USB Audio Problems Late 2013 iMac - Clicking / Popping / Dropouts

Hi!

I have same kind of problem with sound. I also had problem with freezing iMac, that I talked about at this discussion thread:

https://discussions.apple.com/thread/5592496?answerId=24312665022#24312665022

So, at this point my iMac's whole motherboard is changed and it seemed to help for the freezes. I have to say seemed, because I got it back from service at couple of days ago.

I have founded out this about the sound popping and clicking by doing lots of tests with my iMac:

1. It happens no matter what output I use: iMac's internal speakers, analog audio out, digital audio out (from analog audio out with belkings analog to digtal converter) and with USB audio out.

2. It happens if output format is more than 44,1 kHz and with higher value it gives more popping to compared to lower setting. If I use 44,1 kHz I can use all output methods (internal speakers, analog audio out, digital audio out and USB audio out) without popping.

3. It is worse with OS X 10.8.5 than with OS X 10.9.1

4. In OS X 10.9.1 I can use 96 kHz with optical out without popping - at least if there is popping it is not disturbing. With 10.8.5 also the 96 kHz was unusable.

5. In OS X 10.9.1 with USB out this popping happens a little bit also with value 96 kHz. The 192 kHz is useless.

My D/A converter is Cambridge Audio DacMagic Plus and my speakers are Genelc G1 (2 pcs) and Genelc F1 subwoofer. I have tested also my other computer's speaker system (Logitech Z-5500) via optical cable and same results with that one. Also Genelecs' were connected without DAC (directly to analog audio out) and the problem was there also with that configuration.

I do not use audio in, so I have no knowledge if it is also faulty - so I am not creating any music etc with my iMac.

My local Apple's service partner is currently investigating this problem and hopefully I have something to report to you later on. One thing that could cause this might be the fusion drive like someone(s) have been reporting to this thread, because I installed the OS X to external usb drive and the sound was ok, when I booted the system from it.

-TS Ahde

So if I run on an external drive -- instal Mavericks there? Is the internal drive available for data, or does it need to get ignored?

Hi cmackg!

At least in my case when I was using os x booted from external drive:

1. fusion drive was available.

2. I had some problems with authorizations, because I created different user id to external drive than there was in fusion drive's os x. I created different user ID, because I wanted to be sure that os x was booted from external drive and best way to notice that was to create different user id (to see it directly from login window).

2. I was amazed that some of programs that were installed on fusion drive's os x were available on external disk's os x's application menu (from dock). Not all programs were available, but example VLC player was available on external disk's os x - it (VLC player) also worked just fine...

At least that was how it worked on me.

But I will wait for fix or something, because I bought iMac with fusion drive to get quicker startup and overall behaviour and if the SSD part of fusion drive is not used (by partioning), all of that speed will be more or less lost.

-TS Ahde

Hi,

i have the same problems using Focustite Scarlett 18i8. My iMac has Fusion Drive too and is about 1 week old.

With Apogee Jam USB in and intern Speakers out i had not so much problems. But after a few minutes some times i get probs anyway. It gets better when i plug in USB direct in the iMac (before i used an USB Port).

With iMac Late 2011, normal Harddisc and Maverick i had no Problems.

It´s frustrating. So i think about switching to a thunderbolt Interface. Has someone testet an Interface with thonderbolt?

Guitarmic

I have a new iMAC 27 inch OS 10.8.5, purchased Dec 31, 2013. I had done a lot of research about how Garageband was working with the new computer. It was challenging reading through tons of complaints. At the time my concern was just Garageband. I felt reassured enough about that problem to go ahead and make the purchase. I did have to make a number of calls to both Geek Squad (I'll never use them again) and to AppleCare around a number of setup issues I never faced before with my Mac SE, followed by 2 Power Macs. I recently purchased a wonderful new Neumann microphone, and a Focusrite Saffire PRO 24, hooking it up with an adapter: Firewire out of the Focusrite, and adapter wire connecting to Mac's Thunderbolt. I plugged headset in to Focusrite, and there is no connection...just a message saying something like: No Drives (other than hard-drive). Many calls later to Guitar Center, who have been helpful and friendly. The audio interface shows no connection to the computer. The fellow at Guitar Center began researching, calling Focusrite and discovered what a lot of us know, namely that there is a bad audio problem with the new Mac. A couple of folks at Apple (AppleCare and the Apple store) tried to convince me to upgrade from MountainLion to Maverick and my instinct has been that that won't fix anything, and will probably just be some new things to learn. Guitar Center suggests swapping out the SaffirePRO 24 for the 18i8, which is USB to USB, but given what I've been reading here, the IMAC's USB 3.0 (which I was told works with 2.0) is not going to recognize the Focusrite. It is now too late to get my money back on this Mac. It looks like splitting the fusion drive is the best solution. Here's my opinion for what it's worth. Steve Jobs was incredibly tuned in to what people really needed. He was aware of what we needed before we knew we needed them. Mac WAS an easy computer, great for all graphic, video, and audio recording. I never had any problems remotely this bad, and I go back to around 1988 with my first Mac. Perhaps, the leadership at Apple, after Jobs, is nowhere nearly as tuned in to how we all work with these machines. It seems like the slim IMac 2013 is more show (looks great on my desk), and way less Genuinely Easy performance. These horrible audio changes were made with no one at Apple working closely with 3rd party providers, and that is a sign of poor leadership of the company, insensitivity to the large number of people having these audio problems, and a terrible lack of honesty at Apple. Apple should quickly have let me know, "We hear you. We know there is a problem. We are very sorry. We are working on a fix for these problems day-and-night and we will keep you posted. We WILL solve the audio issues." Instead, I don't see or hear anyone at Apple really jumping in. Many of us are professional musicians, and we cannot afford to not be able to record. Hello Apple! You really need to openly cop to the problem, notify owners and distributors of the new Macs, and let everyone know that you acknowledge the problem, are working on it, and the problem should be fixed by x-date. You are truly starting to alienate far more people than who take the time to post here, long-time Apple/Mac devotees, who just love what Steve Jobs created. Please remember who he was, what he did, what his philosophy was, and you'll be able to solve this problem beyond a shadow o

