Low and distorted sound ?

Squaresoft74
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Low and distorted sound ?

Unread post by Squaresoft74 »

Hello,

Been playing with the PCE core lately but was kind of surprised about the sound being that low by default.
So i ended up taking my Supergrafx out of its box after some years of hiatus to double check and it's indeed way lower with the MiSter compared to the original system for some reason.
I've made some quick recordings of PC Gengin here where you can also notice some sound distortions that don't happen on the real hardware.

I know the SGX has the HuC6280A revision chip that was supposed, as far i as understood, to fix some sound issue over the regular HuC6280, but i don't own the original PC Engine model to compare in case the MiSter core is based on that specific chip.
dshadoff
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Re: Low and distorted sound ?

Unread post by dshadoff »

So you are talking primarily about output levels/volume ?

As it is possible in the PCE core to have PSG, ADPCM, and CD sound all mixed together, the volumes have been adjusted so as not to clip (digitally) when they are all taking place simultaneously. Your HuCard example has only one of these sounds, so it doesn't maximize the output levels. I expect that if you took the output from a CDROM unit (in conjunction with the SGX), they would either be comparable or one would have a higher likelihood to distort.


When you talk about "distortion" in these recordings, it's not clear what in particular you're talking about, particularly as these recordings are not adjusted to be similar levels.

It would also be easier to describe and point out if you could find an example which occurs on a track without so many simultaneous layered voices.
Squaresoft74
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Re: Low and distorted sound ?

Unread post by Squaresoft74 »

Hi Dave,

I was pointing out the PSG volume output compared to my SGX.
It's about the same difference when comparing against my Duo R (which currently can't read discs anymore as far as testing possibilities go).

As for the distortion with PC Genjin, well it's more something that sounds off on some tracks with one of the PSG channels that caught my attention.
Like if it had a wrong pitch or something like that.
I was considering getting a Hes rip for quick and easy testing, but the current one i can find won't work on real hardware/MiSter.
Squaresoft74
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Re: Low and distorted sound ?

Unread post by Squaresoft74 »

I checked PC Genjin again using my SGX, Duo R and MiSTer but this time with my Sony CRT TV.
MiSTer being connected via Antonio's VGA->Scart cable here.
I didn't get those random distortion anymore with this setup.
I guess it was down to my other modern TV also applying some weird audio filtering when the game mode is enabled. :oops:

As for the global volume output, MiSTer's 4x mode is still slightly lower than real hardware.
Not sure if that could be tweaked without breaking the current overall balance.
pacoarcade
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Re: Low and distorted sound ?

Unread post by pacoarcade »

In my experience using jotego's CPS1 core it depends on the TV. With a Sony Trinitron KV-B2513E I have to set volume to more than 5/10 and it gets a bit distorted. With a LG CF-28A56 it sounds fine, but there's a humming sound appreciable when there is no audio.

This user talks about using a small preamplifier due to low volume coming from the HDMI to VGA adapter.

I'm using a Rankie HDMI->VGA adapter + SCART cable.
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