[Csnd] Quadraphonic reverb
| Date | 2026-06-02 14:39 |
| From | "Jeanette C." <000015cdd0ffa6cd-dmarc-request@LISTSERV.HEANET.IE> |
| Subject | [Csnd] Quadraphonic reverb |
Hey hey,
I'm currently working on something with a quadraphonic setup and I wondered if
some of you had practical approahces to reverb.
I'd like to use reverbsc. How do you deal with that? Just use two reverbsc
with the same setting? Slightly different settings or...
I'd appreciate any practical tips from you quadraphonic desperados. :)
Best wishes and thanks,
Jeanette
--
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| Date | 2026-06-03 14:54 |
| From | Oeyvind Brandtsegg |
| Subject | Re: [Csnd] Quadraphonic reverb |
| Attachments | screverb_crush.csd |
Hi Yes, screverb is a good candidate to build a multichannel reverb, but it is easier of you use the code version (the original Sean Costello code that led to the implementation of the screverb opcode). In the Csound code version, you have access to the separate delay lines, and can route them individually. As it uses 8 delay lines for stereo, you can duplicate it as needed (say, 8 delay lines per 2 speakers) and then send a few of the delay lines from one 8-line module as input to the next and thus daisy chain the reverb modules together. F.ex: Reverb 1 for output 1,2 uses delay line 1 to 8, feeding back to themselves Reverb 2 for output 3,4 uses delay line 9 to 16, feeding back to themselves Then route delay line 1,3,5 feed to the input of Reverb 2, and route delay lines 10,12,14,16 feed to the input of Reverb 1. It makes even more sense if you have even more output channels. I do have an 11-channel version of this somewhere on a backup. For now, I just found the stereo version of the reverb in Csound code (attached). You can take it apart and invent your own configuration extension and routing, thinking of how parts of the reflections from one side of the room feeds into the late reverberation of the other part of the room. Øyvind tir. 2. juni 2026 kl. 15:39 skrev Jeanette C. <000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>: Hey hey, |
| Date | 2026-06-03 15:08 |
| From | "Jeanette C." <000015cdd0ffa6cd-dmarc-request@LISTSERV.HEANET.IE> |
| Subject | Re: [Csnd] Quadraphonic reverb |
Hi Øyvind,
many thanks for this suggestion and the way to work it. I will definitely give
this a try. It sounds promising. There is one question though: when I set up
additional delay lines for the other two channels, should the delays have the
same length or should I vary the initial times slightly to avoid
comb-filtering effects? This part of reverb setup has always really foxed me.
:)
Best wishes,
Jeanette
--
* PeerTube: https://makertube.net/@jeanette_c
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| Date | 2026-06-03 15:23 |
| From | Oeyvind Brandtsegg |
| Subject | Re: [Csnd] Quadraphonic reverb |
You can use other prime number delay lengths for the extra delay lines. It can seem like you have to be very careful about the delay lengths, but also remember that the delay times are modulated by ifs, and as long as the lfos are out of sync with each other, you are less likely to hit harmonic relationships between the delay lines. You will occasionally pass through a harmonic relationship between single pairs of delays, but it will not build as they are being modulated. A simple solution is to do what is done in the freeverb algorithm, where each stereo channel has a 1 sample delay time offset in relation to the other. This gives some decorrelation between channels. Or find other delay times in the approximate same range. Just trust your ears, if it sounds good it should be ok. If you want to stress test the inharmonicity, run a short white noise burst into the reverb. That should trigger any ugliness lurking in there ;-) Øyvind ons. 3. juni 2026 kl. 16:08 skrev Jeanette C. <000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>: Hi Øyvind, |
| Date | 2026-06-30 16:25 |
| From | "Jeanette C." <000015cdd0ffa6cd-dmarc-request@LISTSERV.HEANET.IE> |
| Subject | Re: [Csnd] Quadraphonic reverb |
Hello Oevind,
thanks again for the SCReverb code. I have adapted it and it basically works.
But in the original code only a1 (the left input) is passed into the reverb. I
have passed my first input into delaylines 1,3,5,7, the second into 2,4,6,8,
the third into 9,11,13,15 and the fourth into 10,12,14,16. The feedback
connection between the two sets of 8 I have done like this: 1,2,5,6 feed into
9,10,13,14 and 11,12,15,16 feed into 3,4,7,8.
