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View Full Version : Taking the pressure off the CPU????




e-clipse
Aug 18, 2006, 10:23 PM
I am new to Macs. I was wondering if one of you audio tech savvy guys could help me understand something.

Back when I was a PC guy, if I wanted to spare the CPU from doing all the work I bought an internal audio card (interface) . The card then ran in ASIO
with virtually no latency. I could pile a multitude of tracks and tons of effects, while the CPU bar barely budged forward, and the music barely even hiccuped , even with only 512 megs of ram.

My question is, how do I get the same result with my MacBook Pro? If I bought a firewire 400 audio interface would that take the pressure off the CPU, giving me better results? Or would I need a Firewire 800 express card?
Or is this possible?



zimv20
Aug 18, 2006, 10:59 PM
a run-of-the-mill firewire converter box won't do what you're asking. most DAWs are written to be "native", meaning the audio calcs, plug-ins, virtual instruments, et. al. are all running on the mac CPU(s). this is true of PTLE, Logic, Digital Performer, Garage Band, et. al.

a notable exception is ProTools HD, the rather expensive solution which gives you some number of PCI cards that do the calcs.

there're also the UAD cards, which allow off-loading of plug-ins only (and maybe virtual instruments? not sure). but plugs have to be written specifically for that platform, it doesn't allow any ol' plug to be processed on it. of course, that won't work on your laptop.

zimv20
Aug 18, 2006, 11:05 PM
btw -- are you asking theoretically, or have you actually run out of CPU power on your MBP? i ask because the songs which maxed out my dual/500MHz g4 p'mac used only 25% of my CPU on my current p'mac, a dual/2GHz g5. i'd expect you could do a lot of processing on your machine before running into trouble.


here's a real example: this session, with a decent number of plugs (but no virtual instruments) uses about 10% of my CPU:

http://www.boxsetauthentic.com/images/gear/ptconsole.jpg

e-clipse
Aug 19, 2006, 10:56 AM
Rossetta
I do not ever run out of CPU power, but I do see it raise up to 80% fairly easy. I get a lot of hiccups which could be a ram issue. In Reason 2.5, which is under Rossetta, many of my tracks usually come to a halt, with a pop up menu telling me that my computer is too slow to play the track, bounce the track to a stereo AIFF file.

Universal
In GarageBand, after I have laid down 5 to 6 real instrument tracks, I start getting 500 ms to 1 second latency, which makes it nearly impossible to do any more work on the track without bouncing tracks. I do not want to bounce the tracks, because I would like to be able to come back to the project and have full control over each individual track.

zimv20
Aug 19, 2006, 11:01 AM
In Reason 2.5, which is under Rossetta
why not simply upgrade to 3?


In GarageBand, after I have laid down 5 to 6 real instrument tracks, I start getting 500 ms to 1 second latency
yikes. i take it you mean that you're monitoring track #7 after it's been processed by GB? if so, there are a number of ways to monitor signal #7 before it even hits the converters. does your interface not offer no-latency monitoring?

e-clipse
Aug 19, 2006, 11:29 AM
I plan on upgrading to Reason 3.0.5 Universal. First, I want to upgrade my ram. I will probably upgrade it second. So, in GarageBand... after I record the track, I should turn off monitoring except on the track I plan to record? Would that save me from latency issues? I am using the core audio from the MacBook Pro. When I use GB, I make sure to optimize audio for recording live tracks and large track counts by changing the buffer size.

zimv20
Aug 19, 2006, 11:49 AM
in GarageBand... after I record the track, I should turn off monitoring except on the track I plan to record?
that's not what i meant. you obviously need some tracks playing, so you can lay down the new part. for that new part, you have to find a way to monitor that w/ either low- or no-latency. in PTLE, i simply turn on Low Latency Monitoring, which provides latency low enough to be acceptable to most people i work with.

i don't know GB, so i don't know if it offers something similar. if not, then you have to split the signal in analog, after the pre but before the converters. many h/w interfaces provide a way to do it. if yours doesn't, then you're in a bit of trouble if the same box provides the pre and converters (a serious design flaw, imo).

with a separate pre and converter, you could use a y-cord, or half-normal a patchbay (which is basically a y-cord). some pre's offer two outs: balanced and unbalanced. i've used the unbalanced out for monitoring before. of course, if you have a (good-sounding) mixing board, you could route the signal through there and use any of a number of ways to split the signal.

i don't know your setup -- maybe post that and we can go from there.

e-clipse
Aug 19, 2006, 12:07 PM
My setup is basically non-existant at this point.

