Sunday, June 8, 2014

Home Sweet Home

Back home.  My own system is oh so special in so many ways.

1) Whole house coverage.  The combination of omni super tweeters (which contribute magic you don't directly hear so much…but take it away and the magic disappears), dipolar electrostats, and powerful stereo subs means that sound penetrates everywhere in the house.  Thankfully the bedrooms can be mostly cut off with the new soundproof doors and wall.  But open them up, and the party goes on everywhere.  The kitchen is a great place to listen to the living room stereo.

Is this important?  Audio purists say no, you want to hear only the speakers in the sweet spot, and nothing but the speakers.

But nearly all of my listening is "non-serious", the music is background to other activities, or I am not sitting in the sweet spot.

2) Whole living room coverage.  On return from vacation, I first sat in the couch.  The sound was surprisingly good, in fact--possibly more positive feeling bass than the sometimes anemic sweet spot bass.  Way off axis, but there was still an image…with all parts playing.  For enjoying music--it was surprisingly close to the sweet spot…and without the need for perfect centering as in the sweet spot.

3) Multilayered depth, and especially at the sweet spot.  I've readjusted sweet spot chair in both axes a bit, a couple inches farther back, and the centering is now right on.

Frequency balance, especially the highs, is superlative, Class A.

Bass deep and incredible, but still a bit lumpy.  Class A-.

Imaging wide and multilayered.  Class A.

Grade A-+ (just a tad short of Grade A).

That's listening to the DVD-Audio of Santana Supernatural, which I've been spinning since arriving in San Antonio in the wee hours of Saturday morning.  Stereo track of course, which is 96kHz 24 bit, played through Denon 5900 (a top of the line product once, with separate power for the Burr Brown 1720 powered outputs) into a Lavry AD10, then on to digital preamp, crossover, and equalizers, expressed back into analog through Burr Brown 1704 powered Onkyo RDV-1 for the Acoustat powering Aragon 8008 BB.

It occurred to me that I'm not getting the full potential information because of the lossy sigma delta conversion in the Burr Brown 1720 DACs.  Estimating this to be a 4 bit sigma delta converter operating at 256fs, we have this much information at fs:

256 * 16 = 4k

A lot more than DSD's 64 (!) but still not good.

Whereas 16 bit PCM gives us:


So, for awhile I connected to the PCM output of the denon, which gives me 48kHz 16 bit apparently because of DVD-Audio operation without the manufacturer setting the hires digital output allowed flag.  But I didn't figure that out until a few hours of listening to this 16 bit quality.

I didn't like it.  Yes, in some ways, I could hear superior inner definition.  I heard a great deal more harshness too.  But big stuff, like the deepest bass, is merely sliced off.  In a strange way, you get more micro detail without the macro detail that makes it meaningful.

This suggests to me that there are issues with my way of calculating information.  DSD might actually have more than 64 units of information at Fs.  Of course this is certainly true if DSD has higher than Fs/2 bandwidth, which it does.  To me, it's not clear how to adjust the formula.  But I'd say we have one datapoint here:

DSDei is around 16 * 64

Because the between the translated sigma delta, at 4k previously calculated information, seems better overall than pure pcm at 64k.  Of course the underlying information stream is far richer too.  But if it were really choked off at 4k units of information vs the 64k of 16 bit PCM, that shouldn't matter.

I may be able to preserve the information by making a master link recording of the analog output of the Onkyo RDV-1 which uses a full 24 bit ladder DAC.  I'd use the Lavry AD-10 for digital conversion, feeding the AES/EBU inputs of the Masterlink.  Then I could edit that into a DVD-Video disk with unprotected digital output at 96kHz.  That does require the more expensive version of Diskwelder Bronze 1000m.  Then I could play through existing system w/o loss from sigma delta converters, whatever it actually is, via the digital outputs of the Denon 5900, or through a future SPDIF connection from kitchen.

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