Even with the lowcut filter (butterhp), I get some bass rumble at longer
reverbs. I'll try experimenting with putting an atone inside the delay network
as well, so I actually have a low frequency damping. But it's a nice sound!
Best wishes,
Jeanette
Oeyvind Brandtsegg, Jun 3 2026:
> Hi
>
> Yes, screverb is a good candidate to build a multichannel reverb, but it is
> easier of you use the code version (the original Sean Costello code that
> led to the implementation of the screverb opcode). In the Csound code
> version, you have access to the separate delay lines, and can route them
> individually. As it uses 8 delay lines for stereo, you can duplicate it as
> needed (say, 8 delay lines per 2 speakers) and then send a few of the delay
> lines from one 8-line module as input to the next and thus daisy chain the
> reverb modules together.
>
> F.ex:
> Reverb 1 for output 1,2 uses delay line 1 to 8, feeding back to themselves
> Reverb 2 for output 3,4 uses delay line 9 to 16, feeding back to themselves
> Then route delay line 1,3,5 feed to the input of Reverb 2, and route delay
> lines 10,12,14,16 feed to the input of Reverb 1.
>
> It makes even more sense if you have even more output channels. I do have
> an 11-channel version of this somewhere on a backup.
> For now, I just found the stereo version of the reverb in Csound code
> (attached). You can take it apart and invent your own configuration
> extension and routing, thinking of how parts of the reflections from one
> side of the room feeds into the late reverberation of the other part of the
> room.
>
> Øyvind
>
> tir. 2. juni 2026 kl. 15:39 skrev Jeanette C. <
> 000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>:
>
>> Hey hey,
>> I'm currently working on something with a quadraphonic setup and I
>> wondered if
>> some of you had practical approahces to reverb.
>>
>> I'd like to use reverbsc. How do you deal with that? Just use two reverbsc
>> with the same setting? Slightly different settings or...
>>
>> I'd appreciate any practical tips from you quadraphonic desperados. :)
>>
>> Best wishes and thanks,
>>
>> Jeanette
>>
>> --
>> * PeerTube: https://makertube.net/@jeanette_c
>> * GitHub: https://github.com/jeanette-c
>> * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
>>
>> Csound mailing list
>> Csound@listserv.heanet.ie
>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>> Send bugs reports to
>> https://github.com/csound/csound/issues
>> Discussions of bugs and features can be posted here
>>
>
> Csound mailing list
> Csound@listserv.heanet.ie
> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
> Send bugs reports to
> https://github.com/csound/csound/issues
> Discussions of bugs and features can be posted here
>
--
* PeerTube: https://makertube.net/@jeanette_c
* GitHub: https://github.com/jeanette-c
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
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| Date | 2026-07-01 09:05 |
| From | Oeyvind Brandtsegg |
| Subject | Re: [Csnd] Quadraphonic reverb |
Hi Jeanette So cool that you made it! The routing seems good. There might also be many other routing architectures that should work well. I'm not sure about the LF rumble, but a wild guess could be that the feedback routing within and between the sets of delays might create a long chain delay that will resonate at lower frequencies. The random deviations of delay time will probably have less effect on the longer (chained) delay lines, and this might be the reason why you get rumble buildup. all best Øyvind tir. 30. juni 2026 kl. 17:24 skrev Jeanette C. <000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>: Hello Oevind, |
| Date | 2026-07-01 09:57 |
| From | "Jeanette C." <000015cdd0ffa6cd-dmarc-request@LISTSERV.HEANET.IE> |
| Subject | Re: [Csnd] Quadraphonic reverb |
Hi Øyvind,
many thanks for the feedback, no pun intended (or is it?).
Anyway, with atone inside the delay lines, it works fine. And the rumble only
starts appearing at more feedback. I'm looking forward to using it in my
current project. I'll stick with the stereo basis as long as possible, before
I get to the proper 4-channel finish.
Best wishes,
Jeanette
Oeyvind Brandtsegg, Jul 1 2026:
> Hi Jeanette
>
> So cool that you made it! The routing seems good. There might also be many
> other routing architectures that should work well.
> I'm not sure about the LF rumble, but a wild guess could be that the
> feedback routing within and between the sets of delays might create a long
> chain delay that will resonate at lower frequencies. The random deviations
> of delay time will probably have less effect on the longer (chained) delay
> lines, and this might be the reason why you get rumble buildup.
