More wisdom from Paul McGowan

[amirm]

Well I have only rarely measured 120dB+ peaks, but this completely ignores the point that the LOWEST level one ever needs to RECORD is NEVER 0dB.

Well, this was analyzed too:

The analysis here is much more complicated as you can't just use a SPL meter. You have to perform a spectrum analysis and convert the resulting noise measurements to equivalent tones as to then compare it to threshold of hearing (solid line). Once there, we see that the quietest performance rooms straddle threshold of hearing and at mid-frequencies where our hearing is the best, will go below even 0 dB.

 

[amirm]

If someone owns speakers which can handle this dynamic range - does he really wants to destroy his ears while listening at the original sound level?

The peaks in music are not continuous or anything remotely like a sine wave or plain noise. So while these numbers are indeed large, they are not what we usually imagine as causing hearing damage. Most of the peaks last a few milliseconds.

 

[Wombat]

Well, this was analyzed too:

View attachment 30150

The analysis here is much more complicated as you can't just use a SPL meter. You have to perform a spectrum analysis and convert the resulting noise measurements to equivalent tones as to then compare it to threshold of hearing (solid line). Once there, we see that the quietest performance rooms straddle threshold of hearing and at mid-frequencies where our hearing is the best, will go below even 0 dB.

View attachment 30151

Anybody have this ideal audio system for personal use? Headphones, excepted.

 

[amirm]

Anybody have this ideal audio system for personal use? Headphones, excepted.

When we had our showroom at Madrona, we had measured performance to 116 dB SPL and very quiet room. So quiet that when you went inside, you immediately felt it. It was a great sensation to hear the smallest detail yet have peaks that were kind of scary.

 

[Wombat]

When we had our showroom at Madrona, we had measured performance to 116 dB SPL and very quiet room. So quiet that when you went inside, you immediately felt it. It was a great sensation to hear the smallest detail yet have peaks that were kind of scary.

Very good, somewhat uncommon, and a few orders of level short of the ideal described.

However, I would be happy to have such a listening experience capability at home.

 

[RayDunzl]

When we had our showroom at Madrona, we had measured performance to 116 dB SPL and very quiet room.

I briefly caught 116.9dB peak at the listening position (10 feet) as measured by a UMIK-1 and REW here, as an experiment with a "calibrated" drum solo.

Sounded good, but also sounded like someone was taking a baseball bat to the speakers.

A few seconds - just long enough to get a reading - was enough for me.

I don't remember being concerned with the noise floor during that exercise.

 

[solderdude]

The ears have a 'variable' volume control so while listening to high SPL for prolonged time is not recommended the ears make themselves less 'sensitive' when subjected to constantly loud sounds. So being at a rock concert near the speakers while sounding extremely loud will not sound as loud as a short 'attempt' at home as the ears are in a more sensitive state.

Those that visited loud concerts/parties/disco's (in the old days) will probably have noticed how quiet the world around them is for about 15 minutes or so when one steps outside or visiteds the loo. The AGC in the head is dialed back slowly to normal levels.
At night a similar effect happens.
One can listen to music at a normal level during the day and don't find it loud but when left in the same position and swicthed on again later at night at the same level dials it back quickly.

The dynamic range we can hear remains about the same... it is just the 'reference' level we unconsciously 'shift'

I prefer not to subject myself to high average levels of SPL but do love an undistorted high peak now and then.
Play 'La Folia' comfortably loud and with plenty of headroom as an example on a system that can reproduce such dynamics flawlessly.

How did this end up being about high SPL... Oooohhh ... Paul's loud yet skillful incorrectly wrong opinions with the usual ... weeelllll ... in it, after that the nonsense and deceitfully wrong hypothesizing follows skillfully mixed with some truth to hide the nonsense as truth.

 

[Blumlein 88]

https://www.audiosciencereview.com/...-range-from-recording-to-listening-room.8205/

A thread I've started on just this topic of dynamic range.

I forget where, but some research info indicated instantaneous dynamic range of human ear is around 60 db. The ear alters its sensitivity to manage the entire 120 db or so that is possible.

It also was enlightening working around some machinery that was creating 105 to 110 db SPL in a building where I once worked. By donning good ear plugs and knocking the level down by 30 db, the nuance and detail you could hear was tremendously better. Instead of a deafening cacophony, you could now hear tiny little details, like a rod bearing starting to wear, a wrist pin starting to slap a bit, transmission bearings beginning to get noisy from wear. Even hard to describe sounds indicating you needed to adjust mixture of the methane powered engines. You couldn't separate out any hint of any of that at 105 db SPL. Your ear was overloaded, insensitive, and distorting.

 

[Krunok]

And those dolts would be mistaken

Here's a screenshot from a System of a Down show I was at a couple of months ago.
Not sure of the accuracy of the app on my iPhone, but it was a wee bit loud (about 25m from the stage).


View attachment 30079

Such apps require mic on your phone to be calibrated to show correct SPL.

 

[dc655321]

Such apps require mic on your phone to be calibrated to show correct SPL.

Given I mentioned my uncertainty in the app's accuracy, what's your point?

 

[Blumlein 88]

Such apps require mic on your phone to be calibrated to show correct SPL.

