November 2006 has seen the start of building a dedicated 2-channel listening room (a.k.a. "the man cave"). For the interest and benefit of others wishing to do likewise, I will try and relay details of the event that is expected to take 4-6weeks to complete.
* DESIGN
It all starts with a piece of paper and creative thinking of an audio designer which I found locally. Measurements were taken, consideration was given to room layout and planned speaker firing position. In my case I had two concrete block support pillars in the basement room and a lowish hanging support bean that sits atop the pillars. A structural engineer was called in to see about moving the posts and yes anything is possible with enough money . . . but the beams would stay put but be replaced by smaller footprint jack posts.
* ACOUSTICS:
The soundproofing would consist of Roxul acoustic and thermal insulation in the ceiling followed by Sonopan and 5/8" drywall to contain the sound. Special isolation clips for wall decoupling are used to isolate and 'float' the walls while rubber gasgets go between the concrete floor and wooden 2"*4" framing. J-molding, accoustic taping, 1/4" gasket for the ceiling/wall connection, air duct dampening material, insulated flex duct, external door with weather stripping were all used too.
* ELECTRICAL:
Four dedicated circuits will be installed: (i)a planned subwoofer on a 20 amp, 12 gauge Romex wired circuit, (ii) analog will also have a 20 amp, 12 gauge wire (in the event that my current 6watt/ch. amp gets replaced with a behemoth amp, (iii)digital will be a 15 amp, 14 gauge wired circuit, and (iv) a misc circuit for lights etc will also be 15 amp, 14 gauge. Isolated grounds will be created in the breaker box and plastic not metal recepticle boxes will be used to ensure only 1 end of the circuit is grounded (grounding both ends will cause the wire to act like an antenna!).
Planned future purchases include:
* Apple Mac Mini with silent hard drive and external RAID 1 disc storage for musical files
* Metric Halo LIO-8 Pro DAC
* Parametric EQ within the Metric Halo to tame the lowest bass mode peaks
I hired a small firm to design a dedicated music room in my unfinished basement which was no small feat. A contractor was hired to build it to spec and it was finished in January 2007.
Hemi-Cylindrical Diffuser / Bass Trap for Front Wall
A DIY hemi-cylindrical (poly) diffuser that doubles as a bass trap having OC701 fiberglass within its cavity. It's a 160degree arc from a 48" diameter Sonotube with red oak veneer on the exterior. The hard exterior diffuses mid/high frequencies in about a 110degree arc. With a total thickness of 30 inches, the hemi will absorb down to about 65Hz [1130/((30*7)/12)=64.6]
Front Wall Corner Bass Traps
A pair of DIY hemi-cylindrical (poly) diffuers that double as bass traps are in each corner. Eash is a 100 degree arc from a 48" diameter Sonotube with OC701 fiberglass in its cavity. They're covered with black speaker cloth to visually dissapear into the black coloured front wall. The total depth is 39" (27" radius + 12" air space) which absorbs down to about 49Hz. All hemi-diffusers can be pulled away from the wall to whatever depth is needed so as to tailor the low-end absorption.
Side Wall Reflecting Panels DIY
I built 3 reflecting baffles for each side wall. They are 3/4inches thick and run about 12feet long. Each baffle can be opened to any angle between 0 - 90 degrees. Right now the bottom baffle is open 30 degrees so that ear-level reflections are sent upwards to the ceiling diffusers, whereas the middle and top baffles are both open 20 degrees. The bottom baffle has a pair of GIK D1 QRD-like diffusers at each side wall's first two reflection points to help widen the apparent sound source width.
Skyline Diffuser for Rear Side Wall Treatment
A DIY Skyline diffuser for the rear right side wall. Uses 8 different cell depths in 1.5" increments with a maximum cell depth of 10.5". Being conservative, 10.5" is 50% of a 645Hz frequency which it will very effectively diffuse down to and likey another 0.5-1 octave lower. * Prime Number used = 547 * Primitive Root = 2 * 26 Columns * 21 Rows * 501 individual blocks of wood!
