[miatadan]

Amen to your warning about hearing damage.

It's important to note that rock and unamplified acoustical music are different in this respect. Acoustical music has a peak-average ratio of 10-20 dB and those brief peaks and hearing loss is dosage-related. It may seem paradoxical, but loud acoustical music requires more power than heavy metal, because both perceive loudness and haring damage have more to do with average than peak levels.

The ear is relatively insensitive to peak clipping. I read recently about some experiments in which people couldn't hear up to 11 dB of clipping. (On trumpets, however, they heard only 1 dB of clipping, so it isn't really realistic.) Tube amplifiers, with soft clipping, sound better when overloaded than transistor amplifiers, and good amplifiers recover more rapidly from overload than cheap ones making clipping less audible.

An SPL meter DOES NOT read peaks! A peak isn't a crescendo, it lasts milliseconds and is responsible for the attack or "bite" of a sound. SPL meters are dosage-measuring instruments that were intentionally designed with averaging dynamics. They're good at protecting against hearing damage (use "A" weighting for that) but they won't tell you whether your amp is clipping. You can add 10 dB to the highest meter reading for a ballpark estimate.

Finally, from what I've read, the OSHA dosage maximums aren't tight enough to fully protect hearing.

Is it possible I have incorrect settings on spl meter? I been to live rock concerts and they were a lot louder than my stereo system...

settings I am using:   C weighting ( 2 options A or C ) , range 100 db, response selector on fast ( 2 options are slow and fast )  note:  Studio Six Digital meter is showing both digital display + VU meter, Radio Shack spl meter is VU meter only

both meters giving same reading within 1db

[josh358]

I tested my Radio Shack meter against a certified calibrated meter and it was within a dB or so, so I'm guessing it was spot on. I'm not sure what explains the difference between what you're reading and what you're hearing. A rock concert is going to be louder than anything you can or should play with most home equipment. It could be as much as 120 dB SPL, the OSHA limit, which will damage your hearing in short order.