Syntrillium Backup Forums :: View topic - How to eliminate pops and clicks on playback.

Undrdog · Posts: 34

I'm using win xp with cool edit pro 2, I have Pentium 3, 1 gig 512 sdram, Nvidea graphics and I'm using a Roland ua30 usb interface and a 2 channel preamp for record and playback when using cool edit. I have soundblaster live for general use. I have been trying to eliminate pops and clicks during playback. I've turned off all background programs, ( gone through optimizing cool edit for win xp) and tried adjusting the buffer size and # without any success to this point. (I was wondering if buffer setting outside the norm might be optimal for this type of setup).My probem is when playing back and occasionally on recording I hear pops or clicks. Sometimes more frequently than other times. I would also mention that sometimes the opening notes on playback sound metalic the first time through, and sound better after starting over. Thanks for reading this. Any help would be appreciated. thanks

LaptopPop · Posts: 46

Are you hearing pops and clicks throughout the music, or just at the start?

For ones throughout the music - this often is because of sync problems between the various pieces of digital gear. You would need to check things like wordclock and sync source issues.

For ones at the start -- do you have a period at the start where there is no data on any of the channels? CEP will put a nice pop at the front of your piece if you do... just put a wave file of silence at the start on one of the channels and its happy.

One more question: Are the pops and clicks in the files you are playing, or just an artifact when you listen? In other words, if you zoom into the file, can you see the pops and clicks?

-lee-

Graeme · Member Location: Spain Posts: 4663

Havoc · Posts: 735

Yes, I do have it also Greame. Confined to CEP2 (when I ran the demo), and always at the end in my case. Specially when I played not the whole wave, but just the piece on the screen or stop in the middle of playback. More a kind of stutter, it plays the last buffer a few times I guess. One of the reasons I did not switch yet.

Edit: I almost forgot: do you have a DC offset? This might cause a plop at the begin and end.

Graeme · Member Location: Spain Posts: 4663

Undrdog · Posts: 34

Thanks for the reply. I hear the pops and clicks throughout music. sometime they are very infrequent, but are hard to work around when making live recordings. I can't see the pops when I zoom in. When I start thought I get a metalic sound sometimes on the first attempt and then it will sound ok after that, but quality doesn't seem to be up to media player standards. thanks again for your reply.

andyeb · Posts: 45

Does your motherboard have a VIA chipset, more specifically the KT133A?

These chipsets seem to be problematic for audio work; I've just spent a week troubleshooting an identical problem with an M-Audio Audiophile 2496 together with an Abit KT7A motherboard (VIA KT133A based).

I noticed that the edirol website says that their USB audio interfaces don't work properly with non-intel chipsets too Sad

.

Andy

Undrdog · Posts: 34

No Andyeb it has an Intel chipset. I've found somewhat of a fix by using the Soundblaster for playback. Seems ok but would like to find out and fix problem rather than work around it. thanks all for your help !

andyeb · Posts: 45

Oh well, that ruins that theory! No point in me giving you the run down on how to fix this sort of thing on VIA chipsets then... :clown:

Andy

Havoc · Posts: 735

Okay, so far we have that you are using an usb interface on an intel chipset MB. The clicks are recorded in the data, so not part of the replay only.

Some things to check: do you have udma for your disk if using ide (probably yes, but you never know)? is your usb on a seperate irq? are there other devices on the usb? does it get better if you remove the SB live? can you check what type of usb chip is used (some give problems if I remember from discussions regarding the m-audio usb duo)?

andyeb · Posts: 45

I know we are talking about Intel chipsets here, but on VIA chipsets, this sort of problem is generally due to problematic bus mastering on the PCI bus. Network cards, video cards, some USB controllers and some sound card can cause this sort of problem. In other words, it might be worth disabling absolutely everything that is not essential (by physically taking the cards out where possible) as a test to see if it clears the problem. I've seen disabling USB controllers as one solution to problems with PCI sound cards like this.

Andy

Havoc · Posts: 735

Well the problem is that his audio is on usb......

Spockman · Posts: 1

andyeb · Posts: 45

Jax · Location: Canada Posts: 3

Undrdog, I'm having VERY similar problems. Here's the rundown:

Compaq Intel P3-733
128MB RDRAm
9.1G SCSI (C Smile

(Main temp dir)
80GB Seagate IDE (D,E,F) (Sec. temp dir)
Yamaha DSP Factory (Like O1V Mixing board)
CEP 2.0

I recorded a live gig we did on an adat LX20 using all 8 tracks, then dumped it all (8ch toslink) through the DSP to CEP. I did it song by song, cuz some were better than others. When cleaning up the individual tracks (soft limiting and normalize), all the waves looked great. No clicks or pops.:D

I doubled the vocal and the guitars to a second track (each), so I have 12 tracks playing back at once, back to the DSP factory. This card is a complete mixing console, with 16 inputs, and 4 st buses. I do all mixing in the card (with LUI), I then route it back to 1 stereo track in CEP. Wink

At first, I didn't notice the small clicks, but once I got the mixdown to sound 'good', it was obvious what is happening. Occasionally, at random spots througout the song, I would hear a click or stutter, then I could tell that one (or more) tracks had lost sync with the rest. Sometimes more noticable than others, but there is definitely a time shift of several ms. Sometimes to the point of an audible echo. What gives:???: The waveforms are OK!

I have tried playing with the buffers too, and disabling the hungry auto-scrolling, to no avail. This machine should be able to do this with no problem. I looked at the System performance graphs in task manager, and it shows between 50-90% CPU usage (only on playback, and 2-5% at idle), but very minimal Memory usage. I have no plugin effects going at all - just 12 track playback. OH! also during playback, I can watch the big timeclock (centre bottom) stutter, or hold for a fraction of a second before continuing.>:K

I will try the Win2kP services tweaks at this page: http://www.blkviper.com/WIN2K/servicecfg.htm

And I will also switch from ACPI to Standard PC and/or switch PCI slots. The only other PCI card I have installed is an Intel ethernet LAN card. Any other ideas or solutions:???:

Frustrated,
Jax.

Jax · Location: Canada Posts: 3

Okay, I did something I've been told not to do, but it seems to have worked for now.

I went to task manager (Win2kPro) and elevated the priority of CEP to 'High'. This has stopped all the problems I stated in my last message. I know it's just a band-aid, but it leads me to wonder what other processes are interrupting the audio streams? I have not tried the 'services tweaks' on that link I posted, but their time will come.

For now, everything is ok -- and my mix sounds better than it ever has.

Jax

clintfan · Location: USA Posts: 455