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Q: 3rd party Mac deconvolving app?
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Jul 28, 2009 11:44 PMby Joey Goldstein,Hi John
I've got a copy of the Logic Studio Instruments and Effects PDF (for Logic Pro 8) and I can't see anywhere in the Space Designer instructions where it mentions deconvolving a .wav file of a sine sweep or nayhting remotely like that.
Is this a special non-documented function of SD?
If so, is it possible for you to give me a brief description of how it could be done?
Any info appreciated.
I'm looking into whether it might work for me to keep my present system, buy (or find) a copy of LS8 and see if I can get by and do some of the things I'd like to do.
Chief among these "things" are:
1. Acquire a more complete EXS24 library with more orchestral sampler instruments.
and
2. Gain the ability to create IRs of guitar cabinets to be used with my Axe-FX.
[I suppose that if I did have LS8 running on my system that I could use the IR Util to re-record the sweeps I've already done.]
I know that this is probably just wishful thinking and that ultimately I'll have to spring for a more powerful system to run Logic Studio.
I know that LS8 will be severely hampered on my current G4 1.25mHz system.
Do you happen to know if the IR Utility will even run on a G4? -
Jul 29, 2009 11:37 AMby John Buehler,Regarding the deconvolving with SD, it is not documented. It's been a while but I seem to remember it being easy. I'll poke around later but I have a deadline on some mixes, and then I'm installing 9. See this thread (not that helpful but still):
http://discussions.apple.com/thread.jspa?threadID=1475841&tstart=0
Your computer is fine as far as the IRU goes. Either way you will need LS8 (or 9), so I guess if I were you I'd just start over with the IRU. Don't anticipate that your computer isn't good enough, try it first. And regardless of whether you use SD or the IRU, you will need to convert the SDIR to a .wav, which should be no problem, it's basically an aiff and should be easily converted (although not with Logic). -
Jul 29, 2009 11:58 AMby Joey Goldstein,Hi John
1. I have seen that other thread, thanks.
(I just happen to have a working copy of Logic Pro on my system right now {don't ask me how}, and when I use the Controls View of Sound Designer there is nothing mentioning deconvolution on the rh side or anywhere else that I can see. I can load my .wav file of a sine sweep into SD via the load IR controls and I can do some editing to the sample, and that's about it.)
2. My sine sweeps are already in .wav format.
I thought that after I deconvolve the .wav file that the new file that I'd be saving would have the .sdir extension and that it would be the actual impulse response itself.
Is that not correct?
3. I've also been able to load some guitar cabinet IRs in .wav format created by other people into SD and they seem to work.
Is the .sdir extension just saying that whatever file it is appended to happens to be an audio file created by Sound Designer?
4. I'm closer and closer, minute by minute, to just going out the door and buying a new iMac plus the LE8 to LS Upgrade and be done with it.
Still, I'm cheap and want to keep my money in my pocket.
Thanks for any help/info/tips. -
Jul 29, 2009 12:27 PMby John Buehler,I thought you needed a .wav when you were done. I think that a .wav is the same as an aiff but the data in the word is reversed.
I checked SD, it's right there on the right side of the controls window, (not the editor) there is a "Decode IR" pulldown. Easy.
The.sdir extension is just what you said, and are IRs made by SD (or by the IRU to be used in SD), but they are basically an aif. -
Jul 29, 2009 1:26 PMby Joey Goldstein,Hi John
1. I guess that both .sdir and .wav, and maybe even .aiff, files can be used as IRs within Space Designer.
2. OK. I've been getting some action now with the "Decode IR", but I don't really know what I'm doing.
a.) First it asks me to "Load Coded Impulse Response for Deconvolution". So I load in my sine sweep .wav file.
b.) Then it asks me to "Load test signal". I have no idea what that means, but I go ahead and load the sine sweep .wav file again.
c.) Then it asks me where I'd like to "Save decoded IR", and it generates a .sdir file on my disk.
Needless to say, the resulting .sdir file is useless, presumably because I don't know what to do in step b above.
Also, there are no options for controlling the features of the generated .sdir file, such as the length in samples or in milliseconds.
So what am I missing?
FYI
My sine sweep started out as a 10sec broadband sweep.
After trimming the silent portion it's down to 6.04secs.
This IR I'm trying to create is supposed to end up as a suitable IR for a guitar cabinet simulation within the Axe-FX.
