FWIW, I’ve never measured a tube amp output voltage into a loudspeaker that was anywhere close to what an SS amp delivered into the same load... going back to the 70’s. Admittedly, it’s a small sample, and largely irrelevant as measurements mostly don’t mean diddly. 😎
if the voltage is within, say 10%, then the SPL will be also be very close.
Yes it is.
It’s not that the distortion signature is too small, it’s that no one measures it.
BS - it is measured ad naseum, and produces nausea in people that do not understand it.
No SPL meter is going to be better than ±0.1db @ 85dB. It likely has a nonlinear response. In absolute terms, it’s not even close.
BS - most people probably max out at 0.5 to 1 dB difference.
So getting the two systems within a fraction of a dB is a great start to a controlled listening test.
And I further disagree as I have the NIOSH app on my iPad as many low distortion speakers do not sound like they have a lot of SPL happening.
Then when I turn to someone in the room, we have to shout to hear each other… and when I look at the app says 90dB or more.
However on my wife’s old system it sounds loud at 65dB.
On my old system at about 95dB.
And on some state of the art systems mote like 100+ dB before it “SOUNDS” loud.
Back in the 80’s Bob Carver tweaked an amp to sound exactly like another: The Carver Challenge | Stereophile.com
FWIW, we gave up on matched level listening tests in the 70’s simply because it’s about as worthless reading the spec sheet. An amplifier is but one component in a system. Change one thing, change everything. I think it’s stood me in good stead when a guitarist says "Joe Pass is sitting RIGHT THERE!"
I trust Bob Carver about as much as a preacher.
- He had some good designs, back in the day, but he’s prone to hyperbole and wild eyed ranting.
- Some of his current designs do not meet specs and appear to be dangerous to safely use.
Other the other hand I have heard only good things about Ralph, and his writing indicates that he is learned in the subject and is rationally presented.
Lastly the use of the word “Synergy” has a magical tone to it, that to me is sort of like a synergy of faults summing to zero.
(IMO) It is easier to build systems were output impedances are low, input impedances are high, the FR and PR is flat… than spicing up bright and warm gear like a sweet-n-sour pork where things are starting out in major conflict.