my singular has finished (Singular)
Hi folks,
Merry Christmas! 
I have completed a pair of Singular recently. A pair of Lowther PM2C was mounted and the speaker is driven by a current source amp (designed by Nelson Pass).
![[image]](images/uploaded/image79.jpg)
They are in high gloss red finish and looks great. 
The speaker is placed in a room of size around 400 sq. ft., around 3 ft from side and back wall.
The first listening impression is clean and tight bass with good definitions. I have added a passive EQ network, without the network, the so-called "Lowther shout" was present.
Will let it burn in for some time and have some good music during holidays......
Thanks Bert for sharing the design.
Cheers
my singular has finished
by Bert 
, Friday, December 23, 2005, 23:07 (6697 days ago) @ mdlover
Hi Albert,
Merry Christmas!
Thanks, same to you and your family!
They are in high gloss red finish and looks great.
Great! You like to built speakers eh? :wink:
definitions. I have added a passive EQ network, without the network, the
so-called "Lowther shout" was present.
Could you share the diagram of the used network with us?
Ciao,
Bert
--
BD-Design - Only the Best!
my singular has finished
Hi Bert,
Regarding the EQ, it is a series combination of a 4.7u + 8 ohm and then across the Lowther.
Cheers
Albert
![[image]](images/uploaded/image80.jpg)
my singular has finished
by Bert , Friday, December 23, 2005, 23:39 (6696 days ago) @ mdlover
Hi Albert,
Regarding the EQ, it is a series combination of a 4.7u + 8 ohm and then
across the Lowther.
Thanks. I have played with EQ's made like that but it only works when the amp is sensitive to impedance changes. I thought that a current source amp was not sensitive to impedance at all... :confused:
I am not an electronical expert though so if I am wrong then please educate me so that I do understand... 
Ciao,
Bert
--
BD-Design - Only the Best!
my singular has finished
I thought that a current source amp
was not sensitive to impedance at all... :confused:
Hi Bert,
With a current source style amp i.e. high or very high output impedance the series filter has no or little effect as the voltage across the filter is allowed to vary whilst maintaining more or less constant voltage across the driver due to constant current through it and so no filter effect.
To make a filter work with a current source amp you have to divert current away from the driver so the driver current develops less voltage across the driver. You do this by putting the filter components in parallel with the driver - these then divert current from the driver at the frequencies relative to the driver impedance that they become active.
So the filter has the same component values as a series filter but in parallel rather than in series...
Hope this makes sense to you!
James
my singular has finished
Thank you James for the explanation.
Cheers
Using a Current Source Amp in general...
by Bert , Saturday, December 24, 2005, 09:20 (6696 days ago) @ James D
Hi James,
Hope this makes sense to you!
Not at this moment (early in the morming...
) but if such amp works opposite compared to normal amplifiers then such an amp will not work on normal speakers such as multi-way speakers with their serial filters? 
Bert
--
BD-Design - Only the Best!
Using a Current Source Amp in general...
Hi Bert,
Normal speaker (with passive crossover) is supposed to be driven by normal amp (voltage source), the result will not be good when matching with this kind of current amp.
You might find these articles interesting.
http://www.passdiy.com/pdf/CurrentSourceCrossoverNetworks.pdf
http://www.passdiy.com/pdf/cs-amps-speakers.pdf
Cheers
Albert
Thanks for those...
by Bert , Monday, December 26, 2005, 17:52 (6694 days ago) @ mdlover
--
BD-Design - Only the Best!
What about the other speakers?
by Bert , Saturday, December 24, 2005, 09:24 (6696 days ago) @ mdlover
Hi again Albert,
The speaker is placed in a room of size around 400 sq. ft., around 3 ft
from side and back wall.
What are these other speakers in the room? How would you compare the Singular to those?
Ciao,
Bert
--
BD-Design - Only the Best!
What about the other speakers?
Bert,
There is a pair of Fostex FE167 in folded quarter wave pipe. The next is a two way system which consist of Coral compression driver + an exponential wood horn and a pair of Fostex woofer.
The two way system is not connected since I'm designing an active crossover for them. Will let you know when they are up and running.
The Lowther + Singular is better than the Fostex FE167 in terms of bass, clarity, speed and with a better tonal quality.
Cheers
Albert
What about the other speakers?
by Bert , Monday, December 26, 2005, 17:50 (6694 days ago) @ mdlover
Hi Albert,
There is a pair of Fostex FE167 in folded quarter wave pipe. The next is a
two way system which consist of Coral compression driver + an exponential
wood horn and a pair of Fostex woofer.
Thanks for the info, always nice to know more about speaker systems when shown on a picture...
The two way system is not connected since I'm designing an active
crossover for them. Will let you know when they are up and running.
Always a pleasure, you have your Singular as reference to tune the filter...
Ciao,
Bert
--
BD-Design - Only the Best!
my singular has finished
I have completed a pair of Singular recently. A pair of Lowther PM2C was
mounted and the speaker is driven by a current source amp (designed by
Nelson Pass).
Is the amp an F1 or F2 design? Can you share the design?
my singular has finished
Is the amp an F1 or F2 design? Can you share the design?
it's an F2. some folks has done some reverse engineering
http://www.diyaudio.com/forums/showthread.php?postid=683361#post683361
mine was using c-l-c filtering instead of active regulation.