how to measure response of speakers

[justinc]

This may be a stupid question but what is required to measure the frequency response of speakers once one builds them. All I have is an spl meter and also a microphone. What program is used to generate those nice graphs etc... I'm totally new to this so any help is greatly appreciated. Thanks

[SY]

It's not a stupid question, but it's one whose answer could fill a book. And, in fact, it has: Joe d'Appolito's "Testing Loudspeakers" is extraordinarily useful.

Basic equipment you need is a test mike, a sound card, appropriate software (Speaker Workshop is popular and deservedly so), an amplifier, and a few bits of wire and resistors. You can be set up for under $200, even less if you've already got a calibrated test mike.

[cjd]

FWIW - I don't think having the right equipment is the tough part, at least if you're using Speaker Workshop. Setting it up so you get consistent results can be an interesting saga.

Note: Not all sound cards are up to the task.

And, room can play havoc with things.

C

[wintermute]

couldn't agree more with cjd on the soundcard front!!! I started with a SB16 (woefull) then went to a turtle beach motego II (slightly better than woefull) and now have an Audigy II ZS which is excellent

on the speaker workshop side of things make sure you get and read this: http://www.audiodiycentral.com/resou...nual%201.0.zip

should save you a lot (but probably not all) of grief.

Tony.

[johninCR]

I'd just use the spl meter as a tool and and instrument for calibrating your ears. Your ears are much more sensitive than any spl meter once you get them used to what actual spl levels are accross the frequency range. I just disagree with this big focus on graphs. What matters is what your speakers sound like in your room at your listening position and that result is often so drastically different than what is measured at 1m using some crude attempt to create an anechoic test, that it's all but useless. Not to mention consistency.

Response graphs are useful in comparing different drivers to help decide which ones to buy. After that what matters is what they sound like.

[RJ]

I just use a Radio Shack SPL Meter. Even to adjust crossover points and slopes.
If I want a fancy graph I can input my data in a spreadsheet program.
But why do that. Flat Is Flat.....

[SY]

RJ, it's often useful to separate room effects from direct sound. Or to figure out polar pattern Or to see what's a diffraction effect and what's driver breakup. You just can't do that with a simple SPL meter. Impulse/MLS is much more versatile and powerful- and these days, it's no more expensive to do.

[bzdang]

Audiotester.de

I could have bought CLIO with all the hours I spent trying to get speaker workshop, my brain and my computer to cooperate.

Audiotester works without hair pulling, is inexpensive, does basic things well enough, and you can try it out to the point of getting real measurements before buying.