I know you have a copy of Robert Ellis's album- check out "Bonnie" for a real red light special. I think he now knows to do better on the next album.
Slacker, I have the same issue :-(
I cannot use digital input because my digital source always seems to clip the DCX input.. I do not like using the DCX to attenuate the input signal, and my source has no output level control..
I mentioned on another thread whether changing 110 ohm resistor on the DCX DSP board to 75 ohm would help with this as I am using SDiF not AES/EBU, but i was told it wouldn't help at all, so I'm stuck using the analog input, which isn't too bad as I'm using the Didden active i/o mod..
Murphy
Thing that I don't understand is if I turn down the input gain, I am doing so in the digital domain, not the analog domain. So if I have my input gain set to 0 dB but am clipping, how would turning down the gain help against clipping? It has already clipped at the A/D, no ?
Considering a massive upgrade of my "already modded" DCX - going to SPDIF input with all xfmr based outputs to passive ganged volume controls and even then maybe to a preamp (amp is difficult load).
Considering a massive upgrade of my "already modded" DCX - going to SPDIF input with all xfmr based outputs to passive ganged volume controls and even then maybe to a preamp (amp is difficult load).
I dont quite understand it completely myself..??
But DCX uses 'bit stripping' for level attenuation,, so definately don't use the DCX level controls for below 0dB!!
Murphy
Fellas,
When using the digital input, the input clipping indicators are completely unreliable for identifying actual clipping. They can be flashing yellow/red all the time and you still might not be clipping. This question has already been asked and answered numerous times right here in this interminably long thread.
The only reliable clipping indicators on the DCX are the six OUTPUT indicators. If those are flashing red then you can be assured you are waveform clipping.
Cheers,
Dave.
When using the digital input, the input clipping indicators are completely unreliable for identifying actual clipping. They can be flashing yellow/red all the time and you still might not be clipping. This question has already been asked and answered numerous times right here in this interminably long thread.
The only reliable clipping indicators on the DCX are the six OUTPUT indicators. If those are flashing red then you can be assured you are waveform clipping.
Cheers,
Dave.
Fellas,
When using the digital input, the input clipping indicators are completely unreliable for identifying actual clipping. They can be flashing yellow/red all the time and you still might not be clipping. This question has already been asked and answered numerous times right here in this interminably long thread.
The only reliable clipping indicators on the DCX are the six OUTPUT indicators. If those are flashing red then you can be assured you are waveform clipping.
Cheers,
Dave.
Thanks Dave,,
It's pretty amaxing to have a thread going strong for so many years!!
I just joined recently,, it's too much to try and catch up on everything in this thread
So, you suggest dont worry if input lights a flashing red?? Is this only for digital, or also for analog??
Ta
Murphy
If you clip with digital in, it is clipping on the source! Meaning, your source is recorded with lots of 'max' digital codes. No amount of attenuation will change that. You can decrease the input level on the DCX and it will sound less loud but the clipping will not be removed because it is on the source signal. The signal is coded in the digital stream and not in the actual voltage level of the S/PDIF or AES/EBU signal.
What you should do is find a CD or whatever that has been decently recorded, admittedly not so easy with recent CD material.
jan didden
digital input
Have I read this correctly?
I think you are saying the clipping indicator for a digital signal is detect "max" digital codes.
Have I read this correctly?
I wouldn't say don't worry about it, but be aware of it. It's not unusual to see the input indicators flashing red quite a bit when you have program material recorded at (and close to) 0dbFS. Jan is correct that this "clipping" is "embedded" in the source signal. You could digitally attenuate the signal before it enters the DCX and the red clipping indicators will no longer illuminate, but you're not correcting "clipping" behavior by doing that.
It's still not a bad idea to attenuate digital inputs by 3db or so because this can alleviate waveform clipping downstream in the DCX when you have engaged crossover filters (or other EQ) that alter the crest factor to a higher peak level. In this case also, the output channel clipping indicators are a good indicator of possible problems.
Also, with a stock DCX, there's an op-amp stage in the output analog circuitry that's very close to clipping at max levels. The modified DCX solutions (like Jan's) solve that problem and many others.
Based on your avatar, it appears you already have a Didden modified DCX? I'm not sure of the clipping behavior of the analog input portion of that unit.
Cheers,
Dave.
Yes I have the full Pilgham mods (apart from 4396's which i haven't installed yet).. And yes, having analog input adjust via the Didden mod is pricelsess,, so clipping on analog input is never an issue (only Digital)
Thanks Dave and Jan for explaining the issue of digital input clipping..
I must have poorly 'mixed' digital music then, because they all seem to have this 'max code' issue.. Any examples/sample of a 'good' digital mixing so I can better see for myself ??
Thanks
Murphy
For your calibration pleasure, here are 3 FLAC files to test your DCX input. (604KB)
All 3 tones are middle C sine wave. 44.1KHz, 16 bits, mono. 15 seconds each.
There is full scale, -1dB and -3dB. None of these are clipped, but the 0dBFS file is at the max it can go without clipping. If you set your DCX inputs to 0dBFS gain and have no EQ on the inputs, then the 0dB file is the hottest you'll get without clipping.