Some of these will identify the phone and thereby be calibrated.

 

[SIY]

Some of these will identify the phone and thereby be calibrated.

This. I used several iPhone apps that gave results pretty close to my calibrated PCB mike/ AP interface and analyzer combo.

I miss the jack on the older iPhones. iSEMcon makes/made a great little mike that plugged in and had excellent calibration and frequency response.

 

[Krunok]

Some of these will identify the phone and thereby be calibrated.

Some will, but not all mikes of the same model of the phone have identical characteristic so I wouldn't reallly assume it is properly calibrated.
If that method would be sufficient than also individial mic calibration wouldn't be necessary as all mikes of the same model would have identical chatacteristic.

Anyway, for SPL estimation this is sufficient but nothing more than that.

 

[Krunok]

Given I mentioned my uncertainty in the app's accuracy, what's your point?

Oh, we are a little touchy today, aren't we..

 

[Blumlein 88]

Some will, but not all mikes of the same model of the phone have identical characteristic so I wouldn't reallly assume it is properly calibrated.
If that method would be sufficient than also individial mic calibration wouldn't be necessary as all mikes of the same model would have identical chatacteristic.

Anyway, for SPL estimation this is sufficient but nothing more than that.

While true, I think the consistency of microphones in phones is likely not so bad. Such manufactured products seem more consistent than some imagine. I've only limited proof of that comparing some phones with calibrated microphones. Typically the ones I've had hands on roll off below 200 khz and are pretty flat up to 8 khz. Beyond that they are more variable.

https://www.parts-express.com/dayto...-for-tablets-iphone-ipad-and-android--390-810

This which SIY already mentioned is a very good solution for cheap until everyone decided to kill off real headphone jacks on cell phones. OH, btw, I've found Android devices to be variable with this for some reason. Laptops and Apple products work well with it. This little microphone seems rather close to a UMIK-1.

 

[Krunok]

While true, I think the consistency of microphones in phones is likely not so bad. Such manufactured products seem more consistent than some imagine. I've only limited proof of that comparing some phones with calibrated microphones. Typically the ones I've had hands on roll off below 200 khz and are pretty flat up to 8 khz. Beyond that they are more variable.

https://www.parts-express.com/dayto...-for-tablets-iphone-ipad-and-android--390-810

This which SIY already mentioned is a very good solution for cheap until everyone decided to kill off real headphone jacks on cell phones. OH, btw, I've found Android devices to be variable with this for some reason. Laptops and Apple products work well with it. This little microphone seems rather close to a UMIK-1.

When I compared linearity curve of my calibrated microphone with the microphone in my Sasmung A6+ the results were so-so. It probably various pretty much between manufacurers or even models.

But even with my calibrated microphone I'm not sure I'm getting correct SPL readings with REW as I don't have reference device to calibrate the absolute SPL with.

 

[Blumlein 88]

When I compared linearity curve of my calibrated microphone with the microphone in my Sasmung A6+ the results were so-so. It probably various pretty much between manufacurers or even models.

But even with my calibrated microphone I'm not sure I'm getting correct SPL readings with REW as I don't have reference device to calibrate the absolute SPL with.

Yes, one of the nice things about the UMIK-1 is you plug it in, run REW, supply the cal curve, and you get the proper readouts without having to cal it yourself.

What is your calibrated microphone, and how are you connecting to it? Might be possible to get close with a little calculating of the various factors involved.

 

[Krunok]

Yes, one of the nice things about the UMIK-1 is you plug it in, run REW, supply the cal curve, and you get the proper readouts without having to cal it yourself.

What is your calibrated microphone, and how are you connecting to it? Might be possible to get close with a little calculating of the various factors involved.

This little guy. I connect it to my laptop's microphone input via TRRS cable.

 

[Blumlein 88]

This little guy. I connect it to my laptop's microphone input via TRRS cable.

Good, I have one of those. I'll be busy the next couple days at least.When I can I'll try and figure out what is the right calibration on it for level vs the Umik and the known input characteristics of my laptop.

Which laptop do you use?

BTW, if you have or can use an Android or iphone there is software that calibrates the result. AudioTool is it. You could use that to set a level on a speaker. Leave the speaker playing at the same level (maybe pink noise for this), then move it to your laptop and set calibration level on the laptop.

Key spec is sensitivity of 10 millivolt per Pascal. A pascal is 94 db SPL. Perhaps with the input specs for your laptop you could figure out what level it should calibrate out to.

 

[Krunok]

Good, I have one of those. I'll be busy the next couple days at least.When I can I'll try and figure out what is the right calibration on it for level vs the Umik and the known input characteristics of my laptop.

Which laptop do you use?

BTW, if you have or can use an Android or iphone there is software that calibrates the result. AudioTool is it. You could use that to set a level on a speaker. Leave the speaker playing at the same level (maybe pink noise for this), then move it to your laptop and set calibration level on the laptop.

Key spec is sensitivity of 10 millivolt per Pascal. A pascal is 94 db SPL. Perhaps with the input specs for your laptop you could figure out what level it should calibrate out to.

I'm using Lenovo Ideapad 700.

I'm now on holidays away from home so I can't test AudioTool but thank you for your help!