Why does Logic 10 sound different to Logic 9 ? Logic 9 seems to be better....!?

Well, the easiest workaround.. (and please take this in the spirit it is intended) is to use LP9 for existing LP9 projects... as LP9.1.8 works fine with Mavericks...and happily coexists with LPX... and use LPX for new projects.. which is exactly what i have done... when there is any noticable differences. I must admit, I have noticed few such differences myself but then I don't use Logic's built in FX.. (certainly very rarely the built in EQ and Compressor for example) that much but rather a 3rd party EQ/Compressor/Mastering plugin so i assume thats probably why...

Good point on the third party plug ins. I use mostly Logic plug ins, and I have to get my Waves plug ins working again, since I updated the software.

Did you ever Find this Work around for logic 9 to x?

You are perfectly right, LPX sounds very bad, I can compare it to a broken piece of equipment. I find no pleasure at all working with it.

Blimey, a thread getting on for nearly 3 years old and so many participants never did the null test, or, at least; never posted the results of a null test.

At some point, the way audio is summed in Logic was changed. I don't know what version but it was 9 or 10 I think. May have been when it went 64 bit but I could be wrong.

Mike

I can confirm Logic X outputs differently than Logic 9. A project that I rebounced with the same settings in Logic X without any changes clips whereas it didn't in Logic 9, without even sounding noticeably louder. I haven't checked to see whether the changes are on a macro or micro level (e.g. plugin/asset-specific). I guess there's not much we can do about it besides tweak the audio to work around the changes.

DO A NULL TEST! Everybody is sooooo sure they hear a difference, but nobody seems to be able to do a decent null test. This to me means that all that is happening is PERCEPTION BIAS and ego. None of you have "great ears, better than the best trained engineers and musicians". If the difference actually exists, you can PROVE it with a null test. NOBODY has done that so far - or maybe they have, and it nulled, and they were embarassed and never reported back.

Wouldn't the fact that the exact same content clips when bounced in Logic X but not in Logic 9 prove there's a difference in sound? Still, I'm sure some people still have both programs installed so if someone would like more evidence by doing a null test, be our guest.

I do not believe any claim until I can replicate it, since people can make zillions of mistakes in Logic, it being such a deep program. I have been on these fora for eight years, and more than 90 % of all issues are down to pilot error, even very experienced users still may make simple mistakes. Like in science, the only thing that can convince me is replication of the results. If they can't be replicated, it is a form of pilot error. Also, nobody seems to realise that the audio engine is not in Logic, but in OS X.

I did a null test between LP9 and LPX (on the same OS!), and they nulled perfectly.

Ah so you've already done a null test. Well in any case, at least for me, there's a difference somewhere so if it's not Logic then I guess it's pilot error (though not due to any manual changes by me) or OS X.

Eriksimon wrote:

Also, nobody seems to realise that the audio engine is not in Logic, but in OS X.

I don't think that this is correct. Where do you have this information from? Some years ago, I was involved with the technical details of the logic audio engine, and I can guarantee you that it stands on its own. While macOS/iOS/etc provide a framework for setting up Audio Unit graphs and rendering them within Core Audio and this is used by many applications, DAWs usually don't make use of it. The framework just does not provide for the flexibility, performance and scheduling requirements that typically arise. Last time I checked, anything related to the actual signal processing in Logic was handled exclusively by logic code and the only interface with CoreAudio was when the signal was passed to the HAL node for low latency output. Things may have changed in the meantime, but I don't think so.

An example for a macOS application that lets CoreAudio handle everything is AU Lab, which is part of the macOS developer tools and meant for AU testing and debugging.

I cannot remember where I got this info, it was off a site that compared many OS's (Linuxes, Windowses, Mac OS 9.2.2 and some X's and even some dedicated audio hardware OS's) in their audio fidelity - OS X was the "best" (least noise, most flat response across the spectrum). In fact, I now recall that the most recent Mac OS X on that site was Leopard, so it's been a while. But I believe it was some Californian Universities' site, so there was solid reason for me to trust the information. BUT, like any human, my memory is not flawless, and I am willing to change what I think I know if it turns out to be inaccurate. However, a null test between two audio files created by the same app on different OS's may well show differences, so a failing null test between LP 9 on OS X 9 and LP X on OS X 11, doesn't prove to me that LP 9 and LP X are different. Only a correctly failed null test between those two on the same OS would reliably confirm that there must be a difference between the apps.

I am pretty sure that Logic also uses OS X audio for certain basic/fundamental processes - and of course it also has something of an audio engine, but I do not think it has a completely independent audio engine. It taps into coreaudio - no, now I think of it, what is needed to make Logic capable of recording and playing back audio? You need to enable core audio. Which is part of OS X, not Logic.

Ok, I think I know what you saw. There is a website that compares the quality of the built-in resamplers of different OSes (and some application specific resamplers). In days where different applications can talk to the audio hardware with their own sampling rate, the OS is responsible for converting the sample rate on the fly with low latency. That's where you can make a number of different trade-offs. Those usually involve latency, phase response, aliasing and high frequency roll-off. I would not call this part of the audio engine of logic. Any serious DAW (including Logic) demands that the audio interface runs at the same sample rate as the DAW and bypasses the resampling stage entirely.

The website you refer to is probably either this one or referring to it:

http://src.infinitewave.ca/

Please note that the graphical presentation is somewhat misleading. They use a very large dynamic range of 180dB. The stimulation is at 0dB. Any noise below -100 dB is absolutely inaudible, even in the most unfortunate situations. It is generally agree that aliasing rejecting to -80dB is sufficient for high quality audio. The website does not allow to change the dynamic range to reflect that. Also, aliasing over 20kHz is generally also inaudible. The "Acon Digital" converter therefore performs like a well designed sample rate converter and likely has a lower latency than others that seemingly perform better from the time-frequency charts shown.

This quickly gets very esoteric, and some companies are really over-engineering this. There's nothing to say against a little extra safety margin, but creating a sample rate converter that rejects aliasing to below -170dB is ridiculous and helps nobody, even if you factor in accumulation of aliasing noise when multi-tracking. The converter of Ableton Live 9.11 uses a significant amount of CPU cycles to achieve that result and also adds nearly one millisecond of latency as you can see from the impulse response graph. If you look at the response of Live 7, you see how it should not be done. That one is terrible in every aspect. However, the 7, 8.02 and 9.03 converter was absolutely sufficient and it had a much lower additional latency as a result of its minimum phase design, even though the phase response was slightly off above 1kHz (where it doesn't matter that much and every reproduction system messes with the phase response much worse anyway!).

So please, don't fall for this voodoo. There's so much esoteric nonsense going on when it comes to audio quality that I'm surprised nobody has advertised a DAW yet that was only coded during full moons.