High Quality Compact Marine Amp Questions

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jukebox7

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Hello, just stumbled across this forum and it looks awesome! Have a few questions regarding amps/speakers.

Basically I build compact units inside of dry boxes that power Dual LU43PW speakers. The speakers connect to the side of the enclosure using a male 110v plug that plug into an outlet. The amps speaker channels are then connected to said outlet. We've been building these for quite some time and are trying to make the set up alot louder. Currently we use Pyle Hydra Series 400 and 800 watt amps. The amp gets it's audio from an MP3 player via aux cord. These amps are relatively cheap, and do actually produce some great audio quality but the max volume leaves something to be desired.

So basically I am on the hunt for a compact, marine style amp that would be able to push 2-6 of those speakers to their max volume. The dimensions of the inside of the enclosure are 7.75''x 13''x7.5''. We also have an on/off remote receiver and a laptop style cooling fan next to the amp to help with overheating problems.

I've looked at a few different amps and just can't decide what to start messing with first. The following amps were what I was thinking about trying Rockford Fosgate PBR300X4, Rockville dB25, Kenwood KAC-M3001 and Kenwood KAC-M3004.

Price wise we'd like to keep the amp around $60-$125.

If anyone could point me in the right direction or has any other suggestions I would greatly appreciate it!

Thanks!
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If Rockford has something in your price that's a safe bet, American made and has been in the game forever. That would be quite an improvement over what you are using. Most auto amp manufacturers are offering Class D amps, I'd suggest looking into that for your set up, they run cool and typically draw much less current from the battery. I've seen Class D in both Rockford and Kenwood.

Kenwood is well respected in car audio, I personally like Rockford better but on a budget kenwood would be fine.

I think what you are discovering in real life watts are not equal as on paper.

Also, in usingmp3, some files may not have the gain as others. When streaming I notice older music is less loud than newer music or remastered versions. If using streaming services the volume can vary as well. I'm not sure if this is the norm or something to my phone but I can't hardly use Pandora due to its low volume compared to Spotify or Amazon.

Hope all this hot air helps :)
 
Peabody,

Thanks for the information and suggestions! With a class D would still having the fan inside no longer be necessary? We knew going into it when we decided on the Hydra Series that the actual wattage was no where close to what it said. If the 800 watt was truely 800 watts it should make those speakers blare, correct? The mp3's put through these is stuff that I have personally designed and edited to the best of the highest quality, normal music sounds pretty good too.

Moving forward on this next design we aren't apposed to having $2-$350 into it. So would the Fosgate PBR300X4 amp fit the bill for running 4-6 100 watt speakers? Otherwise there is the Kenwood KAC-M1804 and the alpine ktp-445U I guess I see 100 watts per speaker and think I need at least an equal amount of watts from the amp. I am no audio expert by any means haha the hardest part is finding something small enough to fit in the dry boxes we want to use. May need to expand our search for something bigger. Worst case scenario is we buy 4 or 5 amps test them all and send what we don't like back
 
Correct, you should see the size of a home amp that would generate that type of power, 800 watts :). We used to call those type of ratings in car audio "when lightning strikes"

I do believe with Class D you shouldn't need a fan, as long as there is some ventilation or air around the amp. I'd encourage you to explore those for your application.

Your amp does not need to match the speaker in power rating. The speaker rating is sort of a guideline so you don't over power it. How much power you need to drive the speaker depends more on the speaker efficiency which is rated in SPL. I'd say around 89dB or higher should be easy enough to drive and get loud without a ton of power. On the other hand, you want enough power to satisfy the customer so they don't over drive the amp, cause it to "clip", send distorted signal to the speakers. Clipping is the #1 killer of speakers.

I need to look those amp models up but any of those 3 brands are very good. Rockford is typically under rated. You could take an old Punch 45 which was about 25x2 and run an entire car system with it. Alpine isn't quite as brute force but may have an edge in overall clarity in midrange and highs. Kenwood is a decent overall performer. The downside with Rockford on the Class A/B, that type of performance will suck more current from the battery.

I have not had an opportunity to hear any of the Class D.

jukebox7 said:
Peabody,

Thanks for the information and suggestions! With a class D would still having the fan inside no longer be necessary? We knew going into it when we decided on the Hydra Series that the actual wattage was no where close to what it said. If the 800 watt was truely 800 watts it should make those speakers blare, correct? The mp3's put through these is stuff that I have personally designed and edited to the best of the highest quality, normal music sounds pretty good too.

Moving forward on this next design we aren't apposed to having $2-$350 into it. So would the Fosgate PBR300X4 amp fit the bill for running 4-6 100 watt speakers? Otherwise there is the Kenwood KAC-M1804 and the alpine ktp-445U I guess I see 100 watts per speaker and think I need at least an equal amount of watts from the amp. I am no audio expert by any means haha the hardest part is finding something small enough to fit in the dry boxes we want to use. May need to expand our search for something bigger. Worst case scenario is we buy 4 or 5 amps test them all and send what we don't like back
Click to expand...
 
The Rockford new version of the 300x4 is the Rockford Fosgate Prime R400-4D. It is Class D, the power supply is Class D but the output is MOSFET. This is the best choice if the need is power. It's 75 watts rms, if the spects are true, and, Rockford usually is and then some, it's a little power house. It bridges to 200 watts. I also like the variable crossover and even has some tone controls.

The Alpine is Class D and looks to be a nice amp. My concern on both the Alpine and Kenwood is power, both are 45 watts rms which is not bad but both are sort of marketed as head unit upgrades. However, that doesn't mean they can't do their rating.

The Kenwood looks to be some type of hybrid with a convensional power supply and Class D output. Don't look to draw much current though with just a 15 amp fuse. What I like about the Kenwodd is auto sensing on/off, no need for a trigger wire. Although the trigger is usually right along with the RCA if using auto specific cables.

What area are you in?
 
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