So...what constitutes "insane amplification?"

[garyrc]

Thanks guys...

...so, what might require that kind of amplification though besides really inefficient speakers? Is someone really going to notice speakers pushing 600, 700, 1 kW? I'd think your hearing would give out before then.

(You know, besides the 901's.)

 

I only know the 901s, which qualify as "really inefficient."  Looking at both Consumers Reports and Klipsch* data, for the briefest, loudest peaks, 63 watts into a Klipschorn will produce 115 dB (the maximum  SPL called for by both Paul Klipsch and THX for brief peaks in the bass) in a 3,000 cu ft room at normal listening distance.  A Heresy (I) would need 441 watts for just that instant.  The Bose might need a pulse of 1,575 watts.  What size amp can produce that, even for an instant?  Several McIntoshes can. 

 

Bose isn't the only offender.  There are speakers out there that are rated at 85 dB,1 watt,1 Meter.  They could need about 6,000 watts for an instant, in a 3,000 cu. ft. room.

 

Amplifier manufactures often list their "Dynamic Power" as about 2 times rated power.   So, even at the loudest peaks, a Khorn should be O.K. with a really good 32 watt amplifier, a Heresy (I) might need 220 watts, a Bose 901, 788 watt per channel amp, and that 85dB/wt/M speaker a 3,000 watt amp. 

 

The above may explain why the only place I've heard the 901s sound good is at Alphonso's.  He started out with 350 watts per channel, and eventually increased to 1,000 watts per channel.

 

In orchestral music, 115 dB peaks for a few milleseconds are commonplace.  They are so brief, they shouldn't make your hearing give out.  Sustained levels at that SPL, as in some Rock/Metal can damage hearing.

 

* Dope from Hope, V. 16, No. 1, January 1977

Edited January 14, 2016 by garyrc

[Woofers and Tweeters]

 

 

Sustained levels at that SPL, as in some Rock/Metal can damage hearing.

 

huh...what did you say?

Edited January 14, 2016 by jweber

[twistedcrankcammer]

Thanks guys...

...so, what might require that kind of amplification though besides really inefficient speakers? Is someone really going to notice speakers pushing 600, 700, 1 kW? I'd think your hearing would give out before then.

(You know, besides the 901's.)

 

 

not at all dude!

 

every 3 dB is twice as much power, or twice as much sound. The thing that you need to remember is how inefficient the Human ear is as although 3dB is twice the sound pressure, it takes 10 dB for we humans to perceive it as being twice as loud.

 

Now take a speaker comparison of Quartets', which are still efficient at 97.5 dB efficient at 1 watt at one meter. and new Klipschorns that are rated at 105 dB at 1 watt at 1 meter.

 

So if we double the input to the Quartet, at 2 watts, the smaller speaker is putting out 100.5 dB at 1 meter. Double the power again and at 4 watts, the Quartet is pushing 103.5 dB, if you doubled power again, at 8 watts, the quartet would be making 106.5 dB, so it actually takes about 6 times the power to achieve the same output. Think that if the Quartets could handle the power, you would be talking 600 watts to the Quartets to equal 100 watts to the Klipschorns. Now think about some of the really inefficient designs out there and it is easy to eat up a lot of juice.

 

Member J.C. has a pair of 1,000 watt McIntosh Mono Blocks and used to have a hi end pair of McIntosh speakers.

 

Roger

[The History Kid]

Alright, bring me home Roger and Gary -

So when power ratings are presented on speakers as continuous, is this supposed to be the amount of power the speakers can draw before they blow out? How might you determine where the speakers would begin to clip then? I know that even though speakers can be rated at 150 watts, they may clip substantially lower than that.

[twistedcrankcammer]

Very, very easy to hit more than 1,000 watts per channel real quick with a sub!

 

Roger

[twistedcrankcammer]

Alright, bring me home Roger and Gary -

So when power ratings are presented on speakers as continuous, is this supposed to be the amount of power the speakers can draw before they blow out? How might you determine where the speakers would begin to clip then? I know that even though speakers can be rated at 150 watts, they may clip substantially lower than that.

 

 

Clipping can be the speaker or the Amp. A speakers RMS wattage rating is the rating it can take of a sustained constant power over a certain amount of time, without blowing the voice coil.

 

It is pretty easy to exceed the RMS rating with a good clean amp, but running on this edge can quickly run you into problems with the way the source is mixed. You have heard it many times, one CD just sounds louder because of the way it is mixed. Run on this edge, and that CD comes on next and the magic smoke comes out

 

Roger

[ZEUS121996]

I've clipped a couple receivers out but the Klipsch took all of it and laughed

 

Mark

[The History Kid]

I guess 1kW just seems unfathomable because of what I've had then. My 120 WPC power amp is the most power I've ever had. I just personally can't wrap my own head around it on actual application. I understand the math you showed, and I understand the mechanics therein. It just seems like overkill.

Then again, I guess if I'm not toying with pro audio or speakers that work on all levels of the field, I shouldn't really need to worry, right?

[ZEUS121996]

Riiiiiiiiiiiiiiiiiiiight

LOL

 

Mark

[The History Kid]

Riiiiiiiiiiiiiiiiiiiight

LOL

 

Mark

Shut up Mark, we all know that I'll probably go the way of mono blocks eventually, just let me bask in a temporary state of staleness.

