[pardales]

  I have been meaning to get one of these for some time. I have wanted to know what my different listening volumes were and such. I have also wanted to know what kind of bass response I get in my room. Can I use this device to determine that?

Please strive to either respond to me in the utmost of laymen's terms or, direct me to another thread or discussion that has been conducted in laymen's terms. I have never gotten much into the technical side of these things and do not have an electronics background at all. A primer maybe...

Thanks all,

[Blackmore]

Rives Audio has a test disc that lets you test your bass response and has a full set of tones that have been compensated for the Radio Shack test meters frequency response errors.  Then you can download charts from their website and use them to chart your bass response.  I own one and found it easy to use and to understand.  Check them out at rivesaudio.com

[Charivari]

I have also wanted to know what kind of bass response I get in my room. Can I use this device to determine that?

I strongly recommend that you look into Room EQ Wizard. It's a very nice, free software program that's designed to work with the Radio Shack SPL meters amongst others, is fairly simple to use, and yet has powerful features for the advanced user. The help files should be sufficient to guide you through using the program. With it, you can take a mostly automated measurement of your bass response at 1 Hz increments without the need to manually measure each and every frequency at 1/16th octave or however the Rives disc is divided and graph the numbers out. If you should encounter any setup difficulties, there's also a support forum at Home Theater Shack where you should be able to find folks willing to help walk you through the setup and use of the program.

- JP

[billc]

I recently experimented with Stereophile's Test CD 3, which had three tracks, each one of which provide a series of rising (or falling, in the case of the bass) test tones that sound for about 5 seconds each, before moving to the next track.  I was also using a friends old Realistic/Radio Shack analog Sound Level Meter.

The advice provided above - about developing a calibrated table of responses for the meter - is VERY important (Rives, Room EQ).

In my experience the meter significantly under-measures tones below 100 Hz and over 10,000 Hz.  If you follow the procedure for setting a test tone level around 1000 Hz, and look at the graph that results form the tests on your speakers, WITHOUT SOME ADJUSTMENT/COMPENSATION FOR THE INEXPENSIVE SOUND LEVEL METER readings, you will be surprised to see a very curved (as opposed to flat) response.  Do not throw your speakers away at this point.    The inexpensive sound level meters need to have their measurements adjusted for the inadequacies of the meter.  The Rives and other sources can guide you in this.

ALSO - just as important - the decibel level (dB) you read on the meter, depending on where you do your testing and how far you are from the speaker, will include the effects of the room.  Some frequencies will be enhanced, some attenuated.  Do not worry too much, but recognize that you will can see up to 3 dB variation (or more) from the true reading just related to room acoustics.  The goal with this meter is to get a sense of the "response curve" for your speakers and system, and then you can compare the effects of different speakers, shifting speaker position, and adding room acoustic treatments on the frequency response curve.  You can also get a "sense" of the response of your speakers, but recognize that an inexpensive meter, in an acoustically reflective room, will not be able to reproduce the results of "scientific" level test equipment. 

I recently went through the process of testing the frequency response curves on some new speakers, and I learned more about the meter and testing process than I did about the speakers, initially.  The meter IS useful for comparative testing (speakers, acoustic treatment, speaker placement), but is not really all that useful for "absolute" testing of a speaker, IMHO.  At least not without a lot of experience and adjustment.

Bill C

[MaxCast]

Check out this link in our Acoustics Circle
http://www.audiocircle.com/index.php?topic=17842.0
Good info, graphs, test tones.

[bpape]

I'll second the Room EQ Wizard suggestion.  They just released a new version yesterday that includes RTA functionality which is outstanding for sub placement.

As for the meter accuracy, it's not the best in the bottom end but can still be useful for RELATIVE change tracking.  Also, there is a plugin for the EQ Wizard which compensates for the meter's shortcomings.  It's still not perfect as every meter is different but it gets it pretty close.

Bryan

[darrenyeats]

I ferreted some information on calibrations for the RS SPL meter a while ago. Read here: http://forum.inguzaudio.com/index.php?showtopic=12#
Darren

[darrenyeats]

BTW I like the warble tones on Stereophile Test Disc 3. Warbles have some nice smoothing properties that help to see the "underlying picture" of frequency response without getting distracted by what I call "tooth-comb" response plots.

See http://forum.inguzaudio.com/index.php?showtopic=45# where I discuss chopping up the Stereophile Test Disc 3 tones into more useful chunks with Audacity.
Darren

[pardales]

Thank you for all these excellent suggestions. I will begin investigating. I bought the digital meter. The analog was available too. Anyone know if they are equivalent?

[darrenyeats]

If you follow the links from my Reply #6 far enough this is discussed. It depends on the catalogue number.
Darren