[LAU] jconv settings

[Jörn Nettingsmeier]

rosea grammostola wrote:
> Hi,
> 
> I'm trying to understand the fantastic reverb jconv. I know how I can 
> run it.
> 
> 1. in/out is number of ins and outs
yes, in the /convolver/new command. in the /impulse/read command, it's
used to specify *which* in and out. (e.g. there can only be one of each,
per line.)

> 2 partition is frames and should be the same as in jackd(?)

yes, and no. the minimal size is jackd's period size (if you specify a
smaller value, jconv will tell you it's using a value equal to jackd's
period). you can use larger values for more cpu efficiency, at the cost
of higher latency.

> 3. maxsize is length of the file? In what format (kb?), should I 
> customize it using different files? What app can I use to determine the 
> length of the file? How?

not quite. it's the amount of space that jconv allocates, i.e. don't
make it much larger than the largest file you intend to use in that
config, it's wasted.

> 4. Should I do anything with delay/offset/length?

you can use the offset to cut away the impulse of the direct sound, for
aux-send style reverb. cutting the length could make sense if you want
to isolate just the early reflections and omit the reverb tail.
delay is interesting if you want the reverb tail treated separately,
because you must delay it to set in after the early reflections.
check out the example configurations for some rather involved setups
that demonstrate what can be done.

> 5. I'm especially interested in the settings for guitar (if you know 
> some nice Jazz IR files, tell me)

nothing prevents you from using aliki to capture some old fender amps.
but you should take into account that it only makes sense for the linear
operation, i.e. the tone color of the clean amp and speakers. as soon as
distortion sets in, simple IR will no longer cut it.

> 6. For what kind of instruments do you use reverb?

my choice of reverb does not depend on the instrument, but on the
setting. personally, i hate mixing different rooms in a single mix (the
old rocknroll disease of using a special snare reverb, another one for
the rest of the kit and a plate for the vocals).
i choose IRs mainly for decay (do i want to recreate an intimate, small
venue or a concert hall/church) and color (hard, glass walls, or wooden
panelling etc.), and then i stick to one IR for all instruments, varying
the dry-to-reverb ratio to simulate depth. only a few days ago have i
started to experiment with multiple ambisonic IRs (one per instrument
position), but so far i've screwed up. takes a lot of practice and
patience, and it's very easy to mess things up.