My dedicated audio room build - QuadDiffusor's Big Dig

[QuadDiffuser]

Welcome Home!View attachment 138745

Holy cow! Is that a gargantuan light-emissive LED / OLED screen, or a reflective projection screen?
What might your components in their audio rack look like?
There must be some seriously long interconnects between the source components and the pre-amp!

 

[Silvano]

Speaker Choice (final)
updated 2024-Oct

I'm overjoyed to announce that the Von Schweikert Ultra 9 will be my choice of loudspeaker for my future basement listening room. Luck struck - I'm very fortunate to have the opportunity to own a pre-loved pair! These can easily be my "forever" speakers, but hey when the Ultra 9mk2 or Ultra 10 comes along in a few years, there will be an option to upgrade.

View attachment 138644

Congratulations on your catch!...they seem to be highly promising. Hope you can have a lot of fun and can't wait to hear about your impressions. Keep us updated.

 

[QuadDiffuser]

Back to the topic of component racks, very likely I'll be using two sets of the HRS EXRDs side-by-side, each rack having only two shelves to minimize obstructions (height-wise) for the front wall, important for the quadratic diffusors to horizontally disperse decorrelated/randomized musical energy.

The base of (one of) the EXRD shelves will look like this:


After adding another layer on top:


And here are the physical dimensions of the "two shelf" EXRD, assuming the standard 8" component spacing for the bottom shelf:

 

[QuadDiffuser]

Naturally, the Aurender N30 will be my music server since I've had one since a couple of years ago. When stacked, the two chassis are taller than 8", so they will not fit together in the available space in the bottom shelf of the EXRD shelves.

The choices would be to either stack them together (like in the photo below) on the upper shelf, or to separate them on two shelves (upper shelf and lower shelf), biased to the R side of the midline of the rack assembly, as I'm a righthander. Either way, a Seismion platform can be used for active vibration reduction.

 

[QuadDiffuser]

Indulging myself a bit, upgrading the Aurender N30 to the Taiko Olympus may be a possibility if Taiko's tour de force music server demonstrates significantly better performance, an especially likely outcome, given its newly developed and very promising optical output module delivering unsynchronized data, without the imbedded/multiplexed clock signal inherent to S/PDIF, AES/EBU and (unfortunately) I2S protocols which become the limiting factor in optimizing the advantages of MSB's unique Masterclock and DAC architecture.
https://www.whatsbestforum.com/thre...rn-music-playback.37939/page-200#post-1004974

The HRS EXRD's component shelf will need to be sufficiently large to accommodate the extra large chassis of the Olympus.

 

[MarkusBarkus]

...an N30 vs Olympus opinion is of interest to me, QD, and others too I'm sure. I am awaiting shipment of an Olympus, traded up from an Extreme. The N30 came out after I bought the Extreme, so I never did a tete-a-tete between those babies.

Not sure how much/if you followed the Olympus thread, but we are told good power cable makes a difference, even though it's running on battery power.

 

[QuadDiffuser]

The "good" news is that the HRS EXRD's 483mm(D) shelf will just *barely* hold the 500mm(D) x 400m(W) Seismion platform, which will then just *barely* hold the Olympus (see diagram below).

Sort of like stacking one tortoise on top of second tortoise, on top of a third tortoise below, LOL!



The 480mm(W) Olympus's four footers, with the (red) outline of the 500mm(D) x 400mm(W) Seismion Reatio plus.

OK, so 25% of the Olympus's rubber footers will do a "Hang Five" past the 400mm(W) Seismion (surf)board, but I believe (fingers crossed!) the combo will not compromise stability, structural rigidity or vibration dampening.

 

[MarkusBarkus]

...and one could always do a thin-ish slab of "panzer-wood", if doubts were to arise. I seem to recall there was positive discussion about that material on top of the Seismion in that thread. In any case, that would be a very "trick" set-up: Olympus on the Seismion.

 

[QuadDiffuser]

I had already bought my sub-MCB breaker's external box last year (2023) because it was on a "discontinued" sale. I preferred the gold version because it reminded me more of Marvel's Tony Stark (aka Iron Man) but it had already been sold, so I went for the remaining black version.

I'm not a sucker for cosmetic jewelry, but it's actually quite functional and performance-oriented, with maximally large and generous access holes in its back panel. This "black box" will be mounted outside of the R side of the basement wall, and a round hole will be bore through the structural wall to provide access into the audio room's R side, to connect with the six Furutech NCF duplex outlets.

Since the NCF duplex outlets cannot handle the very thick 10mm2 copper conductors in the Ground cable, I'll be using the Furutech FP-209 mini spade terminals to crimp the copper conductors into a gas-tight tab, which will then be screwed into the appropriate position inside the NCF duplex (presumably into the greenish screw on the side).

