Listening Room Plans?

Has anyone in their travels come across standard-issue listening room plans? I am thinking about putting a listening room in my (currently unfinished) basement, 20x20 or 20x30. It would have the advantage of adding value to the house.

 

Mostly what not to do. Like don't make it a cube, or a square if possible.

As far as DO: ROOM TREATMENTS.

Dedicated lines, etc.

 

Wow a 20X30 will do those Aeris justice

 

This is a handy site to use for calculating room modes:

http://www.bobgolds.com/Mode/RoomModes.htm

The Rule of Thirds is a good one to practice - you'd need a 10' ceiling to really nail it in your space, but perhaps 9' could get you close. If 8' ceilings, maybe shoot for 8 x 16 x 24? I have 9' ceilings in my basement so when I do finish the "big space" i'll be shooting for 9 x 18 x 27 with non-parallel walls and, if practical and actually worthwhile, rounded inside corners at the front of the room.

Other than that, make the room lively to start with and deaden to taste with rugs and wall treatments. Plan out your wiring very carefully, run dedicated 20A lines as needed. Honestly everything but the very largest 2-channel systems can survive off one 20A line but having separate lines for sources and amplifiers isn't a bad idea.

What kind of ceiling are you going with?

 

Make sure every corner is filled with something ( book case/ storage etc) .

 

I would suggest spending some time on an acoustic form to get better suggestions.

 

Make a full rear bass trap 2ft thick, for starters. Trust me ,it won't be overkill.

 

Definitely a priority.

 

Why is a square bad?

 

I have no experience with this stuff myself, but I understand the bible for it all is The Master Handbook of Acoustics. Here are some samples of the theories and the dimension rules.

http://www.crutchfield.com/S-xoDIoldbrQJ/learn/learningcenter/home/speakers_roomacoustics.html

http://www.decware.com/paper36.htm

 

I built a small one several years ago. Just some general suggestions; suggestions I used:

1. Don't make it a square.
2. Have items in the room that will 'break-up" the sound; shelves, ceiling fans, furniture, plants in corners, etc.
3. If you can afford room treatments (I used Echo Busters) that helps even more, especially in the corners of the
ceiling.
4. Run dedicated power to the room if possible.
5. Install some better quality electrical outlets if you're running new power. Not sure how much it helps but they
look cool.
6. Think about the furniture, shelving and equipment racks/stands going in there. I've discovered the better the
room looks, the better it will sound. Never underestimate the power of suggestion.

Remember, you don't have to do all of it at once. And enjoy the adventure.

 

Firstly, while I agree that a nicely finished basement can add value to a home, I'm not convinced that a dedicated listening room will, since I imagine most home hunters will not be audiophiles. Things might be different if you were putting in a fancy (cinema-like) home theater room. We'll get back to this in a moment.

Why is a square room bad? Because the same dimensions will excite the same room modes, hence a cubic room is the worst of all worlds!

With regard to rectangular rooms, there are no ideal room ratios, but researchers have been looking at this issue for a considerable time, and there are lists of ratios which are preferred. You can look around on the web, but to get you started consider:

http://www.acoustics.salford.ac.uk/acoustics_info/room_sizing/

http://www.acousticfields.com/ode-to-the-dedicated-listening-room/

To my knowledge, there are no preferred ratios for rooms with non-parallel walls, though I'm sure they can be modeled. Non-parallel can also mean anything from sloping the side walls to having all kinds of sloped areas within the room's perimeter. Given that you will need to resell your house at some point, I would go with a rectangular design and appropriate room treatments to meet your ends.

You also need to consider the following:

1. are you going to use this only as a listening room, or is it doubling as something else?
2. do you want to install permanent or temporary fixtures?
3. are you planning on constructing and/or finishing yourself, or are you getting a builder in?
4. are you a DIY type (or have a pal who is) who can make some/all of the acoustic treatments?

Getting back to the resale value of your home, I would imagine that a nicely finished, plain-ish basement is most attractive to a potential future buyer. So, nicely finished walls, available power, maybe water/waste (for a bar, or similar), nice cabinetry (if that is part of the plan), etc. They are unlikely to care about several independent 20A circuits with hospital-grade power sockets, etc. So, consider how someone else may use the space after you. For that reason, I would also suggest using acoustic treatments that can be easily removed (either to go with you, or to return the room to 'normal' afterwards).

