Best crossover solution for 2.1 from PC with tpa3255?

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Quick question...

I'm planning to do a 2.1 setup from my PC. The PC soundcard has RCA outs.

I'm going to setup a tpa3255 amp for the bookshelf speakers and have a powered sub which would probably have it's own onboard crossover.

What is the normal solution for a crossover, since I don't want the <80Hz to go to the bookshelves, so I can't just use an RCA splitter to both?

I also saw these tpa3255 2.1 amps, but I'm a bit worried about the lack of a crossover frequency control and signal degradation from the bass/treble controls.
 
Thanks for the replies.

I'm not sure about the ground loop thing, I'm not exactly sure what I need to do to avoid it so I'll just cross that bridge if I (hopefully don't) get to it.

I'm not a big fan of installing EQ software as I don't know how it will interact with my recording software, I do music production in Ableton with a Focusrite 6i6 audio interface.

I was hoping for a simple hardware solution.
 
Just use powered speakers with isolation class II amp (no protection earth wire).

I want to have my choice of speakers so I want to use a separate amp, and I'm reading good things about the TPA3255.

Both those software EQ systems I mentioned are in output so only affects for playback ... and both can be easily turned off when not needed.

Now I think about it, that wouldn't work for me...

I don't want to cut the bass out of the RCA completely, because then the sub wouldn't get any signal at all. As I understand it, I would need a crossover after the RCA and before the amp, to split the signal between the bookshelves and the sub.

can this be a solution for you?

X-over realized by Laptop, Open Source and 7.1 AV Receiver over Display Port / HDMI

I have it with 3 way crossover and one additional bass working since 2 years.

regards
Guenter

Interesting info for my Ubuntu HTPC, but I'm using Windows 7 on the desktop machine that I'm planning to set this 2.1 system up for.
 
...

Now I think about it, that wouldn't work for me...

I don't want to cut the bass out of the RCA completely, because then the sub wouldn't get any signal at all. As I understand it, I would need a crossover after the RCA and before the amp, to split the signal between the bookshelves and the sub.
...

Both software mentioned supports multichannel configs so EQ can be done/channel but, 2.1 might need some HW for .1 as you mention.
 
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I would have thought this was a solved problem, but I can't find a 2-way crossover preamp/volume control.

Do you think I am overthinking this and I should just use a simple splitter and forget about limiting the LF to the bookshelf speakers and run them fullrange and just use the crossover on the sub?
 
I just spent 300 bucks on a pro soundcard for music production, I can't use some crappy high-latency 5.1 card.

Not trying to be difficult, I just can't believe Shenzen isn't all over this with $10 crossover boards!

Thanks for the replies all, I'm looking into minidsp or freedsp. Seems like a lot of effort when lots of cheap amps have 2.1, but all the home subs are self-powered, I haven't seen passive home ones, only car enclosures. Hmm. Anyway I'm sure a minidsp will come in handy later anyway.
 
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Hmm... by 6i6 specs, there are four outputs (+ headphone output) to use ... why not just use one of those output ports for sub ... .
As I mentioned already both software which I mentioned handles I/O as mono channels --> by using three mono outputs from 6i6 (two for bookshelf speakers, one for powered sub) with mentioned software you be able to make needed routings and filtering for L/R channels and SUB channel. If there are delay diffrence between the sub and speakers, it can be fixed through mentioned software as well.
 
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I just spent 300 bucks on a pro soundcard for music production, I can't use some crappy high-latency 5.1 card.

PCI(e) soundcards (incl. Intel HDA) can usually reach very decent latencies. Of course it requires good drivers and good OS.


but all the home subs are self-powered, I haven't seen passive home ones, only car enclosures.

If needed, it is trivial to disconnect the internal amp and use the SW and passive. Often the internal electronics is not worth a dime anyways.
 
PCI(e) soundcards (incl. Intel HDA) can usually reach very decent latencies. Of course it requires good drivers and good OS.

Another reason I don't want another soundcard is that Ableton only supports a single soundcard at once.

If needed, it is trivial to disconnect the internal amp and use the SW and passive. Often the internal electronics is not worth a dime anyways.

Good idea, now I'm considering saving time and money and just getting a 2.1 TPA3255 board and doing that. Still not convinced by the quality of the one premade board available that includes a crossover though. There's no way to adjust the crossover frequency, just treble/bass controls.

Seems slightly silly to pay for a powered sub when you're only using it as a passive though. Plus voiding the warranty - I'd need to find a way to get the speaker connectors to exit the enclosure which might mean drilling a hole.

I wonder what the difference in quality of the actual sub driver/enclosure actually is between powered subs, or if you're just paying for a more powerful plate amp.
 
At a yard sale bought one of these.....
Silver W-12 | Subwoofer | Monitor Audio

Plate amp is just a joke.....!(almost every cap is bulged..:eek:) .....although the cabinet and driver are in great condition. :D

Removed the plate amp (500 watt RMS you've got to be kidding !!) and powered from 2.1 Allo DAC with dedicated
Plinius power amp.... when you've current to spare...;)

(.....sub cost....cough...$5.00....cough US....).... :):p:D

Piano 2.1 DAC
Plinius - SB 301 -
 
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Hmm... by 6i6 specs, there are four outputs (+ headphone output) to use ... why not just use one of those output ports for sub ... .
As I mentioned already both software which I mentioned handles I/O as mono channels --> by using three mono outputs from 6i6 (two for bookshelf speakers, one for powered sub) with mentioned software you be able to make needed routings and filtering for L/R channels and SUB channel. If there are delay diffrence between the sub and speakers, it can be fixed through mentioned software as well.

