Re: [hatari-devel] Sound lowpass filtering?

[Anders Eriksson <evldhs@xxxxxxxxxxxxxx>]

------- Original Message -------
On Friday, September 1st, 2023 at 18:42, Brad Smith <rainwarrior@xxxxxxxxx> wrote:

I would suggest the Bubble Bobble title screen and intro (the little jingle that plays after pressing 1 to start the game) to compare against what I already have. Unfortunately I don't think it's compatible with the Falcon though.

Hello,

Falcon headphone jack:

https://www.dropbox.com/scl/fi/o7q3nfn5vsrg1haqa2z0s/Falcon_Headphone.wav?rlkey=5oiqyur8dccj2zojak4r6zp6w&dl=1

STe RCA jacks:

https://www.dropbox.com/scl/fi/8wn0c18glm41qbbbolkv0/STe-RCA.wav?rlkey=dbkmry8j2x122et42e9g8c1eg&dl=1

Hope it helps.

--

Anders Eriksson

ae@xxxxxx

Otherwise any game with good title screen music would probably be good for comparison.

I'll put on my to-do list writing a program that does a more direct walkthrough of the YM sound features (frequency sweep, flat tones, etc.) which could be used for better reference comparisons.

-- Brad

On Fri, Sep 1, 2023 at 12:16 PM Anders Eriksson <evldhs@xxxxxxxxxxxxxx> wrote:

As stated, I do not have experience with STE or Falcon, and I also have found verifiable hardware recordings much more difficult to come by for these machines (especially Falcon), so I can't make any empirical argument about the PWMaliasFilter. I only suspect that it may have the same problem as the LowPassFilter, since it is structurally a very similar filter implementation.

Hi,

I can record from a Falcon and STe.

My ADC is a rather lowcost USB one so quality is likely not the absolute best.

If you like something recorded, please inform me of what.

--

Anders Eriksson

ae@xxxxxx

-- Brad Smith

On Fri, Sep 1, 2023 at 5:57 AM Nicolas Pomarède <npomarede@xxxxxxxxxxxx> wrote:

Le 01/09/2023 à 10:19, Nicolas Pomarède a écrit :
> Le 01/09/2023 à 03:45, Brad Smith a écrit :
>
>> It's been a little bit frustrating that nobody has commented on the
>> sound recordings at all. Has anyone listened to them? Has anyone
>> analyzed them? Do you have subjective feelings about their quality as
>> I do? Do you think my evidence is wrong? Do you have recordings of
>> your own? Do you have an ST that sounds more like LowPassFilter? Has
>> anyone built my proposed changes and listened to them?
>>
>
> Hi
>
> on my side, as I wrote on atari-forum, I was in holidays away from home
> with no correct speakers to do proper listening. Back home now, I will
> try to listen to your recording asap, but I have lot of "real" work at
> the moment, very few spare time, so please allow a little more delay :)
>

So, I had time to listen to your flac recordings. I must admit that for
the first part of the audio I don't hear that much difference/distortion.

But it's true that at +12 sec there're 7 separate notes where a
difference can be heard between the different files and hatari 2.4.1
sounds more distorted than 1040stf

Just a question regarding the recordings made with Hatari : for these 4
recordings, did you also apply the change to move the filter in
YM2149_NextSample_250() (as you describe in issue #1 of your PR) ?
In case I want to do recordings myself to compare with yours, I need to
have filter applied at the same point as you did.

Nicolas