Fantastic new audio amp !
in [Design]
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From: ChrisQ on 23 Nov 2009 16:39 Jim Thompson wrote: > On Mon, 23 Nov 2009 09:25:10 -0600, Vladimir Vassilevsky > <nospam(a)nowhere.com> wrote: > >> >> Jim Thompson wrote: >> >> >>> I was always fond of touting my amplifier as 400W CONTINUOUS RMS, as >>> opposed to those nutcases who spout "music power" or "peak power" ;-) >> Agreed. The real power, not bullshit power, tells a lot about the >> design. However, there is one more parameter: for how long the amp can >> sustain that power level undistorted. >> >> >> Vladimir Vassilevsky >> DSP and Mixed Signal Design Consultant >> http://www.abvolt.com > > In my case "CONTINUOUS" meant exactly that ;-) > > ...Jim Thompson Right, not '1 minute duty' like you see on some motors, but continuous, 24/7 if required and stay within spec :-)... Regards, Chris
From: ChrisQ on 23 Nov 2009 16:43 krw wrote: > > No it isn't. RMS is valid for voltage and current because the square > is useful for calculating power. Umm, isn't that what we are trying to measure ?. > The square, thus the root of the > mean square, of power is meaningless. "Average" power says it all, > regardless of waveform. Any other sort of power is bogus. Why do you think all pro audio gear is specified in terms of rms power output ?... Regards, Chris
From: Spehro Pefhany on 23 Nov 2009 17:08 On Mon, 23 Nov 2009 08:28:42 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: >On Mon, 23 Nov 2009 09:25:10 -0600, Vladimir Vassilevsky ><nospam(a)nowhere.com> wrote: > >> >> >>Jim Thompson wrote: >> >> >>> I was always fond of touting my amplifier as 400W CONTINUOUS RMS, as >>> opposed to those nutcases who spout "music power" or "peak power" ;-) >> >>Agreed. The real power, not bullshit power, tells a lot about the >>design. However, there is one more parameter: for how long the amp can >>sustain that power level undistorted. >> >> >>Vladimir Vassilevsky >>DSP and Mixed Signal Design Consultant >>http://www.abvolt.com > >In my case "CONTINUOUS" meant exactly that ;-) > > ...Jim Thompson Notwithstanding the PMPO type of lies, I have seen serious audio work (new patents and technology etc.) being done to maximize the music or vocal performance from a fixed amount of power input.
From: krw on 23 Nov 2009 17:03 On Mon, 23 Nov 2009 21:43:54 +0000, ChrisQ <meru(a)devnull.com> wrote: >krw wrote: > >> >> No it isn't. RMS is valid for voltage and current because the square >> is useful for calculating power. > >Umm, isn't that what we are trying to measure ?. No, you said that you were measuring power. >> The square, thus the root of the >> mean square, of power is meaningless. "Average" power says it all, >> regardless of waveform. Any other sort of power is bogus. > >Why do you think all pro audio gear is specified in terms of rms power >output ?... The same reason that Monster Cables are so popular; audiophoolery.
From: christofire on 23 Nov 2009 17:57
"ChrisQ" <meru(a)devnull.com> wrote in message news:umDOm.96781$_o.57460(a)newsfe22.ams2... > krw wrote: > >> >> No it isn't. RMS is valid for voltage and current because the square >> is useful for calculating power. > > Umm, isn't that what we are trying to measure ?. > >> The square, thus the root of the >> mean square, of power is meaningless. "Average" power says it all, >> regardless of waveform. Any other sort of power is bogus. > > Why do you think all pro audio gear is specified in terms of rms power > output ?... > > Regards, > > Chris It isn't! A popular manufacturer of professional audio power amplifiers is QSC and, for example, the specifications of their CX-series of PA amps (http://www.qscaudio.com/products/amps/cx/cx2/cx2.htm) give the output powers in W ... not W RMS, just watts. However, they do use RMS, correctly, in their specification of input signal _voltages_ (sensitivity and clipping threshold). Chris(tofire) |