(thd)total harmonic distortion

[djjdnap 10+ year member]

//content.invisioncic.com/y282845/emoticons/banghead.gif.8606515f668c74f6de0281deb475b6fd.gif Now I now what ehe definiton is but does this actually matter in choosing my amp or subs I'm really not shure. But it said 900 x 4ohms at 0.03%thd

Now it definitely doesn't sound like 900 whats to me, So if anyone could posiibly explain this concept or tell me if it makes a difference or not. I read it can also be read as DB decibels and I know thats for subs and 90 is like average for that I do believe.

I don't know Help Comemments whateva you got...

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[wesleysh 10+ year member]

You can deal with higher harmonic distortion levels out of your sub amp. Harmonic distortion is harder to pick up on at lower frequencies. And from what I understand, THD typically doubles when you move from 4 Ohm to 2 Ohm. I think THD under .10 is inaudible.

 

[djjdnap 10+ year member]

well that doesn't make any since since it said 900 watts at 0.03%thd so how can I not hear 900 watts. OR does it not mean anything coherent to my problem??

 

[djjdnap 10+ year member]

by the way I had to llok up inaudible then it sent me to audible bewcause it said not audible but audible means to hear so inaudible must mean not able to hear.

This is for other readers who have no Idea what inaudible meant .

 

[wesleysh 10+ year member]

it just means that any level under .10 can not be detected by hearing it, only testing it. You would not hear anymore harmonic distortion at .07 than you would at .00007.

 

[Mark_ab 5,000+ posts]

I believe the audible THD is higher than that (0.1). Every piece of equipment in your system has some distortion, added together to get the total. HU, amp, eq's, xover's etc. I could be wrong.

 

[wesleysh 10+ year member]

I think RC once said that in practice the number was 2% or so.

I also remember it being ALL of your equipment added together, like you said. I just can't remember how much your amps THD rises when you bridge it or go 2 ohms. I think we don't know certain details about it Mark because its never been a factor for us, lol.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif It really only matters when your using many processors, equalizers and amps with high THD ratings. Or just one REALLY cheap amp pushed too hard.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[mr_unreal 10+ year member]

When your amp is running at 2 ohms, instead to 4 ohms, your THD is said to double, but you also get twice as much power. THD is not always double, but it is always pretty close to it.

 

[Ricky Nichols 10+ year member]

Every piece of equipment in your system has some distortion, added together to get the total. HU, amp, eq's, xover's etc. I could be wrong.

correct

 

[Phatillusion 5,000+ posts]

I believe THD over 1.0 is audible. I would have to look it up to be sure, but I know most of your class D amps are at or above 1.0.

 

[djjdnap 10+ year member]

thanks guys or whatever you r..

 

[taylor 10+ year member]

planet audio 1200d, thd. 0.33

 

[Phatillusion 5,000+ posts]

Originally posted by taylor planet audio 1200d, thd. 0.33

I said most. I think the 8100D is pretty high, I can't remember but I thought I saw 3.0 THD on one class D amp a while ago, I can't remember which one though.

 

[Phatillusion 5,000+ posts]

Okay I did some research..........THD below .10 is inaudible. So wes, you are right, I checked a few amps out some RF, MTX, Kicker, Sony, etc. and a few others and they were mostly around 1-2 THD. So if that planet audio 1200d is .33 Thd, that's pretty good compared to some of the other class D amps.