Dedicated listening room

It’s been a few years but I finally got into a position where I could build a dedicated listening room. I did this once before and no piece of gear I ever tried made as big an improvement in my system’s performance as did setting everything up in a room constructed and optimized for 2 channel audio.

Before I get into all the boring design details, here is a picture of the finished room with my stuff positioned where it pretty much settled in after a weekend of moving things around.



Where I started.

A quick music test-drive of the room confirmed what I thought when I first saw the room before buying the house – size, dimension ratios and solid construction where supporting nice bass but it was bright, bright, bright!

It is easy enough to fix the ‘bright’ problem but I wanted to go further than this. I started by running the numbers for the room and found the size isn’t really too bad as is – problem frequencies would be around 75Hz and 230Hz so I could concentrate some absorption at those frequencies and play with seating position to offset peaks.

The build

I considered shortening the room to optimize the ratios a little more but have some real obstacles to doing this – the windows are 2’ from each end and the breaker panel has to be easily accessible from within the room (Ontario electrical code). Since I’ll be building record racks across most of the back wall anyway and long range want to use Edgar style horn speakers which like as much space between the listener and speakers as possible, I decided to stick with the 22.6’ length.

I figured I could work with the existing walls but the sheetrock ceiling had to go. I wanted to get into the ceiling joists to run some dedicated system wiring, TV/satellite cabling and to partially stuff the joist gaps with fiberglass insulation. I used a combination of open and perforated ceiling panels tuned to deal with the ‘problem’ frequencies and balance out the room reverb time. Tearing down the drywall and stuffing the joists was an ugly job but the room acoustics where transformed with this change.

The new ceiling tiles are constructed from plywood panels of various perforation percentages covered in black speaker grill cloth – large quantities of which I bought on sale from PartsExpress. I drilled ¼” holes in the corner and side panels for a perforation percentage of approx. .18% which should concentrate absorption around the 75Hz problem frequency. I cut large holes in the panels over and between the listening position and speakers to allow some high/mid frequency absorption/diffusion at the first reflection points and to give the ceiling more apparent height – it’s just over 7’ in appearance to the cloth but more like 8’ to the underside of the upper floor.

To balance the partially absorptive ceiling I used wood laminate flooring and an area rug between the listening position and speakers. The rear wall behind the listening chairs will be covered with record racks to help with dispersion and for now I used acoustic absorption panels at the first reflection points on the walls. Longer range I’ll be building some diffusion structures for wall placement and will add floor to ceiling movable drapes to allow a level of room tuning to suit different types of music. This technique worked well for me in the past – bunch up the curtains to expose more reflective surface increasing reverb to suit large scale classical or rock, spread them out to reduce reverb for that small Blues or Jazz club feel.

I’m going to leave the corners at the system end of the room open to try corner placement of my Altec 604’s and long range, some 30Hz corner horns. The rear corners at the record rack end have to be accessible occasionally (breaker panel) so I will build large bass traps tuned to 75Hz that can be moved out of the way if needed.

This drawing shows the ceiling panel perforations and cut-outs, the basic room layout and where I’ll start with acoustic panel absorbers.

Electrical & Room Sims

The room already had a separate circuit for all the wall outlets which is great, I’ll use that branch for all the digital junk and keep the digital noise away from everything else. I added 2 dedicated circuits with 12ga wiring and their own breakers – one for amps and the other for whatever is left. I’m not a ‘cryogenically treated magic dust’ kind of guy but DO see why a good solid AC connection might be important so laid out a few bucks for Hubble hospital grade 20amp outlets. Not really that expensive (bought them at Take Five Audio) but you can really feel the difference with these things – plugs just snap into place. I finished off the ‘gear’ end with wall connections for the main house TV cable and a satellite feed, even though these will only get used for an FM antenna hook-up.

Lighting is aim-able halogen spots on dimmers. I’ve heard dimmers are evil for listening rooms but since these are on a separate circuit (and they where already there), I’ll stick with them for now and see if they are noisy. I tore out the baseboard heaters, class-A tube amps should keep the room warm enough .

