Instruments • Kilohearts Plug-ins Aren't Bit Transparent (Request 64-Bit FP update)

TL;DR request: Dear Kilohearts, please update all your plug-ins (including all 33 snapins) to operate at 64-Bit Floating Point internally and also send/receive their data at 64-Bit Floating Point so there would be no need for a 64-Bit to 32-Bit and 32-Bit to 64-Bit conversion either. So a Full End-to-End 64-Bit Floating Point signal path update please? So that there's no need for dither either.

You can recreate my test here:

• Open a new project in REAPER.

• Go to Project Settings > Advanced and make sure that mixing bit depth is at 64-Bit Float.

• Go to Project Settings > Media and make sure everything there is also at 64-Bit FP.

• On the master bus insert Schwa's Bitter or REAPER's own Bit Meter plus REAPER's own Frequency Spectrum Analyzer Meter.

• Change the Frequency Spectrum Analyzer Meter's floor to -450dB.

• Load a test audio track (preferably sine sweep without added noise).

• Duplicate this track.

• Switch the polarity on the duplicated track.

• Press play and you should see that both tracks null perfectly (they are bit-perfect (identical)).

• Now insert Kilohearts' simplest plug-in called GAIN on the duplicated track and leave its gain at zero.

• Press play again, you'll see that the tracks won't perfectly null anymore. In fact, if you render the result and boost it by +150dB, you'll hear the (truncation noise?).

• Now let's add a second Kilohearts' Gain plug-in after the first one (both on the same track). Change the gain on the first one to exactly -3dB, and change the gain on the second one to exactly +3dB.

• Press play again, and this time, not only will you see the truncation noise, but you'll see the signal coming through as well (especially if it's a sine sweep). All you need to do to hear it as well, is to render the result and boost it by +129dB.

• Let's go even further and copy/paste the Gain plug-in *pair* a few hundred times. Remember, for each kHs Gain plug-in that is at -3dB, you MUST have a kHs Gain plug-in that is at +3dB. Here are my result:

• 4 kHs Gain plug-ins only null down to -124dB.
• 8 kHs Gain plug-ins only null down to -119dB.
• 16 kHs Gain plug-ins only null down to -113dB.
• 32 kHs Gain plug-ins only null down to -107dB.
• 64 kHs Gain plug-ins only null down to -101dB.
• 128 kHs Gain plug-ins only null down to -95.8dB.
• 256 kHs Gain plug-ins only null down to -89.8dB.
• 512 kHs Gain plug-ins only null down to -83.8dB.
• 1024 kHs Gain plug-ins only null down to -77.8dB.
• ...

A few notes:

• I understand some may say that these are not audible and therefore there's nothing to fix.

• It makes me wonder whether this is because Kilohearts' plug-ins aren't internally working at 64-Bit Floating Point precision that causes this?

• I did the same test with REAPER's own faders. Only when I set the gain at exactly 1-Bit increments, did the two track null perfectly. -/+ 6.02059991327dB to be precise.

• Airwindows BitShiftGain nulls perfectly (obviously).

• I tested this in other DAWs with the same result: Studio One, Ardour...

• My test signal peaks at 0dBFS.

So again, please update all your plug-ins (including all 33 snapins) to operate at 64-Bit Floating Point internally and also send/receive their data at 64-Bit Floating Point so there would be no need for a 64-Bit to 32-Bit and 32-Bit to 64-Bit conversion either. So an End-to-End 64-Bit Floating Point signal path update please?



Only one kHs Gain plug-in with gain at 0dB:




2 kHs Gain plug-ins on the same track, the first one at -3dB and the second one at +3dB:




8 kHs Gain plug-ins on the same track four of which are at -3dB, the other four at +3dB:

Statistics: Posted by limitlesssss — Tue Jul 16, 2024 3:39 am — Replies 5 — Views 268

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