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Proprius with a subwoofer.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 10:10am
@Gary.

You should be able to join the two black terminals without any problem, but I've not tried it myself.

The black terminals are at chassis ground (0V) potential.

The thing you should try not to do is short a red to a black... however, after the kit's last outing I hurriedly put the Proprius back on the shelf and plugged in the bi-wired cables, spun a record and couldn't hear anything. So I checked I'd turned up the volumes on the Majestic as well as the pair of Proprius. Then I checked all the interconnects and switches on the Majestic and couldn't find a fault. The record deck was still playing merrily away, so I selected a digital input and nothing came through the speakers either...

I then realised I'd made a tragic error!

I'd been experienting with using one Spatia as send and the other as return. A black and a red to one Proprius terminal and the other black and a red to the other Proprius terminal - same at the speaker end...

What I'd hurriedly done was to plug the two reds to the red terminals and the two blacks to the black terminal...

Got it yet?

Yes, I was playing into a dead short! For somewhere in the region of ten minutes. "Oh dear", I thought.

So, I corrected that silly miswire on the fly without turning anything off or turning the volume down, and I had music again. I listened intently for a good hour to hear if their was any distortion, thinking I could have damaged them, but I couldn't hear any. The amps weren't running hot, so it looked like they survived fuses still intact.

They were designed to do that, but I don't advise anybody doing it to prove the point.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 1:14pm
Originally posted by BAK BAK wrote:

Originally posted by Gary Gary wrote:

... My subwoofer has a speaker level input but uses three wires to connect (+right, +left and -left or right) this is a problem for mono block amplifiers.


This is a speaker-level-to-line-input-level built into the sub-woofer "plate amplifier".
One would connect a + and - speaker wire (speaker wire only) from each channel's output to the sub-woofer "plate amplifier" input.
This should work provided the Proprius amplifiers have a common output ground, not floating (common minus connection).
Come to think of it, the same would be true for a resistor divider connected to the Proprius amplifiers' outputs... again the Proprius amplifiers would have to have a common output ground, not floating.


Only Graham can say if the minus speaker terminals on 2 Proprius amplifiers can be connected / shorted together.

With Graham's confirmation today,
 use your "built in" speaker-level-to-line-input-level connections on the sub-woofer "plate amplifier". Be careful of your polarities as even IEmbarrassed (and those more experiencedEmbarrassed) can miss a plus and minus or plus and plus crossed connection.

 RULE OF THUMB: always double check speaker-to-amplifier connections.Wink

Suggestion: Plug both Proprius power amps into the same AC power source as the sub-woofer "plate amplifier". This will reduce any source of noise or hum.
AND, run the speaker wire only from the Proprius amps' outputs directly to the "plate amplifier" input, keeping these wires 3 foot away from all AC power cables.

If the input to the "plate amplifier" seems to be too loud (input level control set way low) you can put a 4 ohm, 10 watt resistor in series with each plus connection. This will also lessen the load on the Proprius amps' outputs (and giving cleaner sound to the speakers).

Here to help,


Edited by BAK - 31 May 2015 at 1:33pm
Bruce
AT-14SA, Pickering XV-15, Hana EL, Technics SL-1600MK2, Lautus, Majestic DAC, Technics SH-8055 spectrum analyzer, Eminence Beta8A custom cabs; Proprius & Reflex M or C, Enjoy Life your way!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gary Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 2:29pm
Thanks Graham.
Only worry I've got now is if my subwoofer is up to partnering a Majestic, pair of Proprius and PMC twenty 23s.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote discrete badger Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 3:39pm
On line-level subwoofer hum....

I had initial hum problems with my line-level subwoofer connection (only used for the effects in movies, 2-channel goes via speaker-level). Due to not to wanting to dig up a concrete floor, the only feasible routing is via the ceiling, which makes for a 20m run, getting close to some AC cables on the way. 

I followed Graham's advice (from an old posting or blog somewhere) and used coaxial satellite cable to make up a single-channel connection. The hum completely vanished and the SQ is great. Thanks Graham.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 9:26pm
Apologies for my late arrival in this thread. I run 2 REL Q-series subwoofers off the output of my Proprius amps and this setup works fine as it has with my previous amplifiers. Each cable connects both red terminals and one black terminal to the high level input of the sub. Assuming 'plate amplifier' means the electronics inside the subwoofer I am fairly sure the input impedance of the sub will be much higher than that of a speaker, probably 10k or more and it will include attenuation to match the levels as well as the low pass filtering to blend the sub with the main speakers. If you need to attenuate the signal get a resistor of about the same value as the sub's input impedance, that should be in the spec sheet/manual.

Those two subs are also connected to my AVR using phono cables into the low level inputs. I would second Graham's advice about using a decent cable like satellite coax for this.

Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 31 May 2015 at 9:28pm
Graham, I knew the Proprius amps were very well engineered but that is remarkable. How many other amps on the market would take that punishment and still sound great?
Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote BAK Quote  Post ReplyReply Direct Link To This Post Posted: 01 Jun 2015 at 2:45pm
Originally posted by Fatmangolf Fatmangolf wrote:

Apologies for my late arrival in this thread. I run 2 REL Q-series subwoofers off the output of my Proprius amps and this setup works fine as it has with my previous amplifiers. Each cable connects both red terminals and one black terminal to the high level input of the sub. Assuming 'plate amplifier' means the electronics inside the subwoofer I am fairly sure the input impedance of the sub will be much higher than that of a speaker, probably 10k or more and it will include attenuation to match the levels as well as the low pass filtering to blend the sub with the main speakers. If you need to attenuate the signal get a resistor of about the same value as the sub's input impedance, that should be in the spec sheet/manual.

Those two subs are also connected to my AVR using phono cables into the low level inputs. I would second Graham's advice about using a decent cable like satellite coax for this.


Gary and Jon,
 My thoughts were that a coaxial cable might add too much capacitance to the speaker load of the Proprius amps.
 I stand corrected if others have used coaxial cables without any adverse effects.
Satellite coax does have a very low capacitance.

 I have seen some sub-woofer 'plate amplifiers' with a dummy load on the input of 4 to 16 ohms before the speaker-to-line-level conversion attenuator.
 I agree with Jon's recommendation " to attenuate the signal get a resistor of about the same value as the sub's input impedance, that should be in the spec sheet/manual".

 I have noticed the speaker industry calling an amplifier that
is mounted on a "plate" or panel on the back of the sub-woofer cabinet a "plate amplifier".
 I bow to those who have used
sub-woofer "plate amplifiers", they have their uses for some.

I am of the other school of thought that uses a 2 channel stereo amplifier driving just 2 speakers,
the bass and all other frequencies being delivered by the same 2 speaker systems.

Gary, I hope you find the sound you wish to hear. 
Jon, I am glad you chimed in. I would not want to steer any one off track
  Your "hands-on experience" is much appreciated.

Graham, you do have a GEM of a design in these Proprius amplifiers.
Bruce
AT-14SA, Pickering XV-15, Hana EL, Technics SL-1600MK2, Lautus, Majestic DAC, Technics SH-8055 spectrum analyzer, Eminence Beta8A custom cabs; Proprius & Reflex M or C, Enjoy Life your way!
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