# ASIO vs CoreAudio - Sound Quality?



## mattnedgus (Jan 5, 2022)

Does anyone have any experience of, and opinion on, the sound quality difference between PC’s and Macs?


I was hoping someone here might be able to corroborate or contradict my experience:

I need a new computer as 8GB of RAM in an M1 MacBook Air isn’t cutting it. So I pulled out a 3 year old HP i7 laptop Windows PC with 16GB to see if I could get away with it - and thats when I noticed a change in audio quality.

Using the same output chain (Presonus 2626 over Thunderbolt, 48kHz sample rate, Sennheiser HD600 headphones) the PC sounded worse - muddier. I compared both in the same DAW (Ableton 11) and audio streaming via a web browser. In fact I repeatedly listened to the ARO2 demos and found better separation of instruments from the Mac. The PC playback made the instruments sound better knitted together (more cohesive), but further away - less real - and it was less easy to listen to detail.

I can only put it down to the difference in drivers. I wondered whether it was because CoreAudio uses floating point and so reproduces a more accurate representation of the original input?

I’d love to be making this up as a PC would be so much cheaper to build to a higher spec!

Thank you again


----------



## EvilDragon (Jan 5, 2022)

Both CoreAudio and ASIO are using floating point internally, so it's not that at all. Also, these are audio drivers, they are just passing the buffers from your software to the audio interface back and forth, and are doing zero modifications to it.


----------



## easyrider (Jan 5, 2022)

mattnedgus said:


> Does anyone have any experience of, and opinion on, the sound quality difference between PC’s and Macs?
> 
> 
> I was hoping someone here might be able to corroborate or contradict my experience:
> ...


I started a joke thread about this over on Gearspace…









Does a Mac sound better for music production ? - Gearspace.com


My friend says Macs sound better than PCs….. Please post your findings so I can point him to this thread.



gearspace.com






Originally Posted by *thenoodle* ➡️
“I can tap out a beat with my fingers on the side of a Mini and it sounds ok....a little bright, solid metal kind of sound.

I tried the same thing on a Win10 laptop and what a difference! I tapped towards the top rear area of the lid (plastic) and my finger tapping was noticeably more mellow.

My conclusion...if you're tapping on the mini, say the pattern for CCR guitar Chaka Chaka for Looking Out My Back Door....the Apple sounds better.

However, I think the Win10 plastic tapping sounds much better for a finger tapped "Ruby Don't Take Your Love To Town.

Of course, it always gets down to room acoustics and how good you are at tapping your fingers on objects.

Me...I sorta liked the sound of Windows better on this shootout.”


And someone did a comparison with the Presonus 4848 thunderbolt costing just over a $1000 and a UAD Apollo costing $3500

People were pulling words like depth and focus out their arses….but in reality noone could tell the difference.


----------



## mattnedgus (Jan 6, 2022)

easyrider said:


> I started a joke thread about this over on Gearspace…
> 
> 
> 
> ...


​Did they do a quantitative analysis in the 4848 vs Apollo test or just listen?

I don't want it to be true that the Mac is outputting a clearer signal than the PC but I'm so certain I can hear a difference that I've spent hours switching back and forth to try and disprove it to myself.

​


EvilDragon said:


> Both CoreAudio and ASIO are using floating point internally, so it's not that at all. Also, these are audio drivers, they are just passing the buffers from your software to the audio interface back and forth, and are doing zero modifications to it.



Yeah that's what I thought too - I have no preference of OS. Had I not switched straight from one to the other in the middle of a practice session I might never have noticed a difference.

But something somewhere between the DAW and the interface must be different for me to hear a difference, surely? I installed a Logic Pro trial to ensure it wasn't the difference in coding of Ableton across the two OS's. I tried adjusting the output volume on the interface too to ensure it wasn't a loudness change causing a perceived difference.


I think realistically the only way I'm going to be able to qualify my experience is to see if I can measure it. 🤔


----------



## mattnedgus (Jan 6, 2022)

So, my confidence is growing that I'm not getting accurate representation from the PC's output - not unless the interfaces are doing the mixing internally:


I've been reading up on FlexASIO's bit-perfect mode using WASAPI Exclusive mode. It bypasses the Windows mixer and should mean that the interface isn't available for other applications to use...

Except neither the 2626 (Thunderbolt) or 68c (USB) I have is locked-out with the current Presonus drivers - I can still play audio from a browser at the same time as the DAW. I downloaded and tried Audacity just to make sure it's not Abletons doing.

