Hi Josko,

Thanks for sharing your experiences. Actually, your order of preference is exactly what I would expect from someone using an oversampling DAC (which your Weiss is, along with the 99.99% of all other DACs on the planet).

What you're experiencing with AP (I think) is your DAC doing unnecessary oversampling, once this has already been done in XXHE. The point here is that with 4 x AP (I like to call it QAP), no more oversampling really needs to be performed - everything 'nasty' is well outside the audio band. However, delta-sigma DACs have to continue oversampling in order to work. Many multibit DACs also continue oversampling with 4fs material... BUT my contention is that they don't have to.

Although I've never heard it, 8 x AP should be even better... played on a NOS DAC... that can handle 24/352.8K.

In any event, I think the one thing we all agree on is that XXHE is a great player... Welcome to the club!

Mani.

Firstly... Happy New Year to everyone!

Now, I had some time this morning and I really wanted to verify Peter's comment below:


I chose an HDCD track which I know has been mastered with the HDCD options engaged (from the Jacques Loussier Trio playing Satie).

With no upsampling and vol at 0 on XXHE, the HDCD indicator on my DAC lit up, as expected. The sound was very warm and lush... listenable, but not very exciting or foot-tapping.

I then set the vol in XXHE to -6dB, keeping everything else the same. My DAC automatically disengaged its HDCD processing (the LSB had changed after all) and increased its output by 6dB (all as expected). I expected to hear a decrease in SQ... BUT this just wasn't the case. The sound was actually clearer!!! More tuneful. Everything started sounding more real.

Then on to QAP with vol still at -6dB in XXHE (but making all the necessary changes elsewhere for my DAC to accept 24/176.4K). And there was yet another step up in SQ!

But the killer was when I then increased the vol in XXHE to -0dB (and decreased my analogue volume control by as close to the same amount as I could). Now, this sounded very, very good... substantially better than when I started out.

The only thing I can really conclude from all this is that how attenuation is applied is absolutely critical.

Also, don’t worry about buying HDCD material and not being able to decode it properly – it sounds wonderful played on 0.9y-4, with or without upsampling.

Mani.

I certainly didn't. W7 seemed a step-up from Vista... not necessarily in SQ terms, but certainly in latency terms.

I have absolutely no complaints about the SQ of XXHE on W7. But I'm still running the evaluation copy of W7... I wonder if that makes a difference?

Mani.

Well look what you've created now. Us W7 users are all frantically searching for our Vista disks now and dreading hours of reformating, reinstalling and reoptimizing...

Thanks Peter

Mani.

Works for me.

Mani.

IMHO, to hear the real benefits of Arc Prediction, you really need to use it in Quad mode... with a 176.4/192K-capable NOS filterless DAC...

Yes, not too many of those around, I know.

Mani.

Merry Christmas to all XXHE fans!

Here's to a great 2010 

Mani.

Yes, and all of 'these' people have an ulterior motive: either they were on the MH developing/testing team, or they are dealers carrying MH products.

If you own a Veyron, you don't need to brag about it... or show boy racers in their Opel Mantas how inadequate they are 

Mani.

PS. I think only people from Germany would really get the Opel Manta comment... and especially seeing as my name is 'Mani'.

Peter, have you heard of the fluency algorithm that Esoteric uses, called RDOT? Here's some info on it from the Esoteric website:

*************************************
RDOT (Refined Digital Output Technology)

When music data is recorded for CDs, the frequencies that exceed 20 kHz cannot be reproduced due to limitations of the CD standard sampling frequency. Music however, usually consists of frequency information that far exceeds 20 kHz. The effect of not being able to reproduce this additional information is that the listener cannot experience the most accurate and natural sound.

As the solution for recreating sounds above 20 kHz, we use RDOT; a technology that enables interpolation by analogy based on the fluency algorithm. This highly sophisticated RDOT technology uses analogy-based principles to generate all music information likely to occur between data samples. The information is generated from source signals of all sampling frequencies up to 192 kHz, not just the standard CD frequency. As a result, data that exceeds fs/2 is generated. This results in music with natural depth, and listeners can especially feel differences in resolution and reverberation when instrument sounds overlap. The extremely natural timbres and sound fields used to reproduce a live performance are clearly superior.

***********************************************

How similar is Arc Prediction?

Mani.

I totally get this. And if it beats HDCD's Peak Extension, then great. By how much are you hoping to drop the volume before allowing AP to kick in?

