Hi doctordata,All
2cents:
Even if your design do not entirely resemble an ACE-Bass amp you've done a great variant on this theme : I,ve noticed Your design seem to be able to alter the moving mass and damping but not the springiness (compliance) of the system.?
It's not my design , I just followed the schematic in the paper and did the maths .and you're right about the compliance .
That is you control the upper FR boundary while the lower end is solely dependent on the your low-pass filter at the input and the Q setting using the built in negative output resistance feature.
The filter at the input is a high-pass 2nd order Q=2
FYI if not known: Here are two links to similar threads to this one,but the first at least cannot be found here down below in the: 'Similar Threads', I find this to be odd.
ACE-bass amplifier design:
http://www.diyaudio.com/forums/subwoofers/104447-ace-bass-amplifier-design.html
and:
http://www.diyaudio.com/forums/multi-way/83982-enclosure-high-q-driver-4.html#post976317
b
PS: Submitting picture I think resembles the functionality of your design too, can (only?) be found in K.E.S Thesis written in the Swedish language.
JBL K140 response in REW
Did a recap today of my subwoofer amp of post 38 , PSU caps were 30 years old and had some hum and was not so happy with the bass performance anymore .
Caps were only 20% of new value around 2000uF. Repaced them by 20.000uF per side . After replacing the caps hum was gone and as I had it in my workshop I did a nearfield measurement with REW and my modded Umik-1 and a Behringer UCA 202 .
I'm Very happy with the result !!
Hooked it up again , and boy THAT's BASS !!
Cheers .
Rens
Did a recap today of my subwoofer amp of post 38 , PSU caps were 30 years old and had some hum and was not so happy with the bass performance anymore .
Caps were only 20% of new value around 2000uF. Repaced them by 20.000uF per side . After replacing the caps hum was gone and as I had it in my workshop I did a nearfield measurement with REW and my modded Umik-1 and a Behringer UCA 202 .
I'm Very happy with the result !!
Hooked it up again , and boy THAT's BASS !!
Cheers .
Rens
Attachments
Corrections on my quote
My answers are in Red .
Originally Posted by bjorno
Hi doctordata,All
2cents:
Even if your design do not entirely resemble an ACE-Bass amp you've done a great variant on this theme : I,ve noticed Your design seem to be able to alter the moving mass and damping but not the springiness (compliance) of the system.?
It's not my design , I just followed the schematic in the paper and did the maths .and you're right about the compliance .
That is you control the upper FR boundary while the lower end is solely dependent on the your low-pass filter at the input and the Q setting using the built in negative output resistance feature.
The filter at the input is a high-pass 2nd order Q=2 , Fc = 20 Hz
FYI if not known: Here are two links to similar threads to this one,but the first at least cannot be found here down below in the: 'Similar Threads', I find this to be odd.
ACE-bass amplifier design:
ACE-bass amplifier design
and:
Enclosure for high Q driver
b
PS: Submitting picture I think resembles the functionality of your design too, can (only?) be found in K.E.S Thesis written in the Swedish language.
My answers are in Red .
Originally Posted by bjorno
Hi doctordata,All
2cents:
Even if your design do not entirely resemble an ACE-Bass amp you've done a great variant on this theme : I,ve noticed Your design seem to be able to alter the moving mass and damping but not the springiness (compliance) of the system.?
It's not my design , I just followed the schematic in the paper and did the maths .and you're right about the compliance .
That is you control the upper FR boundary while the lower end is solely dependent on the your low-pass filter at the input and the Q setting using the built in negative output resistance feature.
The filter at the input is a high-pass 2nd order Q=2 , Fc = 20 Hz
FYI if not known: Here are two links to similar threads to this one,but the first at least cannot be found here down below in the: 'Similar Threads', I find this to be odd.
ACE-bass amplifier design:
ACE-bass amplifier design
and:
Enclosure for high Q driver
b
PS: Submitting picture I think resembles the functionality of your design too, can (only?) be found in K.E.S Thesis written in the Swedish language.
Rew curve
Can't understand the no replys on this perfect flat response from about 17 Hz to 150 Hz with this simple K140 driver and a couple of op Amps .
here's a link to a guy who had simular experiences with this technique .
PCB for AceBass | Baldin's Blog
We're all exited by those tapped horns , but this is giving BASS in your living room with normal woofers in small boxes . have a look at Baldin's spreadsheet and fill in your speakers TS's
Cheers ,
Rens
Can't understand the no replys on this perfect flat response from about 17 Hz to 150 Hz with this simple K140 driver and a couple of op Amps .
here's a link to a guy who had simular experiences with this technique .
PCB for AceBass | Baldin's Blog
We're all exited by those tapped horns , but this is giving BASS in your living room with normal woofers in small boxes . have a look at Baldin's spreadsheet and fill in your speakers TS's
Cheers ,
Rens
Edit ?
I wasn't able to edit my post , some cyber static ? don't build Baldin's design yet , there are some minor design issues , I tried to contact him , but that didn't work out . The gain resistor in his design does not give enough gain .
But for the rest the spreadsheet is pretty good . I lowered the standard resistor values with a factor 10 and that worked out fine for me ( less hum )
I wasn't able to edit my post , some cyber static ? don't build Baldin's design yet , there are some minor design issues , I tried to contact him , but that didn't work out . The gain resistor in his design does not give enough gain .
But for the rest the spreadsheet is pretty good . I lowered the standard resistor values with a factor 10 and that worked out fine for me ( less hum )
Hi doctordata,
Did you miss this Thread postings?
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html#post2555539
b
Hi doctordata,
Did you miss this Thread postings?
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html#post2555539
b
Sorry mate , Queens Birthday here , will read tomorrow , Thanks ,
Cheers Rens
Logging out , Confirmed ,
High pass is missing
I read the links , Thanks ! very interesting . Good way to recover from Queens Birthday The Stahl design is based on a 6th order BR box and a 6th order design needs a high pass filter with fc = fbox ( and f-3dB in this design) with a Q of 2 . I made the calculations based on a 20 Hz tuning , I measured the filters and there on the spot , so I'm a little surprised that my Rew measurements are down to 17 Hz . ( But who cares and the UMIK-1 has no calibration below 20 Hz ) Baldin's design does not include the highpass filter and it should ! My schematic in post 37 has the filter included, it's the first opamp . I also added a phase inverter with a 2X gain , the last opamp , because my power amp was not inverting as needed in the design . You can select either inverting or non inverting power amps with the jumper. I added the 2X gain for my low sensitive power amp . If the jumper is placed wrongly , YOU WILL HEAR !!!
and the neighbours !!
Cheers ,
Rens
Hi doctordata,
Did you miss this Thread postings?
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html
http://www.diyaudio.com/forums/subwoofers/187677-ace-bass-design.html#post2555539
b
I read the links , Thanks ! very interesting . Good way to recover from Queens Birthday
The Stahl design is based on a 6th order BR box and a 6th order design needs a high pass filter with fc = fbox ( and f-3dB in this design) with a Q of 2 . I made the calculations based on a 20 Hz tuning , I measured the filters and there on the spot , so I'm a little surprised that my Rew measurements are down to 17 Hz . ( But who cares and the UMIK-1 has no calibration below 20 Hz ) Baldin's design does not include the highpass filter and it should ! My schematic in post 37 has the filter included, it's the first opamp . I also added a phase inverter with a 2X gain , the last opamp , because my power amp was not inverting as needed in the design . You can select either inverting or non inverting power amps with the jumper. I added the 2X gain for my low sensitive power amp . If the jumper is placed wrongly , YOU WILL HEAR !!!and the neighbours !!
Cheers ,
Rens