Certainly the -3dB file should show no red light. You can play around with the input gain to see where the red lights come on and off.
Any good CD burner should burn these to CD once you unzip them.
All 3 tones are middle C sine wave. 44.1KHz, 16 bits, mono. 15 seconds each.
There is full scale, -1dB and -3dB. None of these are clipped, but the 0dBFS file is at the max it can go without clipping. If you set your DCX inputs to 0dBFS gain and have no EQ on the inputs, then the 0dB file is the hottest you'll get without clipping.
Certainly the -3dB file should show no red light. You can play around with the input gain to see where the red lights come on and off.
Any good CD burner should burn these to CD once you unzip them.
None of those three files will clip the outputs of the DCX.....IF you have no crossover or EQ programmed.
The red clipping indicators on the input channels will certainly illuminate with the 0dbFS file, but the output indicators should show amber and not red.
However, once you program a crossover the increased peak level of the outputs can slightly exceed the clipping threshold and flash the red indicators. (Even with no EQ programmed.)
Cheers,
Dave.
The red clipping indicators on the input channels will certainly illuminate with the 0dbFS file, but the output indicators should show amber and not red.
However, once you program a crossover the increased peak level of the outputs can slightly exceed the clipping threshold and flash the red indicators. (Even with no EQ programmed.)
Cheers,
Dave.
You're welcome!
Having a section of files for download is something the moderation team has briefly discussed. It would be very useful to our members.
I used a wave editing software called Goldwave that I've used for years. Very handy.
The procedure for those file was basically this:
Sounds complicated, but it isn't. The Expression Evaluator can do all sorts of things, not just sine waves. It's a cool tool.
FLAC is a great format for this as it is lossless and yet these sine wave files go from about 1.2 Meg down to 256K. Quite a saving.
Having a section of files for download is something the moderation team has briefly discussed. It would be very useful to our members.
I used a wave editing software called Goldwave that I've used for years. Very handy.
The procedure for those file was basically this:
- Open Goldwave and create a 15 second blank file. (mono, 16bit, 44.1 in this case)
- Open the "Expression Evaluator" in Goldwave.
- Choose the Sine preset from the menu
- Type in desired frequency (261.6255 for middle C)
- A full modulation sine is generated in the blank file.
- Double check by zooming in on waveform
- Save into desired format - e.g., wave, FLAC, MP3, AIFF, OGG, etc.
- Use "Maximize Volume" control to set peaks to desired level. -1, -3, -8.2, -32, whatever.
- Save each of these reduced volume files.
Sounds complicated, but it isn't. The Expression Evaluator can do all sorts of things, not just sine waves. It's a cool tool.
FLAC is a great format for this as it is lossless and yet these sine wave files go from about 1.2 Meg down to 256K. Quite a saving.
Thanks Panomaniac..
I will download these files and report back with my findings!!
Cheers..
Happy New Year to all great people on this thread!
It has been a while that I have been playing with my DCX. I tried a lot with it. I think it is a good time to look at something else. So I did and wanted to share it with you. It is made by our member Thuneau. Check it out.
DSP Crossover for PC. Frequency Allocator.
I am sure some of you tried it already. I decided to purchase the full version since I do have a need for second active set up, plus it is great for playing with. My favorite feature is cappability to load .frd files of your speaker and place it as an overlay to your crossover. Than you work out EQ until you make it flat. Very cool! What is even more cool is that is made for ASIO drivers and my RME Fireface 800 sings with it perfectly.
Now what would be rally cool thing to do is to add outboard DA converters in order to have the ultimate system. That is nice that all these audio interfaces output analog and digital signals out, unlike DCX. Hmm, here is something for New Year.
It has been a while that I have been playing with my DCX. I tried a lot with it. I think it is a good time to look at something else. So I did and wanted to share it with you. It is made by our member Thuneau. Check it out.
DSP Crossover for PC. Frequency Allocator.
I am sure some of you tried it already. I decided to purchase the full version since I do have a need for second active set up, plus it is great for playing with. My favorite feature is cappability to load .frd files of your speaker and place it as an overlay to your crossover. Than you work out EQ until you make it flat. Very cool! What is even more cool is that is made for ASIO drivers and my RME Fireface 800 sings with it perfectly.
Now what would be rally cool thing to do is to add outboard DA converters in order to have the ultimate system. That is nice that all these audio interfaces output analog and digital signals out, unlike DCX. Hmm, here is something for New Year.
Attachments
feed the same digital stereo signal to both DCX2496.
Then set up 4channels in each to drive a 4way or set up 6channels in one to drive two 3ways and 2channels in the other to drive two bass channels.
Depending on which drivers need more equalisation, the most resource hungry drivers should be fed from different DCX.
Then set up 4channels in each to drive a 4way or set up 6channels in one to drive two 3ways and 2channels in the other to drive two bass channels.
Depending on which drivers need more equalisation, the most resource hungry drivers should be fed from different DCX.