f a doubt. My dilemma...I'll be on the phone with AppleCare over the next 3 days to see how to split the fusion drive. I have not seen any 2014 posts here about this problem and I'd love to hear any updates from others who have been dealing with these audio issues.

I was one of them that had this problem with simple playback with iTunes. I finally returned it and recived my replacement with flash storage and problem doesn not exist anymore, finger crossed, 3rd day. I can't think of anything else's fault but the fusion drive.

I have a maxed out iMac I bought in October 2013, 32 GB RAM, 3TB fusion drive, etc. I started having the issues right off, but wasn't sure if my interface was the issue, or the computer. I got sidetracked in a bunch of other projects. Return to the problem, and I realized my interface worked fine with an older MacBook Pro. It's a USB interface.

So I read all these posts, and decided to skip splitting my drive if at all possible. I got an external SSD drive, installed Mavericks 10.9.1 on it. Problem still persists. Then I dug up a friend's Fireface 800 (uses FW 800 instead of USB), and hooked that up to my computer using the thunderbolt to firewire adaptor. No roblems at all. I left a Logic song that had given me problems running in a loop for a few hours, and no clicks ever.

I have not tried the old OS (running on the Fusion drive) yet, so I cna't be certain, but my experience points to a problem with USB audio at the least. I can see how possibly bad implementation of the Fusion drive splitting causes audio problems when the Fusion drive is your main drive but I had the problems while running off of the external drive.

So, at the least, the USB audio has issues, and perhpas its doubled by using the fusion drive as your main drive.

I'm not really interested in slpitting my Fusion drive -- there's a lot of data on it already. I'm hoping that an OS update down the pik will fix it.

Thank you. That information is really helpful.

I recently noticed this popping: USB > PopPulse PCM1996 MKII DAC

I disconnected the USB cable and used the Optical output instead. Problem solved!

So, FusionDrive or no, I've isolated the issue down to some interaction with USB. Can anyone speak to the differences between USB & Optical on this iMac?

For audio playback there is no audible difference. The practical difference for me is that using the optical out disables the internal speakers so if you want to use the internal speakers you have to disconnect the optical out from the mini jack in back. When using a USB interface you can make this change holding down Option and clicking on the speaker icon in the menu bar or through the sound preferences.

-chris

Hi!

Addition to Chris' answer: At least in my iMac optical audio's max output format (= bit rate?) is 96 kHz. Using USB audio out gives maximum of 192 kHz. My D/A converter is Cambride Audio DacMagic Plus.

My iMac were in local service partner and they replaced Mac's hard drive with new one (I also had quite many of total system freezes and we are hoping that they were caused by faulty hard disk). At least those audio pops are now reduced when using USB out. There could still be something wrong wit OS X, because I have had couple of total loss of audio when using USB out. In those cases I found multiple lines of this messages in console:

kernel[0] USB Sound assertion in AppleUSBAudioStream at line 4821

So, at this point I will wait for public release of OS X 10.9.2 version and hoping that this is some kind of hickup of current Maverick's version 10.9.1.

And also in my case optical out (with maximum format 96 kHz) is working without pops.

-TS Ahde

Agreed. Optical is less than ideal for a number of reasons but at least it's working without having to muck with the Fusion Drive.

Hopefully a fix is on the way.

Hey all,

Just quick question! I came came back to the US for a visit from studying music abroad and bought a 3TB fusion drive 27'' imac. I quickly realized that there was an issue and luckily I read all of these posts you guys posted on here and returned it within the 14-day grace period.

I switched it out for a regular drive, 3TB, because I needed the space an SSD could not offer. I know that the USB issues are occuring also on machines without the fusion drives. I do not have any of my audio equipment with me in the US to test it out - Is there any way for me to test if this USB issue is present on this machine? Which USB peripherals can I plug in to test it out?

Thanks so much. ~

EDIT: I actually forgot that I have a Zoom H4N mic on me that I can probably hook up via USB, trying that now.

Hi!

I'm not sure if this is fully proofed way to test it, but In some point of my audio problems history these same pops and cracks were also present when I was using iMac's internal speakers at maximum bit rate (changed on MIDI settings on Applications --> utilities). I think that internal speakers max value is either 96 kHz or 192 kHz.

But like I said, I'm not sure that this happens for all of us.

-TS Ahde