Amp question...

Thought I would throw this out there for you stereo guys. I know this is a pretty bare bones set up but for now I'm comfortable with that. Just picked up a new-to-me used Malibu. The previous owner took out his amps and sub but left 4 tower speakers and 4 cabin speakers. The speakers are wired in parallel in sets of two so I have 4 wire runs to the amp location in the passenger storage. Each speaker is rated 60 W RMS at 4 Ohms. So, each wire run is 2 ohm.

My question is this. I just bought a Kenwood KAC-X40 4 channel amp. It was on sale and the sales guy said it would be plenty. It is rated for 65 W x 4 at 2 ohms. The speakers in the boat are nothing special and I do not plan on blasting it so the rider can hear it. So.... will this amp be enough power to power all 8 speakers and still sound decent? I was also looking at the Alpine F300 which is slightly less power but close to $100 dollars cheaper.

In the future I'll upgrade to Wetsounds or something else. My plan is to use this amp to power everything for the time being, then, when I upgrade, I'll use it to power just the cabin speakers and re-run all the wiring to have dedicated lines for each individual speaker (no parallel wiring). Any suggestions? Thanks!

Whats the price of the amp? What are you looking to spend?

The one you're talking about would probably be fine but if you're paying retail you likely find something better online for the same money.

This is a killer deal for a BA GT-42 http://cgi.ebay.com/NEW-BOSTON-ACOUSTICS-GT-42-4-CHANNEL-CAR-AMPLIFIER_W0QQitemZ120415059998QQcmdZViewItemQQptZ Car_Amplifiers?hash=item1c094c001e&_trksid=p3286.c 0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39% 3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

I definately didn't pay retail but just found the exact same amp online for a hundred dollars less, brand new. Stupid car audio stores, its going back. That Boston looks sweet, thanks. I'll keep looking. I just wanted to know if that would be enough power.

Yeah but you'll only be showing each speaker about 32 watts each well below their RMS it's better to show them more power RMS than under. Your less likely to damage them.

good info on this site about all things car audio, this article covers too little power to speakers...

http://www.bcae1.com/2ltlpwr.htm

Underpowering speakers is ok as long as you don't try to turn the volume up to compensate and damage them with severe clipping.

From the article:
Note:
If your speakers are capable of handling significantly more than your amplifier can produce, driving them with a clipped signal will not likely hurt them.
If the speakers can handle 3 or 4 times the power that your amplifier can produce, there's virtually no way to damage your speakers (no matter how clipped the signal is).
If your speakers are rated for the same power handling as your amplifier is capable of producing cleanly, driving them with a clipped signal for extended periods of time may cause speaker damage and/or premature failure.
If your speakers are rated for the same power handling as your amplifier is capable of producing cleanly, driving them with a square wave signal for extended periods of time will likely cause speaker damage.

I'm beginning to understand clipping and headroom a little more and would like to over compensate with the amp to have a more clear signal that will be less likely to damage the speaker. Understandably, its going to cost more money to see any real difference. What is the best possible "headroom" to have? 2:1 (amp RMS to speaker RMS)? 1.5:1?

Adam,

If you have 15 dB dynamic range inherent in your program material, that translates to a 1 to 32 power ratio in order to capture the full contrast and clarity. A 90 dB efficient speaker will require 32 watts to develop 115 dB at one meter and will need significantly more power at a greater distance. Unfortunately you're going to experience serious compression in a high noise environment and speakers also compress at higher volumes. It could take over 30 watts just for the background passages to equal the ambient noise levels in a marine environment. So when getting underway the full dynamic range is not going to be achievable as it would be in home or car. We have to adjust our model for boats. You can't have too much power in a boat.

With some limitations, you can exceed your speakers' rating by as much as you want as long as you exercise discipline at the volume control. Peak power is unlikely to damage your speakers as long as the system is set up right. But when your amplifier begins to compress and clip, this heats the speaker and quickly leads to electrical failure. Bad downloads and burnt CDs will really tax speakers. Over-equalization will also cause serious clipping. Speaker mechanical failures are generally caused by faulty system designs, undamped loading and wrong crossover settings.

Its much more involved than just a simple rating. But I think 25 to 30% over the speaker's continuous rating is sufficient and safe, as long as you recognize clipping.

David
Earmark Marine