Hi,

is there a patch out there that works well with a quad setup?

I am not after panning but rather just simulate a room. The source sound will be in the center.

Convolution or algorithm does not matter, but I prefer medium load on my cpu rather than mega high quality reverb.

Thanks!

@cfry This one's not too heavy....... vfreeverb~.pd
Reverb just being delays and filters you can use it twice for quad and use only very slightly different settings for each stereo pair so as to give some different focus.
As your source is central the delays should probably be the same though and maybe you should bounce each pair very subtly back into the others input.
David.

Room simulation in reverb is a dead end. Give it a bit of thought... To reproduce all the discrete echoes of a room, their phase difference, how they bounce back and forth between walls, is a hopeless task. All the good reverb designs are based on what sounds good rather than realistic simulation.

@whale-av is right about doubling a nice sounding verb, changing the settings slightly on each and feeding them into each other. But if you are assuming your sound source and receptor to be at the center of the room, you don't need 4 channels, as left distance = right distance, and front distance = back distance. Indeed if you are assuming a quadratic room with speaker and mic at the exact center you only need one channel!

I find Puckette's algorithm to be very efficient and convincing (rev2~ and rev3~) compared to freeverb which is based on a very arcane algorithm (Schroeder back in the 60ties). Both [rev2~] and [rev3~] have 4 outlets so they can be used for quad mixing, What puckette's algorithm is missing maybe is the allpass smudge of the freeverb/schroeder models...

See also this video on reverb design which goes through the history of reverb algorithms:

@whale-av if I want to give the feel of a huge space, I guess I should add a short delay before the reverb. What would you suggest, if I may ask?

I know you are not asking me, but

The speed of sound is 343m/s at room temperature - so it is reasonable to assume a predelay of 3ms is equivalent to what we perceive as 1 meter of space.

@cfry That's a bit tricky as it depends on the source. Some large / huge spaces are beautiful for a slow solo voice and impossible for a faster piece with multiple instruments and a beat.
The same is true for a reverb effect. Sometimes you have use unnatural settings to achieve what you want and some natural reverb settings will feel completely wrong in a space which looks nothing like what you are hearing.
And huge real spaces (cathedrals) tend to be dull........ long RT60 with loads of low frequencies and no treble..... and I often have to add a more "bright" reverb to make the music intelligible.
As @bocanegra says you are searching for a pleasing sound.
I wouldn't use more than 24ms of pre-delay as it can sound like an echo bouncing around and confuses the ears........ better to increase the reverb time (decay) for a large space and stay with about 14-17ms of pre-delay.
David.

@bocanegra I like [vfreeverb~] although I find it strange that it seems to react different to parameter changes than (original) [freeverb~]. I have yet to try out rev2 and rev3, but I will. Why are there four outlets on these?

My intuition says that it will sound better with four slightly different signals even though the person experiencing the installation will be in the center of the room. I want it to sound unreal, but good unreal.

Oh yeah, the room will be almost pitch dark. You will not see the walls of the room.

@cfry said:

@bocanegra I like [vfreeverb~] although I find it strange that it seems to react different to parameter changes than (original) [freeverb~].

The version @whale-av posted is modified to keep the original freeverb(tm) tuning in miliseconds regardless of samplerate (???)

I have yet to try out rev2 and rev3, but I will. Why are there four outlets on these?

Miller Puckette's idea is to create a "rotary" mixing matrix of delay lines and feed the mix back into them. Here's his original design: http://msp.ucsd.edu/techniques/latest/book-html/node124.html
You can tap up to 16 different outputs from [rev~3] and mix them anyhow you find suitable for your "room".

@bocanegra said:

See also this video on reverb design which goes through the history of reverb

Rarely did I spend an hour or so on YT so well. Thanks a lot. Do you have other interesting lectures like that to share?

@kyro - not reverb relateed, but here's a goodie if you liked the lecture: http://tre.ucsd.edu/wordpress/wp-content/uploads/2016/05/pdreverb.zip - Tom Erbe's pd reverb patches (the one used for demonstration in the vid)