I have a Radium 61 midi keyboard that is only connected by USB because I don't have a midi setup with the Mac like I did with my PC sound card. With only software synths playing, I do not get any latency in the USB transfer from the keyboard. I mainly record guitar tracks through a Digitech RP200A multi-effects processor. I don't lay down speech or vocal tracks at this point. I do not have mic pres or mics except the built-in mic on the MBP. I do not have a hardware mixer. Basically my arsenal is a keyboard, guitar and a set of cheap monitors.


Being a college student, money is spent on school, so buying the gear I need is a long slow process. My only real studio experience is the experience I get from studio recording classes at school.
We use a Pro-Tools Hd rig with a cheap Mackie console and 5.1 JBL Monitors.

My future setup is as follows:
2 896 MOTU Firewire Audio Interfaces daisy chained with 16 mic pres
Mackie Universal Controller with Mackie Big Knob
Logic Pro
Event ASP8'S
Yamaha NS-10'S
AKG C414
AKG 451
Shure 57
Shure 58
Sennheiser 421

zimv20
Aug 19, 2006, 12:32 PM
I mainly record guitar tracks through a Digitech RP200A multi-effects processor.
so is this where you're getting the latency? you play a chord (say), and you hear it in your headphones 1/2 - 1 second later?

zimv20
Aug 19, 2006, 12:45 PM
AKG 451
include the josephson c42's in your search. i've not used them, only heard them, but if i were in the market for a pair of small diaphragm cardioid condensers, i'd start there. they're cheaper, too.

my old studio had a pair of 451's, which we used for pretty much all our drum overheads. we got good sounds from them, certainly, but nothing magical.

and if you want some budget, but excellent, small diaphragm omnis, check out the avenson audio sto-2's. only $500 for a matched pair. i used them once to record a jazz band in a 3-mic setup (3rd mic was for the vocalist). absolute magic on the drums (which were excellent sounding and very well played). you can hear them in action in this mp3 (http://www.boxsetauthentic.com/Music/misc/Jecklin%20Samples%20060130.mp3). the pre's i used were BAE 312a's, and the converter was an apogee rosetta @ 96/24.

Sennheiser 421
i keep putting off buying this mic. someday...

e-clipse
Aug 19, 2006, 12:56 PM
so is this where you're getting the latency? you play a chord (say), and you hear it in your headphones 1/2 - 1 second later?

Yes. It works fine until I lay down 5 or 6 Tracks of guitar. I know... that is a ridiculous amount of guitar tracks. I strum a chord, and get the 500 ms to 1 second delay.

e-clipse
Aug 19, 2006, 01:16 PM
include the josephson c42's in your search. i've not used them, only heard them, but if i were in the market for a pair of small diaphragm cardioid condensers, i'd start there. they're cheaper, too.

my old studio had a pair of 451's, which we used for pretty much all our drum overheads. we got good sounds from them, certainly, but nothing magical.

and if you want some budget, but excellent, small diaphragm omnis, check out the avenson audio sto-2's. only $500 for a matched pair. i used them once to record a jazz band in a 3-mic setup (3rd mic was for the vocalist). absolute magic on the drums (which were excellent sounding and very well played). you can hear them in action in this mp3 (http://www.boxsetauthentic.com/Music/misc/Jecklin%20Samples%20060130.mp3). the pre's i used were BAE 312a's, and the converter was an apogee rosetta @ 96/24.


i keep putting off buying this mic. someday...

We use the 451's for overhead xy coincident mics, which are mainly used to capture large vocal groups. They are also used for drum overhead mics as well. The reason I like them, is you can turn them up loud when using a good mic pre, and get alsmost know noise at all. When the cheap Samsons were put under the same test, they had awful noise.

I am definitely going to look in to the Josephson C42's. I wish to get a project studio together by my Junior year at MTSU. That way, I can improve as an engineer, and get a better learning experience in the studio.

Your omni-directional mics caught a magnificent sound from the group. The recording has that ambient feel of being there versus a studio magic album, which sometimes lacks that organic feel. Great work! I will also check out the Avensons.

The 421's are great for big natural kick drum sounds and bassy or warm vocals. I love it when a mic is so good at doing it's job it requires less eq'ing to get good results.

zimv20
Aug 19, 2006, 01:33 PM
Yes. It works fine until I lay down 5 or 6 Tracks of guitar. I know... that is a ridiculous amount of guitar tracks. I strum a chord, and get the 500 ms to 1 second delay.
actually, i think that's a reasonable number of guitar tracks.

sounds like GB just can't handle it. a shame. regarding the digitech pedal, is that a digital connection between that and the mac? if it's analog, you can split the signal and then rig up some kind of device to mix the monitor split with your pre-recorded tracks (can you solder?). if it's digital, you're kind of stuck. best bet is to bounce down your 5-6 guitar tracks to a single track, just so you can get down the rest of your parts.

zimv20
Aug 19, 2006, 01:39 PM
When the cheap Samsons were put under the same test, they had awful noise.
yeah, i bet.

