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Watt rating of audio equipment

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Tim Koene

Fri Mar 03 2006, 05:58PM

Registered Member #37 Joined: Sun Feb 05 2006, 05:35PM
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Posts: 13

I have heard horn loudspeakers which are 97db/1W/1M efficient coupled to a Sonic Impact T amp. With a few penlites as the PSU it could make cups rattle on the table. Usually speakers are horribly inefficient so most of the energy is turned into heat. 2W of pure acoustic air motion is really a lot!

HV Enthusiast

Fri Mar 03 2006, 06:07PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
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Posts: 3068

wrote ...

Yea, but surely it can only do that for like 5 seconds before it explodes?

Not with an Orion HCCA amplifier. These will run continously at 1/2 ohm loads - they are designed for that. Of course, you pay for that too!

Nik

Fri Mar 03 2006, 07:14PM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

My JVC R-2X receiver lists as putting out 40w RMS per channel, I have 2 35w and 2 70w speakers on it. At 20% volume it is deaphaning and the "output level" meter on it sais its putting out 75-80%. I dont trust the meter but I do trust my ears. Why is it that at 30% I will mostlikely blow out the 70w speakers (it is their RMS value)?

HV Enthusiast

Fri Mar 03 2006, 07:20PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
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It probably depends on the input signal to your receiver. If the signal was very low, then you might need to crank the gain up of the amps using the volume control, and might need to turn that knob to say 50% to get 40W output. However, with a higher level input signal, you might only need to crank the gain up where the knob is at 20% physical position to get 40W output.

Also, its not the power that will kill your speakers here, its the distortion (ie. clipping) that does the damage . . .

Nik

Fri Mar 03 2006, 08:21PM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

There is very little distortion even at the loudest but I forgot completely about the input power beigna factor, I'll mess around with that for a while. Thanks.

HV Enthusiast

Fri Mar 03 2006, 09:06PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
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If your stereo is deafening loud, i doubt you'd be able to detect distortion.

ragnar

Fri Mar 03 2006, 09:17PM

Registered Member #63 Joined: Thu Feb 09 2006, 06:18AM
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I've got an 18-year-old Meyer system here - 1600WRMS.

The amplifier is a three-rack 19" mount with a big tunnel heatsink, difficult to lift with only one person :)

As for the speakers, each channel drives an 18" woofer in one box, and a 15" midrange and 2" horn tweeter in another box.

Four boxes on the room make for spectacular neighbourhood-rattling clarity. And the "sense" lights aren't even on yet. =)

They don't build 'em like they used to, hehehe

Wolfram

Fri Mar 03 2006, 09:28PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

Recommended reading, very funny.

Part Scavenger

Sun Mar 05 2006, 02:11AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

I think the worst thing is these computer speakers that produce "2000W PMPO" from a 10 watt wall-wart power unit. They probably wouldn't make 2000W if you fired them from a railgun at Mach 9.

LOL! That kills!

Geez, you leave for a day, and your thread fills up without you.

The one we picked is a 600W Sony 5.1 reciever, and when a Star Destroyer flies overhead, it's pretty darn impressive!
And yeah, about the "50W per channel" on my stereo." It's PLENTY loud 1/4 way up, but it's has that "cool power" or no distortion at just loud enough. I knew something was up with audio ratings, I have an 100W (from the seventies) ampilifier that you can hear through 3 walls of concrete (one of them solid) and 40ft turned a tad more than halfway up, and then we turn the 1000W amp to max up in Best Buy and nobody pays attention. Something screwy there. Thanks for all the replies!

Tesladownunder

Sun Mar 05 2006, 04:13AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Around 360 MW PPPPMO. From Exploding stuff (post 89)

"The first shot was disappointing as all the current sparked across the 2mm between closest points of the terminals and the speaker cone barely moved. Peak current was 80kA with 70% reversal so voltage at peak current probably dropped 15% from 4.5kV. This is a peak power of 360MW during the first 30uS half-wave.

I tried the other speaker with separated electrodes but this time my cameraman, video grip and CRO technicians were in the pool so no current measurements of PMPO (peak music power output) but likely less than 360MW. This time the cone got blown up in the air and was caught on video nicely. Shame I can't show WMV files here."

Don't forget I had cut the surrounds from the cone and the voice coil to do this... Actually it wasn't really that impressive - just like the manufacturers claims.

Peter

1141531984 10 FT2977 Pulsecapspk2raftercone

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