Question about sound quality in amps

[BMG 10+ year member]

is the THD and Frequency response and such under/over rated differently in different brands like power handling is? or are most all brands exactly what they say?

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[LostCause 10+ year member]

I don't think the human hear can distinguish any THD under 12% or some high number like that. Most amps have something like 0.5% THD so that really shouldn't play a factor in deciding for a SQ amp...more people can shine light on this situation but I'm pretty sure most amps sound the same...it's the power ratings and features that really set them apart.

- Lost Cause

 

[PhatalOne 10+ year member]

THD in relation to Signal to Noise Ratio is important. Because ideally you would like to have as high an SNR as you can find with as low a THD @ whatever ohm you're running that you can find. Because you will get alot more signal distortion in an amp that is 90db's SNR as compared to a
Most decent brands will be honest (anyone who advertises on the basis of Max power ratings IMO is not honest) about specs like THD, SNR, and other important information on the amp. As for the brands I deem not honest, I don't know because I have not and will not buy parts from them.

LostCause, the generally accepted limit for inaudible distortion is

 

[helotaxi 5,000+ posts]

S/N ratio has zero to do with distortion. It is how much noise (background hiss introduced by the amp) the amp introduces to the signal. It is expressed in dB and every 3 dB is a doubling of power. Once you get to a certain point, higher numbers are just that, higher numbers. The noise has gone below the level of audibility long ago and any increase beyond that is moot.

THD, total harmonic distortion, is the non linearity of an amp exhibited in multiples of the frequency tone fed to the amp, generally 1kHz for testing, expressed as a percentage of the output. Less than 1% is generally inaudible. Generally not included in THD is crossover distortion, a spike in the waveform not harmonic in nature caused by the output devices switching on and off, and it is quite audible. Many cheap amps have problems with this.

 

[PhatalOne 10+ year member]

bah, I need to stop posting when I'm tired, I always screw things up. Thanks for setting it straight helotaxi.