guitar amp/cab sims with impulse response loading

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thorgal
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Re: guitar amp/cab sims with impulse response loading

Post by thorgal »

funkmuscle, what are your system specs ?

I can use large IR files no sweat with my system, in RT mode (low latency).

@brummer :
gain setting still resetting to 0 each time the jconv setting window pops up. No clue as to why.
apart from that, the wet/dry is working as expected. Thanks :)
I still find too much gain variation when activating some inserts (the cry-baby insert blows up the overall gain)

Another more conceptual comment : I think there should be only 2 output ports out of "using guitarix with jconv". Your use of jconv is fine and functional, but guitarix uses it as an external app. It's a good work around for the time being. But consider a more integrated solution in future releases. It is probably not desirable to keep the jack routing like this. You'll probably have to create some internal busses for sends like jconv and reroute the bus output ports to the master bus of guitarix. In fact, it will become necessary when you transform guitarix as an FX host.

But for now, it is already very useful :) Just make sure the gain is properly handled as you switch on and off the different inserts.

brummer

Re: guitar amp/cab sims with impulse response loading

Post by brummer »

hi

@funkmuscle
I can use ir files up to 1MB size with a max mem size from 10000 setting for jconv. I set the min partion size to my jack frame buffer size and use the copy funktion from jconv. I cant use higher mem size because of my sys spec.

@torgal

mmm, realy strange with the gain set. I will search for a solution. :roll:
torgal wrote:Your use of jconv is fine and functional, but guitarix uses it as an external app
Yes, the reason is simple: it is a external app. There is no way to use it as plugin. I have talk with Fons about that, he say me he find no way to make it useable as plugin under the exists plugin api's in linux. So I only can use it as external application. Fons have build the convolution engine in the libary zita-convolver, this one can use to build a internal impulse response process, WHEN it is ready. For now, the only way to use this ImpulseResponse engine is as external application, so I build a host around jconv to get get it handled like a plugin.

regards brummer

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

Hey brummer, maybe you can make th jconv gui a standalone for people that want to use it for just reverb or with other guitar amp software or hardware.

my system is an AMD 1.7GB 2000+XP with 1gb of RAM.
is that enough? RT kernel.

maybe it's my jconv.conf files that are wrong.
can someone give me an example of one of your large jconv.conf files?

here is an example of mine:

# Where jconv will find its IR file:
/cd /home/harv/Impulse2/500Cabinet_Impulses/VoxengoBoogex/CabinetImpulses/Large

# in out partition maxsize
# -----------------------------------------------
/convolver/new 1 1 128 721000

# in out gain delay offset length chan file
# -------------------------------------------------------------------------------------
/impulse/read 1 1 0.3 0 0 0 1 Marshall_Plexi_SM57.wav

the IR file is 512kb and the xruns:

alsa_pcm: xrun of at least 0.057 msecs
**** alsa_pcm: xrun of at least 0.058 msecs
**** alsa_pcm: xrun of at least 0.063 msecs
**** alsa_pcm: xrun of at least 0.062 msecs
**** alsa_pcm: xrun of at least 0.034 msecs
**** alsa_pcm: xrun of at least 0.035 msecs
**** alsa_pcm: xrun of at least 0.044 msecs
**** alsa_pcm: xrun of at least 0.056 msecs
delay of 5364.000 usecs exceeds estimated spare time of 2378.000; restart ...
**** alsa_pcm: xrun of at least 0.032 msecs
**** alsa_pcm: xrun of at least 0.066 msecs
10:16:55.481 XRUN callback (10 skipped).

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

anybody around guys? this is annoying me that everyone can use jconv with large IR files and I can't.
I got jace to run the files but they all sound like if they're in large hall and I have no reverb on the guitar IR files.
I can use guitarix to load the small files but large(512kb) goes crazy with xruns.

thorgal
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Re: guitar amp/cab sims with impulse response loading

Post by thorgal »

funkmuscle, you seem to allocate A LOT of RAM for your IR file. Is it justified ? I use 120MB on my 4G RAM system, that's ~ 3%. You use 720MB on a 1GB RAM system, that's ~ 70%!
You may want to decrease it to about 10% and see what you get.

