How many watts?

[Macca]

Aleph 5, not Alpha 5. The Aleph 5 is a Nelson Pass design..

Doh, I need to learn to read more carefully.

You know NP likes to tailor his sound?

[Qwin]

There are many factors to consider, not just watts.
My 3 way system is bi amped.
I use a 12w valve amp into the 8ohm mids/twt, both 93dB sensitivity.
The bass driver is 4ohm and 89dB sensitive, I use a 4ohm/700w class D to power this.
I can take this to ear bleeding levels and the 12w keeps up for mid/twt, I can't hear it, but if it is clipping it is the typical valve situation of gradual less obvious clipping, until you reach the extremes.
When balancing the levels of mid/twt to bass, I have to attenuate the 12w valve amp, as its output is too loud. This is due to a combination of driver sensitivity and the gain of the respective amps. The valve amp has relatively high gain and typically class D are lower gain. Gain is the multiplying factor of the Amp.
I also use a Linkwitz Transform circuit on the bass at line level, it gives a 10dB boost at 20Hz giving my sealed box 12" driver a flat response to 21Hz and an f3 of around 18Hz, so a Sub is not needed here.
With a LT circuit, for every 3dB in boost, you double the watts required at that frequency, so x2x2x2 would be appropriate for a 9dB boost. The headroom on my class D comes into play here.
Your source output level is part of your total gain chain, is it a line level signal like a phono stage, or a hot output from a modern DAC. The power amp is a multiplier so what goes in, dictates what comes out. Its sensitivity comes into play here.
For good bass at high SPL you need plenty of watts and current on hand.
The upper frequencies are far less demanding.
So driver sensitivity, amp gain, source signal strength, room size and your take on what an acceptable SPL is, are all part of the equation.

[Filterlab]

Doh, I need to learn to read more carefully.

You know NP likes to tailor his sound?

I do. I have one to listen to in my system available, so I'll do that before committing to a purchase. I'm not in a hurry, plus Edward's Neurochrome 686 is on its way to me in the meantime for a week or so for a bit of a listen.

[Macca]

Will await your write-up with interest.

[Filterlab]

Me too.

[cooky]

Sound pressure level (SPL) falls off as the inverse square of the distance. So compared with that at 1m (as quoted in your speaker sensitivity of 95dB/W), listening at double that distance of 2m will reduce the SPL by a factor of 4, or 6dB, to 89dB/W. Thus trebling the distance to 3m will reduce the SPL by a factor of 9, or 14dB, to 81dB/W.

Your amp can produce 60W/channel (or 17.8dBW), so the maximum SPL from each speaker will be 81 +17.8 = 98.8dB, and since there are two speakers an SPL of 101.8dB in total.

102dB (above the threshold of hearing) is classed as very loud (https://audiology-web.s3.amazonaws.c...5.32730330.pdf) and if maintained at that level (assuming the amplifier doesn't overheat) would cause some hearing loss after about 10 minutes.

Or to put it another way - you have plenty of power for your needs, provided you don't listen to continuous sine waves at a high level for long periods of time.

Slight calculation error above: 95dB@1=89dB@2m=83dB@4m= 85.6dB@3m so max from a pair is 85.6+17.8+3=106.4dB. Even more reasons to look after your hearing.

[Audioflyer]

I found this interesting on YouTube.

https://www.youtube.com/watch?v=vaiEDYB5c9M

[Macca]

I found this interesting on YouTube.

https://www.youtube.com/watch?v=vaiEDYB5c9M

As someone says in the comments I'd like to see him try that again with an amp that has a maximum output of 1 watt.

If I am using amps with level meters (and with more slightly more efficient speakers in a smaller room than his), it is true that most of the time less than a watt is being used. But you can see on the meters that occasionally 40 watts and more are used on peaks. Knock the sensitivity down 3dB and that would be 80-plus watts on peaks.

I worked out long ago I need at least a 50 watt amp to get the levels I like without clipping. And I don't listen at high volumes.

[Pigmy Pony]

Like a car with a big powerful engine, you don't need to drives at ten tenths to feel the benefit

[Macca]

Like a car with a big powerful engine, you don't need to drives at ten tenths to feel the benefit

“The pace of the Megane is too leisurely to be called quick. Uphill runs become power sappingly mundane whilst overtaking National Express coaches becomes a long, drawn-out affair. Not my words, Carol, those are the words of Top Gear Magazine.”