Mani.

Sorry, I didn't make myself very clear, did I? I was referring to the 6dB increase in volume that BADA users are experiencing. This isn't really down to AP reconstructing lost peaks. As you said, this would be pretty incredible...

Mani.

There are 3 HDCD 16-bit amplitude encoding options:
1. Peak Extension
2. HDCD Limiting
3. Low Level Extension

Along with HDCD 16-bit Dithers, these were designed to produce the best possible 16-bit HDCD-encoded release masters from analogue or 20/24-bit sources.

From the Model Two manual:

**********************************

Peak Extension is a restorable (with HDCD decoding) soft peak limiter that allows peak levels up to 6 dB above standard full scale level (+6 dBfs) on HDCD 16-bit recordings without generating “overs”. The limiter has a carefully crafted “easy-over” curve, designed to mimic the sound of analog tape saturation that operates over an input signal level range of -3 dBfs to +6 dBfs, in effect squeezing the top 9 dB of the input signal’s range into the top 3 dB of the 16-bit recording.
During HDCD 16-bit decoded playback, Peak Extension peak limiting is undone by the HDCD decoder using a precisely mapped inverse of the limiting curve controlled by the hidden LSB code, and the dynamics of the original material are restored up to +6 dBfs, thus extending dynamic range by up to 6 dB.

HDCD Limiting functions exactly the same as Peak Extension during recording, except that during playback the limiting curve is not undone with HDCD decoding. During HDCD decoded playback, HDCD Limiting has the same effect as during undecoded playback.

Low Level Extension is an average signal level based low level compression / expansion system used on HDCD 16-bit amplitude encoded recordings which very gradually raises gain a preset amount when the average signal level drops below a preset threshold. During HDCD 16-bit decoded playback the compression curve is expanded back to linear gain by the HDCD decoder using a precisely mapped inverse of the compression curve controlled by a hidden code, producing a dynamic range and resolution floor beyond 16-bit. During undecoded playback low level information normally lost by standard 16-bit players is preserved, providing more accurate timbral and spatial reproduction.

HDCD 16-bit dither options allow optimizing perceived timbral and spacial accuracy with different types of source material during HDCD 16-bit A/D conversion, or when converting 24-bit or 20-bit signals to HDCD 16-bit.

************************************

Mani.

Well, there's nothing like Jamaican inspiration Considering the prevalence and level of compression nowadays, this would be really

No, to understand why they apply 6dB attenuation to 16-bit material in the BADA, you need to understand the 3 HDCD 16-bit amplitude encoding options. To avaoid going too OT, I will give a brief overview in a new thread.

In any event, none of this has anything to do with Arc Predicition, other than the fact that using AP on 16-bit material will switch off the 6dB attenuation in the BADA.

Mani.

Of course, my comments in the previous post might well not apply to the BADA. It could well be that the designers decided to reduce the output for all 16bit material by 6dB... in the event that some of it might be HDCD-encoded, thus requiring this attenuation for the HDCD 'Peak Extension' process to work effectively.

The only rationale that I can see for doing would be to normalise the output between HDCD and non-HDCD material from the BADA's outputs. But this then imposes 6dB of digital attenuation (still a 'no-no' in many people's eyes) on >99.99% of the 16bit material that just doesn't need it...

Of course, this 'imposed' 6dB attenuation is then lifted in the BADA once XXHE's upsampling increases 16bit material to 24bits.

My sincere apologies to earflappin if I came across as arrogant in my previous post.

Mani.

No, 24bit is not louder than 16bit.

However, 24bit is louder than HDCD-encoded 16bit... on an HDCD-capable DAC/player... because of the 'Peak Extend' feature.

It now all makes sense to me now. Earflappin must have been using HDCD-encoded 16/44.1 material when evaluating Arc Prediction using the BADA. With no AP, the BADA would have engaged the HDCD processing and reduced the output by 6dB, in line with the HDCD specs. However, engaging AP would have changed the LSB, and the BADA would have switched the HDCD processing off, increasing the output by 6dB.

This is all down to earflappin using HDCD-encoded files. If he had used 'normal' 16/44.1 files, this should not have happened.

[EDIT: I prefer playing 16bit HDCD-encoded files back without any upsampling, to take full advantage of the HDCD 'Peak Extension' and 'HDCD Limiting' processes.]

Mani.