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

thorgal, I messed around for about 3 hours until I got it. thanx...
funny thing, I use a wet signal and the sound is like a huge hall. the same IR file through a vst with same settings sound like the amp is in my face.

just did what you mentioned and still killer xruns with an IR file at 512kb..
partition=128
maxsize=128000

jackd message:

delay of 5318.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5341.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5319.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5322.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5296.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5355.000 usecs exceeds estimated spare time of 2419.000; restart ...
delay of 5297.000 usecs exceeds estimated spare time of 2413.000; restart ...

been comparing jace, jconv, and jack_convolve to the vst IR loaders made for guitar and jack_convolve works exactly like them except on larger IR files I get the above jackd message.
I ran guitarix through jack_convolve and it rocked. Now, just getting the larger files to work.

thorgal
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Re: guitar amp/cab sims with impulse response loading

Post by thorgal »

could you upload your IR file somewhere ? I am interested in testing it. Thanks.

By the way, what's your jackd version ? I work with the latest SVN, it works better than the packaged one, which has many small problems (package = 0.109.2, IIRC).
I also don't work with jackdmp, it's never been as performant as jackd even though I run a Core 2 Duo system

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

I use jackd 0.115.1(svn)...I use ArchLinux which uses mostly the latest or bleed edge apps. Very easy to configure apps for your machine.
So you are using 64bit then right? Your cpu is dual core, isn't that 64bit?
That would run IR files way better than my AMD 1.7gb.....


sorry, no way of putting up IR file but it's any file over 100kb.

thorgal
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Re: guitar amp/cab sims with impulse response loading

Post by thorgal »

my system is 32bit.

brummer

Re: guitar amp/cab sims with impulse response loading

Post by brummer »

hi

I found some nice ir files releated to marschal here:
http://www.grgr.de/IR/
look for the Ampeg V4B Bass Amp files. They are only 15,7kb and sounds real good.

@funkmuscle do you ever try to run jack with a higher Frame Period (1024) and set the min partion size to this ? I hope you have set your system to

Code: Select all

@audio           -       memlock         unlimited
brummer

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

Thanx for the IR file. I have it already... if I run jackd at 1024, it works but the latency is crazy especially when trying to record a track in Ardour.
I use the IR file to record the tracks live. I don't record the track first then add the amp/cab sim.

brummer

Re: guitar amp/cab sims with impulse response loading

Post by brummer »

if I run jackd at 1024, it works but the latency is crazy especially when trying to record a track in Ardour.
sure, but now, if we know that, we can search better for the reasons why. 8) Something in the float isn't working like it have to be. For example, I, when I run a live audio session I set up my system to the best known settings with a rt-setup script. That make it zb. posible for me to run 1gb ir files with 128 partion. I have a PIII with 528MB Ram, you see, it's real poor. 8)

I set my harddrives to ultra dma III , I push the latency for the pci bus for my audiocard and give the irq from my card realtime priory = 99

here it is, but note, you cant use it like it is, this one is for my system. If you wont to try it, you must set your harddrives and the irq from your soundcarte.

Code: Select all

if [ "$USER" = "root" ] ; then
 hdparm -X66 -d1 -u1 -m16 -c3 /dev/hda #set here your harddrive
 hdparm -d1 /dev/hda # and here
 hdparm -X66 -d1 -u1 -m16 -c3 /dev/hdc  #if you have two ore more
 hdparm -d1 /dev/hdc
 setpci -v -s `lspci | awk '/[A,a]udio/ {print $1}'` latency_timer=80 # check for your soudcarte and set latency
 chrt -f -p 99 `pidof "IRQ-5"` #set here the irq from your soundcarte
echo " setup for audiosession complet "
else
echo " sorry, you must be root to run this script  bye"
fi
And you run jack with "No Memory Lock" uncheckt.?

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

gonna try the hdparm and other things because this is crazy. brummer, why does the jconv when set to 100% wet sound like I've added reverb to my system when all I've don't is load a guitar IR file?

brummer

Re: guitar amp/cab sims with impulse response loading

Post by brummer »

when you set the slider to 100% wet, you get only sound from jconv, the wet/dry slider in guitarix is direct befor the outputports to jack, after the balance slider, the singnal will only slide between the outputports (guitarix:out_0, guitarix:out_1 are the normal output, guitarix:out_2 and guitarix:out_3 are the outputs to jconv) there is no reverb, at this point is nothing add or sub by guitarix. In this case you get the same sound when you start jconv over the commandline and connect it with qjackctl. :D

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funkmuscle
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Re: guitar amp/cab sims with impulse response loading

Post by funkmuscle »

I run it wet because that's what the guys at all the IR files for guitar says to do. I run it wet with the vst plugins and they sound so real.
I think jack_convolve runs wet by default because it sounds like the vst IR loaders.
I get a true amp sound with it.
I do a: jack_convolve --gain=x <IRfile> and that sounds like any of the vst plugins.
just can't load the large files.
my soundcard shares the irq with the usb port...could that be an issue?

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