Same watts at 8 and 4 ohms?

Story time!!

Absolute Sound:

One of the Ten Most Significant Amplifiers of All Time

Stereophiles John Atkinson: HQD LOUDSPEAKER SYSTEM and ML2’s

I first heard the Mark Levinson HQD loudspeaker system some ten years ago, at the Festival du Son in Paris, in the days when it was a real hi-fi show. Perhaps even more so than by the speakers, however, impressive as they were with their stacked Quads, Decca ribbon tweeters and Hartley 24" woofers, all in beautiful beech woodwork, I was bowled over the amplification used: six Mark Levinson ML-2 monoblock power amplifiers. Capable of just 25W output each, these class-A monsters were the first true high-end amplifiers I had ever heard. The memory of effortless low-frequency reproduction, coupled with a magically liquid midrange, lingered on.

The ML2’s drove these double stacked Quad 57’s with Decca Kelly horn loaded ribbon tweeters from 10khz up, and used 2 x 24" Hartley bass units from I think it was 80hz down.
http://www.kaponk.com/2019/08/15/hqd-loudspeaker-system/

A friend Otto Major (rip) Quad 57 restorer guru. had this very speaker system, except the amp used was my own built 150w Class-A water cooled self contained mammoth of an amp, 2 preferable 3 man lift.
This system, it was something to hear. The Harley’s were mounted in the brick wall behind the Quads and they used the next room!!! as the speaker box. the FS was I think 16hz.

Linn LP12 Black Widow arm with the best cartridge I’ve ever heard a Stax CP-X Electrostatic cartridge.
https://www.vinylengine.com/turntable_forum/gallery/image/11682/source?sid=eefee7d56ce857f513c305e4e...
https://www.vinylengine.com/turntable_forum/gallery/image/11675/medium
That used a tube HT power supply. Here one dismantled for repair.
https://www.vinylengine.com/turntable_forum/gallery/image/15730/medium

https://www.vinylengine.com/turntable_forum/gallery/image/11679


Cheers George

invalid,

Here are some amps (more like welding machines) that can do double the power:

D'agostino Relentless.
Pass labs, almost all their amps.
Boulder 3050 monoblock,

and there are more......

@mt9894, one of my restrictions is that for these speakers to stay in the living room, the stuff driving them needs to be fairly small and discrete.

The H2O is only 14x14x 6-in tall. All black and one small LED in the front, it easily disappers.

If performance to you is most important then it can't be beat. Look at the inside in that 6moons review. You will not find that in any $2K amp and the ability to drive Scintillas.

If size and looks are more important then there's plenty of class-D amps that are simply modules thrown together in a shiny chassis.

You can't have it all.

Cakyol,                                                                                                 those amps are underrated on there 8ohm power specs there isn't any amp that can actually double it's output power, it is impossible. Like Georgehifi says it would be perpetual energy to be able to do that. I have a krell amp that claims that spec but it can't technically do it, it can come close but the lower in resistance the less likely.

I have a krell amp that claims that spec but it can’t technically do it

What a lot are doing is to underquote the 8ohm wattage to make the 4ohm look like it doubled.
  
You see it all the time now in the Stereophile spec bench tests, where the manufacturer says it’s 150w into 8ohms and 300w into 4ohms the gullible see this as doubling. Then Stereophile show the 8ohm is actually is 200w measured and the 4ohm remains still as 300w, nowhere near doubling then. It’s not illegal, but also not honest either.

I’ve been asking Stereophile to "call them out on it" now for ages in the measurements section, but at least they measure and show it for the reader to make up his own conclusions about it. Suppose they have to be careful where there advertising dollars are coming from, and not to rock the boat too much.

Cheers George