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View Full Version : db651 amp needed?



rjgaumer
12-28-2010, 12:45 AM
do i need an amp for the cabin speakers? how will the quality be?

KG's Supra24
12-28-2010, 01:05 AM
Yes you will want an amp. An amp would make a dramatic difference. The head unit def cannot give much power to the Polks.

I am pulling my factory 4 channel amp out of my boat. I might be interested in selling. It is a Kenwood KAC 8402. PM me if you want to discuss it.

mmandley
12-28-2010, 08:47 AM
Bare minnimum is a 50 watt RMS to each Polk but they prefer a 80 to 120 RMS amp because the Polks sound better they louder they go.

KG's Supra24
12-28-2010, 09:43 AM
Aren't the polks rated at 50w rms?

EarmarkMarine
12-28-2010, 10:12 AM
Consider that if you are running the coaxials highpass, as you would if you have a subwoofer, operating with a reduced bandwidth you can comfortably exceed the speakers rated power as long as you keep it clean. An honest 60 watts RMS is a good level for these in the boat. Another one-third power will only yield a 1 dB increase which is the smallest increment that you can discern. Also, as you double the power you will not get the expected 3 dB increase as you approach the speaker's top end. Understand that eventually compression enters into EVERY speaker. And with compression you lose dynamic contrast and clarity. So the key is balance.

David
Earmark Marine

cab13367
12-28-2010, 03:24 PM
do i need an amp for the cabin speakers? how will the quality be?

If you want to be able to hear the music clearly while underway, you will need an amp to overcome the wind and engine noise. I have a JL Audio M6600 6 channel amp delivering 75W rms at 4 ohms to each of 6 db651's and I can hear my music loud and clear while towing a wakeboarder, tuber, etc. It also helps that I have a sub so I run the amp and speakers on high pass.

Al

Brianinpdx
12-28-2010, 05:20 PM
Rj - Do you need? No. Should you have? Yes....

As everyone has pointed out, powering your cabin setup will give you some real benefit's. If you are going to add an amplifier to power them, take the time to look at your whole stereo system and plan accordingly to run the correct gauge power cables, distribution block if needed. Fusing etc... It might sound like crazy complicated stuff but its not and people here can walk you through the correct setup.

Also, one of the real benefits of having a amplifier in the mix is because you can run your polks in HP (highpass mode) and limit the amount of freq range the speakers will see. Trust me, your polks will love you for this. Often times people take the time to upgrade speakers, but when they go back and drive them from a head unit and max out the freq range + deck power, the result is ugly.

If you need some guidance on the stereo layout, shoot me a PM... I've got a couple of PDF's I can shoot you.

Cheers,

-Brian
Exile Audio

KG's Supra24
12-28-2010, 05:32 PM
The "New stereo install help please" thread also has some good diagrams that attempt to break the wiring down to more simple instructions.

Brian, maybe some of your PDF's could find a home there.

rjgaumer
12-28-2010, 05:37 PM
thanks alot for all the help guys. I have decided to definitely throw an amp in her. That will make a total of 4 amps in my baby. :)

KG's Supra24
12-28-2010, 05:47 PM
thanks alot for all the help guys. I have decided to definitely throw an amp in her. That will make a total of 4 amps in my baby. :)

Then i would highly recommend the thread mentioned above as well as "Gauge of Speaker Wire". Both of these threads are tied to systems running 4 amps.

MLA
12-28-2010, 07:13 PM
thanks alot for all the help guys. I have decided to definitely throw an amp in her. That will make a total of 4 amps in my baby. :)

Really :confused: 3 amps in there already and the in-boats are still on the head-unit?

I would put on the breaks before adding in that 4th amp, step back and look at the whole picture: What all you currently have in the boat that is being or needs to be driven by an amp, what amps you have and what they are driving. How the components are wired to the amp(s) and what you want to have when it's completed. Just a suggestion.

KG's Supra24
12-29-2010, 10:05 AM
^ Good point. You need to know the final result before starting.

Brianinpdx
12-29-2010, 11:40 AM
Ditto what MLA said. Only possible reason I could think someone would be running that many amplifiers is if they are Bi-amping the towers?

OP> give us some insight on your current system setup. Include model numbers if possible. And also how your power / ground / distribution / battery setup looks like. This will give the peanut gallery a good baseline to provide constructive comments with.

-Brian
Exile Audio