Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems +3dB "LevelPerfect" Tweak Performance Improvement Poll

If you can't find it on your own, I HIGHLY recommend you use the new tool I wrote. I'm now using it myself and no longer have to do Hex addition in my head.

It's quicker, easier, and easier to try multiple experiments and you can see the effects and trade-offs at a glance before uploading to processor.

https://www.meridianunplugged.com/u...bb=showflat&Number=116105#Post116105

Was wondering what the difference was. Will do that-- Thanks George.

Joe

FYI.

Just tested G91DH.

In 2-Channel Mode there is no 3dB attenuation.

In HT Mode there is the 3dB attenuation.

The MSL Trick DOES NOT work on the G91. It was ignored.

Also I played an artifically clipped CD and Clip lights did not come on.

I'm not convinced of this as it seems contrary to everything the 518 is designed to do. The 518 manual states that dither is applied when performing a "Step up in dynamic range". This would only be necessary if a non-trivial DSP operation is being performed.

However, I accept this is unclear. Maybe I'll do some experiments with my Tascam when I (eventually) get home. (Holiday extended by six days minimum at the moment...).

One thing's for certain though. Adding my 518 in front of all my stereo sources prior to Radiance/HD621 will be a good thing to do, particularly if I can automate the amount of digital gain on a per-album/track basis.

It can do all the cool stuff it wants to internally (apply dithering, shaping etc.) in 72 bits. But if you stretched 16 into 24 (from SPDIF input to SPDIF) output you'd be pushing the low level bits of the 16bit word (very audible bits) down into the into low level bits of a 24bit word (very inaudible rangle).

Take my DAC resolution test for example. The limit of my system is 19-20bits (period). Anything beyond that at max volume it out of reach.

Now lets say I take a 16bit file and I put something in the low bit (all 0 above it). Now if you "stretch that out" those low bits would be now in the lowest 2 bits of the 24bit word (the ones you cannot hear). Top 20 or so bits would be now be 0 (the ones you can hear). You have something you could hear now you can't.

Everything works from 0dB DOWN, the negative scale. There is a lot of history and SPDIF compatability involved.

What your doing is thinking I have say a value of 1 in a 16 bit word and the least significant bit would be set top represent it. And if you convert it to 24bit that would move to the least significant bit(s) of a 24bit word. That is not how it works.

This link helps explain some of it. It's exactly the same for 24bit. 24bit just goes 8bits MORE NEGATIVE.

If you did "stretch" 16 to 24 that would be an "Expander" which would be just as bad as over compression (which is what the article below is about).

http://www.chicagomasteringservice.com/loudness.html

Reposted below with new diagram

Shame I don't understand the diagram

I don't understand anything, but I'm fascinated all the same.

Ok. Time for analogy in DECIMAL. You all have 10 fingers I hope.

I'm only explaining the 16 vs 24bit because you need to understand that first.

Say we have a new currency called the dollar.

But it's limited to 4 digits.

0 to 9999.

10 years goes by with this new currency.

Every is priced in dollars.
Money is printed in dollars.
Trading is done in dollars.
Gold is in dollars.
Machines accept dollars.
etc.

Nothing cost more than 9999 dollars in this little world. But also no less than 1 dollar.

But folks are complaining they can't sell something for 1.5 dollars or 0.5 dollars. They don't have enough granularity (resolution). They don't care about the 9999 limit, it's fine.

Ok we need a new 6 digit system.

We could do it two ways.

1) Burn all the currency we have and introduce a new currency called the minidollar (worth 1/100 of dollar). Range is from 000000 999999 (6 digits). Reprice everything. Redo all machines that accept dollars. Man that's expensive.

2) Or we introduce an additional coin, called a Penny (1/100 of a dollar). Still 6 Digits. But now we can go from 0000.00 to 9999.99. And folks are happy because a dollar is STILL a dollar. Old currency can stay as is. Old machines still work and people can now charge a 1.5 dollars or 0.50 dollars. Only new machines that need to accept pennies need to be built (think better DACs here, but old DACs work too).

The only thing different is where we put the decimal point in the two choices. Same resolution on both schemes. Both 6 digits. But second scheme is more compatible with the original 4 digit system.

That's what happens when you go from 16bit to 24bit. They only added fractions to the bottom. They don't go any louder.

The top 16-bits are still the same SIZE (loudness). That did not change.

The top bit in 16-bits is just as loud at the top bit in 24bits. Actually all 16 top bits are the SAME.

Just like in the currency system the top digit is the same size in 4 digit scheme and the 6 digit scheme. 1000 == 1000.00 or 9999 == 9999.00

I don't know if it will help you guys but I updated the picture.

I added the dB Scale on the side of both the 16bit and 24bit word.

Note how they line up from the top down. NOT from the bottom up.

Anything below -108dB (Around there) gets extremely difficult to hear. You would never want to "stretch" the top 16bits down into the abyss (low 8 bits).

I also added a Noise Floor line (this is approximate and will vary with room, DACs, Preamps and Amps). You need something above noise floor to hear it.

George - thanks for explaining your two cents worth! The time and effort you have put into developing and explaining this solution is greatly appreciated. Whilst I wouldn't say I understand it perfectly, you explanations have been well described and informative. Thanks again.

Tom

My fingers go to 11.