Topic: 24 bit > DAT

[Steelcorner27]

Just wondering what a Tascam DA-30 MKII would do with a 24 bit spdif signal, would it dither or truncate the singnal to 16?

Thanks
Brad

[nickgregory]

all DAT machines would truncate it

[mmedley.]

all DAT machines would truncate it

Not all. The DA-45HR can record 24bit to DAT. 

...but yeah, 16bit only DAT machines will truncate.

[nickgregory]

all DAT machines would truncate it

Not all. The DA-45HR can record 24bit to DAT. 

...but yeah, 16bit only DAT machines will truncate.

fair point

[JasonSobel]

also, I think some of the home Sony DAT units (not sure which ones offhand) use SBM-1 technology.  they might dither down the 24 bit signal to 16 bit, which is better than just truncating it.

[mhibbs]

also, I think some of the home Sony DAT units (not sure which ones offhand) use SBM-1 technology.  they might dither down the 24 bit signal to 16 bit, which is better than just truncating it.

Even if they have SBM, I doubt it is active on a digital input. 

[wbrisette]

also, I think some of the home Sony DAT units (not sure which ones offhand) use SBM-1 technology.  they might dither down the 24 bit signal to 16 bit, which is better than just truncating it.

Even if they have SBM, I doubt it is active on a digital input. 

That's correct. SBM only works on the analog inputs, not the digital inputs.

Wayne

[F.O.Bean]

so what does a truncated signal sound like

[Brian Skalinder]

so what does a truncated signal sound like

Try it, Bean.  Load up a 24-bit file in Wavelab.  Truncate it to 16-bit.  Compare.  I hear a loss of detail overall (not surprisingly), especially in the attack and decay of transients.

[Chanher]

I feel like a truncated 16-bit file is still a perfectly acceptable back-up, I've done both truncated and analog back-ups into my jb3, and I prefer truncation.

[F.O.Bean]

so what does a truncated signal sound like

Try it, Bean.  Load up a 24-bit file in Wavelab.  Truncate it to 16-bit.  Compare.  I hear a loss of detail overall (not surprisingly), especially in the attack and decay of transients.

how would i truncate that signal in wavelab tho

[wbrisette]

I feel like a truncated 16-bit file is still a perfectly acceptable back-up, I've done both truncated and analog back-ups into my jb3, and I prefer truncation.

Sometimes they can sound very good. Saturday I did a 2 channel mixdown (from 6 channels) on the DEVA and fed that to the archivist of Oslopo for their set at Harvest Moon Festival in Austin. The DEVA only sends out a 24-bit AES signal out the digital output. The Tascam DA-P1 he used truncates the additional 8-bits and we listened to some of it later (I listened in the field with my Etymotic ER-4), and it sounded just fine.

Will the 24-bit file sound better? Yes, but as a backup or even a master depending on the source and other factors, a 16-bit truncated file sounds just fine.

Without dithering the next best way to get from 24-bit to 16-bit in the digital world is to use 16-bit floating point, processed in this manner will sound pretty good, and usually as good as any of the dithered files. That said, you have few devices taking in a 24-bit file and doing much more than just chopping off the LSB 8-bits.

Wayne

[wbrisette]

so what does a truncated signal sound like

Try it, Bean.  Load up a 24-bit file in Wavelab.  Truncate it to 16-bit.  Compare.  I hear a loss of detail overall (not surprisingly), especially in the attack and decay of transients.

how would i truncate that signal in wavelab tho

If it's anythign like the Mac, you simply use the save as function and tell it the format is 16-bit not 24 and make sure you haven't enabled the dithering routines.

Wayne