spectrum analyzers

[Dave Jones]

Okay, this is not about loudspeakers per se, but I'll bet you guys know all about this stuff.

I've read ads for software that can be used to analyze loudspeaker frequency response, using a sound card. Those ads say you will need a "calibrated microphone." I wrote to one such software company asking where I could get such a thing, but no one returned my email. (If they had any business sense, they would be _selling_ the required microphones, and not letting emails from prospective customers go unanswered.)

So, what's the deal with "calibrated" microphones?

Is a calibrated microphone an ordinary microphone that's been calibrated somehow? And if so, how? Does one adjust the microphone itself... or what?

There are always ads on ebay for spectrum analyzers like this one: http://cgi.ebay.com/ws/eBayISAPI.dll...em=3042678525. Notice that the ad says there is a microphone input, but says nothing about a mike. So, what kind of mike would it take?

Are those spectrum analyzers any good?

[leadbelly]

http://www.speakerbuilder.net/web_fi...diymicmain.htm

[Dave Jones]

Originally posted by leadbelly
http://www.speakerbuilder.net/web_fi...diymicmain.htm

Are you sure of that link? I get "430 Not found
Unable to resolve name: www.speakerbuilder.net"

[Ken L]

Originally posted by Dave Jones
Are you sure of that link?

Try it again


It worked for me

regards

Ken L

[r0cket-]

Originally posted by Dave Jones


Are you sure of that link? I get "430 Not found
Unable to resolve name: www.speakerbuilder.net"

For whatever reason, that domain seems to have pretty frequent problems. Try it again later and see if it resolves. I've had a lot of problems with it myself, but the information there is worth the effort.

[Dave Jones]

The software I was looking at is from "True Audio". In their FAQ, it says you need both a calibrated mike and a mike preamp. Yes?

It also gives an address for a fellow who can calibrate a microphone. I'm still wondering what that entails. If you send a microphone off to be calibrated, do you get back a microphone that's been modified somehow? Or do you get back a datasheet that has to be fed to the software by some means? What if you are using it with a garden variety "EQ/Spectrum analyzer"?

Here's the link: http://www.trueaudio.com/rta_faq1.htm

[jleaman]

i wish i could find a audio control one. i miss those. it was a "eq" and a spectrum analyzer in one. you could use a mic too. i've looked on Ebay a lot but still yet to find one. DAM..

ever seen the movie ferris Bulers day off. he had one on top of his carver amp OHHH i so want one now.

[kelticwizard]

Damn, Dave, whenever I read your posts, your computer can't get to a URL or download a program. Maybe you should switch back to Win 98SE, LOL.

Anyway, try this for that link.
http://www.speakerbuilder.net/web_fi...diymicmain.htm

[jleaman]

Like this..

http://cgi.ebay.com/ws/eBayISAPI.dll...&category=3271


does any one know where to either buy a kit or a schematic to build such a display.. i like all the lights and stuff. Ive looked and looked every where but cant see a schematic for one i don't want the eq par just the graphical display.

[kelticwizard]

Dave:

For testing speakers, there is always the freeware Speaker Workshop. Apparently takes some time to set up, but the people who do it are well satisfied.
http://www.speakerworkshop.com/


A "calibrated microphone", to my understanding, is merely a mic with flat response. This is as opposed to many microphones which have up-and-down response.

The WM 60AY available at Digi-Key is cheap, ($2.20) and Siegfried Linkwitz recommends them. I am sending away for mine this week. Even without the mod, they give flat response.
http://www.linkwitzlab.com/sys_test.htm#Mic