Sound Level Meter - Worth it?

[Srini]

Hi,
I wanted to get your experience and opinion on whether it is worth spending 50 bucks on a Radioshack Sound-level meter for audio calibation in setting up of VT-12 + STF-3 combo.
Thanks
Srini

[daltonlanny]

Hi,
I wanted to get your experience and opinion on whether it is worth spending 50 bucks on a Radioshack Sound-level meter for audio calibation in setting up of VT-12 + STF-3 combo.
Thanks
Srini

ABSOLUTELY in my opinion!
It is especially useful for testing the bass range for different room placements, of the sub, when used in conjunction with the HSU bass test CD-R, or similar test CD.
Remember to add about 11 db to the readings you obtain at 16hz, 7db at 20hz, 5db at 25hz, 3db at 31.5hz, 2db at 40hz, etc., because of the roll-off of the mic and/or unit at these frequencies using the C-weighting and SLOW response on the meter.
Hope this helps!
Lanny

[coachstahly]

I ordered the same system you have (am waiting since the STF-3 is out of stock) and in order to be ready I bought a Radio Shack analog meter and the AVIA dvd. I went ahead and calibrated my cheap Pioneer speakers, that came with my much nicer Pioneer A/V receiver and DVD player, so I would know what to do when my Hsu's get here. I noticed a much better overall sound experience from my speakers, even though they're not that good. I'm relatively new to HT calibration, but I would make the suggestion that you make the investment and go for it. In my first time through the dvd, I noticed a lot of things that escaped my ears - frequency gaps (ranges where frequencies were noticeably softer (less dBs than the surrounding tones)) and dB differences between speakers (not off by much, but enough to show on the meter and make a difference when corrected), just to name a few. I think it's worth it, and I've got some small, poorly made speakers right now.

[AudiblConoiseur]

http://cgi.ebay.com/AWESOME-SPL-ANALOG-SOUND-LEVEL-METER-AUDIO-SPEAKER_W0QQitemZ160080129141QQihZ006QQcategoryZ25 423QQssPageNameZWDVWQQrdZ1QQcmdZViewItem?hash=item 160080129141

here is one...

[Stan]

Yup a meter is the way to go.

BTW I was the first or among the first to use and post about using a R-S meter corrected, and for more than just setting an SPL level. This was around 94 or 95, in the old AOL AV forums. Of course as you get more sophisticated it's other shortcomings become an issue, for example, if you are measuring distortion. At that point buying a better microphone makes sense. Then you can do THD tests, measure > 126 dB (important if you measure at the cone / port / passive radiator) and enjoy super accurate calibrations and low noise floors.

Stan

[will95]

Stan,

What equipment do you use for your measurements?

[tdekany]

Hi,
I wanted to get your experience and opinion on whether it is worth spending 50 bucks on a Radioshack Sound-level meter for audio calibation in setting up of VT-12 + STF-3 combo.
Thanks
Srini


I have a Pioneer receiver and their Auto setup is right on. You can see cnet's review as well. I do have the RS SPL meter. So if you happen to have a new Pioneer you don't need it.

[AudiblConoiseur]

but what do you do if you set it and the Pioneer sets the mains to large with the sub on? you don't want the lfe to go to the mains in this case and for them to run large! how can we avoid this?

[Stan]

Stan, What equipment do you use for your measurements?

I use all sorts of stuff. Such as specialized test CDs/DVDs, SPL meters, signal generators, lots of software based analyzers/generators/simulators, various calibrated microphones, packages like Spectra, LinearX stuff, LEAP, special sound cards, etc.

[dafeist]

Im with audibl on this one. I have a pioneer receiver and the mcaac always puts the speakers to L, even with a sub connected. I then just manually drop them down to S but dont know if that is making a difference where I would need to recalibrate. I dont have an spl so I cant do a before and after test. So can I just run the mcaac, drop the speakers down to S, and keep it calibrated?

[feisty]

Would like someone to respond to the last post. I have a Pioneer receiver and having the same issue. At times, I thought the sub was not working. Mains are oldies but goodies-ADS Monitor series with dual 8" woofers. Can you set the mains to small manually and not upset the auto calibration?