The recording has that ambient feel of being there versus a studio magic album, which sometimes lacks that organic feel. Great work!
thank you, that's what we were going for. the group hated everything they'd done previously in the studio, and told me they wanted that "feels like i'm there" sound.

it was the first time i'd done a live recording, and also the first time with such a setup (including a jecklin disc between the avensons). we did two nights, and i learned a TON. unfortunately, due to some number of factors, the thing won't be released. i'm a dumbass for doing it pro-bono.

The 421's are great for big natural kick drum sounds and bassy or warm vocals.
have you tried it on electric guitar yet, instead of a 57? in addition to my own 421, i'm saving up for a nice ribbon mic to try the combo.

e-clipse
Aug 19, 2006, 01:53 PM
It is sad that the project won't see it's way into production. I always put myself in those situations too. You live and learn.

It is digital. I guess GarageBand remains limited, so you have to move to Logic, or your tool of choice. I guess I am just going to have to deal with saving multiple projects for just one song.

1. Saving all tracks individually just incase I do not like the bounced tracks for reasons such as eq, volume, or effect .

2. Saving bounced tracks to new project for recording new tracks.

We have never used a Sennheiser on a guitar, but I am sure that could do wonders for heavy metal, rock, or blues. And the ribbon could capture the crispness of the amp's tone.

zimv20
Aug 19, 2006, 02:33 PM
I guess I am just going to have to deal with saving multiple projects for just one song.
again, i don't know GB, but after doing the submix, try turning off (mute? another method?) those individual tracks and see if that works.

and we're just talking about overdub time, i thought. at mix time, you should be able to turn the individual tracks back on and mix it fine.

in thinking about this, i'm surprised that GB would choke from just simply playing back audio files. are there plugs on those tracks? try turning those off. also, are you using an external drive for your audio? playing back from the (slow) internal drive, which is also busy doing work for the OS and the GB app itself, could cause problems.

e-clipse
Aug 19, 2006, 03:03 PM
Sorry... I did not explain myself right. It won't choke during mixing time. From now on, I will record the basic structure of the song in Garageband, and then take the tracks that are not needed and cut them and paste them into the mixdown project. GarageBand does not use any other plug-ins besides it's own, which are not that great.

At this time, I am using a 5400 RPM internal drive that came in my MBP.
I plan on getting a Lacie mini external drive with extra firewire port for chaining and usb hub.

zimv20
Aug 19, 2006, 03:24 PM
I plan on getting a Lacie mini external drive
that may do it right there. internal drives can handle a couple tracks okay, but i think you're seeing the limits.

e-clipse
Aug 19, 2006, 03:53 PM
Thank you for helping me troubleshoot what is holding me back in my music producing experience in the Mac world.

zimv20
Aug 19, 2006, 04:07 PM
you are most welcome.

zimv20
Aug 19, 2006, 10:11 PM
Event ASP8'S
dunno if you're ever at gearslutz, but i ran across a couple threads today about the asp8's. here (http://www.gearslutz.com/board/showthread.php?t=82042) and here (http://www.gearslutz.com/board/showthread.php?t=80043).

fwiw, i currently have mackie hr624's (which i think i've outgrown). i'm probably going to pick up something new in the next month or two. at the top of my list atm are the adam p-11a's.

e-clipse
Aug 20, 2006, 12:24 AM
Wow! I noticed jazz tone's reply regarding the click sound which is common is kick samples. It is hard for me to get rid of it to with the cheap bookshelf speakers. I end up monitoring on 3 or 4 sets of speakers back and forth til I can eq or filter it out of the equation. I know that is just one guy's review, but he hit upon an important point to electronica artists. There were actually more JBL bashers than Event.
I also discovered that the school, Full Sail has replaced most of the monitors in the classrooms with JBL LSR6300'S. I will investigate this more. The old JBL's at school are easy on the ears at extra long listening periods. (talking 8 to 10 hours)

Those guys got a great deal at Guitar Center. Here in Nashville, we only have two large music stores, which are Sam Ash and Guitar Center. Guitar Center has better staff, with a good attitude, which is most important. The Sam Ash guys have a chip on their shoulder and kill the vibe to shop and enjoy the experience.

