Anyone know some decent free SPL meter software & "white noise"?

[Spasticteapot]

First, I'm a student. Please don't tell me to "go buy a SPL meter". I'm new to DIY speakers, and a good SPL meter would mean that I could'nt build any speakers 'till I get some more money.

Anyway, does anyone know of some decent software that will allow me to measure the output of a speaker? I have some Teslas I'd like to try, but they have nearly no bass, and I need to figure out what they need in the way of crossovers. I have a laptop, a cheapie microphone, and a headphone->RCA adapter, and that's about it.

Finally, a link to some downloadable "white noise" for testing a speaker would be dandy.

[bwaslo]

Try using Praxis in "free/demo" mode, it will let you run it as a Real Time Analyzer and provides pink noise output (which is what you want with an RTA type analyzer, not white noise) from the soundcard.

http://libinst.com/praxis_downloads.htm

[zlast]

http://www.speakerworkshop.com/FAQ.htm

SPL meter

http://www.trueaudio.com/

[Spasticteapot]

Thanks!

Can anyone reccomend a cheap microphone for this?

[nunayafb]

You either need to spend money on the spl meter or buy a calibrated microphone($$$$). If you dont do one or the other you will not accurately measure spl levels. Unless you know the error and adjust for it.
The radio shack spl meter is like 20 bucks($29?) and the mods to make it very accurate are cheap and easy.
If you build a mic/preamp and mod an RS spl meter you can stay around 60-80 dollars, good mics will start at $50 and I dont remember if that is the calibrated units price or just the uncalibrated.

[fcel]

This is the corrected/modified Radio Shack SPL meter from ATI. Still $29.95. Accurate and real cheap.
http://store.acousticsounds.com/brow...tion=equipment

[joe carrow]

I was just thinking about investing in an SPL meter too. Do you know how different this modified meter is from the normal one?

Also, the page says it's back-ordered. I've never been to that website before- do you know if they're likely to get it back in stock?

Thanks in advance.

[pinkmouse]

I've got a SPL meter built into my Nokia cellphone! Never used it for testing speakers mind you.

[fcel]

Joe,

From what I have read, ATI SPL meter is the same one as the Radio Shack model except that ATI have fixed/modified it so that it's also accurate at the lower frequencies. Now, finally, people can "set-up" their subwoofer placement correctly!

It is because of the modification that I have ordered one (already owned a RS SPL meter for years) and I was told that it's backordered 3 weeks, that was about 2 weeks ago.

I did not try to order it directly from ATI, for some reason it cost more if purchase from ATI. http://www.atiaudio.com/?fa=product&id=170

[joe carrow]

fcel,

Thanks- I think I'll just get one of the $50 digital ones that don't have extended bandwidth. I already have a Behringer ECM8000 room measurement mic, so if I'll use that if I need to fine tune low frequencies. I think I'm really just looking for something to say "My office is XX decibels. It's time to put up some curtains!"