Boom! Thanks Peng!
I am going to conclude that scooting a little closer will definitely take a little heat off my speakers at high volumes. The folks over at Ascend have been a little bit hit and miss to contact lately, with everything going on but they always eventually get back to me. I think I'm gonna shoot Dave an email and ask him ask about max spl at 1 meter, like you suggested I do with Ed for my Ultras.
You know what's interesting, tho maybe not overly surprising? My Monolith runs MUCH cooler powering my 4 ohm Sierra towers than it does my "8 ohm" Ultra towers. It's gets good and warm with the Ultras, but barely more than lukewarm with the Sierras. Even after some some very spirited listening sessions.
In general, when you consider stereo and room gain the volume at the listening position can be surprisingly close to rating at 1 meter (when accurately specified).
Ascends are among the best manufacturers at accurate sensitivity specifications.
Here is recent article on Audio Science Review:
Speaker sensitivity is an important aspect that can sway potential buyers towards or away from a specific model or brand. Thus, it gives an incentive for manufacturers to fudge their numbers; this fudging can be accomplished via the frequency range, weighting, in-room estimates, etc. I decided...
www.audiosciencereview.com
Adding power to speakers that perform will with power (with good distortion characteristics) can lead to listening at higher levels. A small radio can seem too loud because the distortion is makes it unpleasant. That said, I have found I enjoy my Salons for casual listening at less than one watt. Of course, I'd like a near perfect 1'st watt
THX specifications are for a single speaker but this is not representative of any realistic listening session.
To estimate my power usage I used the following procedure.
I played 250Hz, 1kHz, and 2kHz 0 DBFS (maximum volume) sine-wave tones and measured the voltage at the speaker adjusting the processor until it was as close as possible to 2.83 volts. The volume matches the speakers sensitivity rating. While playing the tone, I measured the SPL at my listening position of 11 feet.
The Salon2s are rates are 86 dB at 1 meter. The measured SPL was also 86 dB (with two speakers playing). The Salon2s are basically 4 ohm speakers that doubles to power. For my spreadsheet, this means -31 is 86 dB at 11 feet. From there I computed the attached power levels. Since I know my habits, the left column indicates those levels. Fortunately, the AHB2 amplifiers have accurate and clip meters per channel that illuminate for 1/4 seconds when the amp hits 1% distortion.
With music, they clip as expected with recording that peak at full scale (too many recording are maximized for volume).
Into 4 Ohms, the AHB2s deliver 180 WPC and they are not clipping at -10 so these numbers are conservative.
I also plugged in these numbers into the Crown power calculator: 3.5 meters, 101 dB, 83 dB sensitivity (for 4 ohms) and the required power is 773 watts.
My measurements and calculation show 64 watts stereo or 128 watts for a single speaker.
The Aquaman 4K BD has some formidable bass and I turned it up -15 (which is 3 dB louder than I found comfortable) and there is no clipping and the Salon2 3 8 inch woofers are really moving.
Unfortunately AVR amps are seldom measured as diligently as dedicated power amps and not going into protection is not a good indicator of distortion driving reactive loads.
Those measurements don't really exist. We know a lot about how amps play 1 kHz sine-waves into reactive loads.
- Rich
