What speakers should I replace the MM651UM Polks with?"
Answer: For the best speakers in a 6.5" coaxial go with the JL Audio MX650 or the Wetsounds XS650. The Polk MM651UM will sound similar to the JL Audio MX650. The Wetsounds XS650 is a little more aggressive in the treble.

Quote: "I had never before played around with the M502's "extra bass feature". Well, while testing the system out I blew one of the MM651UM speakers as I really like to play music really loud."
Answer: Pick one...either the bass EQ at a background listening level or loud with no bass EQ. The 'Extra Bass' feature has a center frequency of 50 Hz with a potential 12 dB boost. No 6.5" coaxial can reproduce 50 Hz despite the false specs. Yes, perhaps the 6.5" can reproduce 50 Hz at an output level much lower than what you can discern. On the flipside, a 12 dB boost represents a 1 to 16 ratio in the power increase. So if you are at 10 watts and hit the +12 dB boost, you are suddenly at 160 watts.
That's just going to tear up the speakers. LOUD and a +12 dB bass boost just don't mix. Better off adding a subwoofer.
 
@David Analog you are a walking encyclopedia of audio knowledge! I never understand everything you post, but damn it is interesting. :)

Where do you get all this info on audio equipment?
 
Thanks for the heads up guys. I have similar Clarion head unit and I will make sure that bass boost feature is off.
@Irvs Since I have same speakers & same amp i'm curious as to what did you have the HTX4 amp settings at when you blew the speaker? Gain? Crossover switch High or Low? What level did you have the variable crossover setting at on the 50-250 range? HTX4 manual

I currently have my amp set at around 50% gain, 4 channel mode, High X-over selected and variable crossover at 65 (and that "bass boost" off on the head unit). My understanding is that the high crossover at 65 acts as a filter and plays on frequencys above 65mHz. Per the manual, "Crossover Controls: This amplifier is designed to play frequencies between 50 Hz and 250 Hz. The amplifier is equipped 2 different optional settings. High-Pass (HI) or Low-Pass (LO) (See below) “High-Pass” designed to play only the frequencies above where the crossover is set at. “Low Pass” designed to play only the frequencies below where the crossover is set at."

By the way, the only goofy thing I have found after my install is the power button on the head unit, will turn everything on, but will not turn the head unit off? Not the end of the world,as I can mute it or turn the battery switch to power it off. But just a little annoying.
 
Thanks for the heads up guys. I have similar Clarion head unit and I will make sure that bass boost feature is off.
@Irvs Since I have same speakers & same amp i'm curious as to what did you have the HTX4 amp settings at when you blew the speaker? Gain? Crossover switch High or Low? What level did you have the variable crossover setting at on the 50-250 range? HTX4 manual

I currently have my amp set at around 50% gain, 4 channel mode, High X-over selected and variable crossover at 65 (and that "bass boost" off on the head unit). My understanding is that the high crossover at 65 acts as a filter and plays on frequencys above 65mHz. Per the manual, "Crossover Controls: This amplifier is designed to play frequencies between 50 Hz and 250 Hz. The amplifier is equipped 2 different optional settings. High-Pass (HI) or Low-Pass (LO) (See below) “High-Pass” designed to play only the frequencies above where the crossover is set at. “Low Pass” designed to play only the frequencies below where the crossover is set at."

By the way, the only goofy thing I have found after my install is the power button on the head unit, will turn everything on, but will not turn the head unit off? Not the end of the world,as I can mute it or turn the battery switch to power it off. But just a little annoying.

My gain is set up at approximately 50%. I am on the 4-channel mode and the crossover is set up to pass everything above 50hz.

Overall, I think this setup sounds much nicer than when I had the clarion xc1410.

I've replaced the speaker and have disabled the "bass boost" feature on the head unit. Sometimes I feel that even when the bass is set at -7 it s too much for some songs!
 
Hey guys. I've been having an issue with the stereos "mids and highs". Sometimes the stereo sound beautifully full of bass, mids, and highs. Other times the mids and highs just aren't there when playing the same song.

I have the clarion m502, 4 Polk mm651um and the wetsounds htx-4 as some of you may recall.

The battery is able to crank the boat when this happens.

Any suggestions?
 
Is this over Bluetooth, fm radio, aux cable? Do you know what voltage is at on battery? Is it normal at start or end day? Do you have a charger?
 
Is this over Bluetooth, fm radio, aux cable? Do you know what voltage is at on battery? Is it normal at start or end day? Do you have a charger?

It happens on Bluetooth and on tuner tuner towards the end of the day after charging the battery prior to launching the boat.

The battery where this happens is on an optima bluetop marine battery. It's been replaced 3 times already since March of this year due to it not holding a charge by sams club.
 
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It sounds like a battery issue. What is the issue with the battery for being returned? How are you charging it/maintaing it?
 
It sounds like a battery issue. What is the issue with the battery for being returned? How are you charging it/maintaing it?

I charge it overnight prior to using it all the way..... According to the chargers fully charged led. However, when time comes to crank the engine it acts as it it is completely dead.....and that's when I take it in to Sam's to be tested and they just give me a new one.

I have another brand new Duracell marine battery that I need to test the stereo with.
 
What charger are you using? Have you put your own voltmeter on it? Something seems weird and definitely I think your stereo is linked to battery problems. I just put Optima BlueTops in my boat and hope there are no issues with my own boat!
 