Axe-FR cab IRs need to be 512 or 1024 samples long @48k. My Project and my sine sweep .wav are all set to 48k.
Assuming that I figure out what to do for step b above and I mange to obtain a decent .sdir file that works as a cabinet IR, how can I open up the .sdir file in an audio editor for further processing?
Can I just change the extension to .wav? -
Jul 29, 2009 2:40 PMby John Buehler,1) yes, all formats ok in SD.
2) You need to load in the original sine wave before convolution so it has something to compare it to. The original sweep and the post-convolution sweep need to start at the same time, do not trim the front.
3) Open the .sdir in an audio editor other than Logic. I use Audio Finder. Soundtrack Pro might do it. Swapping out the extension might work, but probably only if you make it an .aif, not a .wav, because it is inherently an .aif. -
Jul 30, 2009 12:01 PMby Joey Goldstein,OK. I see now in the Space Designer 7 manual that the Test Tone file is supposed to be the same file as the sine sweep file.
But the resulting .sdir files I'm getting don't seem to be right.
They seem to be an IR of a flat frequency response, not the freq response of the speaker.
Actually, to start with I've been trying to get an IR of a passive analog speaker simulator box made by Palmer (PDI-09), rather than a real speaker. I figured it would be simpler to start with because I wouldn't have to deal with any mics.
I'm pretty sure that the recording of the actual sine sweep through the PDI was done correctly. 10 sec sweep, 20 - 20k.
Has it ever been confirmed that the Space Designer 8 Decode IR functions actually work the way they did in SD7?
I mean, I know that the functions are there still, but maybe they don't work.
They are not mentioned in any of the LS8 support documentation.
Maybe, since LS8 includes the Impulse Response Utility, and since I don't have this utility installed on my system, I'm missing the Application Support files that are needed to make this work?
Oh well. This is frustrating.
I don't really want to buy LS or a new computer to run LS (which is probably what I'll end up doing anyway) until I'm sure that some of these features are going to work out for me.
And my current little system is running really well right now. I don't really feel like I need a new computer yet. But I'm getting there. -
Jul 30, 2009 1:50 PMby John Buehler,It is unclear to me what you are saying, but SD 8 has worked for me before. The sweep before and the sweep after need to be compared, not the same sweep twice, that would result in no change and a flat sound. That is what you are doing, right? First you link to the post-sweep file, then you point to the pre-sweep file.
Using the IRU is way easier. No idea why you need to do this in SD. If you are using a legit copy of LS8, you would have the IRU, it was made for this, and that's all I use now. And if you don't have a legit copy, then I'm wasting my time trying to help you. The task you are trying to accomplish is done with the IRU. And you don't need a new computer to run it. -
Jul 30, 2009 2:25 PMby Joey Goldstein,1. At the moment I am not using a legit copy of LS8 (I've strongly hinted so several times already), so I'm sorry if I'm "wasting your time".
Like I said before, I'm trying to make sure that I'll be able to do these things if and when I do upgrade my computer (many important features of LS8 will hardly run at all on my present system) and then upgrade from LE8 (yes, I am a legit owner of LE8) to LS.
I just want to be sure that I'm not going to be wasting close to $2k. Hopefully you can understand that and cut me some slack.
2. What "pre-sweep file"?
I have my recording of a 10sec long sine sweep through the Palmer speaker emulator (generated by LE8's Test Oscillator plugin, and recorded in LE8). That's the file I want to deconvolve and use as an IR.
3. Am I also supposed to record some other type of a "test file"?
If so, then what do I need to do to do this?
Any help you offer is greatly appreciated. -
Jul 30, 2009 5:16 PMby John Buehler,You want to make sure that you can do what you want to do with SD, even though no one uses SD for this. You are "testing it out" using a cracked piece of software to do it, which has obviously got the possibility that it doesn't work. It makes no sense man. So I will explain it once more, and then I'm done.
In order for convolution to work, the engine needs to know the file that you started with, the dry, unprocessed sine wave sweep BEFORE it ever went through anything. That is the test file. It gets compared to the one that went through whatever it is you are emulating, and then it calculates the impulse. If you just feed it the post-sweep file, it has no idea how to calculate it. That's why the IRU exists, so that the whole process is done by the software, from sine wave to SD preset. Otherwise, using the SD method, there are many chances for operator error. You want to make sure that it works in SD, but no one does this, they use the IRU! That's why this is a waste of time. So, good luck. Buy Logic. The IRU works fine.