Hemi-Cylindrical Diffuser/Bass Trap for Rear Wall
Another two DIY Hemi-Cylindrical (poly) diffusers - one per back wall corner - to diffuse mid/high frequencies and absorb low frequencies as its interior is stuffed with OC701 fiberglass. Dynamat Xtreme (for car doors) was put on the hemi's inside to help reduce resonances and add stiffness. It's a 130 degree arc from a 48" diameter Sonotube.
GIK D1 QRD-like Diffusers for rear wall
6 are placed on the back wall (3 columns of 2) in front of 3 GIK Monster bass staps.
GIK Acoustics Monster Bass Traps for rear wall
3 total: Used on the back wall.
RPG Skyline (HP) Diffusers for Ceiling Treatment
9 Total: from speaker plane forward to listening chair.
RPG Skyline (LP) Diffusers for Ceiling Treatment
3 in Total: used on the dropped part of the ceiling between the front of the left speaker and the listening chair.
George Stantscheff Lightspeed Passive Attenuator
Passive attenuator that uses the special LDR (light dependant resistor) which has the ability to change it's resistance according to how much light LED (light emitting diode) is shone on it, hence it can control the volume without any mechanical contacts needed in the signal path. www.lightspeedattenuator.com
Art Audio PX-25
Fantastic sounding and very powerful despite being a 6 watt/ch. SET amp. With the KR Audio PX25 tubes and Sophia Electric 274B tubes and NOS input tubes.
FAB Audio Model 1
A 2.5 way with 1" tweeter and twin 10" drivers. High efficiency speakers (97dB).
Rythmik Audio F15
Two servo controlled subs each with a 15" driver and 370watts Class A/B each sub. Wonderfully musical.
Foundation Research LC-1
This is a bi-directional line conditioner filter and Cardas power cord all in one for the Audio Aero CD player.
TG Audio Lab HSR high purity silver interconnect
1.5 meter shielded
TG Audio Lab Speaker wire - silver
8 foot with spade ends
Audience PowerChord (4 foot)
4 foot power cord for Art Audio PX25 amp.
Dayton Audio OmniMic
Precision audio measurement system.
Sennheiser HD-600
headphones
StudioTech Component Cabinet U-22T
A rosewood cabinet with ventilation slots on the side, six shelves, cool looking doors and great WAF.
Wattgate 381 Ag AC Duplex Outlet
Audiophile grade AC repectacle. I bought two Wattgate 381's to be used on dedicated digital and analog circuits.
Hurray for Fab Model 1's with PX25 amps! I'm glad the Art Audio has worked out so well for you, Kevin. That tube really kicks out the jambs, doesn't it? Now we really have to trade listening sessions.
Geeze don't use my system as any kind of benchmark fergodsake - it sounds like crap, trust me ;-)
Actually, while I've never heard the AU24 wires, some people whose ears I trust say they are very, very nice. They always crop up in the sorts of discussions where I start pushing Bob's stuff, so my bet is they'd do really well. My dealer is going to get me a meter of Kimber Select 1031 to try against my TG. I'll let you know how it goes, but from the descriptions I've heard of Au24 it would be right at home with our spakers.
A good 8-watt SET should be fine for volume - mine is 6 or 8, and I can get way more clean volume than I need in my 12x19 room. On the other hand, I bet these puppies would sound amazing with a nice 845, and with 20W on tap you'd have no power issues either. The amplifier universe is open before you - may the Force be with you.
Nice system, Kevin - especially those speakers ;-) I've come to the conclusion that a sub is a must with them, though. A sub, a lower powered SET amp and some nice interconnects, and you'll be all set.
For grins, look into getting some Isoclean fuses for both the equipment and the LC1 - lots of bang for the buck in those little guys. Oh, and some Walker SST contact enhancer too - another effective, low cost tweakeroo.
