24 bits

[Yiannis]

Hi,

My setup is:DP-Motu 2408mk1-HEDD 192.
I am going in the HEDD at 24/48 and SPDIF out to 2408.

My question is how will I know if I am recording trully at 24bits?
I have done this test,
A sine wave into HEDD at 24/48 and out to motu via SPDIF.
Watching Spectrafoo's Code meter I don't see any difference between 16/24.
Any help please?

Yiannis

[2leod]

Well, one way to tell is that a minute recorded at 24 will be larger file than a minute recorded at 16...

[Yiannis]

Well I think that if you set your software at 24bits and record audio via a 16bit convertor the file gonna be larger but the bit depth still 16bit.

[2leod]

I'm confused... where is your 16 bit convertor? You said the HEDD is at 24 bit and the signal is not seeing another convertor until it hits the D/A... am I missing something?

[Jesse Skeens]

I use Wavelabs bit meter and it deffinatly shows blank spots for the lower 8 bits if you arent recording at 24. Ive used it to test my Creamware system.

Jesse

[Yiannis]

The HEDD is at 24bits.the path is HEDD-2408-DP.(24bits)

What I see is blank the 8 lower bits.
Motu mentions that 24bit can be recording using the 2408mk1 via SPDIF.

So.....what is happening?

[Yiannis]

Lower bits are from 1-8 or 17-24 ?

[Yiannis]

Anyone who could help to solve this mystery.....??

[2leod]

Sorry man, don't think I can help you. If I understand you correctly you are saying that even with everything in your chain set at 24 bit you think that you are only seeing 16 bit... right? Not sure what you mean by the lower 8 bits, though. I know the HEDD set at 24 bit passes 24 down the S/PDIF, I do this all the time , but I'm not familiar with the 2408 or DP. You say that MOTU mentions that you can record at 24 through S/PDIF on your unit, are you sure you have everything set right on the box? Have you tried sending something other than a sine wave into Spectrafoo, like pink noise? Unless you have a defective HEDD, it sounds to me like your issue is at the 2408 or maybe how you are interpreting the data you are getting...

[Yiannis]

thank you man!
when I put the sine wave into the HEDD, I turn the process knob from 24 to 16 but still no change at the foos code meter!

I will check it with pink noise!

[5down1up]

what source feeds the hedd ?

have u tried sending an " analog " signal and let the hedd do the conversion ?

[Yiannis]

i have try a drum loop from a sampler.
The same results.
anyone familiar with spectrafoos bitscope?

[Mantra]

I thought the MOTU 2408 Mk I was a 16 bit unit.

[Yiannis]

20bit analog in/out 24bit digital in/out

[Stoneface]

I'm assuming you do have it set to 24-bit in DP? If so and you can't seem to rectify the problem, I'd recommend dumping that mkI and at least getting an MKII. I'd be willing to bet that is where your problem is, regaurdless of what the specs say.