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View Full Version : POLK AUDIO db6501 COMPONENT SPEAKERS



David Davidson
04-28-2010, 11:40 AM
I just installed a whole new sound system in my boat last night. After it was all said and done, the component speakers don't sound half as good as the coaxial speakers (db651's) that I installed in the front. I have a Sony XM604M amp pushing them all and a Sony CDXM60UI receiver. Does anyone know why the coaxials would sound so much better than a component system? From what I have heard the component system is supposed to blow the coaxials away.

brain_rinse
04-28-2010, 11:47 AM
Can you describe how the amp is wired to the speakers? Are you talking sound quality or loudness?

David Davidson
04-28-2010, 12:06 PM
The amp is wired to the crossover that comes with the system and from there the wires go to the woofer and the tweeter. The sound clarity is great at low power but when you crank them up the coaxials blow them away in loudness and clarity. I have tried every switch on the amp but nothing makes the rear speakers sound any better. The components are not closed in like the coaxials, that is probably the problem.

brain_rinse
04-28-2010, 01:22 PM
I was thinking more about how many speakers you had and how they were hooked to the amp. Do you have just 4 cabin speakers running on a 4 channel amp?

David Davidson
04-28-2010, 02:00 PM
I only have 4 speakers and I am running a 4 channel amp.

brain_rinse
04-28-2010, 02:19 PM
Short answer: you're under powering the components. They are rated at 100w continuous but your amp is only pushing 60 watts RMS. The coaxials are rated at 60w continuous which is right in line with the amp.

Razzman
04-28-2010, 02:28 PM
Just for the record and to help troubleshoot;

Are you sure they're phased correctly?
What do you have the crossover frequency set at?
Where do you have the gains set?
What is your power source for the amp?

Razzman
04-28-2010, 02:34 PM
Short answer: you're under powering the components. They are rated at 100w continuous but your amp is only pushing 60 watts RMS. The coaxials are rated at 60w continuous which is right in line with the amp.

It's 100 rms max but even at 60 rms they should sound decent. I'm suspecting that amp though and betting it's not accurate with
60 rms @ 4ohms. I've never been a fan of Sony gear.

brain_rinse
04-28-2010, 05:21 PM
It's 100 rms max but even at 60 rms they should sound decent. I'm suspecting that amp though and betting it's not accurate with
60 rms @ 4ohms. I've never been a fan of Sony gear.
I agree, and you're helping fill in the "long answer." I just had a second to respond and was shooting from the hip.

All your questions are spot on. You first need to verify everything is set up correctly, including power source, gains, phase, x-over, etc. I was assuming that with a 4 channel amp and 4 speakers, and passive crossovers on the components, that the install was fine. Add to that the fact that db651s sound great even on deck power but that components require some real power... and that the sony amp's specs didn't align with the components, and that they tend to suck... and...
Like I said, shooting from the hip. :p

David Davidson
04-29-2010, 11:16 AM
* Are you sure they're phased correctly?
-Still need to check...

* What do you have the crossover frequency set at?
-The tweeter is set at -3db, no other settings on crossover.

* Where do you have the gains set?
-I have the rear components set higher than the front coaxials.

* What is your power source for the amp?
-Battery.

Razzman
04-29-2010, 11:27 AM
* Are you sure they're phased correctly?
-Still need to check...

* What do you have the crossover frequency set at?
-The tweeter is set at -3db, no other settings on crossover.

* Where do you have the gains set?
-I have the rear components set higher than the front coaxials.

* What is your power source for the amp?
-Battery.

I meant amp crossover, may bad. Do you have a subwoofer? If so the amp crossover frequency should be in the 100-120hrtz neighborhood to start. Without a sub you'd want a lower freq setting so you have a good blen for highs and lows. If with sub you should also make sure the amp is set to hi-pass for the speakers and low-pass for the sub, cut the subs freq at around 80hrtz to start.

Play with the hi-low freqs to get a good "blend" between the speakers and the sub if applicable.

Reference "how to set gains" in the how-to section to make sure your getting the most from them and the amp.

Do you have a dedicated battery for the stereo or just one battery?

What size power cable is going to the amp? 8ga, 4ga etc.

EarmarkMarine
04-30-2010, 05:37 PM
David,

There will be a slight reduction in sensitivity between the coaxials and components. The separate components will have an insertion loss due to a multi-component outboard crossover where as the coaxial is strictly 2nd order highpass.

However, the component has a full 1-inch dome versus a 3/4-inch dome. And, because the midbass cone has a solid dustcap (without a tweeter mounting post) it has more surface area. This more than offsets the moderate efficiency difference.

Try bringing the tweeter on the components up to zero dB and gain the coaxials down a bit on the amplifier to bring these speakers into balance. Without photos and without all the particulars its hard to speculate, ie: positioning, phasing, acoustic isolation, etc. And numerous other considerations. Also, check to see if both front and rear amplifier active crossovers are set the same (either 'fullrange' or very low just for protection since you don't have a sub yet).

David
Earmark Marine