outboard function gen. instead of soundcard

[dallaire]

Hey guy's, I'm thinking of purchasing a dedicated function generator and frequency counter instead of using the laptop setup and sound card that I am currently using. The frequency gen. that is pc based seems to be spot on, when I compare its output freq. to my Fluke meter. What I don't like is the small fluctuations in voltage through the freq. range. I was told here in the forum that this is the sound card inaccuracies I am seeing. I want to be able to measure the TS parameters accurately, is this outboard/non pc based equipment a better way to go? I have the fluke meter and was thinking of buying one of the B&K Precision units (function gen/freq counter) I just started reading Joe D'Appollito's book Loudspeaker testing and think I will have to read it about 20 times till all sinks in.
Anyway, any thoughts on the hardware question?
dallaire

PS - I am using so far the constant voltage tech. using an old Onkyo reciever for amp for test purposes, fed by USB soundcard hooked to laptop.

 

[pinkmouse]

All the SW based PC measurement packages I have seen have a calibration routine built in to cater for SC inaccuracies. If you're doing it manually then gross inaccuracies may be a problem, but there is no point in going for accuracy beyond three significant figures anyway.

 

[Pano]

And if you want to buy something, why not get one of the USB Woofer testers? They are fast, easy to use and accurate. $100-150 gets you one.

Then you'll have software to drive it and give you all the T/S reports you want, as well as impedance curves.

 

[dallaire]

Yea, thats not a bad idea at all! I used speaker workshop for a while but it is to much of a pain to get all the settings setup correct even with the "jig" I have built. I will check these program/soundcard setups. Thanks
dallaire

PS. The one reason I was going the large hardware route was I'm getting a gift cert. from a large electronics store locally that sells B&k gear, they unfortunatly don't sell software of any kind

 

[cuibono]

not sure if you feel like building something, but I'm going to do this before too long:

http://sound.westhost.com/project86.htm

 

[dallaire]

Yea, I have read alot on Rod's site, some very interesting stuff! I did just purchase the "Smith and Larson Audio" Woofertester 2,software and hardware package, seems to be a nice package, hope its all of what it seems to be It seems to do a bit more than some of the ones out there. I checked with Parts Express, there's seems to be a little basic but not as expensive.
I ordered a amp board once from ESP audio and was not at all imprresed with the lack of quality!, never even finished the amp project, I was so discouraged with the board. Marchand stuff is awesome in comparison, sorry thats my two cents. Rods articles though I do find very interesting!
dallaire

PS- thanks Panomaniac for the suggestion, Maui, boy lifes tough huh?