Ableton Forum

Just for the record, there is a principal difference between reverbs based on convolution like Altiverb, and algorithmic reverbs like the PSP reverb, the Lexicon stuff and Live's reverb.

I could write a long story now, but in short here is the pros and cons of both approaches:

Convolution:

+ infinite number of possible rooms
- needs good IR to create good results
+ very high density of reflections, therefore quite naturalistic
- no slow variation over time as with good algorithmic reverbs, therefor a bit static and cold
- high CPU
- high latency
- no way to achieve real time change of parameters for special FX
+ convolution can be used to create very special rooms, like being inside a bottle etc..
+ most "invislble" reverb, perfect for adding subtle room.


Cheers, Robert

Robert - on your last point, my dealings with reverb seem to have two distinct sound qualities, not there or HEY EVERYBODY LISTEN TO THE DAMN REVERB!. So are you saying convolusion reverb might be a better option for unskilled labor such as myself?

Opus wrote:

Meef Chaloin wrote:WTF? Since when has Altiverb been for XP as well?

i think since Version 6.

Opus wrote:

Meef Chaloin wrote:WTF? Since when has Altiverb been for XP as well?

i think since Version 6.

no no no, that's echo not reverb!!!
....how many timess....

lola wrote:Sir

I just bought SIR2, but without the HDIR extra package. Instead I went for the Bree Casedy (Bricasti M7) impulse response library. Like I said in another thread, I wish I could afford the real deal...

http://www.knufinke.de/sir/sir2.html
http://www.studiodevices.com/
http://www.bricasti.com/m7.html

Robert Henke wrote:- no slow variation over time as with good algorithmic reverbs, therefor a bit static and cold

Yup, that's the biggest downside of a convolution reverb, but this only becomes a real issue, if the music itself isn't dynamic enough! A band won't have this problem...

Robert Henke wrote: - high latency

Hmm, I haven't noticed high latencies with any of the convolution reverbs I've tried and I'm very sensitive to this...

Robert is correct that there are pros and cons. You wouldn't really want to be using a convolution reverb on a live set unless you froze or flattened the track or rendered it as audio, because of the very high 8,000 plus latency samples many of them incur. However, they accurately represent acoustic spaces so well and often do sound great. I think most of us have heard of Altiverb and anyone who has used it thinks it is an awesome sound - just that the price is very high and hard to justify when other alternatives such as SIR (free but more limited) and the much cheaper (sub 200 dollar) SIR2 and Voxengo Pristine Space (also know as SOnar's 'Perfect Space' which they license to Cakewalk) are almost as good and cost only a 3rd of what Altiverb costs.

well, if you buy a 2nd laptop just to run a stereo send to Altiverb you should be fine. The thing about Altiverb is that it's very easy to over use it. It only needs a subtle signal to add realism to the track. It really adds a deep organic sound to the mix this way. Keep the mix knob way down and the decay way down. If you clearly hear the reverb while it's on, it means it's up too high. You want to use just enough so you only notice it when you bypass it. If you aren't aware of a reverb in the mix until you bypass it, then you're right on the money. Unless you're using it as an effect, like throwing sounds in the back of the mix, then bringing them to the front, or having a sound panned to one channel with the reverb mixed near 100% on the opposite channel, or even a reverse reverb, then I always do those tricks in the studio and render them for live..

leedsquietman wrote:You wouldn't really want to be using a convolution reverb on a live set unless you froze or flattened the track or rendered it as audio, because of the very high 8,000 plus latency samples many of them incur.

I'm really wondering why you guys (Robert and you) are making these general statements about the latency of convolution reverbs...

Convolution technically needs a what is called block-wise calculation to be efficient.
This means audio signals are stored in a buffer, processed, and put out. There is a connection between the size of the buffer and the CPU the process needs. The smaller the buffer, the higher the CPU load. Therefore, putting a convolution reverb in a DAW that has latency compensation such as Live will increase the total latency of the system, which might be an issue in some cases, like dealing with live input of instruments. In a mixing or editing situation this is mostly no problem at all.

Algorithmic reverbs do not need to be processed block wise, or there is at least no benefit from very large block sizes, and therefor they do not need to introduce additional latency to the DAW.

However, if latency is perceived as a problem or not is a highly individual preference, so it comes down to the same thing as usual: do or use what ever you like most.

Robert

I like the ArtsAcoustic reverb. Pretty simple but sound great to me and its not convolution and doesn't take much CPU.

I just use Acoustic Mirror in sound forge and a nice set of impulses.

I also use Acoustic Mirror occasionally.

It's not a generalization. SIR imparts 8,960 samples of latency (according to the plugin information in Cubase SX3), and other convos are usually there or thereabouts in my experience. The worst offender is actually the multiband compressor in Cubase, with 12,160 samples of latency.

Algorithmic reverbs are much better for lower latency needs.

I've used altiverb before but I tend to stick to lives reverb and blackwaterreverb I think is what it's called. thats when I'm using software. I use alesis quadraverb gt and midiverb 3 often for hardware. I don't ever feel like I'm missing anything and needing to go with altiverb. the alesis racks aren't the best but I like them.

a lot of the artists I listen to didn't need to use IR reverbs, they made their music before that was even a possibility. what they used on their records sounds great to me so I don't really see why I would go with something "better". if I want the sound of an actual room on something I've been known to take a mic and record the sound of my monitors in the back of the room. of course it's not the quality of a proper IR but it's mine.

I would definitely like to get a spring reverb though, but I have other things to buy first

The thing that sets Altiverb apart is the library, which is very extensive, with lots of microphone positions and surround configurations, that's what you pay for.

@ Robert & leedsquietman: SIR2 does not introduce any additional latency to the DAW! Obviously you gentlemen aren't aware of that...

How do you know this?

I don't have SIR2 so cannot compare and Live doesn't give you plugin information. Live will auto delay compensate for this, so in a mixing situation, the original SIR or whatever is still OK. Just not a good option for tracking ...