Using a sound level meter

[Inkabodpain]

I just purchased a analog sound meter from Radio Shack 44 bucks . Need some pointers on using S.L.M . I tried messing with it not sure if I used it correctly. I set it on a tripod at my seating position and ear level pointing mic part of S.L.M towards the center channel/tv . I then turned on tv ,a/v receiver and 2 channel external amp. Selected menu on receiver and selected manual speaker level adjustment. At the very top of that menu is a master db setting goes from -80 to +12 (not sure where to set that at) on the same menu page directly under master db setting is the individual speaker db volume setting i set all those to -10. I then set the S.L.M to A at weighting and slow on response and finally selected the range at 80 . This is what I did. Turned on meter started main db at a level where the needle on meter almost peaked. I then started lowering the master db until it hit -10 on meter , the master db level at that time was at -2 . I then started to raise the db level until each speaker reached middle of meter 0. Did I do it properly or "E.P.I.C..F.A.I.L.U.R.E !" this was the out come of what I did. This was done on a Pioneer VSX 94TXH and a B&K 200.2 600watt 2 channel amp.

Master db -2

Left +7 Center +6 Right+7

SL +7.5 SR +7.5

SBL +9 SBR +7.5

[Rich_Guy]

I have always used "C" weighting and slow (also at the 80 range), this is what I read to do and I have never tried "A" to see what difference it made. I also point the meter at the center but angled slightly up, not directly at the speaker. I don't think it should really matter but I have always prefered to 0 my center channel then match all my other speakers to it.

I definitely think my system has always sound much better and much more balanced after I started using the SPL meter to make the adjustments.

[willland]

It does appear you have it down correctly. The "A" weighting is for test tones and the "C" weighting is for music.

This was done on a Pioneer VSX 94TXH and a B&K 200.2 600watt 2 channel amp.

The B&K Reference 200.2 is rated at 225w/ch at 8 ohms and 375w/ch at 4 ohms not 600w/ch.

Bill

[Quiet_Hollow]

I'm still not sure what the OP is trying to accomplish.. Are you trying to establish reference level or are you just matching everything up??

[Inkabodpain]

I believe I am trying match everything.

[Rich_Guy]

It does appear you have it down correctly. The "A" weighting is for test tones and the "C" weighting is for music.

Hmmm, I never heard that before, I don't recall my sources anymore its been too long, but I had always seen to use "C" which was referring to test tones for level matching, so "C" is what I have always used. Like I said I've never even tried "A", since "C" has always worked beautifully.

[Rich_Guy]

Here are a few sources for using an SPL meter, they recommend using "C" weighting.

http://www.aperionaudio.com/AperionU/spl.aspx

http://www.audiophilia.com/hardware/spl.htm

http://www.agoraquest.com/viewtopic.php?forum=49&topic=34252

[Don Richard]

A weighting has low and high frequency rolloffs that approximate vocal frequencies. C weighting is flat from 31.5 Hz to 8000 Hz.

[willland]

It does appear you have it down correctly. The "A" weighting is for test tones and the "C" weighting is for music.

Hmmm, I never heard that before, I don't recall my sources anymore its been too long, but I had always seen to use "C" which was referring to test tones for level matching, so "C" is what I have always used. Like I said I've never even tried "A", since "C" has always worked beautifully.

Instructions for Radioshack Sound Level Meter

By Candace Horgan, eHow Contributor

A Radio Shack sound level meter is a tool that lets the user measure the volume level coming from a pair of speakers. A sound level meter can be used to fine tune a home stereo system and get the best sound from it, and also help to protect your hearing from suffering damage.

Setting up the Sound Level Meter

The sound level meter has two settings: A-weighting or C-weighting. A-weighting lets you measure specific frequencies between 500Hz and 10,000Hz. C-weighting measures the frequency response from 32Hz to 10,000Hz. Select A to measure the sound in an area; select C to measure music sound levels.

After selecting A or C-weighted, choose a fast or slow response time. Fast is used to measure peak levels and slow measures average levels.

Ranges

The Radio Shack sound level meter can measure up to seven output ranges. Each range covers 20db. For instance, setting the SLM to a range of 120 will record sound between 110db and 126db. If the volume output is below or above the selected range, the sound level meter will flash "overrange" or "underrange."

Understanding how to measure the average sound levels using the sound level meter can help you avoid hearing damage from listening at loud levels for too long. The U.S. Department of Labor has specific recommendations for maximum listening time at different volume levels. For instance, at 90db, you can listen for up to 8 hours with no damage; at 100db, that time is reduced to 2 hours. If you set the sound level meter at 100 and use C-weighting and you start getting "overrange" signals, you know you have your system set to play too loudly.

Using the Sound Level Meter

Using the sound level meter is simple: point the unit's microphone at the speakers and play back the sound through the speakers. Record the measurements on a piece of paper. You can fine-tune placement of your speakers by using a test CD, available at Radio Shack, that cycles through specific frequencies and records how loud each tone is. The goal is get a flat response reading of 0 for each tone.

Sorry guys, I misinterpreted the instructions that came with mine. Please forgive my ignorance.[:#]

Bill

[Islander]

Did I do it properly or "E.P.I.C..F.A.I.L.U.R.E !"

Epic failure if you don't get the settings perfect on the first attempt? Of course not!

An epic failure would be if you managed to blow up your speakers and that caused your house to burn down. []