_(Remembering back now, some months before I got this Mac I couldn't use Ableton and browser-with-sound at the same time with the 68c on my main PC - so perhaps Windows or Presonus have changed something in recent months?)_

ASIO4ALL and ASIO2KS uses Kernel Streaming according to this: FlexASIO Github page rather than WASAPI but even then it sounds like the interface should still be locked to a single application (unless the hardware supports internal mixing). This method itself is a non-recommended method:

"Different device drivers implement KS calls in different ways, report different topologies, and even different ways of handling audio buffers. This presents a lot of opportunities for things to go wrong in a variety of different ways depending on the specific audio device used."


----------



## marclawsonmusic (Jan 6, 2022)

Why not just print the same audio from both machines and do a null test? Isn't that one way to quantify the differences objectively?


----------



## MartinH. (Jan 7, 2022)

marclawsonmusic said:


> Why not just print the same audio from both machines and do a null test? Isn't that one way to quantify the differences objectively?



Mit need to record it from the output signal of the audio interface onto another device to rule out differences between the drivers. But null tests would be the first thing I'd try too.


----------



## EvilDragon (Jan 7, 2022)

Did you make sure all OS enhancements are disabled?






In theory, ASIO driver should be bypassing this all, but you never know...


----------



## mattnedgus (Jan 8, 2022)

marclawsonmusic said:


> Why not just print the same audio from both machines and do a null test? Isn't that one way to quantify the differences objectively?





MartinH. said:


> Mit need to record it from the output signal of the audio interface onto another device to rule out differences between the drivers. But null tests would be the first thing I'd try too.


Wouldn't a null test within the same DAW result in the sine wave and it's opposite being re-combined before they're sent out of it? I just had a quick scan through this link but I might have misunderstood. Would be grateful if you could set me straight if so  



EvilDragon said:


> Did you make sure all OS enhancements are disabled?
> 
> 
> 
> ...



Yeah I just double-checked and I don't have the 'Enhancements' option at all. I agree the interface should be locked to the application in a Windows environment. It's a puzzler!

I ran some tests using RoomEQ Wizard (REW) today and without changing any variables (just matched up the settings in REW) I got different results. This ones for the headphone output on the PC (green) and Mac (red):






I'm not sure what real-life effect the differences would have - but they aren't as closely matched as I would have expected if ASIO was working properly. 

I've no idea what the notches in the PC-measured (green) plot suggest is happening to the signal?

With my limited knowledge I also think CoreAudio (in green below) is filtering above 14kHz. Although I don't think this is influencing what I've been hearing, the fundamental curve plotted on the distortion chart shows a roll off from there:


----------



## MartinH. (Jan 8, 2022)

mattnedgus said:


> Wouldn't a null test within the same DAW result in the sine wave and it's opposite being re-combined before they're sent out of it? I just had a quick scan through this link but I might have misunderstood. Would be grateful if you could set me straight if so


You can null-test with anything, I wouldn't use a sinewave for this, better use some music that you know well. Record the output to the same recording-device (portable recorder with line in or another computer for example) from both test setups, and then compare in any daw, doesn't matter which one. At the comparison stage you phase align both recordings perfectly and then flip the phase of one. What you still hear is the difference between both audio signals. If they are the same, you'll hear nothing. I would almost guarantuee that even two recordings from the same source won't be 100% the same because you're using an analog recording process and are bound to get some random noise in that way. But it should be able to tell you if there are considerable differences. 

But it looks like your measurements are already doing that. That Mac curve looks to me like it was "enhanced" for a more pleasant sound. You may prefer the Mac sound but I wouldn't be surprised if it's actually the ASIO one that is correct.


----------



## mattnedgus (Jan 8, 2022)

MartinH. said:


> You can null-test with anything, I wouldn't use a sinewave for this, better use some music that you know well. Record the output to the same recording-device (portable recorder with line in or another computer for example)



Thank you Martin - I might give this a try. I can run the audio back in through the same interface


----------



## mattnedgus (Jan 9, 2022)

I've given up 😂

The Mac vs PC (Quantum 2626) null tests weren't as decisive as I'd hoped and it didn't help that I made the mistake of doing the tests across a driver change which caused more uncertainty 😭

There was a difference though! One null test (using an older driver) was clear with no audible or visible result and suggested the Mac output was identical to the PC. This driver also let the DAW take exclusive control of the 68c USB interface.

The other null test (using the same driver as I started this thread with) resulted in a very low level of audio that could be also seen on the VU meter suggesting a disagreement between the output of the two computers.

But I couldn't say why the difference was... a different output level due to the driver change, a nudged gain control, a temperature change or inequivalent frequency responses (phase responses were different 🤔🤷‍♂️)!?

And at this point I've been so back and forth my heads': 🤯 - I'm even willing to consider there's been some unconscious bias! 

PC it is!


----------



## tc9000 (Jan 9, 2022)




----------



## Jeremy Spencer (Jan 10, 2022)

mattnedgus said:


> PC it is!


It's entirely possible your brain was unconsciously trying to justify the PC route


----------

