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Proprius Amp tweaking......

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Post Options Post Options   Thanks (0) Thanks(0)   Quote BackinBlack Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jan 2016 at 7:41am
I would suggest that you try just your single pair of Proprius first. I have used them in the past with supposedly power hungry loudspeakers and found them to be more than adequate in volume and control of the speakers, good tight bass with remarkable low extension and that smooth treble Graham manages to design into all his products.
Just listen, if it sounds good to you, enjoy it.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote morris_minor Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jan 2016 at 8:26am
Originally posted by Gary Gary wrote:

I've been using Proprius amps with PMC Twenty 23's for a while now and I'm very happy with them. The amps were an upgrade from a pair of Audiolab 8200MB's rated at 250 watts. The Proprius very convincingly outperform the 8200MB, the biggest suprise for me was how much of an improvement there was with bass control, depth and detail.
My Proprii drive a pair of PMC Gb1i speakers, and forum member msphil uses his with PMC Fact 8s. It should be remembered that the Proprius' 25 watts are "Yorkshire Watts" and thus in a different league to lesser watts . . Wink
Bob

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Aussie Mick Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jan 2016 at 1:13pm
Plus one for "don't worry about power". My Proprii drive the Australian built Noteperfect Ovation speakers. Many people use them with 100-150w of valve or solid state amplification to excellent effect. However, one of the amps I tested at home before purchasing the Maj/Pro duo was the L***a T****a integrated. It sounded wonderful. The Slee combo sounded just as wonderful but more open (wide open!), half the price, and more flexible. Kept just as good control over the crossoverless midrange driver as the 150w beast. But, better texture and more nimble. It's a falsehood to say a watt is a watt is a watt.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote msphil Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jan 2016 at 1:52pm
I can testify to the power and quality of the Proprius amps. I have used them with a pair of Mission 753 speakers as well as the wonderful PMC Fact 8 speakers. Both sets of speakers sound fantastic and as far as sound volume is concerned can knock the roof of your house! I haven't yet been able to turn them up beyond half volume! In my opinion, and a PMC dealer who heard them, they are fantastic amps especially when played using a Majestic DAC/preamp! The PMC dealer said that my system sounded better than the one that they use for demonstrations. Their system costs over £10,000 for each item. Conservatively I would guess it adds up to over £30,000-£40,000!
'You are, through your soul not your body, a human being.'
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 08 Jan 2016 at 6:41pm
Hi Francis, you're already tuned into the message but I must belatedly add my bit about driving a variety of speakers including Monitor Audio GX100 (120 Watts 88dB/W) and GX300 (can handle 200 Watts 90dB/W), Acoustic Energy AE505's (100 Watts I think and 86dB/Watt) with the Proprius amps at levels from a whisper to a scream, to use a cliche.

I usually listen at relatively low levels 60-70dBA but have run each of these continuously at 100dBA (slow response) with undistorted (but very loud ) music in my living room. There was plenty of headroom and the amps running warm to the touch. When I trialled the Proprius against the CA 840A v2, a huge powerful amp of 2 x 200W, it was more open and the Proprius bass was deeper and firmer with the AE505's and GX100's I had available at the time.

@Bob, I love the idea of the Yorkshire Watt.
Jon

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Post Options Post Options   Thanks (0) Thanks(0)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 09 Jan 2016 at 4:22pm
Originally posted by Graham Slee Graham Slee wrote:

A pair of Proprius were used for a music evening in a pub venue in the Midlands a few months ago.
OK, they did use a pair of Klipschorns which are quite sensitive. I am told the event was packed but it was loud enough to get over the noise of the crowd. It was basically a disco using a disco front end with a quality mixer.

John C did comment however that on leaving the venue quite late, the sound could be heard from the car park across the road at a volume fitting for a disco.

Attendees commented on the good quality of the sound and the organisers have asked to use the pair of Proprius again. By the way, the phono preamps used were a pair of Gram Amp 2 SE which the organisers had bought.

So, are they going to be loud enough?

Just because the speakers have a rating of 300 watts does not mean they need 300 watts.

On our two own events (which we invited everybody to but only 30-40 turned up) we demonstrated that 25 watts per channel (real rms) could drive the relatively inefficient 11 Ohm LS35A speakers to a really healthy volume with excellent sound quality in hotel conference rooms much larger than the usual domestic living room.

But, even after saying all that, I guess people may not be convinced.

 Any quality-built amplifier (like the Proprius) with greater than 20 watts rms power output is sufficient enough to drive speakers available today with very pleasing results.
 (By quality-built I mean: one that has enough current and voltage "headroom" designed-in, wide enough frequency response to not hinder delicate or powerfull sound passages, and extremely low distortion measurements at loud and quiet sound levels.)

The Proprius amplifiers can produce 26 watts rms driving into an 8 ohm speaker load... rms = rout-mean-square (another mathematical term for average power).
 That same rms power can be as much as 52 watts peak power, or more, even 70 watts instantaneous. That is the solid state circuit doing it's best into 8 ohms.
When driving into 4 ohms it will be almost 2 X as much!

