SPL Experiment

[RayDunzl]

I cringe when I read somebody reporting SPL, since the value is rarely specified with the type of reading or device.

Having REW installed here, and able to pull up multiple instances of the SPL meter, which claims useful accuracy when used with a calibration file and measurement mic, I took a measurement.

Daytime, "Spice of Life" electric jazzy fusion trio - electric guitar, electric bass, electric drums - playing at Daytime Comfortable Loudish (for me) levels, level selected by ear and not by measurement, with the material fairly consistent over the time for the range of volume...

I wanted to see how the A/C/Z weighting readings compared with musical content, and the difference between Fast and Slow integration.

Below, L = level, A/C/Z = filtering, S/F = slow or fast integration or averaging time, Peak is probably the instantaneous wave maximum, and the big number is the Le - integrated over the entire time of the test.

Observations:

• The max numbers for the different filters and integration times are similar, within 2dB.
• The min numbers are different, about 10dB range, owing to the higher level of infrasonic noise in the environment, filtered by A weighting, and less so by C. Min is achieved between tracks on the CD.
• The Le - I'll interpret this as the "perceived level over a long time", in this case, about 77dB, about 7 dB below the fast and slow max readings.
• Peak is the same on all meters, about 15dB above max, 20dB above long term average Le.

 

[RayDunzl]

I put on the next CD, and I felt the need to turn it down a notch right away. The meters were still running, showed 103.1 peak and 91.2dB LZFmax.

 

[RayDunzl]

I turned it down another notch, and was happy. Over time, this is the result (after a meter reset):

I'd say this CD is a little more dynamic, and has a slightly punchier bass, which shows up in the differences between the A and Z measurements.

Le is within a dB or so, but peaks (likely led by the bass) are 7dB hotter.

 

[FrantzM]

I have been very busy lately so not much time to play with HiFi ..
Using the SPL meter on my HTC One:

With LS50 alone average listening level around 85 dB for soul satisfying music

With Subwoofers swarm.. Average level for same music, same person and same soul ... drops to 75~80 dB...

 

[RayDunzl]

With Subwoofers swarm.. Average level for same music, same person and same soul ... drops to 75~80 dB...

Well... Let me go back to what prompted my experiment. It happened to be you (sorry)...

I have read some people saying that their system is so resolving that they rarely go over 75 dB of max SPL ... I can only to that ...

75 "max" - that would, from my little experiment, infer 90-95dB peaks... Which isn't far off the mark for critical listening in Late Night silence, probably pretty loud at 3am in a dark room.

 

[Blumlein 88]

I have been very busy lately so not much time to play with HiFi ..
Using the SPL meter on my HTC One:

With LS50 alone average listening level around 85 dB for soul satisfying music

With Subwoofers swarm.. Average level for same music, same person and same soul ... drops to 75~80 dB...

So if you had sub-subwoofers would it drop 5 db more for soul satisfying music?

Incidentally I have had the same experience. Gear like the LS50 or other monitor speakers can sound pretty good, but you want it a bit louder for what little low end you can get from it. Provide a woofer or switch to a speaker with a bigger bottom and it takes less volume to have a large satisfying playback level with some boogie to it. The effect seems even more so with well recorded classical.

 

[Blumlein 88]

Well... Let me go back to what prompted my experiment. It happened to be you (sorry)...



75 "max" - that would, from my little experiment, infer 90-95dB peaks... Which isn't far off the mark for critical listening in Late Night silence, probably pretty loud at 3am in a dark room.

My sound levels are similar for similar conditions as what you list. Also a bit off topic, at one time I used switched resistor attenuators I put together myself. In trying to have enough control without needing too many levels I was pondering the same ideas, how loud is satisfying how much does it vary etc. etc. With digital recordings more than 90% of all music I have plays with an average level between 15-20db below peak level mostly near 15 db. Since digital music usually is set to get near 0 db max that greatly restricted how much volume control range I really needed.

 

[Ben Dover]

My sound levels are similar for similar conditions as what you list. Also a bit off topic, at one time I used switched resistor attenuators I put together myself. In trying to have enough control without needing too many levels I was pondering the same ideas, how loud is satisfying how much does it vary etc. etc. With digital recordings more than 90% of all music I have plays with an average level between 15-20db below peak level mostly near 15 db. Since digital music usually is set to get near 0 db max that greatly restricted how much volume control range I really needed.

I play music very loud Is that bad?

 

[Blumlein 88]

I play music very loud Is that bad?

Depends on your definition of loud. Loud enough long enough and you get hearing damage. Doesn't have to be loud enough to cause ringing ears or anything. Just long hours over time with ears stressed adds up. You can follow Osha or other gov't guidelines. As you will see below, 80 dbA average levels and less don't have much limits. 85 dbA for eights hours is suggested. Every 3 db louder reduce the length of time by half. So they don't recommend any exposure at 140 db, but 139 dbA for .11 seconds (loud rifle wearing muffs maybe). So with 97 dbA average for 30 minutes with music you would reach their suggested limits while still experiencing some peaks of maybe 117 db with some music.

The American Conference of Governmental Industrial Hygienists (ACGIH) has established exposure guidelines for occupational exposure to noise in their Threshold Limit Values (TLVs). The following is a summary of these limits:

• Exposures are based on a 3 dBA exchange rate.
• The PEL is 85 dBA. Based on the 3 dBA exchange rate, allowable TLVs for noise range from 80 dBA for a 24-hour period to 139 dBA for 0.11 seconds.
• No exposure to continuous, intermittent, or impact noise in excess of a peak C-weighted sound level of 140 dB is allowed.
• A hearing conservation program is required when workers are exposed to noise above the TLV levels.

The National Institute for Occupational Safety and Health (NIOSH) recommends the following noise exposure criteria [Criteria for a Recommended Standard: Occupational Noise Exposure. NIOSH Publication No. 98-126, (1998, June)]:

• An eight hour TWA limit of 85 dBA, with a 3 dBA exchange rate.
• Implementation of a hearing conservation program at an eight hour TWA of 85 dBA.
• Using hearing protection for exposure that equals or exceeds 85 dBA as an eight hour TWA.
• Reduction of expected performance of hearing protectors (25 percent for muffs, 50 percent for formable plugs, and 70 percent for other plugs).

 

[Phelonious Ponk]

Can't say I"m measuring the sound pressure in my room, but I'm guessing that I listen quietly compared to many. Realistic concert volumes? Maybe. What concert? From what seat? I've been playing in rock and roll bands all my adult life. I get enough volume doing that, thanks.

Tim

 

[Fitzcaraldo215]

I play music very loud Is that bad?

What? I can't hear you.