Well, I had my beer. Here goes: At least 300W into 8 Ohms and about 550 into 4 Ohms. Oh, and if you using those high sensitivity 93dB/W squakers, get rid of them.
;-0
Just Kidding.
Must be related to speaker efficiency and room size. My 90W Marantz can drive my '702's to uncomfortably loud levels (according to the neighbours) but it sounds no where near as good as my 300W self buid amp.
Maybe 50W is a reasonable compromise!
;-0
Just Kidding.
Must be related to speaker efficiency and room size. My 90W Marantz can drive my '702's to uncomfortably loud levels (according to the neighbours) but it sounds no where near as good as my 300W self buid amp.
Maybe 50W is a reasonable compromise!
Hello Bob,
Very interesting read (Workshop 5). For speakers of 83db/1m I guess 250 watt peaks is not unreasonable. I have some old Celestions that I use for initial design and testing rated at 82db/1m and you really notice the hit that sensitivity takes on achievable SPL's. Another reply mentioned 'scoping across the speakers... something I've done many times when testing, and found that around 40 to 45 volts peak (80 to 90pk/pk) would be way over any "normally loud" listening session, and that's on the Celestions. So that puts the amp around the 100w rms level... and tbh I would never want to listen at those levels. Switch to the B&W703's at 90 db and it's just overkill.
So the figures I think agree quite well with your findings. I find a good system is a joy to listen to, one where the dynamics seem to come across well... one that make the hairs on your neck stand up.
The listening room etc of course has a huge impact too. A lightly furnished room of modest dimensions will not soak up the sound in the same way as an hotel room full of people.
Thanks
"I may be on the lowest side for the loudness."
I don't think so, for one thing you say it's in a lively room.
For what I consider "normal" listening that figure sounds about right.
I think music has a "correct" or "natural" level it should be replayed at in a given room... it's a level where the timbre of instruments sounds correct together with a sense of the scale and dynamic of the original work.
Good systems seem to be able to routinely achieve this I find... and on a wide range of material.
So many posts since last night... going to take me a while to read all this.
It's been mentioned a couple of time that using a CD recorded at 0db may not be a true indication of maximum levels in practice.
At a simple level I regard the 0-65536 (16 bit) as an "absolute" If a player outputs (say) 2volts RMS for 0db, then my understanding is that corresponds to "level" 65536 ? The DAC can not produce any more than that... anything over that and it's a non valid number.
That's the basis of my very simple experiment. That a 0db test disc sets a maximum possible level that no transient could exceed.
Bob Cordell mentions a couple of specific recordings of large dynamic range, yet even here the "peaks" (to my understanding) do not exceed that absolute DAC output level that a 0db test tone would give. If anything has been clipped, then it's already been done at the mastering stage.
Is my thinking corect there ?
Now recordings like Bob mentions can and do sound very impressive on a good system... what you are noticing is the very large dynamic range. Those peaks though, must fall within the 0db maximum output level that the CD system can reproduce.
It's been mentioned a couple of time that using a CD recorded at 0db may not be a true indication of maximum levels in practice.
At a simple level I regard the 0-65536 (16 bit) as an "absolute" If a player outputs (say) 2volts RMS for 0db, then my understanding is that corresponds to "level" 65536 ? The DAC can not produce any more than that... anything over that and it's a non valid number.
That's the basis of my very simple experiment. That a 0db test disc sets a maximum possible level that no transient could exceed.
Bob Cordell mentions a couple of specific recordings of large dynamic range, yet even here the "peaks" (to my understanding) do not exceed that absolute DAC output level that a 0db test tone would give. If anything has been clipped, then it's already been done at the mastering stage.
Is my thinking corect there ?
Now recordings like Bob mentions can and do sound very impressive on a good system... what you are noticing is the very large dynamic range. Those peaks though, must fall within the 0db maximum output level that the CD system can reproduce.
Excuse me for my naiveness, but I see it quite simply:
If a 150+150W amplifier sounds better, at normal home listening levels, than a 10+10W amp, as it often happens, it's not for the headroom, it's just because the powerful amp has a hefty, heavy power supply, and the DC voltage does not sag.