>
> all best
> Øyvind
>
> tir. 30. juni 2026 kl. 17:24 skrev Jeanette C. <
> 000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>:
>
>> Hello Oevind,
>> thanks again for the SCReverb code. I have adapted it and it basically
>> works.
>> But in the original code only a1 (the left input) is passed into the
>> reverb. I
>> have passed my first input into delaylines 1,3,5,7, the second into
>> 2,4,6,8,
>> the third into 9,11,13,15 and the fourth into 10,12,14,16. The feedback
>> connection between the two sets of 8 I have done like this: 1,2,5,6 feed
>> into
>> 9,10,13,14 and 11,12,15,16 feed into 3,4,7,8.
>>
>> Even with the lowcut filter (butterhp), I get some bass rumble at longer
>> reverbs. I'll try experimenting with putting an atone inside the delay
>> network
>> as well, so I actually have a low frequency damping. But it's a nice sound!
>>
>> Best wishes,
>>
>> Jeanette
>>
>> Oeyvind Brandtsegg, Jun 3 2026:
>>
>>> Hi
>>>
>>> Yes, screverb is a good candidate to build a multichannel reverb, but it
>> is
>>> easier of you use the code version (the original Sean Costello code that
>>> led to the implementation of the screverb opcode). In the Csound code
>>> version, you have access to the separate delay lines, and can route them
>>> individually. As it uses 8 delay lines for stereo, you can duplicate it
>> as
>>> needed (say, 8 delay lines per 2 speakers) and then send a few of the
>> delay
>>> lines from one 8-line module as input to the next and thus daisy chain
>> the
>>> reverb modules together.
>>>
>>> F.ex:
>>> Reverb 1 for output 1,2 uses delay line 1 to 8, feeding back to
>> themselves
>>> Reverb 2 for output 3,4 uses delay line 9 to 16, feeding back to
>> themselves
>>> Then route delay line 1,3,5 feed to the input of Reverb 2, and route
>> delay
>>> lines 10,12,14,16 feed to the input of Reverb 1.
>>>
>>> It makes even more sense if you have even more output channels. I do have
>>> an 11-channel version of this somewhere on a backup.
>>> For now, I just found the stereo version of the reverb in Csound code
>>> (attached). You can take it apart and invent your own configuration
>>> extension and routing, thinking of how parts of the reflections from one
>>> side of the room feeds into the late reverberation of the other part of
>> the
>>> room.
>>>
>>> Øyvind
>>>
>>> tir. 2. juni 2026 kl. 15:39 skrev Jeanette C. <
>>> 000015cdd0ffa6cd-dmarc-request@listserv.heanet.ie>:
>>>
>>>> Hey hey,
>>>> I'm currently working on something with a quadraphonic setup and I
>>>> wondered if
>>>> some of you had practical approahces to reverb.
>>>>
>>>> I'd like to use reverbsc. How do you deal with that? Just use two
>> reverbsc
>>>> with the same setting? Slightly different settings or...
>>>>
>>>> I'd appreciate any practical tips from you quadraphonic desperados. :)
>>>>
>>>> Best wishes and thanks,
>>>>
>>>> Jeanette
>>>>
>>>> --
>>>> * PeerTube: https://makertube.net/@jeanette_c
>>>> * GitHub: https://github.com/jeanette-c
>>>> * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
>>>>
>>>> Csound mailing list
>>>> Csound@listserv.heanet.ie
>>>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>>>> Send bugs reports to
>>>> https://github.com/csound/csound/issues
>>>> Discussions of bugs and features can be posted here
>>>>
>>>
>>> Csound mailing list
>>> Csound@listserv.heanet.ie
>>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>>> Send bugs reports to
>>> https://github.com/csound/csound/issues
>>> Discussions of bugs and features can be posted here
>>>
>>
>> --
>> * PeerTube: https://makertube.net/@jeanette_c
>> * GitHub: https://github.com/jeanette-c
>> * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
>>
>> Csound mailing list
>> Csound@listserv.heanet.ie
>> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
>> Send bugs reports to
>> https://github.com/csound/csound/issues
>> Discussions of bugs and features can be posted here
>
> Csound mailing list
> Csound@listserv.heanet.ie
> https://listserv.heanet.ie/cgi-bin/wa?A0=CSOUND
> Send bugs reports to
> https://github.com/csound/csound/issues
> Discussions of bugs and features can be posted here
>
--
* PeerTube: https://makertube.net/@jeanette_c
* GitHub: https://github.com/jeanette-c
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
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