Compressed PCM samples in the M3: is lossless compression?

klarnet basowy · Post by **klarnet basowy** » Tue Nov 13, 2007 1:21 pm

One of the difference often higlighted between the M3 and the Oasys is that M3 has compressed PCM samples, while Oasys has linear PCM samples.
Is the compression in the M3 lossless? Or the compression causes a sound quality drop?

thanks in advance

k.b.

Ps. I'm not complaining on M3 sound quality, I like it very much, it's only technical curiosity

Animal · Post by **Animal** » Fri Nov 23, 2007 6:11 am

I'm not sure, but I guess that the compression affects the speed of loading new sounds when changing patches. This issue is discussed here.

It should be lossless compression though, I think.

dorremifasol · Post by **dorremifasol** » Fri Nov 23, 2007 11:20 am

PCM compression is always lossy in synthesizers, and a requirement to fit large amount of samples in a ROM chip. But you shouldn't worry about if it sounds good for you, for most sounds isn't noticeable.

Evidently, as the OASYS is focused on delivering the highest possible audio quality it doesn't use compression for the samples. The differences in sound are evident between the M3 and the OASYS, as it is the price also.

anhe · Post by **anhe** » Fri Nov 23, 2007 11:41 am

The Oasys uses lossless compression since os 1.3.

klarnet basowy · Post by **klarnet basowy** » Fri Nov 23, 2007 12:24 pm

dorremifasol wrote:The differences in sound are evident between the M3 and the OASYS, as it is the price also.

And sound quality differences is also evident between M3 and Triton series synths.

Anyway, maybe the difference in sound quality is also due to the different synthesis algorithms.

Andrew

rfoshaug · Post by **rfoshaug** » Sat Nov 24, 2007 12:13 am

Computer memory (ROM and RAM) is not so expensive that it explains the price difference between M3 and OASYS...

Actually, as cheap as memory is these days, there can't be much to save by using compressed samples in the M3. Something tells me that there is another reason why they compressed some of the samples. Maybe faster loading times? I don't know. But the extra PCM ROM hardware that would be required for all M3's samples to be uncompressed wouldn't cost many $'s...

What I do know, however, is that the M3 sounds very sweet. There seems to be more presence in bass and treble compared to the Korg Karma (using the HI synthesis from the Triton series).

MartinHines · Post by **MartinHines** » Sat Nov 24, 2007 4:21 am

rfoshaug wrote:Actually, as cheap as memory is these days, there can't be much to save by using compressed samples in the M3.

But the extra PCM ROM hardware that would be required for all M3's samples to be uncompressed wouldn't cost many $'s...

I think the issue IS cost. Given the Korg M3, Roland Fantom X, and Motif XS ALL use Sound ROM compression, if cost was not an issue one of them would have the extra RAM.

As I have stated before, I have been told that the actual cost of any hardware has a 3x-5x cost impact on the retail price. Therefore a $50 addition in hardware will turn into a $150-$250 retail price impact.

dorremifasol · Post by **dorremifasol** » Sat Nov 24, 2007 9:21 am

Do not confuse the kind of compression found in synthesizers with regular compression used in daily PC tasks such as ZIP, RAR, etc.

I have worked with many sound chips of game consoles (which are complete synthesizers by themselves), and all of them had some kind of compression, mostly based on ADPCM algorithms. Decompression is always made in REALTIME by the sound chips, there is no sample loading / decompressing procedure.

You can not compare computer RAM to specialized synthesizer RAM or ROM. One is sold in million of units and the other is sold in much less quantities, that makes a big difference in the price.