Output measurement vs peak output volts * peak output current

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jaylevine

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This may be a totally invalid question but I’m trying to reconcile some specifications I reviewed today.

I was looking at the spec for my class-d amp to try to determine if my amp is a good candidate for driving a new set of Maggie’s I have on order (brand shall remain nameless to keep this academic).

I’ve always understood that generally Maggie’s require a lot of power, more specifically high current (vs outputting high voltage at low to moderate levels of amps).

Anyhow, my amp claims to output 400 Watts into 8 ohms and 800 watts into 4ohms. However the spec also states peak voltage output of 80volts and peak current output of 21 amps.

Isn’t volts x amps = Watts?

What am I missing?

Thanks

FullRangeMan

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This may be a totally invalid question but I’m trying to reconcile some specifications I reviewed today.

I was looking at the spec for my class-d amp to try to determine if my amp is a good candidate for driving a new set of Maggie’s I have on order (brand shall remain nameless to keep this academic).

I’ve always understood that generally Maggie’s require a lot of power, more specifically high current (vs outputting high voltage at low to moderate levels of amps).

Anyhow, my amp claims to output 400 Watts into 8 ohms and 800 watts into 4ohms. However the spec also states peak voltage output of 80volts and peak current output of 21 amps.

Isn’t volts x amps = Watts?

What am I missing?

Thanks
Isn’t volts x amps = Watts? Correct.
80x21=1680W peak
400W should be RMS or AES.

JLM

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Correct, volts x amps = watts.

Before class D, old school thinking said you needed "beefy" power supplies (plenty of reserve) to provide a commanding grip on difficult to drive speakers, like Maggies.  In general speakers are current loads (they respond more to the current provided than the voltage) yet most amps are "voltage sources".

Why not just ask the factory what they recommend?  Who should know better?  And if they give you an answer you don't like, maybe you should move on to a different brand of speakers.

jaylevine

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Correct, volts x amps = watts.

Before class D, old school thinking said you needed "beefy" power supplies (plenty of reserve) to provide a commanding grip on difficult to drive speakers, like Maggies.  In general speakers are current loads (they respond more to the current provided than the voltage) yet most amps are "voltage sources".

Why not just ask the factory what they recommend?  Who should know better?  And if they give you an answer you don't like, maybe you should move on to a different brand of speakers.

I've got no beef with the brand, of either the speakers (Magnepan) or the amp (D-Sonic). I was just trying to fill in the gap of my understanding. FullRangeMan's answer, and a quick Google of RMS vs Peak, did that for me.

Thanks

Letitroll98

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Maggie's are actually pretty easy loads for amps able to deliver current into 4 ohms.  They are fairly non reactive and stay above 4 ohms throughout their range.  I'm interested in hearing about a class D amp that doubles it's power into 4 ohms, usually they're about the same regardless of load.

jaylevine

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Maggie's are actually pretty easy loads for amps able to deliver current into 4 ohms.  They are fairly non reactive and stay above 4 ohms throughout their range.  I'm interested in hearing about a class D amp that doubles it's power into 4 ohms, usually they're about the same regardless of load.

I'll report back once I get the .7s (expecting them by end of next week).

I'll be hooking them up to my D-Sonic (rated at 800 watts into 4 ohms see https://www.d-sonic.com/products/m3a-800s-stereo-amplifier.html), followed by my Bob Latino VTA 120 (Bob doesn't publish full specs but I think it is rated at 60 watts in ultra-linear mode).

Jay

Elizabeth

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Why not just ask the factory what they recommend?  Who should know better?  And if they give you an answer you don't like, maybe you should move on to a different brand of speakers.
It is unusual to seek a speaker to match an amplifier. usually folks find the speaker they like, and match the amp to the speaker. (when I wanted Magnepans, I did a bunch of searching for what amps folks like with them. My answer was Bryston. But I do see a number of folks using ClassD.
One thread: https://forum.audiogon.com/discussions/best-cheap-amps-for-magneplanar-speakers
One less about Class d but interesting anyway: http://audiokarma.org/forums/index.php?threads/magnepan-and-amp-requirements.512611/