Hi.
I've asked for opinion on the active-cross-over design in this thread: http://www.diyaudio.com/forums/multi-way/271951-el-cheapo-active-loudspeaker-3.html#post4284493 ( post28), but maybe this subject deserves a separate thread.
I have not done a active cross-over of this size before. There are many options for placing the different stages in the signal-chain. Some options will put more opamps in each branch, but maybe this is not a big problem?
Is there any good guidelines out there on this subject?
A quick sketch of my best guess on the overall design so far:
Kind regards
I've asked for opinion on the active-cross-over design in this thread: http://www.diyaudio.com/forums/multi-way/271951-el-cheapo-active-loudspeaker-3.html#post4284493 ( post28), but maybe this subject deserves a separate thread.
I have not done a active cross-over of this size before. There are many options for placing the different stages in the signal-chain. Some options will put more opamps in each branch, but maybe this is not a big problem?
Is there any good guidelines out there on this subject?
A quick sketch of my best guess on the overall design so far:
Kind regards
Grounding: star-wise
Filter-Sequence: I have build a 4th order LR filter (low and hipass) for my loundspeakers. I have used BB OPA134PA. These are FET-input op. The input impedance must be lower or equal 2kOhms. Two 12 db blocks are connected in series.
PSU: I have build a -15V/+15V with TL082CP voltage reference and a series bipolar transistor. The PSU has a floating ground and no 50Hz hum is fed into the filter.
Filter: the filter is non-symetrical and I am using a OP (DRV 143PA) to make it symetrical.
Filter-Sequence: I have build a 4th order LR filter (low and hipass) for my loundspeakers. I have used BB OPA134PA. These are FET-input op. The input impedance must be lower or equal 2kOhms. Two 12 db blocks are connected in series.
PSU: I have build a -15V/+15V with TL082CP voltage reference and a series bipolar transistor. The PSU has a floating ground and no 50Hz hum is fed into the filter.
Filter: the filter is non-symetrical and I am using a OP (DRV 143PA) to make it symetrical.
If you chain multiple filtering blocks i would say to be sure to buffer each.
I would place bsc (575hz highshelf) before the first cross over (4th order 120hz) because it is minimum phase correction. As a bonus you'll gain headroom for the medium and treble before the first cross over.
Maybe check the B5 manual from Firstwatt as an example and get inspired by.
I would place bsc (575hz highshelf) before the first cross over (4th order 120hz) because it is minimum phase correction. As a bonus you'll gain headroom for the medium and treble before the first cross over.
Maybe check the B5 manual from Firstwatt as an example and get inspired by.
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