@Irvs It is also important to fully charge the batteries before storing the boat. A battery that is stored discharged will develop a crystallized lead sulfate coating on the plates and not be able to be recharged.
 
What charger are you using? Have you put your own voltmeter on it? Something seems weird and definitely I think your stereo is linked to battery problems. I just put Optima BlueTops in my boat and hope there are no issues with my own boat!

I use an AGM charger.... Can't recall the brand. I've been relying on what the console days ; hence, I haven't measured the voltage as the problem happens with my fluke dmm but am very curious now to know how it varies.
 
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@Irvs It is also important to fully charge the batteries before storing the boat. A battery that is stored discharged will develop a crystallized lead sulfate coating on the plates and not be able to be recharged.

I fully charge the battery every time I get home from using the boat.

Going to test it today with a different battery.
 
Oh dear jetboaters.....sigh......

It wasn't the battery voltage, the amp nor the head unit....i replaced them all. Although not fully confirmed, I have a strong belief that the problem is the speaker tweeters. I cannot hear them at all!

With that said, I am moving away from the mm651um speakers and opting either for the jl mx650 or the wetsounds xs 650s speakers.
 
Oh dear jetboaters.....sigh......

It wasn't the battery voltage, the amp nor the head unit....i replaced them all. Although not fully confirmed, I have a strong belief that the problem is the speaker tweeters. I cannot hear them at all!

With that said, I am moving away from the mm651um speakers and opting either for the jl mx650 or the wetsounds xs 650s speakers.

Although I like the JL Audio MX650 over the Polk Audio MM651UM, this particular Polk sounds most similar to the JL.
Both the JL Audio MX650 and Wetsounds XS650 would be my first choices. The two do sound different. The JL Audio uses a lower resonance and smoother soft dome tweeter with a 2nd order crossover. You won't find a more revealing midrange and seamless transition from midbass driver to tweeter. Very smooth. Vocals are the best among all marine speakers. The Wetsounds uses a hard metal dome tweeter. Not quite as smooth through the mids. Has a moderate accentuation in the treble which is often welcomed when underway and facing some wind and noise. So the two sound a little different. There's always some subjective preference as to which camp you're in....soft dome or hard dome.

Before moving onto an upgrade, I would try and figure out how the Polk Audio tweeters blew. This isn't normal and the Polk isn't particularly fragile. Are you boosting the treble tone control? Are you over-driving the amplifier into clipping when underway and when clipping can be hard to hear? Is the system correctly tuned?
 
@David Analog, thanks for responding. Very informative posts as always.

I am having a hard time believing how they failed at what appears to be at the same time.

I like playing the stereo loud and with plenty of treble. I did hear some ocassional distortion/clipping at times and backed off the volume. I play the stereo loud for hours at a time in the Florida hot summer weather.

I would really like to not blow up more speakers.

Amp is at about 50% gain and configured in high pass modes at frequencies above 50hz.

Thanks for the help.
 
Irvs,
If both tweeters blew at the same time, I would say that eliminates any defective condition.
50% gain doesn't mean much since the source voltage and other factors will determine the amplifier output.
A seemingly moderate +6dB treble boost is four times the power over a portion of the audio spectrum....the part the tweeter plays.
An amplifier, most any amplifier, can exceed its full rated power by a fair margin at a significant distortion level (hard clipping).
During hard clipping the signal greatly compresses (squares off). The continuous power can keep growing. The tweeter is then energized to a greater degree and for a longer time and has less opportunity to dissipate the thermal build up. Guess what comes next.
The human auditory system begins to mask volume as a day of loud music passes. Its a preservation mechanism and is normal for everyone. What would be heard as blatant distortion early becomes harder and harder to detect as the day runs longer. Nothing appears loud at the end of the day. When underway, with competing noise, this further compounds the issue. Based on that, you must always trust the original set-up numeric volume levels instead of your ears.
Get your next speakers from Odin at Earmark Marine so he can guide you in the initial set-up and how to best use the system under a range of conditions.
 
David Analog,

I should be getting my wetsounds xs650s speakers tomorrow along with a Kenwood KMR-d765bt HU. Will keep you posted on how pleased I am with the sound. I did not end up getting them from earmark because I had ordered them before "they" got back to me, the order had shipped, and I wanted them ASAP.... :/ Otherwise, yeah, I cannot find a lower price than what they quoted me. <----One other thing: they are not authorized internet sellers....

Thanks for all your help!
 
David Analog,

I should be getting my wetsounds xs650s speakers tomorrow along with a Kenwood KMR-d765bt HU. Will keep you posted on how pleased I am with the sound. I did not end up getting them from earmark because I had ordered them before "they" got back to me, the order had shipped, and I wanted them ASAP.... :/ Otherwise, yeah, I cannot find a lower price than what they quoted me. <----One other thing: they are not authorized internet sellers....

Thanks for all your help!

Yes, Earmark Marine certainly is an authorized marine audio on-line dealer for Wetsounds, JL Audio and much more as evidenced by their logo featured on those manufacturer sites.
It's a shame that you didn't go through Odin at Earmark Marine because his technical support may have served you well both now during the tuning process and if you ever had a future problem. Oh well. All I can do is send you in the right direction.
 
Omg. Yes, you're right. Oops. I missed their logo on the wetsounds website.
 
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