Have you ever noticed how powerful do tube radios with single class A output stages seem ?
Marco
If a 150+150W amplifier sounds better, at normal home listening levels, than a 10+10W amp, as it often happens, it's not for the headroom, it's just because the powerful amp has a hefty, heavy power supply, and the DC voltage does not sag.
Have you ever noticed how powerful do tube radios with single class A output stages seem ?
Marco
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that makes a lot of sense.
If the amps are not clipping and/or limiting then changing the amp power upwards should not make any difference to the sound at the same SPL.
Mooly,
I think you have set your target too low at 105dB peak SPL @ 1m.
You have used a normally recorded CD that has probably been very compressed to make use of all the bits, all the time. This style of recording music results in a very low peak to average range.
Your experiment utilises this low peak to average range and omits to include for the normally recorded dynamics of uncompressed music/audio.
If you adopt ~110dB @ listening distance (usually 2.4m to 3m) then that target will require much more output from the speakers. Get this by using higher efficiency speakers (big and expensive) or using more amplifier power (much cheaper that results in higher distortion from the heavily driven drivers).
The problem with doing it the loud way and using high power and/or high efficiency is that the noise floor becomes noticeable. This is the big challenge that needs to be overcome in designing good audio systems. This may well be the reason that CDs and MP3s are recorded up to the max., to avoid the noise floor and all the crossover distortions etc. that exist down there.
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It's horses for courses really....
I recall listening to some Celestion SL6 speakers of around 82dB/W being driven by a 50WPC rms amp in a small bedroom. The amp was audibly clipping on peaks and yet it was not difficult to have a conversation in the room!
On the other hand the speakers I use at the moment (KEF Reference 105/3 mk4) are 92dB/W and I can get all the level I need from a 15WPC class A amp.
I would agree that in cases of things like large Maggies in a large well furnished room you may well really need several hundred watts.
It never ceases to amaze me how many less technical hi-fi freaks are using 100W + amps with speakers of 88dB/W or more, in a small room and with neighbors that won't stand for it...... and yet believe that they really need all that power.... and that maybe they should upgrade to something bigger!
When I explain that they have probably never peaked beyond 30W and are averaging 0.5W, I get some very funny looks!!
I recall listening to some Celestion SL6 speakers of around 82dB/W being driven by a 50WPC rms amp in a small bedroom. The amp was audibly clipping on peaks and yet it was not difficult to have a conversation in the room!
On the other hand the speakers I use at the moment (KEF Reference 105/3 mk4) are 92dB/W and I can get all the level I need from a 15WPC class A amp.
I would agree that in cases of things like large Maggies in a large well furnished room you may well really need several hundred watts.
It never ceases to amaze me how many less technical hi-fi freaks are using 100W + amps with speakers of 88dB/W or more, in a small room and with neighbors that won't stand for it...... and yet believe that they really need all that power.... and that maybe they should upgrade to something bigger!
When I explain that they have probably never peaked beyond 30W and are averaging 0.5W, I get some very funny looks!!
Geez, no tube heads around?
The guys listening to these 5-10W amps, mysteriously happy with so little power?
Don't forget, it's always a compromise - more power means more complex design, more parasitics, bigger transistors with worse characteristics...
Have fun, Hannes
The guys listening to these 5-10W amps, mysteriously happy with so little power?
Don't forget, it's always a compromise - more power means more complex design, more parasitics, bigger transistors with worse characteristics...
Have fun, Hannes
Not exactly. The difference with high power amp is not just only maximum volume level, BUT ability to drive difficult loads, huge power supply etc. Usually one get quite a difference between low power amp and high power amp, even if both work well below clipping of the smaller unit.