 

[QuadDiffuser]

The guts inside are what matters most.
Here is a photo of a sample installation, showing how/where the conductor cables connect.


N is "Neutral" (blue), and G is "Ground" (green/yellow); note the "star" configuration of both Neutral and Ground.
The bus bars and stars are gold-plated heavy duty high-purity copper for maximum conductivity and minimal corrosion risk.

The "live" conductors are the brown cables which slot into the top of the individual breakers, whose conductive internal components are all cryo-treated, and platinum plated.

From post #160 (background information):

Until advised otherwise, my baseline design goal for now is to have super-low impedance ground conductor from each of the AC duplexes back to the sub-MCB breaker box's copper bus bar in a "star grounding" configuration. Effectively, one/single ground for the entire audio system, located at the bus bar of the sub-MCB breaker box, which in turn is grounded to the utility main's bus bar (via copper rods buried deeply in wet soil).

The utility company will be providing 200A of 3-phase 240V 50Hz electricity to my doorstep. From the main breaker box inside the house, I'll be tapping a single 63A branch and delivering it down to the basement's dedicated audio sub-MCB breaker box, similar to the light bulb icon's branch of L2 (yellow) + N.



The other two branches will be used for 1) general household appliances, and 2) high power appliances like air conditioning condensers and water heaters. Hopefully, these high power appliances will not require a three-phase feed which could potentially pollute the dedicated audio feed!

To ensure that there will be no inter-duplex outlet ground loops, I'll be using identical-length ground conductors (10mm2 gauge, having exactly the same impedance/resistance by being exactly the same length of say 7.00m) between the AC duplexes spread throughout the room in a fan configuration (see diagram in posting #150), back to the dedicated sub-MCB breaker box.

For the AC duplexes located furthest away, the ground conductor cable will not have much slack. For the AC duplexes located closer, there will be slack in the ground conductor cables - the excess will be coiled loosely below the dedicated sub-MCB breaker box.

I'd love to hear advice and recommendations from you and other WBF members regarding the AC power delivery schematic above! Am I following "best practices", and on the right path to achieving the best possible power delivery and noise isolation?

 

[MarkusBarkus]

...star configuration? More like SUPERSTAR! Nice.

 

[QuadDiffuser]

Check out my (still raw) basement audio room using Matterport's 3D virtual reality!
Use your mouse to look around the 9.7m(L) x 7.1m(W) x 4.2m(H) room, through the 360-degree camera.

Explore 73GW Audio Room in 3D

Matterport 3D Showcase.

my.matterport.com

 

[MarkusBarkus]

...love that tech, QD. Thanks for the look. Such a nice project.

 

[Holli82]

Holy cow! Is that a gargantuan light-emissive LED / OLED screen, or a reflective projection screen?
What might your components in their audio rack look like?
There must be some seriously long interconnects between the source components and the pre-amp!

That is s projection screen that rarely gets used now.

Component rack:



Yes there is one long ( and expensive) interconnect between the amp and preamp

 

[QuadDiffuser]

Most in-wall AC cables (with three separate insulated conductors) claim to have good EMI/RFI rejection geometries have feeble twist angles, (perhaps just 20 degrees), and the cross section of copper conductor is typically just 4mm2. Therefore, I don't think using "audiophile" in-wall AC cables are a good idea.

Using significantly thicker and far more conductive 6mm2 conductor PVC insulated wires, I tried hand-twisting two of them together and achieved an overlay angle between them of perhaps 30 degrees (see the loop of two twisted wires in the photo below).

I'm assuming that this twist angle would be sufficient to achieve sufficient electromagnetic cancellation (via coupling) to mitigate any EMI/RFI pollution ingress, even without any foil shields. Am I correct?



The straight wire (brown here but ought to be yellow/green to conform to code) with the partially stripped insulation on the L end is a 10mm2 insulated cable, which I'll be using for the Ground wire with the lowest practical impedance/resistance possible. At this thickness of 10mm2, it is too stiff to twist onto another wire of similar cross section, but I won't have to worry about this because this cable will run straight between the AC duplexes and the sub-MCB breakers without any twists, only occasional bends to conform to the PVC routing pipes.

 

[QuadDiffuser]

Here's a conversion chart from AWG to mm2.
According to the chart below, 6mm2 is 14% thicker than 10AWG, and 10mm2 is 19% thicker than 8AWG.

 

[QuadDiffuser]

As local code requirements do not permit any electrical work which deviates from "official" guidelines, most of the build-out of the basement audio room will unfortunately not start until after the official inspection in 2025-Q1. In the meantime, much work will be done in the other two rooms, both having very generous dimensions, including ceiling slab heights of 4.2m.



