OK, so I'm not exactly up to snuff on what products are out there and I'm looking for a physically small 2-channel amp to power the bass shakers in my car. Since it's for the shakers and not real speakers I'm not after anything high-end, just a serviceable amp with 35-50W of sine-wave power per channel (into 4 ohms). Any suggestions?

I actually purchased 2 of the cheapest amps I could find from Parts Express and I'm not exactly thrilled with either one of them (imagine that). I've had good luck with buying drivers and other electronics from them and they seem to provide more data on audio products than most places. So I figured I could at least believe the "RMS Power" ratings they provided. Not!

One amp was supposed to be 35W RMS @ 4 ohms, 70W "Max" per channel. In actuality it was struggling to make 16W. My first clue was that it had a 5 amp fuse - how do you get 70W out if you're only putting 60W in? So that one got put back in the "return to sender" bin real quick.

The second one was rated for 45W RMS per channel and actually managed to squeak out almost 30W. Under the right conditions (square waves) it could even produce the rated 45W per channel.

I figure if I have to send the one amp back I might as well ship them both and look for something a little better. I'm willing to spend $100-$125 if it gets me something decent in a small package.

.

 

Will this work, or do you want something a bit smaller?
Soundstream PCA2.200

Maybe this one?
Orion HP2300

This one is good as well....
Hifonics Hawk

So is this one....
Hifonics Falcon


Here is a great sale....

This amp is 55x4@4 or 110x4@2
I know you only need a 2 channel, but for 89 bucks, why not have a spare 2 channels for whatever reason?

Hifonics TX4405

Let me know if any of these work. If not, Ill keep beating you over the head with links.

 

Thanks. I'm ordering the 2x50W Hifonics because I like the size. When it arrives I'll let you know if it's really 50W.

 

Cool. It has been my experience that they underrate their amps. Ive installed a slew of them this past year, and they have been good, solid performers. Hope it works well for you.

 

yup, my limited knowledge of HiFonics is that they're solid amps for the money.

i would have put together a very similar list as Dave.

 

Suggest you look at Boston Acoustics GT-20. Small size and superior quality.

Link below:
http://www.bostonacoustics.com/car/car_pro...&product_id=249

Flish

 

OK, results are in. This is sine wave power per channel at clipping, both channels driven, 4 ohm loads. I don't have 'real' audio test equipment so I use a scope to determine clipping and a good meter to measure RMS voltage and do the math to determine power (V^2/ohms).

12v - 29W
13v - 35W
14.4v - 43W
14.4v bridged - 90W

While it's not as much power as I wanted it's a very small amp so I'll probably keep it and see how it does in the car. I like that it's less than 2" high so it should fit nicely above the gas tank along with my old Kenwood (which is a 4x50W amp that puts out 55W per channel).

.

 

Hmmm.....43 out of 50....I guess its not too bad, and close to advertised numbers, but I guess its not 50wrms CEA certified.

 

Part of the problem is a lack of standards, even for common terms like "RMS Power". If you get technical, over-driving an amp so it produces nothing but square waves and then measuring the power output with a "True RMS meter" is a legal definition of RMS power (and it will be about twice the "sine wave" power output that most people think of when they hear the term "RMS Power").

I've not actually looked for it but it would be interesting to see the actual test procedure for the CEA certifications. I heard the testing is done at 14.4 volts, which in my opinion is nothing more then the manufacturers agreeing to lie consistently. I did find it refreshing that Boston rates their amps at 12.6 volts, but even their 50W amp is physically larger than I want, and about 3 times what I want to spend. The Blaupunkt digital amp I had was a great size and had plenty of power - just kept blowing up. maybe someday we'll have digital amps that don't self-destruct.

 

Bob --

does the HiFonics list a 50 Wrms x channel @ YY% THD? perhaps they're pushing the THD number hard to get the 50 Wrms?