Singular with AER mk1 EQ-Network? (Singular)
Hi Bert,
I have the Singular with older AER mk1 (Lowther magnet) and would like to experiment with an EQ-Network. You mentioned this EQ in other posts about the Singular, but I could´nt find what resistor, coil and capacitor you used.
Thanks for your help!
Lars
Singular with AER mk1 EQ-Network?
Hi Lars,
Here is an EQ-filter you can try for your hybrid AER drive unit. Let me know what you like or dislike about it.
![[image]](images/uploaded/image12.gif)
The filter is doing two things, it reduces the rising respons of the AER drive unit and it corrects the impedance after that. Your tube amplifier will like that...
It is possible that the reduction is too much, then the 18 ohm resistor has to be made smaller. If it isn't enough then the value should be increased.
The impedance correction has to be adjusted also if you change the vlaue of the 18 ohm resistor though but that can be optimised later when you're happy with the EQ.
Ciao,
Bert
Singular with AER mk1 EQ-Network?
Hi Bert
It seems that the impedance correction is taken care of by a zobel in the form of the 4.7uF capacitor and 22R resistor.
Does this mean that the rising response is dealt with by the 18R resistor and 1.2mH inductor?
Also, you mentioned that the 18R can be reduced if the reduction of the response is too much, but that the impedance correction would need to be adjusted.
Do you have a formula to calculate the required components for this response and impedance correction circuit or is it based on experience with this particular AER drive unit?
Thanks.
Rgds
garbage
Singular with AER mk1 EQ-Network?
The filter is doing two things, it reduces the rising respons of the AER
drive unit and it corrects the impedance after that. Your tube amplifier
will like that...
Yes. And if you would like to spend more time on flatening the impedance, you could use a RCL (a serial R-C-L in paralel with the speaker terminals) circuit after the filtering circuit. Then the filter will also be phase corrected. Audible? For sure.
Wether you would like it or not? Well.....
Best regards
GC
Singular with AER mk1 EQ-Network?
Hi GC,
Yes. And if you would like to spend more time on flatening the impedance,
you could use a RCL (a serial R-C-L in paralel with the speaker terminals)
circuit after the filtering circuit. Then the filter will also be phase
corrected. Audible? For sure.
Not too hard to do when the driver is playing in free air but when loaded by a system (reflex, Singular, BLH, etc.) with different amounts of real acoustical damping makes it hard to make a standard version for all... 
Ciao,
Bert
Singular with AER mk1 EQ-Network?
Hi Bert
Not too hard to do when the driver is playing in free air but when loaded
by a system (reflex, Singular, BLH, etc.) with different amounts of real
acoustical damping makes it hard to make a standard version for all...
That's so true.
The same goes for the filter and RC suggested. The AC impedance is always dynamic when music is playing, whereas applied components are not. Playing loud results in higher DC impedance due to temperature raise in the VC, which again results in the components arn't "attacking" correctly.
Anyhow the impedance do not vary that much playing normal listening levels, so it's worth a try.
Your suggested circuit will work anyhow and will also linieralise the overall phase = improved front/back placements of instruments.
BR
GC
Singular with AER mk1 EQ-Network?
Hi GC
Anyhow the impedance do not vary that much playing normal listening
levels, so it's worth a try.
The below graph is taken off Rod Elliot's pages. It shows rising impedance curve of a loudspeaker.
![[image]](http://sound.westhost.com/lrp-f34.gif)
Rgds
garbage
Singular with AER mk1 EQ-Network?
Hi Garbage
The below graph is taken off
Rod Elliot's
pages. It shows rising impedance curve of a loudspeaker.
The graph shows an ac impedance plot of an ordinary driver.
The impedance raise is caused by induction in the voice coil. This will not affect the sound if there is no filter components in the system. It will however affect the amplitude linearity of a given amplifier. I.e. tube amps. This due to the rather high output impedance.
If you take a driver with a very strong magnetical field in the VC gap of the magnet system, the raise is less significant as the induction is reduced by the more saturated iron surrounding the VC.
Bert suggest to liniarlise the impendance with an RC curcuit in order to make the LR filter work better and more symetrical. Further it gives more optional "settings" as you have 4 components to play with instead of 2.
(Sorry Bert for anticipating what you had in mind with your filter)
Here is an example of a driver which has been corrected for both ac impedance and dc impedance caused by the serial components in the filter.
Nothing said about the sound.
![[image]](images/uploaded/image75.jpg)
Best regards
GC
Singular with AER mk1 EQ-Network?
by Bert 
, Thursday, January 04, 2007, 00:52 (6313 days ago) @ GC
Hi GC,
Whow! Knowing that parallel components used are audible then I would think that all these parts would harm more than they will gain in overall quality...
Looks like politicians who have nothing else to do than thinking of new rules to cure "non existing" problems and creating new ones at the same time.
Never heard it but my first thoughts are; throw away that drive unit!...
Ciao,
Bert
--
BD-Design - Only the Best!
Singular with AER mk1 EQ-Network?
by Bert , Thursday, January 04, 2007, 00:46 (6313 days ago) @ GC
Hi Garbage,
It shows rising impedance curve of a loudspeaker.
It shows the rising respons of a woofer or something else with a high inductance coil.
AER drive units have a very low inductance and the strong magnetical field keeps the rising impedance pretty low so these do not need an impedance correction.
Adding the EQ makes the impedance rise a lot more (caused by the 1.2mH coil) and that "should" be corrected for amplifiers (usually tubes) who can't handle this.
Ciao,
Bert
--
BD-Design - Only the Best!