Why Pioneer before Allen & Heath?

[Shishdisma]

Almost certainly agree with your summation Shishdisma that it most likely overloaded the input stage of my processor although I would like to add that an XTA 448 processor and an MC2 E45 amp is not a bargain bin setup :-)

In my case, it was a Behringer Xenyx, for no real reason. It was just a personal reference.

[makar1]

It's my plan to burn a 1kHz sine wave to a CD at 0dB Full Scale and get my scope on it to see exactly what is happening. I'll post a video if anything interesting occurs.

Here's a similar test done on the DJM 600.

http://www.youtube.com/watch?v=hImlXort_WY

You'd need an oscilloscope to do the test properly as they can easily handle much stronger signals than any audio hardware. How do you plan on playing back your sine wave CD?

[synthet1c]

...and that's why I hate my DJM-600, never knew about the master and gains not distorting it, I always had them way down, I guess that's why I always had such a bad noise floor.

[FilthyDave]

I do have a scope

I'll be using a CDJ2000 in order to match the setup that has been causing me problems. That will output a 0dB FS 1kHz recording at 2Vrms (according to the manual)

If you look at that video you'll see the yellow trace which is coming out of his soundcard has a peak to peak measurement of less than 4v (the yellow wave has been scaled so that each square represents 1v and the blue wave scaled to 2v. Look closely at the bottom of the screen)

At approx 3.8v p-p his card is only kicking out 1.34Vrms and is approx 4.76dBu down compared to the output of a CDJ2000

Unless the source is at a strong enough level no matter how much you turn up the gains it's never going to clip.

[makar1]

Listen at 4:50 where he says he uses a function generator too, and gets no clipping.

[Timbo21]

That DJM 600 vid.

Well, most Dj's turn up the EQ, and too far. So, what kind of headroom are you getting with a reasonable level of EQ, something like all bands set to 2 O'clock?

[FilthyDave]

The results of today's experiment



This video only shows part of the tests we did but I've detailed my findings below

The source was a 1kHz 0dB FS recording burnt on to a CD which when played delivered a 2Vrms signal (top wave on scope)

The channel strip won't clip but if the master is turned up to full it will clip quite easily when the -6dB Attenuator is not engaged

You hear me say 'over' towards the end of the video that is when the 'over' light on the master output meters activates as I raise the master output

Turn the attenuator on and it is possible to max out the master but you only have to nudge the EQ out its centre notch and the master output will start clipping

This video only shows one channel it does not take into account the summation of multiple channels whilst mixing and how that will affect the master output clipping

[makar1]

Looks like the red LEDs on the channel meters don't matter too much, and that there is still around 8? dB of headroom above the +10 red LED on the Master output when attenuation is set to 0. That seems to add up to the 19dB of headroom above 0 quoted by Pioneer.

The +10 signal is about half the p-p amplitude vs the clipped waveform, so at that point you could fit in two red-barred decks of in-phase sine waves. Normal music I'm guessing will be more forgiving.

[synthet1c]

if you keep making vids, can you show where the clipping starts on the mixer or say the position.

[Timbo21]

It would be good to see how it performs with some EQ, would it not?