Subwoofer testing

gatemplin

I've noticed a few questions about PEQs like the BFD lately.

If anyone has a Radio Shack SPL meter, and you want to measure your subwoofer or speakers for use with a equilizer, for calibration, or just to see what it will do, let me know. I can send you test tones and a spread sheet I made.

You just burn the tones, measure them with the meter. Then type in the measurements, and the spreadsheet corrects them and graphs them for you.

Early B.

Thanks!!

PM sent.

okiepolkie

Do you need email, or physical addy? I'd like this to do some sub tests.

Let me know what I need to do.

Zach

gatemplin

okiepolkie wrote:

Do you need email, or physical addy? I'd like this to do some sub tests.

Let me know what I need to do.

Zach

Just send me a PM with your email and I'll send it off. You just need MS Excel to use the spreadsheet, and a CD player that reads MP3s, or else you need to convert them to wav.

You can post the results in this thread if you'd like. Just use the "Prnt Scrn" button to capture the graph and table, and then save it as a .jpg and post it.

The Graph tab will allow you make your own graph with whatever scale you want.

If anyone has any questions about how to measure or anything like that, feel free to ask.

dholmes

Thanks gatemplin with my question I had, so even a newer Rat Shack meter is off by as much as 10-12 db? My meter is at lest 10 yrs old, just wondering when you use the meter to see how much spl your system has is that # off also? thanks

gatemplin

dholmes wrote:

Thanks gatemplin with my question I had,

No problem, glad to help.

so even a newer Rat Shack meter is off by as much as 10-12 db? My meter is at lest 10 yrs old, just wondering when you use the meter to see how much spl your system has is that # off also? thanks

I would assume that all RS meters are off by about the same amount. They probably all have the same electret condenser microphone. The meter isn't meant to be accurate at those low frequencies.

For the spread sheet, I used some values from a full range calibration file for the RS SPL meter, and some of the common RS meter correction factors I had saved.

okiepolkie

Your reply might apply to this question as well, but will the digital spl meter have the same corrections, or are they different? I bought my meter before I found this forum, and naturally thought the more expensive one was better.


I did get the test tones and they seem to work just fine on a CD. Do you have any, or know where to get, test tones for the entire audible frequency spectrum? My dad and I are both science teachers and it would be nice to use as a teaching tool when it comes to sound.

Thanks again for all of the help.

Zach

gatemplin

okiepolkie wrote:

Your reply might apply to this question as well, but will the digital spl meter have the same corrections, or are they different? I bought my meter before I found this forum, and naturally thought the more expensive one was better.

I have used both the analog and digital RS SPL meters and didn't notice any difference, and have never read about any difference. They probably use the same condenser mic element and circuitry. If you find something different, let me know. Here is a link to the correction factors from the SVS site and more info on the SPL meter : http://www.svsound.com/questions-faqs-rscomp.cfm

I did get the test tones and they seem to work just fine on a CD. Do you have any, or know where to get, test tones for the entire audible frequency spectrum? My dad and I are both science teachers and it would be nice to use as a teaching tool when it comes to sound.

Thanks again for all of the help.

Zach

Here is a list of low frequency sinewaves: http://sinewaves.bfdguide.ws/

There are also tone generators that you can download and make your own.

okiepolkie

Thanks, if you keep giving info like this, I won't take the time to just enjoy the music.

dorokusai

That looks neato torpedo, PM sent.