166 db calibrated cheapie termlab for DMM's

[Jeremiah25 10+ year member]

Oh, forgot to mention, if you notice the smallest difference in the scores was obtained right around 50hz. That is also the resonant frequency of my explorer. I have a feeling that the reason the scores were the closest to the same in that frequency range is because of the fact that it is the resonant frequency range. I will try to test my theory about this on another car with a higher resonant frequency sometime, to see if the smallest difference in the meters is in resonant frequency range of that car as well.

 

[DaGh0st 5,000+ posts]

So was it Higher or lower then the TL?

and what DMM are you useing exactly?

Edit : just saw the chart looks to be higher //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Bloodstalker999 10+ year member]

TTT very interested if anyone has tested this meeter

 

[jmanpc 5,000+ posts]

TTT very interested if anyone has tested this meeter

that meter is pretty much the best in the business. the DMM that is.

 

[xterra_on_22s 10+ year member]

man so it was well worth it

 

[req 5,000+ posts]

nvm.

edited.

so basically your results say its more or less 2db off from the TL with a good fluke?

 

[aaron7114 10+ year member]

I would like to get one of these until I can afford a TL. Anyone wanna sell theirs?

If so PM me.

 

[Johnny Drama 5,000+ posts]

I am sending mine to Chad Hicks as soon as he replys back with the OK to ship.

This way everyone will have two sets of data to read. I appologize that I havent been able to come through on my end. I have a lot going and its really ot a good enough excuse.

I am trying to make it right.

-J

 

[Jeremiah25 10+ year member]

OK I hooked up an amp and tested the differences today. These results were obtained while using my Fluke True RMS DMM to measure the mV output from the Make it louder.com sensor. I made a chart to show the differences in the readings. Please note that the termlab scores were always higher than the makeitlouder.com meter, and the chart shows the difference in the scores at each frequency. The scores were taken between 140-145 dB due to the use of a small amp, LOL. I have not gotten the chance to test the meters at an SPL level higher than that, and probably won't have the opportunity too until I get new amps.

So was it Higher or lower then the TL?
and what DMM are you useing exactly?

Edit : just saw the chart looks to be higher //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

nope it reads a little lower than the TL, or at least my setup does //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Jeremiah25 10+ year member]

nvm.
edited.

so basically your results say its more or less 2db off from the TL with a good fluke?

Less than 2 dB at all frequencies. The maximum difference I saw was 1.6 dB, but there were far more results around a 1 dB difference.

This cheapo meter seems pretty good. I have tested it in various weather conditions, temperatures, and barametric pressures, and it seems very consistant. It is a little confusing at first, and it takes a little longer to use because you have to figure out what your score was based on the mV output, but all in all, I'm pretty impressed. Some meters are so inconsistant that they won't even tell you for sure if you are gaining SPL, losing SPL, or staying the same. This meter is not like that. I definately think it is good enough that you could use this meter to test with to try to get louder.

I hope everyone keeps in mind that the results I have posted were obtained by using 1 of these meters and a $400 fluke DMM. That setup is not really much cheaper than a TL. Also, I have no idea if these meters are consistant to each other or not, because I have only tested one of these meters. If I had 2 or 3 of these meters to test, I might decide they are junk, because I could have totally different results with different one while using the same DMM, but from what I've seen I definately think it's worth the eBay price. One thing I do know for sure though, is that the scores will vary based on the DMM used. A $5 DMM is not going to read mV's the same or as consistantly as a $400 dollar fluke DMM.

 

[jdawg 5,000+ posts]

Can you test it against one of the $5 Harbor Freight DMM's ?

 

[lilmaniac2 5,000+ posts]

I am sending mine to Chad Hicks as soon as he replys back with the OK to ship.
This way everyone will have two sets of data to read. I appologize that I havent been able to come through on my end. I have a lot going and its really ot a good enough excuse.

I am trying to make it right.

-J

Jntar i had matt send you the pm, ill pm you my address also, i was at work and couldnt log in

 

[Johnny Drama 5,000+ posts]

I replied to you...

 

[Chevyaudio 5,000+ posts]

Jntar=FAIL

 

[Jeremiah25 10+ year member]

Can you test it against one of the $5 Harbor Freight DMM's ?

I think it would be a pointless test. I've owned a few of those DMM's and no 2 of them read the same, so it's not like you could draw a conclusion that it would be off by a set value.

Now on the flip side, I think you could probably use one of those cheap DMM's and still get consistant results with this SPL sensor, because once you are up in the 140 dB range you have to gain a several mV's in order to gain a dB. For example, 140dB is 320mV output, and 141dB is 359 mV output. So there is a 39 mV difference from 140 to 141 dB's. Even a cheap DMM should be sensitive enough to draw some conclusions with that much spread. The difference is even higher the louder you go. For example 150 dB is 1012mV output, and 151 dB is 1135mV on my sensor. So by the time you are to that level you are looking a 123mV difference in 1 dB. It's hard to explain what I am trying to say, but hopefully you get the picture. It's kindof cool really, because you can detect even the smallest difference. Say I'm consitantly getting 1140mv output, and I change something and the output jumps to 1147 mV. That change is much less than 0.1 of a dB on the TL, but you can still tell that you gained with this sensor, whereas on the TL you couldn't.