I spent some time evaluating various building materials to get a somewhat balanced reverb time in the neighborhood of .4 seconds with the curtains able to ‘adjust’ it downwards. I put together a spreadsheet so I could run the numbers and graphically see the results.

I loaded the absorption co-efficients for the materials I’d be using and played with amounts and the perforation percentages of the ceiling panels to arrive at the balance shown. The numbers here look decent enough with a relatively good balance across the frequency spectrum and the curtain adjustment I was hoping for seems to nicely reduce reverb. There is lots of absorption in the bass frequencies which is nice since this can be such a bitch to get in a retro-fit room.

I know this is all numbers and theory which I usually have a MAJOR problem with but past experience using this technique told me these squiggly lines can indicate the right path to a nice sounding space.

Holy Bald-headed Nurses in Toronto,BillFort what a room! It looks like something out of a freakin magazine. I am in awe.

Alan

Wow!

Billfort,

That is beautiful! Excellent job.

Well, it’s FINALLY done, I’ve been listening to the new space for a few days now and even though there is more to do with tweaking and set-up, I have to say it was definitely worth it. Bass is greatly improved over my last room, more dynamic, fast and clean with no boom, bloat or one-note thump.

I initially thought bass was lighter or that maybe the 1.6w of my 45 SET was not up to dealing with the increased volume of the new space but nope – when the program material HAS big bass it is there in spades, bloody surprising really. I think the boomy bass you often get in small rooms can give you a false sense of weight and energy down low and my old room probably had that. Listening in this room has been a real eye opener and I’ve been plowing through my piles of LPs again and again to hear everything from a whole new perspective.

And the issue of the 45’s power…well, there are a few things I like about the 300B’s and they really kick-ass in the bass now with the EML tubes but overall, I still LOVE and prefer the 45. I’ll be trying a completely different circuit and layout for my next 300B but it sure is nice to have the choice between the two to suit my mood. I figure I better spend a few years or so deciding which I like better .

I'm speechless Bill, and jealous as hell :yes:
That is a beautiful room and the gear ain’t half bad either

/d

Looks great bill ! Cannot wait to hear it.

Wow! That is gorgeous. I've only skimmed the "boring details," but I am really impressed at the thought and effort that went into that room. Enjoy!

That is awesome! Congrats. Wish I could do that.

Something outa my dreams! Fantastic!!!

Love the flat black drop ceiling. It really brings out the rich wood tones. I was thinking of painting my drop ceiling flat black. I think you just gave me inspiration to do so. Thanks.

BTW... hellava job.

WOW! Your room is beautiful. :thmbsp:

Terry

bill-- this post is a) awe inspiring b) educational as all hell c) entertaining. man, i'm impressed!

shrinkboy

Very nice Bill. Seems like yesterday you were still looking for a house. Whew, now look where you are. Fun, fun, fun! :thmbsp:

wow

thats absolutley beautiful. thats my audio nirvana right there. can i move in?
really, thats fantastic! killer work, killer equipment, and stunning elegance!

Wow, thanks for all the compliments guys! This has been a long time coming but it turned out kinda nice, almost makes living with my main system in boxes for half a year worth it .

I have to thank WildWest for all the help he gave me on getting the wiring and lighting right. I don't know what contribution the dedicated audio circuits are playing in system performance but I think Wild's suggestions on how to handle lighting speaks for itself. He's been great in leading a DIY hacker like myself through this stuff and has a keen sense for focusing on what matters and bypassing the audio bullshit - an important balance for somebody on a tight budget like I am.

The room is gorgeous Bill! :thmbsp:

I love the way that you set up the lighting... functional as well as
artistic... makes it look like the system is a work of art on display...

Which it is!

Scott

Wow, what a fantastic looking setup! I'd love to do something like that except I lack the basic ingredients- time, money, skill and really really nice gear!

I'm sure many hours of pure listening pleasure will be had there!

Ya know the more i look at your pics the more I hate you and Luther. You guys make us all look like fumbling gorillas when it comes to workmanship.... Well maybe its cause I am