[derrickdj1]

I can vouch for the Yamaha M 80.  The best of both worlds for a SS amp.  Class for the first 20 watts and Class A/B from 20 watts up to 250 watts at 8 ohms and 400 watts at 4 ohms.  I guess that is why some people call them Legendary amps.

[wvu80]

I only know the 901s, which qualify as "really inefficient." Looking at both Consumers Reports and Klipsch* data, for the briefest, loudest peaks, 63 watts into a Klipschorn will produce 115 dB (the maximum SPL called for by both Paul Klipsch and THX for brief peaks in the bass) in a 3,000 cu ft room at normal listening distance. A Heresy (I) would need 441 watts for just that instant. The Bose might need a pulse of 1,575 watts. What size amp can produce that, even for an instant? Several McIntoshes can.

(respectful snip!, just wanted to reference the post)

 

Thanks for taking the time to write that.  It was very interesting and helps in my audio understanding.

+++

 

You too, Roger.  ^^^  Good post #24.

 

You guys 'splain very well. 

Edited January 14, 2016 by wvu80

[garyrc]

Alright, bring me home Roger and Gary -

So when power ratings are presented on speakers as continuous, is this supposed to be the amount of power the speakers can draw before they blow out? How might you determine where the speakers would begin to clip then? I know that even though speakers can be rated at 150 watts, they may clip substantially lower than that.

 

Paul W. Klipsch was once asked what power ratings meant.  In true PWK fashion, he answered. "probably not much."

 

I think the power rating is determined by running the woofer continuously for a fixed period of time at ever increasing SPL levels, until it fails.  The level at which it fails, or a little lower (formula?) is the power handling rating.  The tweeters and midranges are not used for the overall power rating because, in the types of music that audiophiles used to listen to most often (orchestral), the mid/treble content was much less ... and ... tweeters were easy to blow with a continuous signal.  In orchestral music, the signal in the treble range can be as much as 20 dB (100 times) lower in SPL than the midrange and bass.  The brief peak handling capacity can be from about 2 to 5 times the power in watts as the continuous. 

 

The primary reason I would never run speakers at their rated power is related to what twistedcrankcammer said -- it's too easy to come across a sudden loud passage, or to put on a CD that is much louder, without first readjusting the volume.

 

So, my "100 watt rated, 400 watt peak" Klipschorns are never run at much over 2 watts average (Loud!), with 60 - 70 watts (big room) for those very, very brief 115 dB peaks.  I once had a peak reading meter in line, and hit 25 watts with the finale of a Mahler symphony.  It was about 110 dB for those peaks.  It scared the sh*t out of me, so I backed it off.  Still wasn't particularly distorted, though.

 

[totalcomfort]

Insane is when I can't fit it thru my door or don't have anything that will move it!! It's like owning a vette, you can't use all the power on the roads without going to jail, but it's great to have

[The History Kid]

Gary and Roger - thanks for the descriptive replies. Makes sense a bit more now.

[tube fanatic]

The only speaker which I have ever encountered which truly needed insane high power amplification was the Apogee Scintilla.  Unquestionably, it's the most inefficient speaker I've ever had experience with, and its 1 ohm impedance (yes, you read that correctly) made such demands on amps that few could drive them adequately.  Basically, you needed an "arc welder!!!"  That said, it was an amazing sounding speaker if one was willing to deal with its needs!  What a contrast between those and K-horns!

Maynard

[ClaudeJ1]

Clipping can be the speaker or the Amp

 

 

Clipping is squaring a sine wave when it hits the supply rail voltage. A speaker cannot "clip" by definition and can only thermally compress sound output until it goes silent. IF the amp is clipping in the process, the speaker only goes to DC for as long as the clipping in the amp lasts.

[mark1101]

The system in my avatar is using 5 amplifiers totals 3200 watts (1600 wpc).  Doesn't really go that loud the way I have it setup.

[The History Kid]

Unquestionably, it's the most inefficient speaker I've ever had experience with, and its 1 ohm impedance

How many amplifiers on the market are set to handle loads down to 1 ohm? Seems like a difficult beast to handle.

The system in my avatar is using 5 amplifiers totals 3200 watts (1600 wpc).  Doesn't really go that loud the way I have it setup.

MCM's right? Tri/Quad-amped I'm guessing?

[Fjd]

 

http://quadcities.craigslist.org/ele/5397642295.html

... it's the third or fourth time I've seen Bose amplifiers praised with the phrase "insane amplification." What exactly is it about these amplifiers that some people seem to love so much, and are they typical Bose gear or something more?

 

 

It is a beast of an amp size wise and power.  It can peak 800 watts combined for 2 ch.

 

Some Bose speakers, like the 901, NEED that kind of power to sound halfway good.  The smallest amp I heard back in the day that made the 901s sound good was a Phase Linear 700 (350 w.p.c.).  They sounded a bit better with a McIntosh 1,000 watt amplifier. 

 

 

 

 

I have a post somewhere on the forum adding to Eric2A3's experiences with 901 speakers where I was helping a friend with a 901 speaker implementation and the 901 setup sure liked an inordinate amount of power to sound good.  Here is a little amp porn showing the internals of an old BOSE 1801 amplifier.

 

 

 

 

 

 

 

 

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Edited January 17, 2016 by Fjd