On Tue, 10 Feb 2004 09:31:46 -0500, "Arny Krueger"
wrote:

"Joseph Oberlander" wrote in message
hlink.net

Arny Krueger wrote:


"Matt Zach" wrote in message


I am looking at my first tube amp. It delivers 40 wpc class A. I own
an inefficient pair of A/D/S 810 speakers.
Will I have problems with this amp driving these speakers ?

I can tell you that ADS 810s aren't 100 dB/watt speakers.

Gheez - how deaf are you? I only listen to music that is
maybe 70-80db and has maybe twice that volume in peaks
at most and it fills the house for everything other than
a party.

Ever been to a live performance of the kind of music you like? Ever measured
the actual sound levels?

I've done that for classical music, jazz, chamber music, country, pop, etc.
In the good seats SPL often show metered peaks (short transients are not
reflected) of 95-105 dB.

Rock concerts? Let's not even go there (at least without ear protection!).

100db/watt speakers? That's about what movie speakers are - huge 100db+
efficient JBL arrays.

True in the days of tubes. Believe it or not, some older theaters use some
of the same speakers now that they used back then, only with updated
electronics.

Far smaller speakers that are commonly available can have close to 100 dB/w
sensitivity. Check out your typical stage monitors or the speakers used for
SR. They generally run 96 dB/w and up with some exceptions like Bose.
They're not exactly huge or vastly expensive. However, the laws of physics
must be honored so they are either rather large or have less efficiency or
have limited bass or some of the above.

In new movie theaters there has been this recent tendency to use of smaller,
lower-efficiency speakers with racks of big power amps. I doubt that we'll
ever see much new construction with big bins of 18" drivers like we had in
the "Earthquake" days. Today: long-stroke drivers, small boxes, equalization
and big power amps.

Louder than hell in these huge rooms bigger than my whole house.

The ear is very level-sensitive. If you want a better approximation of the
sound quality of live music, you have no choice but to roughly duplicate
live music SPLs.

Nobody sane *needs* more than 110db, even for peaks unless their hearing
is shot.

The OSHA zero tolerance point is 115 dB, A-weighted. I very much support not
exceeding OSHA recommendations when listening to music.

My largest personal system can do about 110 dB as measured with a SPL meter
without *any* clipping. The system manual gain control on the surround
processor is set with a small marker at the "unconditional no clipping"
point. My system is smaller and less capable than those belonging to several
of my friends. I have a close friend whose system can easily do 120 dB
without clipping or strain. Parts of it will probably hit 130 dB, but
full-range 15 Hz-20 KHz its max is more like 120 dB. It's big and expensive
but at "live concert" SPLs, it's just cruising.

Poor Arnold, now that he's painted himself in a box that he would
normally not have constructed, he's desperately spinning like a
dreidel at Chanakkah. He's now comparing stage monitors to home
speakers, he's bragging about doing 110 dB wow Arnold, *that's*
ammmmazing Now he supports not exceeding 115 dB but previously, not
being able to hit 118 dBs was the mark of poor performance.

Then of course, there's the denial that acoustic suspension speakers
don't address the design of the speaker - that it's just a "marketing
term". I'm sure that even Tom Nousaine could describe the basic design
principle behind such a speaker described as 'acoustic suspension" and
even he would acknowledge that this speaker is inherently less
efficient than some other designs, espcially the kind of designs that
JBL routinely uses - you know, the dreaded marketing term "bass
reflex".

Oh yeah, I currently have absolutely *no* problem hitting 120 dB with
only a 90 wpc SS amp. Of course, I only like to do that for testing
purposes with earplugs. Normally, I'm like most people, I usually
stick with peaks about 98 - 100 dBs for normal loud listening. And
that's on the rare occasion. Normally, peaks for me are below 90 dB.

Previously, with a speaker rated at 88 dB/watt/12 feet, I could fill a
24 by 22 foot space *easily* with two Dynaco MK3s. Could I hit 110 dBs
peaks? I don't know, since I never measured it. Needless to say, I
could play them as loud as I wished without audible clipping. And I'm
guessing that it would be at least 98 - 100 dBs.