[Wig]

Guys,

Can anyone recommend an SPL App that I can download on a phone to ensure that my speakers are properly configured based upon their output?

Thanks,
Wig

[TomS]

Guys,

Can anyone recommend an SPL App that I can download on a phone to ensure that my speakers are properly configured based upon their output?

Thanks,
Wig

SPL and much more http://www.studiosixdigital.com/

[Phil A]

SPL and much more http://www.studiosixdigital.com/

That's what I have and I also got a microphone for the iPhone/iPad from Parts Express.  Also have their PC mic for Room EQ Wizard.

[mcgsxr]

I use a freebie on my iPhone.  Decibel 10th. 

[Phil A]

One limiting factor on a phone (or even on an SPL meter like the old Radio Shack one which I still have) is the microphone.

[Wig]

Guys,

Thanks for all of your responses! The App I downloaded was inconsistent but I found one of my set-up discs and pushed my right spkr back
1" and that seemed to put things back into balance...

Wig

[Mike-48]

One limiting factor on a phone (or even on an SPL meter like the old Radio Shack one which I still have) is the microphone.

Phil just dropped that in, but it's a critical point. The mic is the limiting factor on an app, and since the app doesn't know the characteristics of every phone's microphone, it can be WAY off until you calibrate it, which would require a known reference. That's especially true of anything involving frequency response -- but true of absolute SPL as well.

[poseidonsvoice]

Phil just dropped that in, but it's a critical point. The mic is the limiting factor on an app, and since the app doesn't know the characteristics of every phone's microphone, it can be WAY off until you calibrate it, which would require a known reference. That's especially true of anything involving frequency response -- but true of absolute SPL as well.

Mike and Phil are both right.

Here is an email I recently sent to some of my colleagues and Herb Singleton of CSA (Cross Spectrum Acoustics):

I was looking for an iOS app to use my iPhone's internal mic to perform as a sound level meter (for general use - I use the CSA certified minidsp mic for REAL stuff!). There are a plethora of them. Which ones have been tested? How do they perform against a reference standard? How does the use of an internal mic affect accuracy?

Here are the results: https://blogs.cdc.gov/niosh-science-blog/2014/04/09/sound-apps/

Then they did a study using the iOS apps but with smartphone devices having external mics:

http://asa.scitation.org/doi/full/10.1121/1.4964639

This follow-up study suggests that using external, calibrated, microphones greatly improves the overall accuracy and precision of smartphone sound measurements, and removes much of the variability and limitations associated with the built-in smartphone microphones.

So then they designed their own iOS app: https://www.cdc.gov/niosh/topics/noise/app.html

_______________________________________ _______________________________________ _______________________________________ ______________________________________
Herb's advice was to look at good external mics. He said the best he tested was the Mic-W i436 at $120 retail. He will be selling the mic along with calibration through his website in the future.

The Dayton Audio iMM-6 is a decent alternative at a lower cost, but it has a significant high-frequency roll-off above 12 kHz.

Best,
Anand.

[mcgsxr]

Agree with the reality that a free app is not that accurate.

I have always used it to answer the "approx how loud AM I listening" question vs setting up a serious system using the freebie etc.

[Phil A]

I should also note that I have an outboard (Audio Control) one third Octave RTA for over 10 years.  I have to get used to using the computer audio tools (used them a handful of times) along with the calibrated USB mic.  It is on my agenda just way behind on many things.  I've used the outboard RTA many times.  So it is very obvious to me when I use one of these Apps without a mic.  That's why I got ones for both the iPad/iPhone and PC.

[rotarius]

You can still get the Radioshack sound level meter on ebay for not much money.  An audiophile favorite!

[Phil A]

There were discs made to compensate for the Radio Shack microphone shortcomings and tables like - http://www.subwoofer-builder.com/SPL-corrections.htm

Mine is in the garage.  Have not used it probably in over a decade (and won't be again).  For me with an App and the microphone (under $20) for the iPhone or iPad, which I have anyway, it is an easy decision.  I have the RTA is both App form, on the computer and an outboard unit too so it makes it easy for me.

[Tone Depth]

Does anyone know of any self-calibrating SPL apps for smartphones?

[Phil A]

Does anyone know of any self-calibrating SPL apps for smartphones?

Off the top of my head no but the Dayton Audio mic is not expensive - http://www.titantv.com/Default.aspx

[Phil A]

There's plenty of Apps - e.g. - https://blogs.cdc.gov/niosh-science-blog/2017/01/17/slm-app/   and    http://www.caohc.org/updatearticles/winter2013.pdf?version=012914

[Tone Depth]

Thanks, I understood Android cell phones were built on a standard platform. Perhaps "drift" has occurred over the years since that standard was developed. I may have to get an external mic and see if I can develop a calibration curve for my specific android phone.

[Phil A]

Thanks, I understood Android cell phones were built on a standard platform. Perhaps "drift" has occurred over the years since that standard was developed. I may have to get an external mic and see if I can develop a calibration curve for my specific android phone.

The Parts Express mic comes with calibration - https://www.parts-express.com/pedocs/manuals/390-810--dayton-audio-imm-6-user-manual.pdf

"Calibration:
To deliver the most accurate results,
a calibration file should be loaded into the
software program being used for audio
analysis. This calibration file is generated
based on the serial number of our iMM-6.
To obtain your calibration file in text format
(compatible with most audio analysis apps),
visit DaytonAudio.com and navigate to the
iMM-6 product page. Enter the serial number
of your iMM-6, then click on “Download.”

[Mike-48]

Thanks, I understood Android cell phones were built on a standard platform. Perhaps "drift" has occurred over the years since that standard was developed. I may have to get an external mic and see if I can develop a calibration curve for my specific android phone.

I think that for most purposes, you could just buy a RadioShack SPL meter and use that (along with test tones) to calibrate the phone's mic.