Spl meter and more....

[Chazman]

SPL meter, Recommendations? I want to start learning about room measurement, any pointers (meter, programs, articles) to get started would be much appreciated!

 

[Sonnie Parker]

I would look at getting a calibrated UMIK-1 from www.minidsp.com and download REW, using the combination as an SPL meter. Then you'll also have your measurement mic.

After you download REW.... look in the same Downloads location for the Getting Started with REW Guide... an excellent read and help tutorial that will educate you a good bit.

 

[Wayne A. Pflughaupt]

What Sonnie said. However, if you need something portable that you can take to a friend’s house to help set up his system, or on a commercial airplane to measure cabin noise, or to a jobsite to check noise levels for safety reasons (all of which I’ve done), the Galaxy Audio CM-140 is a popular choice.

In addition, here’s a great informational article about sound level meters.

https://www.prosoundweb.com/topics/...ers_the_primer_what_how_why_techniques_more/#

BTW, using the calibrated miniDSP UMIK-1 mic that Sonnie mentioned with REW, and you have the equivalent of a Class 0 laboratory-grade SLM for a fraction of what a “real” one would cost. I can’t even find a price for one, but basic industrial-grade Class 1 meters sell in the $400 range.

Regards,
Wayne

 

[Chazman]

Thanks guys! I was interested in that combo awhile back but never went through with the purchasing part of it. I've had quite a few guys telling me to get omnimic also. Awful lot of money at the moment considering I know nothing about calibration. 300$ vs. 100$ for the umik. Trying to figure out if the extra 200$ has a reason that's worth it.

 

[Tony V.]

Bought my Galaxy CM140 years ago and still use it regularly. Recently bought the UMIK and will give that a run when I've gotten the new seating and new receiver in place. You can't go wrong with either of the above choices

 

[Matthew J Poes]

The Omnimic is not more accurate than the umik. I'm not sure who told you that but they are confused. The Omnimic is a Umm-6 with measurement software and an individual calibration file (which the Umm-6 and Umik also have). Independent analysis of the accuracy of those calibration files have suggested that neither is perfectly accurate.

If you want more accurate, try a Cross-spectrum calibrated umik or umm-6. More accurate yet requires moving up to something pretty expensive.

My go to suggestion for just SPL meter is to use a smart phone and SPL meter app. If you have an iPhone and Niosh SLM, it meets type 2 specifications and in fact is very close to meeting type 1. That means its every bit as accurate as anything you could buy under $200. Add an external smartphone measurement mic for under $25 and it actually does meet Type 1 standards, and should do so on any phone. The iPhone is preferred over others only because its audio chips and mic are the same, Android phones are all different, some are great, some are not. With an external mic it should be fine unless the phone you have has an unusually poor quality AD converter (which I would doubt).

 

[Wayne A. Pflughaupt]

Great info. Is there a particular SLM app you recommend?

Regards,
Wayne

 

[Matthew J Poes]

Great info. Is there a particular SLM app you recommend?

Regards,
Wayne

Yes! NIOSH has their own SLM. I suggest that one. They developed it and calibrated it so that it is accurate on an iPhone. They did fairly extensive testing as well.

https://www.parts-express.com/pedoc...sh-evaluation-of-external-smartphone-mics.pdf

This was how I discovered it. I was looking at the cheap smartphone mic and found that article. I was impressed. I have this mic and have adapted it to use on my laptop so I can compare it against a number of other mics I have. It isn't the equal of a calibrated UMM-6, but its closer than most would think. Up to 5khz it is basically identical. Above that point it does differ some, but I found orientations that are fairly accurate, and with the Dayton serialized correction file, it isn't bad. For an SPL meter purpose, it is more than adequate. I have a number of SPL meters and borrowed an NTi meter to test my room's noise level a good month or two ago, and the Dayton mic with NIOSH app came very close.