If you go this way with EqualizerAPO then you could use filters something like this to cut the low freq for bookshelf speakers and cut the high freq for sub :

Code:
Copy: C = 0.5 * L + 0.5 * R
# if needed
#Copy: Sub = 0.5 * L + 0.5 * R

# Preamp: -command if needed

# 6i6 outputs 1, 2
Channel: L R
# Delay: -command if needed
# Preamp: -command if needed
# 48dB/oct HighPass filter w/ cut-off at <n> Hz
Eval: cutoff = 80
Eval: Q1=1/(2*sin((pi/8)*(0+1/2)))
Filter 1: ON HPQ Fc `cutoff` Hz Q `Q1`
Eval: Q2=1/(2*sin((pi/8)*(1+1/2)))
Filter 1: ON HPQ Fc `cutoff` Hz Q `Q2`
Eval: Q3=1/(2*sin((pi/8)*(2+1/2)))
Filter 1: ON HPQ Fc `cutoff` Hz Q `Q3`
Eval: Q4=1/(2*sin((pi/8)*(3+1/2)))
Filter 1: ON HPQ Fc `cutoff` Hz Q `Q4`

# 96dB/oct (just double the above)
#Eval: Q1=1/(2*sin((pi/8)*(0+1/2)))
#Filter 1: ON HPQ Fc `cutoff` Hz Q `Q1`
#Eval: Q2=1/(2*sin((pi/8)*(1+1/2)))
#Filter 1: ON HPQ Fc `cutoff` Hz Q `Q2`
#Eval: Q3=1/(2*sin((pi/8)*(2+1/2)))
#Filter 1: ON HPQ Fc `cutoff` Hz Q `Q3`
#Eval: Q4=1/(2*sin((pi/8)*(3+1/2)))
#Filter 1: ON HPQ Fc `cutoff` Hz Q `Q4`

# 6i6 outputs 3, 4
Channel: C Sub
# Delay: -command if needed
# Preamp: -command if needed
# 48dB/oct LowPass filter w/ cut-off at <n> Hz
Eval: cutoff = 250
Eval: Q1=1/(2*sin((pi/8)*(0+1/2)))
Filter 2: ON LPQ Fc `cutoff` Hz Q `Q1`
Eval: Q2=1/(2*sin((pi/8)*(1+1/2)))
Filter 2: ON LPQ Fc `cutoff` Hz Q `Q2`
Eval: Q3=1/(2*sin((pi/8)*(2+1/2)))
Filter 2: ON LPQ Fc `cutoff` Hz Q `Q3`
Eval: Q4=1/(2*sin((pi/8)*(3+1/2)))
Filter 2: ON LPQ Fc `cutoff` Hz Q `Q4`

# 96dB/oct (just double the above)
#Eval: Q1=1/(2*sin((pi/8)*(0+1/2)))
#Filter 2: ON LPQ Fc `cutoff` Hz Q `Q1`
#Eval: Q2=1/(2*sin((pi/8)*(1+1/2)))
#Filter 2: ON LPQ Fc `cutoff` Hz Q `Q2`
#Eval: Q3=1/(2*sin((pi/8)*(2+1/2)))
#Filter 2: ON LPQ Fc `cutoff` Hz Q `Q3`
#Eval: Q4=1/(2*sin((pi/8)*(3+1/2)))
#Filter 2: ON LPQ Fc `cutoff` Hz Q `Q4`

... or use GraphicEQ from EqualizerAPO.

If you want to use ASIO/KS level output instead of Windows default (WASAPI Shared) then use the Equalizer APO Voicemeeter integration option (set Voicemeeter to use ASIO/KS).
 
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At a yard sale bought one of these.....
Silver W-12 | Subwoofer | Monitor Audio

(.....sub cost....cough...$5.00....cough US....).... :):p:D

Wow, $5 for that?!

Probably an angry spouse getting rid of her poor partner's stuff! :D

If you go this way with EqualizerAPO then you could use filters something like this to cut the low freq for bookshelf speakers and cut the high freq for sub :
... or use GraphicEQ from EqualizerAPO.

If you want to use ASIO/KS level output instead of Windows default (WASAPI Shared) then use the Equalizer APO Voicemeeter integration option (set Voicemeeter to use ASIO/KS).

Thanks a lot for the detailed info.

Why would you want to use more than one multichannel soundcard?

Yeah I understand why you would ask that question.

TBH I think that EqualizerAPO setup is not going to work for me.

I have a mistrust of the latency that must be created by running everything through EqualizerAPO and the extra complexity. My whole system is a complicated and fragile ecosystem and I'm skeptical of running Ableton with EqualizerAPO. Ableton is quite sensitive to soundcard and I guess EqualizerAPO creates a virtual soundcard to run everything through? I specifically bought that soundcard from checking the latency numbers and it is one of the best. I'm playing VST instruments live so latency is very important.

I usually run my O2 headphone amp from outputs 1-2 and my monitor speakers from 3-4.

The physical monitor volume control on the 6i6 only affects outputs 3-4, and the new TPA3255 amp that I'm setting up has no volume control so I will need to use that physical control to control the output from the monitor speakers/sub. I need the headphones to run fullrange so I need separate outputs for that or else I'll need to manually adjust the volume of the sub all the time which is not very accurate or convenient.

Not sure I explained that all that well but that's what I'm thinking.
 
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