[coachstahly]

I have an older receiver VSX D814s with MCAAC (without the mic). After I auto-calibrate, ANY change I make disengages the MCAAC. I don't know if this applies to the newer models or not. I do know that when I calibrated with an SPL and AVIA, my sound was a bit better than when the Pioneer did it itself (keep in mind that I had to manually enter some measurements and that my receiver does NOT have a mic to place at the listening position). Hope this helps!

[dafeist]

hmmm, without the mic it cant really run the mcaac can it? I wonder if I could get this info from Pioneer themselves (doubtful). Anyone else know what to do or do we need the spl?

[coachstahly]

I know Pioneer has owner's manuals online (although I'm sure you still have yours). My MCAAC calibrates based on my measurements of each speaker from the listening position (only 1/2 foot increments). That's the only input it needs. Once it gets that, then it runs through the calibration. You can play with settings as it calibrates so as to set individual preferences, or leave it as is. However, once the calibration is complete, any change shuts it off. The only spot I remember for the speakers is at the beginning of the setup. After that, there's no way to change your speaker size. I haven't tried emailing or calling Pioneer directly, but I'm sure you would get an answer (eventually).:D

[dafeist]

I just talked with them over the phone. The dude said that if you change your speaker settings to S if MCACC has elected L, then youve elimated the calibration. He told me to get an SPL and do it manually. Neat, wonder how much I paid extra for that lovely perk...

[AudiblConoiseur]

Remember when in the old days they had to do this... didn't they use their ears or a tuning instrument of some sort? When in doubt, go back to paper and do it by hand!

These systems are great to do this for you but unless they are allowing a little minor adjustments, they may never be right. The system is calibrating based on acoustics and it all depends on how accurate that little mic is! They make you do math long hand in college for a reason - if the battery dies or the power goes out - think about that before you invest in systems that can do this for you. I have no system set up like this on my 1905 and it sounds DAMN good with just the SPL (yes, I know it has a battery ;) ). FYI, I am contempating buying an Audessy system or something like this as well but really don't know that I want it after all. It does come with the newer and better systems though. Either way, the 340's are awesome and sound great so I will leave well enough alone!

[Denis]

Can anyone recommend a place to start on how to go about setting up your system with a SPL??
At the moment i let my yamaha yapo do the calibrating.. but i would like to try to calibrate it with a spl if i could. I just need to know what to do with the SPL once i have it in my hands..

[AudiblConoiseur]

It is easy buddy!

Get the SPL and set it at the LP, facing the speakers (center of them). Don't stand or sit directly behind it.

Get an AVIA or other constant white/pink noise cd and play at reference level of around 76dB, I use 80 b/c it is easy (use SPL to know level).

Your system or disk should play through each speaker individually and lower or increase the gain on that speaker to the 80dB level then move to the next one and so on until you have them all equal

The sub is a little different as you have to add a few dB depending on gain level but you can ear-ball this one a little to sound proper for your taste.

Good luck and don't forget to turn off SPL when you are finished!

[wid]

It is even more critical to use a spl meter while calibrating a sub. When "ear balling" the sub one will no doubt set it around 10db to hot. Also remember to use the correction table for the spl meter when calibrating the sub.

[cyberbri]

The digital RS meters are much more accurate. Within 1dB or so for the bass frequencies found in Avia's test tones. The analog meters are about 2~3dB off in this range, so you have to add 2~3dB to whatever reading you get with the analog. Of course the meters are less sensitive below 35Hz or so, but that doesn't come into play unless you are looking at sweeps and individual frequency response.

[daltonlanny]

The digital RS meters are much more accurate. Within 1dB or so for the bass frequencies found in Avia's test tones. The analog meters are about 2~3dB off in this range, so you have to add 2~3dB to whatever reading you get with the analog. Of course the meters are less sensitive below 35Hz or so, but that doesn't come into play unless you are looking at sweeps and individual frequency response.