The Family Room includes the partially-visible staircase to the left, the elevator whose entrance is obscured (to the L of the three workers), and the large storage room utilizing the space below the swimming pool projection to the right. The TV console and LCD TV will be placed in front of the storage room wall.

The space around the distant wall is the home office/study, which includes the mandatory bomb shelter (entrance obscured by the worker wearing the dark blue shirt).

Much of the Family Room's ceiling will be filled with machinery related to the air conditioning system, pre-cooling dehumidifying machine, fresh air ducts, drainage pipes, etc., altogether consuming about 1.0m of ceiling height in the perimeter areas.

 

[QuadDiffuser]

I found my audio room sofa the other week!

I really like how:
- its main seat cushion is in one continuous piece, so that the bum doesn't have to rest divided and sagging when seated in the center
- its seat is very firm, and hence does not sink
- its seat is relatively high at 49cms, bringing the ear to the typical tweeter axis of a large floor standing speaker
- its top grain leather is thick and durable
- its back rest is firm and sits below the shoulders; the broad space around both ears must NOT be blocked by cushions/headrests!
- there's enough space under the sofa for my two mini poodles to take their naps below, with 17cm high legs



An ottoman will likely be added to add more versatility, and of course, some bass dampening!

 

[QuadDiffuser]

XLPE (cross-linked polyethylene) is a superior dielectric to plain-old PVC, so as the sheath directly contacting the copper conductors, this will likely be a better choice for my in-wall AC cable:


I'll be asking the manufacturer what the "twist" frequency for the two-core version is. Ideally, I'd like to have a tight-as-possible 6-8 full (360 degree) twists per meter, resembling Belden's 2 conductor sheathed cable (circled yellow) below:

 

[QuadDiffuser]

Obtained two samples of the XLPE insulated PVC sheathed cables. Note that there's an optical/perspective distortion in the photo, due to proximity differences to the iPhone's lens/sensor array. The upper bundle is supposed to be smaller than the lower bundle.

Using a bright LED headlamp and a magnifying glass to examine them closely, the XLPE insulation had a wet/transparent sheen reminiscent of Teflon.

The 6mm2 sheath (top) has the following printed: "0.6/1KV XP 2C X 6MM2 P/N <10026001> PSB LISTED TO IEC 60502 Y2021". Its rotational/twist frequency is approximately 4-5 twists per 1.0m.

The 10mm2 pair's sheath (bottom) had the following printed: The 10mm2 sheath has the following: "0.5/1KV XP 2C X 10MM2 P/N <10026001> PSB LISTED TO IEC 60502 Y2023 23022" There is a fibrous wrap around the two 10mm2 sheathed conductors which is missing on the other 6mm2 conductors; believe it's some sort of fiber cover to aid in either holding the twisted pair in place, or helping the twisted pair become sheathed properly. Its rotational/twist frequency is approximately 2-3 twists per 1.0m.

Comparing this to the alternative of twisting two "loose" conductor cables together, the positives are:
- XLPE is acknowledged to be a superior dielectric compared to PVC
- the twisted pair geometry will be predictable and constant, not prone to misbehave by "springing" out of synch
- the solid PVC sheathing is extremely tough, resisting crushing, ingress of moisture, etc.
- the solid PVC sheathing will facilitate installation, enabling the pushing and pulling through tight PVC conduit spaces

Negatives:
- rotational/twist frequencies are not as high as hand-twisting two loose/separate conductor cables together
- maximizing rotational/twist frequency is very important to maximize inductive coupling to cancel common-mode noise, including RFI/EMI
- overall, much bulkier and heavier than "naked" twisted conductor pairs

Mitigants:
- the cable manufacturer can accept a customized order, to employ an extra step during manufacturing to achieve a twist/rotational frequency of 7 twists per 1.0m

This is great news! It's very likely that I'll be going with the 2 conductor 10mm2 XLPE insulated PVC sheathed power cable for my dedicated audio room's AC wiring between the sub-MCB and the Furutech NCF AC duplex outlets.

Many have suggested using thinner (higher gauge) conductors for source components, as they (somehow) sound superior to thicker (lower gauge) conductors. Conversely, thicker (lower gauge) conductors have been reported to be superior for power amplifiers and power supplies because of their superior current delivery characteristics. Many have fallen into this conundrum of not being able to decide which is the better solution, as the two outcomes appear to be mutually exclusive.

I've decided to wire my system with thicker (lower gauge) conductors to maximize current delivery for plugging in amplifiers directly into the dedicated AC duplexes, and *hopefully* through PS Audio Power Plant AC regenerators and PLiXiR toroidal isolation transformers, bend the laws of physics to achieve the speed and delicacy of thinner (higher gauge) conductors for my source components.

Opinions/suggestions are welcome!