planet Z

Date: Tue, 19 Jan 1999 02:27:09 -0500
To: pulsar-dsp@usa.net
From: "Bob Chapman" <bc@artisan.win.net>
Subject: Pulsar creates a Lickin' but keeps on Tickin'

I recently responded to a question about how many tracks one could expect with an audio app and Pulsar running together. I reported that I was up to 26 tracks being fed into Pulsar's mixer with no apparent problem and reported that as the most I tried.

Well I seem to have found my limit... 28 tracks played out of Cakewalk 8.01 into Pulsar's mixer is too much I'm afraid to say. I have an ABIT BH6 w/128mb ram, Celery overclocked to 450 mhz and an IBM 7200 9.1 gig SCSI on Adaptec 2940UW.

The 2 projects (both the 26 track and 28 track projects) have no Direct X plug-ins running...this is straight out of Cakewalk. The files are *however* 24 bit files. I'm just setting Cakewalk to 16 bit for playback purposes into Pulsar until Creamware releases the 24 bit wave drivers. So even though Cakewalk is set to 16 bit for playback with Pulsar, keep in mind that the actual waves being played back thru Cakewalk and into Pulsar are 24 bit waves. So mileage may vary if your project contains 16 bit waves. I would think your track count would be higher. (Oh yeah...forgot...not only are our projects 24 bit but they are also 48 khz...more of a hit).

It definately appears to me that effects via Pulsar do not seem to load down Pulsar at all until you begin to reach your DSP overload. So far I have not reached the overload with inserts and effects. This is good....you can surely add effects and processes in Pulsar for audio and the CPU does not take a hit. There seems to be a lot of headroom for inserts etc,etc..

The only bad thing I have to report about all of this is that Pulsar itself is resource hungry...not even thinking about the SHARC DSP's, just the program itself. I know many are reporting this. It's like if you can get your multitude of tracks to play back in Pulsar you are home free when it comes to Pulsar's inserts...because from then on the SHARC's do the work. But Pulsar itself is a bit of a hog.

I proved this to myself with a simple experiment. The 28 track project that I mentioned above stalls out in Cakewalk when I am routing it to Pulsar's mixer. But when I set up Cakewalk to use my Frontier Wave Center the 28 tracks playback without any problem at all. So Pulsar (the program itself...not the DSP) does take a chunch of CPU that will most likely reduce your track count.

Conclusion...Pulsar's DSP power is great once you get your max track count to playback but the program is hungry for power. I think I will try sub-mixing to get a lower track count so that I can take advantage of Pulsar's effects/processing. On a positive note...if I tried to apply the same amount of Pulsar effects/processes by using Direct X in Cakewalk and playback thru Frontier Wave Center I would probably hit a brick wall much sooner with 28 tracks. So I don't feel so bad...it's a small trade...reduce some tracks, get it into Pulsar, take advantage of the SHARCS for much more effects/processing then possible with Direct-X.

On the other hand I have to stop and think...this is a lot of DSP power I have available now for mixing and effects and I'm able to play 26 tracks of 24 bit 48 khz audio with loads of inserts and no problem. This is *far* better than I have ever had! My goal however is 32 tracks of 24 bit audio with no problem anywhere. I'm close but I think ( I suspect/pray!) that maybe a 10,000 rpm Cheetah on an Adaptec 2940 U2W SCSI card could at least get me the 4 more tracks I'm hoping for. That plus maybe an upgrade to 500/550 mhz later this year would surely do it. If I knew I could do 32 tracks of 24 bit with no problem ever then I would be satisfied for quite a long while. That would be cookin'.....

Date: Sun, 21 Feb 1999 11:11:21 -0500
To: pulsar-dsp@onelist.com
From: "Bob Chapman" <bc@artisan.win.net>
Subject: Hit the DSP jackpot!

Here's some interesting news on the DSP load limit when using Pulsar strictly for Mixing...no synths loaded. I was mixing 26 tracks of 24 bit audio being played back into Pulsar from Cakewalk 8.03. I hit a DSP overload and here's the results of what I ended up getting out of Pulsar before it maxed out the DSP. This might give someone an idea of what you can expect out of Pulsar for Mixing

(18) EQ's running in 18 channels
(6) Mono Compressors runing as inserts in 6 Channels
(1) Stereo Chorus routed out of aux 1 and into (1) Stereo Delay then routed back to Channels Mix 15 &16.

(I had 8 vocal channels sending to the Aux for the Chorus and Delay)

I myself am very happy with these results. Of course I wish I could do much more, but comparatively speaking I consider this very good. There's no way I could run all those EQ's, Compressors, and Chorus/Delay using Direct X. I'd be "brickwalled" way before I even got close to this. So to me this is great that I can run that much.

So here's some ideas on how to get the rest of the tracks EQ'd and Effected when using Cakewalk and Pulsar.

1) I might look into using Direct X EQ'ing within Cakewalk and apply the Direct X EQ but process the results to 2 new waves and then Archive the original in case I change my mind.

2) Another way would be to Solo tracks and run them thru Pulsar's EQ. Setup Cakewalk to record the result. All you have to do is hook up a Wave Dest Module to Mix L/R and you're ready to record your processed waves right back into 2 tracks of Cakewalk. Archive the original tracks in case you change your mind and want to re-EQ later.

3) Another way of course is to process audio thru routing in Pulsar to external devices. But so far we have no digital outboard gear so this is out of the question since the audio would have to go to analog and we want to keep it digital all the way. But for anyone with digital EQ and Processing/Mixer this would be a great way to go also. And of course you could record your results right back into your file.

In the above ideas I was using EQ as an example but we'll probably try all sorts of things such as Reverb and other effects. I figure that if I can do some offline processing I can turn off some EQ's in Pulsar and thereby reduce the DSP load so I can do new EQ's, compressors or whatever. So hopefully by balancing between Offline processing, Pulsar realtime processing, and maybe even a few realtime Direct X plug-ins, we'll be able to get everything mixed the way we want it!