Note that the 11 Ohm LS35A speakers are not that low in efficiency at 88dB @ 1 watt/1.5 meters, and the Klipschorns mentioned above are very high in efficiency  at about 95+ dB @ 1 watt/1 meter ( maybe as much as 98 dB!).
 That means with the same 1 watt input the Klipschorns would be about 10 dB louder!

Your speakers own sensitivity to the power applied to it will tell you how loud that speaker will be at a given power level (not how powerful your amp is).
 If your speakers can handle 50 watts rms and you drive them with 100 watts rms, you can easily burn out your speakers! even at half volume! First to go will be the tweeters.

 I always rate my speakers to handle 2 X the RMS power or more of the amplifier I intend to connect them to.
 And then I want to get speakers with as high an efficiency as possible.

I currently have some speakers rated at 200 watts rms connected to my 60 watt rms amplifier; these speakers have an efficiency of 96 dB @ 1 watt/1 meter.
And they get very loud at just 1 watt... the neighbors complain loud!
I have to keep the volume down to less than 1/2 watt to keep the peace.

See my next post for info about decibel levels and how to approximate decibels at different power levels.



Edited by BAK - 09 Jan 2016 at 4:33pm
Bruce
AT-14SA, Pickering XV-15/625, Technics SL-1600MK2, Reflex M, Lautus, Technics SH-8066, Dynaco ST120a, Eminence Beta 8A in custom cabs;; Using Majestic DAC
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 09 Jan 2016 at 4:44pm
Efficiency is more important than power handling for sound quality.
It is a matter of physics.
Every time a quantity of energy is transformed from one energy form to another there is a loss of energy. The loss can be quantified by measuring the efficiency of the transformation.
With a lower efficiency transformation, less of the original information from the energy source is reproduced in the end result.
 This amounts to less of the original sound energy is reproduced in lower efficiency speakers.

The dissertation below will prove that any quality-built amplifier (like the Proprius) with greater than 20 watts rms power output is sufficient enough to drive speakers available today with very pleasing results.

 (By quality-built I mean: one that has enough current and voltage "headroom" designed-in, wide enough frequency response to not hinder delicate or powerfull sound passages, and extremely low distortion measurements at loud and quiet sound levels.)

A little-known fact is:
 In old-school electronics,
less than 1 watt rms = low power,
from 1 watt to 10 watts = medium power,
greater than 10 watts rms = HIGH POWER...(100 watts rms is extra high but was not mentioned in the reference)

This rating scheme came from early radio days.
 It was found that less than 1 watt rms was all that was needed for "personal" listening; with  headphones or a pocket radio.
 1 watt to 10 watts was needed to fill the average room with sound as with a table radio (most were between 1.5 and 5 watts).
 Greater than 10 watts rms was only needed to fill large rooms.

Average commercial speaker sensitivity today is about 85 dB @ 1 watt rms measured @ 1 meter, in short form...85 dB @ 1 w/1m. That means that you get 85 dB at 1 watt when measured with a sound pressure measurement instrument with a calibrated microphone from a distance of 1 meter directly in front of the speaker, in the center of the speaker's radiating pattern...or straight in front.

 The below is a way to approximate decibel levels.

Now with acoustic power you add 10 dB for every multiple of 10 watts rms... or each time you multiply the power by 10.
 If with 1 watt you get 85 dB,
 then at 10 watts you get 95 dB,
 at 100 watts you will get 105 dB!
Again with acoustic power you add 3 dB for every multiple of 2
watts rms... or each time you multiply the power by 2.
 If with 1 watt you get 85 dB,
 then at 2 watts you get 88 db (+3 dB),
 at 4 watts you get 91 dB (+3 dB),
  and at 8 watts you get 94 dB (+3 dB),

 from above, at 10 watts you get 95 dB,
 then at 20 watts you get 98 dB (+3 dB).

If you have an 8 ohm speaker capable of producing 95 dB @ 1w/1m,
 you will get 105 dB @ 10 watts / 1m,
 and then 108 dB @ 20 watts / 1m,
 and about 110 dB @ 26 watts / 1m (Proprius power @ 8 ohms),
 and 115 dB @ 100 watts / 1m.

You see from above that, if you have a higher efficiency speaker, you will get more sound measured in decibels at any
acoustic power level than you will from a lower efficiency speaker.
You will also be able to drive the higher efficiency speaker with less power to get the same amount of sound!

This is why professional sound systems use very high efficiency speaker drivers.


Edited by BAK - 09 Jan 2016 at 5:19pm
Bruce
AT-14SA, Pickering XV-15/625, Technics SL-1600MK2, Reflex M, Lautus, Technics SH-8066, Dynaco ST120a, Eminence Beta 8A in custom cabs;; Using Majestic DAC
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