With regard to construction, there are several tutorials online on how to install multi-layer walls which will give some isolation to the outside/rest of the house. If you are not doing the building, then you need to bring this to the attention of the builder. Do not forget about the door, as that can be a big source of sound leakage (ditto any windows, so go double or triple pane, if possible). How will the space be heated/cooled? Quiet HVAC systems are pricey (large volume, slow airflow, with dampers/bends to keep noise to a minimum)!

If you are a DIY type, you can make your own tube traps, which you can then place at the appropriate points within the room (again, lots of guides online). Alternatively, you can use something like Corning 703 or 705, 4' x 4' sheets, cut diagonally, and then stacked floor to ceiling in the corners. You can cover the fiberglass with a frame covered in an open mesh material. Again, lots of info online about this.

Alternatively, you will need to buy from the likes of ASC, GWK, etc.

Having very expensive custom panels made by the likes of RPG 'permanently mounted' on the walls may well produce a fantastic listening space, but unless a Forum member was to buy your house from you, it may add no value.

Be sure to run stuff like CAT-6 ethernet, phone, etc., while you are at it. Be sure that the electrical ground is good. Consider analog and digital components on separate power circuits, if possible.

 

Man he sure loves that Golden Ratio! I am using his EM5813s IEMs and I like them.

 

Use heavy drywall and resilient channel.

 

I'm jealous.

We finished part of our basement a few years ago. Ceilings are just over 7' high. I did in-wall wiring and speakers for 5.1 channel (the sub is not in-wall) and a projector and screen. Also put in a modest wet bar. So, more of a home theater/rec room, but it serves as a secondary music system.

If you have ANY issues with water or flooding make SURE you solve those first.

 

The most basic idea would be building a room within the room that is decoupled from the rest of your home. Try to read up on acoustics and physics. I have a best friend who is an acoustical engineer. I shared an office with him a few years ago and his work is definitely on par with rocket science.

 

Isn't that what they did with the in-house studio at Apple Records all those years ago?? But evidently they had all kinds of problems retrofitting the basement of the old townhouse it was built into. Or something like that? Anyway, might be a good case study in how not to do a room-within-a-room...

 

Please don't mention any Magic Alex creations.

 

This looks interesting. Recommended by Alan Shaw of Harbeth here.

 

No glass tables.

 

I few years ago I enjoyed these two listening room build articles even though they were not all that practical.

http://www.positive-feedback.com/Issue16/lavigneroom.htm

http://www.6moons.com/industryfeatures/rives/rives.html

 

Thanks for all of the feedback. I was wondering if a large open space would work. One big problem, though is that I have a supporting pole smack dab in the middle of the room.

 

This is the best information of the thread. Although I do take issue with the Corning 705. At 12" inches tall it works as good as 703 but it is too dense to be useful going deeper. 703 will work better when stacked thicker. Building fluffy pink traps will work better when going floor to ceiling.

I did the 705 triangle wedges. They worked great stacked about a foot tall. So great that I decided to stack them floor to ceiling in the bad corner. Stacking them taller made almost no measureable difference and ended up being a waste of money when I threw them out and rebuilt the corner trap using pink fluffy fiberglass. I asked about this on one of the acoustic forums and the explanation was that 705 was too dense for the sound wave to penetrate more than a foot. The wave will bounce off before penetrating deep enough into the trap, making it a wall like reflective surface instead of an absorber.
Luckily, a coworker did his masters of math on the formulas for fluid flow through a porous object. He was able to second the opinion, in theory anyway, why the porous absorbers would become reflectors when they become too dense for their thickness.

I ended up going even bigger with a fluffy fiberglass corner trap, about 44" across the face of the corner, floor to ceiling. It started small with 1lb per cubic foot, vs 5lbs for the 705. It was good, so I bumped it up to 1.5lbs per cubic foot and it absorbs nicely down to 20hz, reducing ringing. It might be able to handle 2lbs at that size but I haven't tried it. 705 is a waste of money. 703 works just as good at 4" and even better at 12". Anything more than 24" deep I'd recommend dropping below 3lbs.

I agree with Black Elk, build it to suit your livable needs, keeping resale in mind, close to a suggested ratio (no two dimensions the same anyway), then add removable treatments that suit your tastes. There are volumes written about how to fix a room. There are forums dedicated to fixing rooms. I bet they would help better than a forum that specializes in gear and matrix numbers. They were for me anyway. There is no cheap cookie cutter perfect solution so build something that fits your needs. If you want room acoustics summed to a nutshell, this is the best I can do, build an infinitely diffuse room that is seasoned to taste with absorption. Your taste will be different than all of ours. Within that it will get tricky dealing with the physics of lengthy waves combined with aesthetics and use.