Does It have to be loud?

So what max level with an SPL meter did you achieve?

I'm using a Dawson DSM101N multi-meter, which I realize is by no means a truly scientific exactly perfect measuring device. Also, according to manufacturer specification, it has a range of 40-100db, with .1 db resolution, accuracy ± 3.5%dB at 94dB, 1kHz sine wave. I have read higher than 100db within 2 feet of my speaker drivers, at the midpoint of the speaker cabinet (which in my case is 29 inches off the floor) on a number of occasions. I've read as low as 33db in the early morning hours when all lights are off (but the meter has a backlight), there is no traffic outside, other residents of the building are asleep, etc.

Hitting 100db is easy (with my system), and I typically can hit that level while listening to the drums portion of Grateful Dead performances. Many of the drums songs (stand alone drums, not drums within another song) can be 10 minutes or so long, and often contain very low (below 40Hz) frequencies which also makes achieving 100db easy. I personally like to "feel" bass, not just "hear" it.

The loudest I've recorded on my meter is 107db, during the Nirvana song Breed (from 10/31/91, live at the paramount DVD). In this case I was intentionally attempting to crank the volume for the sake of "checking" how loud it could go, and with whatever clarity or distortion. I maintained that level for nearly the entire song, listening at different spots in the room and measuring SPL at different spots, in particular further away from the speakers. I'm well aware that as distance from the sound source doubles, one could expect a decrease of 6db. This was essentially what I was reading. My PLP is approximately 7 feet of so from the speakers, and at the PLP I was getting readings that were consistent with a 10 db or reduction from the measurement at the speaker.

I also believe my system is capable of even more sound pressure, however, I'm reluctant to play at levels over 100db for any sustained period for various reasons, none of which have to do with system capabilities or sound quality.

If you take the SPL meter while music is playing moderately loud, say average 90 to 95 dB, and measure the SPL in room corners you will notice they are much higher than the average SPL. Around 6-9 dB higher! And there are many other locations in the room where very high sound pressures can be found. Standing waves, first reflections, etc. at room boundaries and out in the 3D space of the room. Maybe even at the listening position, you never know. It’s like having an addition 8 to 20 speakers in the room playing very loud. Anyone see any problem with that? 🙄

@gdhal 

Awesome. If that is continuous at 107 dB (not just peaks) at the listening position that is indeed very loud - more than anyone would care to listen for more than a short period. Congrats!

If you take the SPL meter while music is playing moderately loud, say average 90 to 95 dB, and measure the SPL in room corners you will notice they are much higher than the average SPL.

Hello Geoffkait. I shall try measuring in the corners at moderate SPL. In my particular case, the way my listening room "opens up", the only corners I could take a measurement at would be the front wall (behind the speakers). And I have bass traps in those corners. I haven’t measured the SPL anywhere behind my speakers. But as I measure from the front, invariably the SPL is reduced the further away from the speakers I go. But its interesting what you are stating, and I shall attempt some corner readings at my next measurement opportunity.

Awesome. If that is continuous at 107 dB (not just peaks) at the listening position that is indeed very loud - more than anyone would care to listen for more than a short period. Congrats!

Hell shadorne. Yes, that SPL is continuous, however, in fairness it should be noted that (a) I have two speakers firing during music playback, so of course I realize that even though I’m in front of one speaker, some sound from the other is effecting the measurements and (b) one thing which my multi meter lacks is a "hold" feature, whereby it would remain at the top most SPL level. I have to watch it, and it does fluctuate. But the 107db I mentioned in my previous example is easily achievable (with the right source music). And by the way, in the case of Nirvana, most of their music when played very loud makes it somewhat difficult to distinguish distortion from Kurt’s normal vocal intentions :)


EDIT:

By the way, somewhat related.... I never realized how convenient it is to have a an amp with a remote control. In my case, even though I primarily listen in the mid 80’s SPL, often is the case that just a minute or so passage of music within a particular song warrants (in my mind anyway) playing louder/lower with respect to the rest of the song. The remote make it rather convenient to raise/lower even by just a few (5?) db within the same song.

Further @shadorne....

BTW 110 dB is more than 8 times louder than 100...so above 95 db SPL (the max for most speakers at the listening position) it gets very hard very quickly to deliver full dynamic range. (110 dB being 32 times louder than 95 dB)

I’m not sure your statement (quoted immediately above) is accurate. I’ve always been of the understanding that +3db is twice the power, +10db is twice the perceived volume.

By inspection open rooms will not support the pressures that a closed room will. For better or worse. 😛