[The-One]

<10% THD <50hz is considered good usually I think? But what is acceptable? What is bad etc etc? And is 1% THD a lot better than 9% THD?

[paulst10]

Originally Posted by The-One

<10% THD <50hz is considered good usually I think? But what is acceptable? What is bad etc etc? And is 1% THD a lot better than 9% THD?

Basically the lower THD across the entire frequency range the better

I would consider 10%THD @ 50hz quite poor (depending on how many DB's it was producing).

A reasonable THD figure (depending on subwoofer) would be something like 100db @ 30hz with 10%THD

An exceptional THD figure would be something like 100db @ 20hz with 8%THD

[cribeiro]

Originally Posted by paulst10

An exceptional THD figure would be something like 100db @ 20hz with 8%THD

You mean something like this?:

http://personal.inet.fi/private/zipm...15hz%20thd.png

http://personal.inet.fi/private/zipm...thd%20comp.png

It's my setup at home (PB13-ultra in 15Hz tune ).

[paulst10]

Originally Posted by cribeiro

You mean something like this?:

http://personal.inet.fi/private/zipm...15hz%20thd.png

http://personal.inet.fi/private/zipm...thd%20comp.png

It's my setup at home (PB13-ultra in 15Hz tune ).

Well yes I was going to mention the Ultra with those figures, but I didn't want to seem like I was blowing a trumpet or I may find myself moderating the new musical instruments forum

[The-One]

So would say a 5% reduction in THD at 30hz from 9% to 4% say at 100db make a lot of improvement?

Or because the THD is <10% this reduction does not matter

[paulst10]

Originally Posted by The-One

So would say a 5% reduction in THD at 30hz from 9% to 4% say at 100db make a lot of improvement?

Or because the THD is <10% this reduction does not matter

IIRC, the audible threshold is around 10% so anything less than probably wouldn't be audible ?