Hello everyone!
I am in the middle of redesigning my Yamaha av receiver by adding a analogue bass management.
My question is what op amp would you recommend?
The xo will be 80Hz for the satellite and 120Hz for the LFE, however I hit a snag....
The normal hp filter usually 12dB/oct plus tune the satellite sealed enclosure to 80Hz as well
giving the sum of 24dB/oct response. Nice in theory but the sat. rarely give Q=0.707 @80Hz.
Top of that the room gain is kick in ~80Hz as well, messing up the roll off curve.
My way of thinking is to put the sat in a big box, Q~0.5 then make the hp 24dB/oct 80hz and play with the Q of the filter.
This arrangement has other benefit as well. The resonance of the system is out of the pass
band. Would the extra opamp degrade the sound? This is the reason I ask opinion about the opamps.
I hope you able to see the "block" diagram....try open a full size window.
L-----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
R----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
C----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
SL---BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
SR---BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
main L/R/C/SL/SR --SUM/BUFFER--LP80Hz24dB/oct---->to LFE sum/buff
LFE--BUFF+10dB---LPF120Hz------LFE SUM/BUFF--GAIN--POT--OUT
Your opinion appreciated!
Miki.
I am in the middle of redesigning my Yamaha av receiver by adding a analogue bass management.
My question is what op amp would you recommend?
The xo will be 80Hz for the satellite and 120Hz for the LFE, however I hit a snag....
The normal hp filter usually 12dB/oct plus tune the satellite sealed enclosure to 80Hz as well
giving the sum of 24dB/oct response. Nice in theory but the sat. rarely give Q=0.707 @80Hz.
Top of that the room gain is kick in ~80Hz as well, messing up the roll off curve.
My way of thinking is to put the sat in a big box, Q~0.5 then make the hp 24dB/oct 80hz and play with the Q of the filter.
This arrangement has other benefit as well. The resonance of the system is out of the pass
band. Would the extra opamp degrade the sound? This is the reason I ask opinion about the opamps.
I hope you able to see the "block" diagram....try open a full size window.
L-----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
R----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
C----BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
SL---BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
SR---BUFF----HP80Hz24dB/oct----GAIN/BUFFER---POT----OUT
main L/R/C/SL/SR --SUM/BUFFER--LP80Hz24dB/oct---->to LFE sum/buff
LFE--BUFF+10dB---LPF120Hz------LFE SUM/BUFF--GAIN--POT--OUT
Your opinion appreciated!
Miki.