I really love the review between the Adam A7's and the ASP8's. Most people on the forum had good comments on the fatigue factor, which is great news. Maybe, I will take a trip to guitar center and test out the 3 competitors in the mid-range category.

Those Adams look like amazing monitors. I am sure those folded ribbon tweeters are accurately superior to your average run of the mill tweets. I definitely cannot affords those anytime soon. This Mac cost enough as it is! I am happy with it.Thanks for the info!

XP Defector
Aug 21, 2006, 01:26 PM
Are there no such things as ASIO drivers for MAC? I remember on my PC, that ASIO significantly took pressure from the CPU (compared to using Direct X).

e-clipse
Aug 21, 2006, 03:19 PM
On my pc, ASIO reduced CPU usage from 75% to 20%.

Derwood
Aug 22, 2006, 05:45 AM
...on my stock 512mb 1.83ghz MacBook (non-Pro) I can get about 14/15 tracks of audio (no software instruments) before I start running into problems. I obviously mix as I go and lock tracks once I'm reasonably happy. It takes a little time to do so but it certainly helps. I'm running a fair few plug-ins as well. Nothing too intensive, no amp sims or anything, but comp, EQ, High & Low pass filters, reverbs, delay. Combinations of these on each track. I am also running OS X, Garageband and all audio off the internal 5400rpm drive that came with it.

At the moment have a mobile pre USB from M-Audio which I know comes in for a bit of stick but performance per pound, or bang for your buck, it's difficult to grumble. Provides zero latency monitoring is the reason for mentioning it.

I wonder if further dual-core optimization for audio apps will yield similar improvements as today's news about Open GL multi-threading seems to imply for graphics work. Certainly hope so.

Anyways, best of luck with your set-up.

e-clipse
Aug 22, 2006, 10:33 AM
Derwood, can you use 3rd party Vst-plugins or Audio Unit plugins within GarageBand? You didn't mention using any other software for recording except GB. I guess Audio Unit plugins could be used. AI plugins are type of plugin that Pro-Tools is compatible with as well. Because, GarageBand could be totally awesome with Waves Platinum or Diamond Bundle.

I have noticed that reverbs can be the most intensive dsp plugins. When I had my latency issues on my guitar tracks, I did not even use the dsp effects, but did use a few amp simulators. Most of the guitar tracks were processed through a guitar multi-effects floor unit.

Do you think that your audio interface could make the difference in the ability to record numerous real instrument tracks? It might take some pressure off the CPU by taking some work off the core audio on the motherboard.

Derwood
Aug 22, 2006, 11:24 AM
...yep, Garageband will accept AU plug-ins although I've done a fair bit of trawling and, as yet, there seem to be fairly few available as universal binaries. :( Not sure about VST/AI compatability. I'm sure someone else can chime in and shed a little light on that.

You're certainly not wrong about reverbs being processor intensive plugins but as I understand it amp simulators also require some serious grunt. Steering clear might of these might give you a bit more headroom on the track-count front.

As for the audio interface taking pressure off the CPU? Hmmm... Perhaps, although I'm probably not best qualified to comment. I would think that by using an external interface you are removing the monitoring woes from your CPU. Don't know how much of a real-world impact this has but most interfaces have dedicated on-board direct monitoring. That's the only economy that I could see it would give you and what difference this makes to performance is anyone's guess.

When GBand choked on me recently I was running, as I said, around 15 tracks with a variety of FX. Did a quick flick to Dashboard and iStat Pro contained therein and it was quite clear that the bottleneck was the RAM and not the CPU. Processor was stepped down (uh huh!) to 1.5ghz and running at 22-25%, but the free RAM was floating around 7-10mb during playback. I'm assuming that the virtual mem read/writes must have been going like the clappers as well hence all the jitters and stutters.

Honestly, as soon as pay-day rolls round I'm maxing out the RAM, getting a BIG external firewire drive, iDrum and I intend then to start having some serious fun! :D

e-clipse
Aug 22, 2006, 11:54 AM
Me too! I know ram and an external drive with make things easier. I am gonna go with 2 gigs of ram for $163 with a CAS latency of 3. I am gonna by a 250 gig drive from Lacie for $139

My CPU usage on GarageBand is running lightly according to iStat. I guess a lack of ram is the main culprit in GB. I have around 6 megs of ram when running GB.

e-clipse
Aug 22, 2006, 11:55 AM
I will have my ram by the beginning of September. I will then give an update of my performance issues.