Radio Shack Sound Level Meter

jqp · « **on:** 22 Oct 2003, 10:47 pm »

Just bought a RS SP Meter today - have not used it yet but want to get some info before I get home. It is a digital meter and I wonder if these correction values below apply to the digital, analog or both.

Also should I get the analog instead? I will be measureing many kinds of speakers and subs, test cds, pink noise, etc.

Correction Values:

10Hz add 20
12.5Hz add 16.5
16Hz add 11.5
20Hz add 7.5
25Hz add 5
31.5Hz add 3
40Hz add 2.5
50Hz add 1.5
63Hz add 1.5
80Hz add 1.5
100Hz add 2
125Hz add .5
160Hz add -.5
200Hz add -.5
250Hz add +.5
315Hz add -.5
400Hz add 0
500Hz add -.5
630Hz add 0
800Hz add 0
1kHz add 0
1.25kHz add 0
1.6kHz add -.5
2kHz add -1.5
2.5kHz add -1.5
3.15kHz add -1.5
4kHz add -2
5kHz add -2
6.3kHz add -2
8kHz add -2
10kHz add -1
12.5kHz add +.5
16kHz add 0
20kHz add +1

_scotty_ · « **Reply #1 on:** 23 Oct 2003, 12:22 am »

jqp, here is a web address for a graphic illustration of A,B,C weighting curves.http://hyperphysics.phy-astr.gsu.edu/hbase/sound/acont.html#c5

lkosova · « **Reply #2 on:** 23 Oct 2003, 01:06 am »

Return it for the analog meter and follow the instuctions. There are many discs on the market for this purpose.

Larry

jqp · « **Reply #3 on:** 23 Oct 2003, 01:45 am »

Quote from: _scotty_

jqp, here is a web address for a graphic illustration of A,B,C weighting curves.http://hyperphysics.phy-astr.gsu.edu/hbase/sound/acont.html#c5

Thanks for the link - I have seen this before, and now that I have more experience I will save it and study it.

It seems that the C weighting is the one to use...any suggestions on what to do until I get a test CD?

Where is a good place to save money on good test CDs?

jqp · « **Reply #4 on:** 23 Oct 2003, 01:46 am »

Quote from: lkosova

Return it for the analog meter and follow the instuctions. There are many discs on the market for this purpose.

Larry

I was afraid of that...they only had the digital so I will have to order the analog. Meanwhile what would you do with the digital?

lkosova · « **Reply #5 on:** 23 Oct 2003, 01:54 am »

return the digital!!! Your using c-weighted and the analog is cheaper and better at fine tuning.

Any of the known cd programs should work for pink noise etc..the newer ones will do 7.1 vs 5.1 if that is your thing.

Larry

PLMONROE · « **Reply #6 on:** 23 Oct 2003, 02:13 am »

Better exchange it for the analog quick -- if they have one. I understand that Radio Shack has discontinued the analog units and what is left in the stores is all there is.

Paul

lonewolfny42 · « **Reply #7 on:** 23 Oct 2003, 05:58 am »

If anyone needs an analog RS meter , you can check Ebay. Thats where I picked mine up at an excellent price !

Psychicanimal · « **Reply #8 on:** 23 Oct 2003, 12:04 pm »

Rives Audo sells a test tone CD that is compensated for the Rat Shack analog SPL meter.

gonefishin · « **Reply #9 on:** 23 Oct 2003, 02:35 pm »

Quote from: Psychicanimal

Rives Audo sells a test tone CD that is compensated for the Rat Shack analog SPL meter.

I was just going to post this...the rives CD is nice. There is one set of tones recorded flat...and the second with compensation for the analog RS metter...so it reads flat.

Any one else got one?

oh yeah...get the analog if ya can

MaxCast · « **Reply #10 on:** 23 Oct 2003, 03:52 pm »

Anyone have comments on 1/3 octave tones?? Are there Cd's that have 1/4 or 1/5 spacing available?

jqp · « **Reply #11 on:** 23 Oct 2003, 08:59 pm »

Thanks for the info guys!

JUst ordered the CD from Rives Audio.

jqp · « **Reply #12 on:** 30 Oct 2003, 06:16 am »

I found the analog meter and I also received my Rives Audio test CD. So tonight I started playing around with them.

I put the meter on a tripod. This is probably a must as someone has said - much easier and more consistent.

Played through the tones and tried to get a good midpoint at 80db.

I could hear output at 20, 25 and 31.5, but it was very low output. Could feel it as much as I could hear it. Hear some things in the room vibrating around 50 and 63Hz.

Never realized how low the lows were, and how high 12.5 and 16k is. I could not hear aaaanything at 20k.

Noticed I had some major peaks around 6k. Also noticed that with these pure tones, just turning your head slightly can make a big difference in what you hear. Those tones can really get to you.

I really want to get more familiar with proper phase as this is a common problem in system.

When the Mapleshade acoustic jazz recordings kicked in, I was in audio heaven. And the meter did not behave at all as it did when test tones were playing.

I then had to listen to more music! Phoebe Snow and Tchaikovsky.

I will get down to work recording levels and modes and hot spots later this week.

Psychicanimal · « **Reply #13 on:** 30 Oct 2003, 10:57 am »

Is that a picture of you? If so, you must be one of those SCA people...

jqp · « **Reply #14 on:** 30 Oct 2003, 08:49 pm »

Quote from: Psychicanimal

Is that a picture of you? If so, you must be one of those SCA people...

No, but after I picked it for a new avatar, I noticed that I would probably look amazingly like that with long hair and a helmet!

jqp · « **Reply #15 on:** 30 Oct 2003, 08:53 pm »

I decided this should go here as well as in the VMPS topic.

Here is my room/area. Now everything is more to scale. I will map hotspots, etc and repost.

Rob Babcock · « **Reply #16 on:** 9 Dec 2003, 09:59 am »

I bought a Rat Shack analog meter last week- I already had one, but the salesman confirmed that it's been discontinued, and they only had one left in the store.

Damned shame, and I wonder wtf people are gonna use for an affordable meter now.

If you don't have one yet, run, don't walk, down to your local RS and pick one up before it's too late.

robertwb · « **Reply #17 on:** 10 Dec 2003, 03:03 am »

I've had a digital meter for years -I still don't understand why most people recommend the analog one exclusively-is it just a price thing or what?

Marbles · « **Reply #18 on:** 10 Dec 2003, 03:14 am »

Quote from: robertwb

I've had a digital meter for years -I still don't understand why most people recommend the analog one exclusively-is it just a price thing or what?

With the analog one you can see unlimited partial increments of a DB, where as with the digital one it is only 1db increments, so you can measure to much closer tolerences with the analog.