Cyberbri,
No offense, but I think they are alittle less accurate than that.
I bought a Radio Shack Digital Sound Level Meter back in December 2006.
Daisuke Koya, an employee at Hsu Research wanted to borrow it to write a research paper on the the meter, so I sent it to him.
I asked him if he could also test it to see how accurate it was.
He agreed, and checked it with high dollar test equipment and microphones.
The meter measured:
- 9.7 db @ 16hz
- 6.3 db @ 20hz
- 4.5 db @ 25hz
- 2.9 db @ 31.5hz
- 2.0 db @ 40hz
- 1.1 db @ 50 hz
It was less accurate than I wanted/expected, but I simply add the above values to the readings I obtain at these frequencies and it works very well indeed. A great tool for setting up subs in a room!

[cyberbri]

That's about what I would have expected. Accurate enough for calibrating the subwoofer with the tones, which are usually around 50~80Hz or so. (the sub calibration tones, not the sweeps that go down to 20Hz)

Here are the overall average compensations:
http://www.hometheatershack.com/forums/bfd-rew-downloads/19-bfd-guide-room-eq-wizard-downloads.html
(download the Excel files to see)

The old analog meter was really off. The digital meters, and the new analog meters as well, are pretty accurate.

[Lwang]

Cyberbri,
No offense, but I think they are alittle less accurate than that.
I bought a Radio Shack Digital Sound Level Meter back in December 2006.
Daisuke Koya, an employee at Hsu Research wanted to borrow it to write a research paper on the the meter, so I sent it to him.
I asked him if he could also test it to see how accurate it was.
He agreed, and checked it with high dollar test equipment and microphones.
The meter measured:
- 9.7 db @ 16hz
- 6.3 db @ 20hz
- 4.5 db @ 25hz
- 2.9 db @ 31.5hz
- 2.0 db @ 40hz
- 1.1 db @ 50 hz
It was less accurate than I wanted/expected, but I simply add the above values to the readings I obtain at these frequencies and it works very well indeed. A great tool for setting up subs in a room!

From my experience, the analog seem to be less accurate. Given its logarithmic scaling. Getting any info in the -4 and less range is pretty much guessing. While the digital unit has a linear +/-10dB scale, so getting any reading from -10 to +10 are all equally the same.

Try this, play a 75dB signal reference to the meter being set to 70dB and the meter showing +5dB. Now switch to the 80dB scale. The reading would not be -5dB. If you try the same thing with the digital meter, the reading should be closer to each other.

The analog meter is good for walking around with it and finding the center point of a peak or null in your room, since you can see the minute changes of the meter and where it goes up higher and higher until it starts going down again.

[M. Campbell]

Is there any risk or drop in quality of the results if you use the test tones provided by the receiver versus using a source DVD such as Avia?

[Ddavidson]

The digital RS meters are much more accurate. Within 1dB or so for the bass frequencies found in Avia's test tones. The analog meters are about 2~3dB off in this range, so you have to add 2~3dB to whatever reading you get with the analog. Of course the meters are less sensitive below 35Hz or so, but that doesn't come into play unless you are looking at sweeps and individual frequency response.
If you prefer WYSIWYG for some of the Shack Meters.

RS SPL METER (33-2050) MODIFICATIONS
http://mysite.verizon.net/tammie_eric/audio/rsmeter/33-2050/33-2050.html

RS DIGITAL SPL METER (33-2055) MODIFICATIONS
http://mysite.verizon.net/tammie_eric/audio/rsmeter/33-2055/33-2055.html

RS SPL METER (42-3019) MODIFICATIONS
http://mysite.verizon.net/tammie_eric/audio/rsmeter/42-3019/42-3019.html

Ddavidson

[jerry22m]

Regarding small and large speaker settings someone on this forum was nice enough to point out under auto setup if you scroll down to option and press enter on remote then select yes for thx speakers mcacc will do auto setup and keep speakers set at small. Regards Jerry

[Macfan424]

Regarding small and large speaker settings someone on this forum was nice enough to point out under auto setup if you scroll down to option and press enter on remote then select yes for thx speakers mcacc will do auto setup and keep speakers set at small. Regards Jerry

I've never been able to get my 1015 to behave that way. Maybe it works differently on the Elites or the xx16 series.

However, it doesn't matter much. All I have to do after running MCACC is to manually switch the front speakers back to small. None of my other setting change. I've verified this with my SPL meter. The settings are dead on.:cool: