Hello,
Are there any circuits for stereo to 2.1 method ? I cannot find or searching it wrong. I'd like to have circuit which do this. Stereo signal IN, put two potentiometeres one for the stereo control one for the .1 sub. The best would be a cricuit with a low pass filter for the .1 part.
Thanks
Are there any circuits for stereo to 2.1 method ? I cannot find or searching it wrong. I'd like to have circuit which do this. Stereo signal IN, put two potentiometeres one for the stereo control one for the .1 sub. The best would be a cricuit with a low pass filter for the .1 part.
Thanks
to do this properly you really want an active crossover that filters above (say) 80Ha for your mains, and below (again say) 80Hz for the sub.
I have seen a lot of cheap "2.1" amplifier modules online, often sourcing from Asia, that do not filter the bass from the main speakers.
This is unfortunate as:
- Having a sub out is great,
- Keeping sending the sub signal to the main outputs will mean they are till trying to generate the low frequencies, which presumably they are not doing well, else why a sub?
- Even if the mains "can" handle the sub signals, you lose the benefit of removing the cone excursion on the bass-mid driver at low frequencies, which is a huge benefit of having a sub.
- you do not benefit from the bass-mid (mains) not seeing the voltage at the amplifier required to deliver sub output. (those sub signals represent a lot of power out)
This is a long winded way of saying that you should be looking for an active crossover. There are plenty out there.
- I suggest minimum 12dB/octave, prefer more
- I would start at 80Hz xo give or take
- Put the volume control in front of it...
As an example, but your mileage might vary..... NEW ! ! 2.1 24dB/oct stereo active crossover single sub output Buttkicker PCB. | eBay
I have seen a lot of cheap "2.1" amplifier modules online, often sourcing from Asia, that do not filter the bass from the main speakers.
This is unfortunate as:
- Having a sub out is great,
- Keeping sending the sub signal to the main outputs will mean they are till trying to generate the low frequencies, which presumably they are not doing well, else why a sub?
- Even if the mains "can" handle the sub signals, you lose the benefit of removing the cone excursion on the bass-mid driver at low frequencies, which is a huge benefit of having a sub.
- you do not benefit from the bass-mid (mains) not seeing the voltage at the amplifier required to deliver sub output. (those sub signals represent a lot of power out)
This is a long winded way of saying that you should be looking for an active crossover. There are plenty out there.
- I suggest minimum 12dB/octave, prefer more
- I would start at 80Hz xo give or take
- Put the volume control in front of it...
As an example, but your mileage might vary..... NEW ! ! 2.1 24dB/oct stereo active crossover single sub output Buttkicker PCB. | eBay
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I have an old Reckhorn F-1 that I use for this type of thing. Imperfect, but a stellar bargain, I got mine for $50 back in the day. It's old, but I think in the past I had found schematics for it on line. A quick google didn't show it for me, but if you search some dusty old corner of the internet you might be able to turn it up...
Thanks[/QUOTE]
The attached file is the KiCad drawing of my 5.1 preamp for our TV. The top left corner U4 A & B, U5 A & B and U6 B
do what you're asking. I got the values for the filter wrong so it's 100Hz. To change it to 80 Hz change R20 and
R22 to 39.2K. Gain is unity.
G²
I did one last year that was basically part ESP P88 as a stereo gain section and a mono mixer. See the following thread and I had to use a FET in the mixer stage due to DC offset. You can always add a pot to the mixer.
Active pre amp DC offset increases with 2 modules used
The mono stage can be replaced with the LP section of ESP P81 and I've built those as a separate unit. This gives a buffer (I added gain to U1A), a filter (I used 80Hz) and phase change via a relay. I did have some noise and added 100K to ground at the end of the circuit after the 10uF cap.
12dB / Octave Linkwitz Riley Crossover
If you have a look around at the ESP site you can mix and match stuff to suit.
Active pre amp DC offset increases with 2 modules used
The mono stage can be replaced with the LP section of ESP P81 and I've built those as a separate unit. This gives a buffer (I added gain to U1A), a filter (I used 80Hz) and phase change via a relay. I did have some noise and added 100K to ground at the end of the circuit after the 10uF cap.
12dB / Octave Linkwitz Riley Crossover
If you have a look around at the ESP site you can mix and match stuff to suit.