 

[Matthew J Poes]

Ok sorry, I just took a look and it appears that there is no Android app that is recommended. The SLM is only for iOS. I guess the reason is that the android phones all use different hardware so the app can't be calibrated to the phone so easily.

I revise what I said earlier. If you have an iOS phone, I suggest an SPL meter app, its accurate. If you have an Android, sorry! My guess is that the existing apps might be accurate on some android devices, but without having a calibrator or reference meter you would have no way of knowing. If someone wants to bring me a bunch of android devices, I'd be happy to test them on a calibrator and set of test tones against a reference measuring device to see how close we can get and if there is one to recommend with a particular phone.

 

[soundset]

Hi everybody. I'm looking for an inexpensive (up to 50$) microphone to adjust the sound in cars. I'm doing installation more then 14 years, but only now decided to take up tuning the sound)
Thanks

 

[Tony V.]

if you have a smart phone there are plenty of apps that will do SPL readings

 

[soundset]

I have smartphone, but I dont have microphone to PC or SmFone/IpadMini to correct tune EQ in clients cars. Very often install SUBs and AMPs in cars, and other car audio. I have 3 mics from Handsfree: Nokia, Bury & Pioneer, but must have pro-mic... As WM-61 by Panasonic or pro-mic Behringer etc.
Thank you for answer)

 

[Tony V.]

MiniDSP UMIK1 would be your best choice but it $75
https://www.minidsp.com/products/acoustic-measurement/umik-1

 

[Matthew J Poes]

The UMM-6 from dayton is another good choice.

If $50 is your absolute limit then you might look at either the iMM-6 https://www.parts-express.com/dayto...-for-tablets-iphone-ipad-and-android--390-810 or the minidsp pmik-1 https://www.minidsp.com/products/acoustic-measurement/pmik-1-detail

These were designed for use with smartphones but can also be used with laptops and free measurement software. They would require a TRRS extension cable however, which you can get from Amazon. I would not buy the one that Dayton sells, it has a bad connector. I’ve used these against better mics and they are fairly accurate.

 

[soundset]

The UMM-6 from dayton is another good choice.

If $50 is your absolute limit then you might look at either the iMM-6 https://www.parts-express.com/dayto...-for-tablets-iphone-ipad-and-android--390-810 or the minidsp pmik-1 https://www.minidsp.com/products/acoustic-measurement/pmik-1-detail

These were designed for use with smartphones but can also be used with laptops and free measurement software. They would require a TRRS extension cable however, which you can get from Amazon. I would not buy the one that Dayton sells, it has a bad connector. I’ve used these against better mics and they are fairly accurate.

its so good mics) and good price. What you think about Pioneer CD-MC20 as my first microfone to learn REW? what is inside it and what parameters...

 

[soundset]

now I have 4 mics, very old. Connect to jack cable to notebook and calibrate in/out channels. But... How calibrate microfone on EQ in REW?
P.S.: sorry, my english is "weree vel")

 

[Matthew J Poes]

now I have 4 mics, very old. Connect to jack cable to notebook and calibrate in/out channels. But... How calibrate microfone on EQ in REW?
P.S.: sorry, my english is "weree vel")

I’m sorry I’m not totally sure what you are asking. It’s generally not a great idea to use a microphone that isn’t designed for measurement because the response will either be unknown or more likely not flat and extended. Some studio mics will work because they have a response down to 20hz and are flat, but not extended to 20khz (which is ok because you should only eq bass).

You can’t correct the response of a mic unless you have a correction file or a reference mic. If you don’t have those two things you will need to purchase a calibration mic.

As for eq, I suggest taking measurements of your system with your mic and posting results first. Eq is a vast subject.

 

[Tony V.]

Agreed, there are not many mic's out there that have a calabration file for REW. A vocal mic for example won't have the ability to read the full frequency range. The mic's we mentioned farther up are the best choices as they have the ability to read full range and the calibration file is already created.
The Pioneer CD-MC20 is a dedicated mic for a receiver and unless you know the spaciffic specifications of that mic it won't give you reliable results.

