mystery low end distortion

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jdbosshog

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Help! I've been using Cubasis for about a year with no problems.
I have a Midiman sound card on a Dell PIII 700 with 128Mb RAM.
I am now getting distortion during playback of low frequencies when I record anything new. When I record a kick drum direct from an Alesis DM5, for example, even when I record at half the usual level, (no clipping lights coming on at anytime during recording or playback) I get that horrible digital distortion that everybody knows and hates. Whats more, if I play back the same track by dragging the magnifying glass cursor over the track, it sounds fine- no distortion! I don't think it's my mixing board because all my old tracks play back fine, and I tried recording straight from the DM5 (again way under the normal level) completely bypassing the mixer and still get it. It seems to be happening on low frequency
recordings like bass guitar and drums, but I haven't got past
these tracks to try vocals or guitars. So, is it my sound card
going bad? Do I have some setting set to 8 bit somewhere,
Did another setting inside Windows98 get changed, (I haven't
changed anything that I know of)? The only thing I have changed since this started happening is the location of the def.all file, but I don't think that should affect what I'm hearing. Any help would be appreciated. Thanks in advance.
 
I think the fact that you can get a clean sound by dragging the magnifying glass over the part rules out some possibilities. It means that you've recording the signal cleanly. It also means that the soundcard is OK. I'd also confirm this by playing the WAV file using some other program such as Windows Media Player, though I'd expect this would sound fine.
Do you get this distortion when you do normal playback and solo the offending track? Or is it only when all tracks are playing?
I'd suspect that there could be some sort of processing somewhere in the Cubase chain that is boosting the level. Maybe there is something turned on that you don't mean to be on. The first thing I'd try is to create a new song, create a new track, and import the bass or drum WAV file into track. Then playback and see if it is distorted. If not, then there is some setting in your original song that's not set right (overloaded reverb plug-in? EQ boosting the bass?) If it still sounds distorted, then you might suspect that what ever is set wrong is even set wrong in your def.all file. Retrieve the original def.all file from the CD, create a new song with that and import the WAV file to see if the distortion is present. If that is is still distorted, then I think I've run out of ideas.
 
Thanks for the quick reply. Yes, I still get distortion whether I
play a single track that is solo'd or several tracks, or any combination. I like your ideas about importing the tracks to a new
song, and using another WAV player. I'll try these tonight. I've looked everywhere to see if I have something in the signal chain
turned on that might be overdriving the signal but to no avail. I
was just about to upgrade my sound card to a Delta10-10 and move to a better version of Cubase but I want to solve this mystery first. Again, Thanks for the help. JDBossHog
 
After I wrote that I realized that it's partly incorrect to say that there could be something overloaded in the Cubase signal chain. I'm thinking too "analog". Internally Cubase uses 32-bit floating point numbers; the dynamic range is so large that it is extremely unlikely that overloading is happening. The only place you'd get trouble, I think, is just before the numbers are converted back to integers at the master volume stage. But then if there we overloading there, you'd see it when looking at the master levels. Nevertheless, I'd still try importing the WAV file into a new song just for something to try. In fact, if your old songs play OK, try importing the new WAV into the old song and see what happens.

If it's not Cubase and it's not the sound card, then the other possibility is the driver. But this doesn't seem possible either since your old songs play OK. But as an experiment you might at least try switching to the Windows MME driver and see if that makes a difference.
 
Another good suggestion about changing the driver, I will try that
as well as importing the WAV file into an existing song, as well
as starting a new song using the old def.all file. I never really supected an internal dynamic range problem, only because I work with other kinds of 32 bit floating point data all day long and have rarely seen data that couldn't be described with 32 bits, plus I'm not doing anything I haven't done
already for the last year as far as I/O levels and S/N ratios. I'll
try these 3 suggestions tonight and let you know. A thousand thank yous! JDbosshog
 
OK, so I couldn't see the forest through the trees. I thought I
had turned off all effects in the master section in the def.all
file, but as it turns out I accidently had a free plugin called mda_limiter called up as one of the available effects (something I don't even use). I had recently changed this file to try and clean it up and have my own default settings. Even though I was getting no clipping lights to come on anywhere, it was overdriving this plugin. Thanks for the suggestion of importing an existing WAV file into a new song. That's how I found the problem. Boy do I feel stupid. Thanks for the help. JDbosshog
 
That's good to hear. I guess you can overdrive a plug-in even though it's using 32-bit floating point. But then I suppose anything's possible in a third-party plug-in since you don't know what's going on in there.
 
have a check that you're not recording the monitor input, i.e recording TWO kick drums. cubase 5 has a TrueTape facility. i know you said you're not using 5, but check your version doesn't have something similar.
 
Is the bass drum perhaps been EQd? When you drag the icon over it to audition it it may sound fine but general playback it may have heavy bass EQ. Also how can you be sure the problem is coming from the bass drum? I guess if you have already imported it into another song and it distorts then that means it must be the bass drum ..... doh *slaps head*

What about this? - is your sonfg consistant in terms of sample rate? Is every track recorded at th same sample rate. This could explain it. If you listen to just one track slowly it may sound ok but if the bass drum is recorded at 96k and the rest at 44.1 then thst could be the problem as the prog will so a sample rate coversion.... then again I could be talking bollox here but it i best to check all possibilities.
 
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