Hello all,
I need your help in defining a small project.
I currently use a Raspberry PI 3B+, with an external cheap I2S DAC.
The DAC is a ES9023, without any output buffer.
The DAC feeds then my amplifier, a Technics SU-V9, and the following speakers (Grundig).
I'd like now to add a subwoofer to the system (I will build it, later on).
My idea was to build a dedicated board, wuith the following features:
- DAC output buffer, using an op-amp or discretes
- Subwoofer output, with low-pass filter (with tunable frequency) and variable gain
- Separate supply rails for Raspberry, DAC and analog part.
I have no problem for the last point, this is part of my work; I'd like instead to ask for your help for the first two points.
Do you have any suggestion, any schematic, for such stages?
Thank you in advance!
Ciao,
Giovanni
I need your help in defining a small project.
I currently use a Raspberry PI 3B+, with an external cheap I2S DAC.
The DAC is a ES9023, without any output buffer.
The DAC feeds then my amplifier, a Technics SU-V9, and the following speakers (Grundig).
I'd like now to add a subwoofer to the system (I will build it, later on).
My idea was to build a dedicated board, wuith the following features:
- DAC output buffer, using an op-amp or discretes
- Subwoofer output, with low-pass filter (with tunable frequency) and variable gain
- Separate supply rails for Raspberry, DAC and analog part.
I have no problem for the last point, this is part of my work; I'd like instead to ask for your help for the first two points.
Do you have any suggestion, any schematic, for such stages?
Thank you in advance!
Ciao,
Giovanni
Moreover:
Do you think it would be better to provide an highpass filter to the L/R channels?
In other words; should I cut off the frequencies played from the subwoofer from the normal L/R speakers?
I could even lower the gain of bass frequencies from the SU_V9 amplifier.
Do you think it would be better to provide an highpass filter to the L/R channels?
In other words; should I cut off the frequencies played from the subwoofer from the normal L/R speakers?
I could even lower the gain of bass frequencies from the SU_V9 amplifier.
Ideally you'd use a full active crossover, ie filter both. However tunable filters are more complex and doing a full tunable crossover in analog is rather complex.
Hi, a discrete built non global feedback circuit with filtered output for the subwoofer comes to mind. I would keep it simple so 1 normal stereo output and 1 (mono or stereo) output for the subwoofer amplifier.
The normal channels don't need high pass but that is an opinion. The less you do with they signal the better it is (old fashioned).
The normal channels don't need high pass but that is an opinion. The less you do with they signal the better it is (old fashioned).
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If you don't filter out subbass from the normal channels you may be pushing the cones to the end-stops for no reason - very distorting. And this also increases the power dissipation in those drivers.
Less signal processing is usually less performant, simple maths, nothing to do with fashion! With any multi-way speaker system you want to keep the wrong frequencies out of each driver to prevent high dissipation, cone-breakup, endstopping, premature clipping, etc etc - each then gets to handle the one piece of spectrum it handles best.
Less signal processing is usually less performant, simple maths, nothing to do with fashion! With any multi-way speaker system you want to keep the wrong frequencies out of each driver to prevent high dissipation, cone-breakup, endstopping, premature clipping, etc etc - each then gets to handle the one piece of spectrum it handles best.