 

[soundset]

Thanks guys)

 

[Chazman]

The Omnimic is not more accurate than the umik. I'm not sure who told you that but they are confused. The Omnimic is a Umm-6 with measurement software and an individual calibration file (which the Umm-6 and Umik also have). Independent analysis of the accuracy of those calibration files have suggested that neither is perfectly accurate.

If you want more accurate, try a Cross-spectrum calibrated umik or umm-6. More accurate yet requires moving up to something pretty expensive.

My go to suggestion for just SPL meter is to use a smart phone and SPL meter app. If you have an iPhone and Niosh SLM, it meets type 2 specifications and in fact is very close to meeting type 1. That means its every bit as accurate as anything you could buy under $200. Add an external smartphone measurement mic for under $25 and it actually does meet Type 1 standards, and should do so on any phone. The iPhone is preferred over others only because its audio chips and mic are the same, Android phones are all different, some are great, some are not. With an external mic it should be fine unless the phone you have has an unusually poor quality AD converter (which I would doubt).

So I've decided with the umik 1.someone on another page also brought up cross spectrum. Said they calibrate each mic individually and also give a couple cal files, one for ht, allowing more accurate measurements having the mic pointed up instead of at the source. Make sense? Any one familiar? I'm just wanting to verify that it's worth the 30+$ over buying it at minidsp or parts express.
Btw, I just installed noish Mathew. Gonna play today. Thx

 

[Chazman]

So I've decided with the umik 1.someone on another page also brought up cross spectrum. Said they calibrate each mic individually and also give a couple cal files, one for ht, allowing more accurate measurements having the mic pointed up instead of at the source. Make sense? Any one familiar? I'm just wanting to verify that it's worth the 30+$ over buying it at minidsp or parts express.
Btw, I just installed noish Mathew. Gonna play today. Thx

I just read on minidsp that the umik-1 comes with two cal files. One for two channel and one for 5+ home theater. For pointing it to the ceiling. So cross spectrum is not unique in that way. Why do a hand full of people tell me to get it from cross spectrum?

 

[Tony V.]

Cross spectrum gives you a much better calibration file meaning you get even more accurate readings from the mic. The mic will come with a certificate stating it is calibrated. For most of us the extra cost is not necessary unless your doing this professionally and are setting up recording studios or the like.

 

[soundset]

hi guys! What do you think about it?)

30$ KIT) + cables + connect to laptop or soundcard-->laptop

 

[soundset]

http://allegro.pl/aluminiowa-obudowa-do-mikrofonu-wm-61a-czarna-i7140585609.html#thumb/1

 

[Matthew J Poes]

So I've decided with the umik 1.someone on another page also brought up cross spectrum. Said they calibrate each mic individually and also give a couple cal files, one for ht, allowing more accurate measurements having the mic pointed up instead of at the source. Make sense? Any one familiar? I'm just wanting to verify that it's worth the 30+$ over buying it at minidsp or parts express.
Btw, I just installed noish Mathew. Gonna play today. Thx

The calibration files are not special to HT nor does pointing at the ceiling have anything to do with HT. It's a convention for measuring room acoustics that is thought to increase the amount of room information that is captured in a given measurement as compared to pointing the mic at the speakers, which would increase the amount of direct information. There are arguments for and against doing this. Mics are not accurate at 90 degrees unless designed for that and so a calibration file is needed to correct it's response.

For what it's worth, the cheap mics we all tend to use aren't perfectly accurate in either orientation and both need corection.

Cross spectrum calibrated each mic against a reference mic in three orientations (0, 45, 90 degrees). Their procedure seems accurate and relies on the comparison calibration method.

Dayton and Minidsp both calibrate mics individually known as serialized calibration. I can't confirm this but I believe they use an electrostatic calibration method in which the capsule is replaced with a capacitor. It is supposed to be very accurate but they doesn't seem to be necessarily true.