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I "suppose" that the need fore bigger and bigger amps happens when you get beyond a certain "size"
Maybe it just comes from actually getting relatively smaller and smaller headroom "ratio"
And with exeedingly bigger amps the power supply becomes more and more stressed and under dimensioned
All in all, the gained clean undistorted power gets relatively smaller and smaller, and ends in a quest fore the unobtainable exstreme high power amps
But whats the point of having 500watt if it turns into heavy distortion at less than 100watt, if you can get close to 60watt of clean power with a 100watt amp or so
My 40watt monos deliver maybe 35watt clean power, and seems quite effective
Sure, I have no doubts that you can build a very good 150watt making 100watt of ultra clean power, but its beyond the just ordinary, expencive and heavy
Any point in mentioning that my 40watt AB monos each have 500watt supply, and drives anything, low impedance speakers especially
And that with just single pairs of MJL21193/94 and single pairs of 15.000uf supply caps
Only trafos and heatsinks are big
Maybe the same could be achieved with multiple supply caps and smaller trafos, but dont know
Tho with high impedance speakers they do seem to loose significant power
Maybe it just comes from actually getting relatively smaller and smaller headroom "ratio"
And with exeedingly bigger amps the power supply becomes more and more stressed and under dimensioned
All in all, the gained clean undistorted power gets relatively smaller and smaller, and ends in a quest fore the unobtainable exstreme high power amps
But whats the point of having 500watt if it turns into heavy distortion at less than 100watt, if you can get close to 60watt of clean power with a 100watt amp or so
My 40watt monos deliver maybe 35watt clean power, and seems quite effective
Sure, I have no doubts that you can build a very good 150watt making 100watt of ultra clean power, but its beyond the just ordinary, expencive and heavy
Any point in mentioning that my 40watt AB monos each have 500watt supply, and drives anything, low impedance speakers especially
And that with just single pairs of MJL21193/94 and single pairs of 15.000uf supply caps
Only trafos and heatsinks are big
Maybe the same could be achieved with multiple supply caps and smaller trafos, but dont know
Tho with high impedance speakers they do seem to loose significant power
IMO the real problem is a low sensitivity speaker (like 84dB/W/m, quite usual) with difficult complex impedance characteristics.
SET guy here 😉
My amps are only 8 watts, so I have high-efficiency speakers...but on the same token, I've listened to a lot of power-hungry speakers that I like too. Nothing particularly wrong with that as long as you have the amplification to drive 'em.
I would guess most people listen to fairly affordable speakers...though maybe a little low on sensitivity, these have usually only a handful of parts as crossover, hardly a really reactive load. Low impedances due to MTM (paralleled woofers) is common on the other hand.
Still, the paradox is how tube amps with their highish output impedance, low bandwidth and little power are regularly praised, while solid state amps are much more asked to deliver.
Maybe this issue will remain unsolved for quite some time, but a bit of pub talk can't hurt 😉
Have fun, Hannes
This can never be solved virtually, as many have quite different imagination if they read same words. Only real life comparison tells something.
Besides, sensible listening level is very relevant to the ambient noise. If you live in a city with high ambient noise you will need much more accoustic power than a person living in a rural environment.
Many of us grew up with an instrument in the home, a piano for instance. How load should your amplifier/speaker combination have to play to mimic the piano. It is also important to know the real distance from the source as acoustic attenuation in space is a square of the distance.
Pavel says listen to it and decide how loud you want it to be to sound nice to you.
What is a very interesting fact is that you can withstand far higher acoustic power level if it is undistorted
Pavel says listen to it and decide how loud you want it to be to sound nice to you.
What is a very interesting fact is that you can withstand far higher acoustic power level if it is undistorted
2 X 100W rms is a minimum to reproduce accurately a piano played
at full volume, that is, as much as 40 notes simultaneously
using the sustain pedal or heavy chords with octaved basses played
at full percussion..
This is only valid at the place of the player, and with a Bosendorfer
or an expensive Steinway or Yamaha , all 3 being grand pianos, of course..
That said,the concertists pianists are listened to in theatre like rooms, at a distance of 5 metres at least, so a concert piano level is easily reproduced at home with as low as 2 X 10W ,or even less if the speakers are in the 90db+ efficency range...
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