This, i can agree with wholeheartedly.


If anything, try and get the highest power amp into the highest ohm number.

I never really thought about it before, but when dalton said that the higher the ohm, the better the sound quality, i had to hear it for myself and hence why we made our own test.

In my opinion, it definitely proved that the higher the ohm, the better the sound quality... 1ohm sounded raspy and crappy to me, meanwhile the 4ohm, even slightly underpowered sounded much warmer and in tune with response.

 

Well the way ive always understood it was the higher the ohms the harder it has to work to put out the same amps.

Say my 1ohm stable amp pushing out 750watts at 2ohms will run cooler then

A 1 ohm stable amp pushing out 750watts at 4 ohms... but i could bewrong.

 

For the most part, watts are watts, and any given amp of the same technology (class D, for example) will generate approx. the same heat output for the same power level.This amount of heat is based on the efficiency of the amp. When I say same, I don't mean actual temperature of the heatsink, but rather actual BTU's, or deg. per sq. cm, output.

Now, an amp designed to push 2000 watts at 4 ohms will probably have more heatsink than an amp designed to push 2000 watts at 1 ohm. So, it will run at an overall cooler temperature.

In your example, I would expect that the 1 ohm stable amp that puts out 750 at 4 ohms will be a physically larger amp, and would therefore run cooler in overall temperature.

This is probably over simplified, but I believe it is a good rule of thumb.

Toby

 

WARNING...I'M BORED TODAY, SO THIS IS LENGTHY, YET INFORMATIVE

This is highly subjective, in more than a couple ways. For one, sound quality is terribly subjective to begin with. As Dalton said, there aren't any sound quality meters, at least not that I know of.

Second, we don't know how over or under built the power supply of the amp used in this test was. If it was nearing its limits at 1 ohm, then things like headroom would go down, and the amp would be more prone to clipping its output wave, which would affect sound quality.

Another thing to consider is speaker parameter / box design. Most TS parameters are what is known as small signal parameters. That is, they are derived by using very low wattage into the speaker. Speakers are not linear, and these parameters can vary substantially as power goes up. So, at lower power, the speaker would behave much closer to the TS numbers that probably lead to the box design.

As has been said, though, typically higher ohm loads are typically associated with better (as Dan said, warmer) sound. I think this is more true with Class D stuff (most low impedance amps are some variant of class D), which by nature, is 'choppy'(they use a switching method to re-create the sine wave, vs variable output...more efficient, but also not as accurate)...this is why you rarely, if ever, see class D used for anything but subs. In between "on's" the amp has no control over the woofer. Fortunately, this happens so fast, it is nearly impossible to hear in frequencies below 200 hz, or so. As the reproduced frequency starts to approach the switching frequency, sound quality suffers.

Class A/B, amps sound much better, but are less efficient. Class A is the best sounding / least efficient combo, and are quite rare in car audio. The old Orion HCCA's were borderline class A, but also stable down to 1/2 ohm stereo. The sound quality of these amps seemed to go up, substantially, as the impedance went down. My guess is because the high current here was much more controlled than in a class D situation.

If you ever have the opportunity, try putting 400 class D watts to a sub, and then replace it with 400 Class a/b watts, and I think you'll hear a difference.

Short story...if you have room and money, equal power to higher impedance subs will probably yield better sound quality. Get that power from something class A/B, and it will be even better still.

Toby

 

All I gotta say about that bet... Ohms Law FTMFW.

http://en.wikipedia.org/wiki/Ohm's_law