James Perrett wrote: ↑Tue Oct 11, 2022 9:02 pmHugh Robjohns wrote: ↑Tue Oct 11, 2022 4:23 pm
Wasn't that related to a digital output word length issue? Or am I thinking of something else?
Yes, the word length output was only 16 bits no matter what setting was selected. However, I couldn't reproduce the issue on the ASP008 that I have here and it doesn't apply to the newer ASP800 or ASP880.
It was actually 20bit.
The longer form is that I had a problem on a job with one of my ASP008s. It wasn't a disaster as I had a spare one to swap in and carried on. Back at base, trying to fault find what had happened (of course I couldn't replicate it!), I put an AES analyser on the output of the faulty unit and noticed that it said that the output was 20bit despite the light on the front of the unit saying 24bit.
Thinking that was odd I toggled through the word length settings and found that the output remained at 20bit, regardless of what the indicator lights said. So I checked another unit and found it was the same. And another.....and another....and... found that all nine ASP008s I had, did exactly the same thing. (I also toggled through the sample rates and found some random ones being output as I ran through the settings indicated - maybe those were part of the problem I'd had the day before? Dunno - didn't persue that after finding the word length thing.)
Not being overly impressed with this, I emailed Audient tech support to find out what was going on. Their inital response was that there were different versions of the AD option card, not all supported the different word lengths, and mine must be that type. It went on to say "You don't really lose performance with this, as the converters do not have the necessary specifications to take advantage of 24 bits word length, and the last 4 bits ended up always being the same value anyway. This is part of the reason why the newer digital boards didn't support the option to change the word length."
Being (more than) a bit surprised at this answer I did a polite "you what?" type email. The reply I received, whilst polite (the tech support folks were always polite - no problem there), didn't improve things as it said that, if my cards don't switch word length when the switch is pressed, then this is normal. Also that the ADAT outputs (which I always understood to be fixed at 24 bit) were actually fixed at 20 bit too. And helpfully explained... "The reason the converters can't take advantage of 24 bits is that the noise floor is about -118dB, so any extra dynamic range over 118dB will just be just taken up by the noise. Word length of 20 bits already provides 120dB of dynamic range, which is more than enough, and 24 bits bumps this up to 144 dB which is complete overkill."
Now being pretty pissed off, I said it would've been nice to know that the outputs were fixed at 20bit rather than switchable regardless of what the front panel indicators said or all the paperwork, which described 24 bit converters with switchable wordlength. The response, from a different tech support person, was "There were various versions of the digital card in the ASP008 some of which were able to produce 24, 20 and 16 bit recordings hence why the option was there initially, however, it wasn't possible to lock out the bit depth selectors when cards which didn't have this functionality were fitted."
That's where I ran out of patience and, rather than send a less than polite "wtf" message I left the discussion there.
My annoyance was partly from being told that the thing behaving other than as advertised, as described in the manual and all other tech documentation, and as indicated by the front panel, was 'normal'. And partly from having been sold something that wasn't as described and when raising this, being told that it didn't matter because I didn't really need the described spec.
anyway as a lower spec was "more than enough" and the advertised version was "complete overkill". Both points on which I may differ.
I understand the logic in the argument that the noise floor of the system can't make full use of 24 bit conversion but that isn't the point. Most of the work I do is live recording or on location stuff where the background noise is higher than the noise floor of a 16 bit converter, let alone 20 or 24 bit but that's not the point either.
If I buy something which is described as offering 24 bit conversion and has the option to output a 24 bit word length and switchability to others I expect it to deliver that. Especially on the days when I'm using a 16 bit link and was going on the basis that selecting the 16 bit output on the converter would deliver an appropriately dithered 16 bit output rather than leaving me unknowingly truncating a 20 bit one. (We just thought the 16 bit output sounded a bit rough compared to the nomal output, put it down to dodgy dithering or some other problem, and made a note not to use it that way unless we really had no choice.)
Ok, so they changed the cards to fixed 20 bit and couldn't lock out the switching but where was the note on the this on the website, in the documentation, or on a sticker or sheet of paper packed with the unit? This can't have been a short term thing since my preamps were acquired over several years and all had the problem card fitted so it's not like there wasn't time to let customers know about it.
I felt and still do feel that in continuing to describe the conversion as 24 bit, without clarifying that it gave a fixed 20 bit output, was misleading/mis-selling it. And with the attitude that it's 'normal' and the implication that I'm wrong in raising it as an issue, my faith the integrity and honesty of the company evaporated and within a few weeks I'd sold all my ASP-008s, (making sure to advertise them as having fixed 20 bit outputs! Though a few people still contactred me to tell me that they were 24 bit.) I also got rid of all my ASP 880s as the whole experience had left me feeling pretty negative towards Audient. (I should make clear that, when tested, none of my ASP 880s had this problem and I was assured that neither it nor the ASP 800 has never been affected by the issue described and both types always output 24 bit.) However, as a result of how this went, I'll neither buy nor reccommend an Audient product again.
Notwithstanding that, I was happy with the sound of Audient's preamps (including in the ASP008) and, as an analogue in - analogue out unit, it's fine. It did make me glad that we usually used it that way and did the conversion elsewhere.
