Sound Modes

Deathlike2 · Post by **Deathlike2** » Mon Jan 10, 2005 7:50 am

I understand that the Gaussian Interpolation mode sounds the most accurate for the SNES. I'm wondering of all the other options (including the low bass filtering options) and how they fare (which is better, and what is different about them???) If this could be added to the documentation, that would be greatly appreciated. I'm also curious as to what those modes offer in the way of Square's SPC issue that I've heard about.

Also, I'd like to know the difference between linear interpolation (the interpolation available in Snes9x) and Gaussian interpolation (whether it is one and the same or different - if different, what differences are there and which is more accurate??)

Thanks in advance.

Post by **Agozer** » Mon Jan 10, 2005 8:08 am

My tests with the different sound option had little to no difference when used with the infamous 'Squaresoft SPC sound rape'.

Low Pass filter adds more bass to sound, but the sound output is a bit muffled at the same time.

Nightcrawler · Post by **Nightcrawler** » Mon Jan 10, 2005 2:16 pm

That does sound like a good idea. Lots of people constantly ask what the difference is between the sound filters and options are.

It would be nice to give a bit of description about each one.

It would also be nice to say a few words about each video filter as well That question also comes up all the time.

Clements · Post by **Clements** » Mon Jan 10, 2005 2:45 pm

It's all to do with Mathematics and adding values between or superimposing polynomials onto the raw sound output to smooth out the data to make it sound much nicer. The more smooth the waveforms are after interpolation the better it's going to sound.

To my knowledge, the 8-Point algorithm is the most sophisticated and sounds best. Low-pass is completely different. They block out unwanted high frequencies, making the bass a little better. Works great with subwoofers.

There's good info on Cubic spline in comparison to linear interpolation here:

http://en.wikipedia.org/wiki/Interpolation

... and info on Low-pass here:

http://en.wikipedia.org/wiki/Low-pass_filter

Enjoy. The details of these methods are a little pointless to add to a readme. Just look the stuff up and you'll find info.

Cloud Strife · Post by **Cloud Strife** » Mon Jan 10, 2005 3:39 pm

Ooooh. So THAT's what a Low Pass filter is. See, I was pretty close because I though it had to do with low sound bandwidth/frequency being filtered. Getting back to the "Square SPC sound rape" issue, couldn't Pagefault and the rest of the Zsnes add a hack to get around it? I mean, since the SPC700 is so freakin' hard to emulate in the first place? All other SuperNES emulators either fully emulate it, or add hacks. (If I could just find the correct processes)

creaothceann · Post by **creaothceann** » Mon Jan 10, 2005 3:41 pm

There was a hack in 1.36 for that, wasn't it?

Joe Camacho · Post by **Joe Camacho** » Mon Jan 10, 2005 5:56 pm

Cloud Strife wrote:Ooooh. So THAT's what a Low Pass filter is. See, I was pretty close because I though it had to do with low sound bandwidth/frequency being filtered. Getting back to the "Square SPC sound rape" issue, couldn't Pagefault and the rest of the Zsnes add a hack to get around it? I mean, since the SPC700 is so freakin' hard to emulate in the first place? All other SuperNES emulators either fully emulate it, or add hacks. (If I could just find the correct processes)

You already know the answer to this.

Nightcrawler · Post by **Nightcrawler** » Mon Jan 10, 2005 6:46 pm

Clements wrote:It's all to do with Mathematics and adding values between or superimposing polynomials onto the raw sound output to smooth out the data to make it sound much nicer. The more smooth the waveforms are after interpolation the better it's going to sound.

To my knowledge, the 8-Point algorithm is the most sophisticated and sounds best. Low-pass is completely different. They block out unwanted high frequencies, making the bass a little better. Works great with subwoofers.

There's good info on Cubic spline in comparison to linear interpolation here:

http://en.wikipedia.org/wiki/Interpolation

... and info on Low-pass here:

http://en.wikipedia.org/wiki/Low-pass_filter

Enjoy. The details of these methods are a little pointless to add to a readme. Just look the stuff up and you'll find info.

I don't think it's pointless. It's an option in ZSNES and it should be described by say one or two sentences or ranked as being better or worse than another option if applicable in the documentation.

Non technical people will look at your interpolation link and not undrstand a single thing. I wasn't implying a detailed description b added to the readme. Just something general for the masses.

Post by **Agozer** » Mon Jan 10, 2005 6:50 pm

Nightcrawler wrote:
Clements wrote:It's all to do with Mathematics and adding values between or superimposing polynomials onto the raw sound output to smooth out the data to make it sound much nicer. The more smooth the waveforms are after interpolation the better it's going to sound.

To my knowledge, the 8-Point algorithm is the most sophisticated and sounds best. Low-pass is completely different. They block out unwanted high frequencies, making the bass a little better. Works great with subwoofers.

There's good info on Cubic spline in comparison to linear interpolation here:

http://en.wikipedia.org/wiki/Interpolation

... and info on Low-pass here:

http://en.wikipedia.org/wiki/Low-pass_filter

Enjoy. The details of these methods are a little pointless to add to a readme. Just look the stuff up and you'll find info.
I don't think it's pointless. It's an option in ZSNES and it should be described by say one or two sentences or ranked as being better or worse than another option if applicable in the documentation.

Non technical people will look at your interpolation link and not undrstand a single thing. I wasn't implying a detailed description b added to the readme. Just something general for the masses.

A very good idea. I think that all the options should be explained at least to a degree, unless the function of a checkbox or a window is "fool-proof".

MisterJones · Post by **MisterJones** » Mon Jan 10, 2005 7:39 pm

Video blitters could also come with screenies for people to compare.