Listening room design

Steve

I have seriously considered building a Hifi room over my garage and the internal measurements would be identical to yours.

I think the major thing is not to use wooden joists or floorboards but rather concrete joists and slabs which are extensively used nowadays.

I would also ensure that the room could be used as a a fifth bedroom, if ever we sold the house.

A room that size could easily accomodate all your kit, plus a decent set of speakers such as DBL's and also large racks to accomodate ones collection of vinyl which is always space consuming.

Its not an expensive thing to do, because according to an Estate Agent friend of mine, you nearly always get your money back when you sell the house. So it's like having a free room.

More people are demanding 4 bedrooms plus a study, so building a music room, goes a way in acheiving what they want.

I would definitely go for it.

Regards

Mick

Steve/Mick,

In April this year, the whole task of building/conversion/etc. became a lot more difficult when they introduced new regulations. I can email you a copy if you like (in .pdf). The upshot of it is this: don't assume that you can use all of your space - certain amounts of space would be required for energy conservation and other things that I can't recall. Just be prepared.

Secondly: get a copy of Cara 2.1+. I did just that and though it isn't the easiest thing to get your head round, it's useful for getting a feel for the way different materials and dimensions can affect the acoustics of a room. Unfortunately, Cara is really designed for existing rooms and not for those who are starting with a clean sheet, so the number of variables might make it more difficult. Saying that, if your room is of a standard shape then you're half way there. If you want to pop by some time and borrow the cd then you're welcome (just so long as you loan me some interesting cds at the same time )

TC '..'
"Girl, you thought he was a man, but he was a Muffin..."

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Originally posted by Top Cat:
Steve/Mick,

In April this year, the whole task of building/conversion/etc. became a lot more difficult when they introduced new regulations. I can email you a copy if you like (in .pdf). The upshot of it is this: don't assume that you can use all of your space - certain amounts of space would be required for energy conservation and other things that I can't recall. Just be prepared.

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The architect was discussing that last night - it seems the main upshot is that lots of additional insulation is required.

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If you want to pop by some time and borrow the cd then you're welcome (just so long as you loan me some interesting cds at the same time )

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Sounds good - once I've got the outline plans I'll do that.

As for interesting CD's, didn't you want to borrow some of my Chesky ones?

Regards
Steve

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Originally posted by Mick Parry:

Its not an expensive thing to do, because according to an Estate Agent friend of mine, you nearly always get your money back when you sell the house. So it's like having a free room.

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It looks like the extension will cost about £25K plus I've budgeting another £10K or so to put an AV system in there. I'd probably put a screen & projector in with an AV system using wall speakers and the hi-fi system (probably using my Naim kit) would be totally seperate from the AV system (not ideal having both in the same room I know).

Regards
Steve

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I've got an architect drawing up initial plans for an extension to my house which will be used as an AV/listening room...?

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Two aspects for consideration, really:

First off, isolation: keeping the noise in, in a domestic setting. Mass is your friend, accept no substitutes lightly. Masonry walls (no surprise in the UK), and as much mass as possible in the separating wall(s) and floor. Blockwork internal partitions - dense blockwork, not the aerated stuff; as heavy a floor construction as possible, meaning concrete slab or beam-and-block. This is your first line of defense.

Insulation in cavities has a much smaller effect than even a small amount of mass so don't worry about that; but the standard mineral-wool types are well suited to this purpose anyway and will help damp sound transmisson around the cavities. Neither should you overlook the ceiling; a double layer of plasterboard here, with the usual insulation laid directly on top, will help quell the most usual failure point - acoustic coupling through the roof void. More generally, the actual construction needs to be detailed to minimise flanking transmission paths as far as possible, though many are unavoidable.

Much of the quality of the whole actually comes down to the skill of the builder/contractor and vigilant site inspection. In the past I've had very expensive acoustic partitioning b&(*&^ed-up by contractors who treat it like any other plasterboard job. The devil is in the details.

Still on isolation, you need to pay attention to the in-air paths. Once you have a lossy shell, you can undo the good work with even small holes. Lip seals to the communicating door to the AV room are a must and will make a surprising difference; the door itself should be solid core, ie heavy, and not the usual cardboard rubbish sold here for use as internal doors.

The second issue is the acoustics of the space itself. These really are adjustable and can't actually be settled or finetuned until you have all the furniture and kit setup. One item which will make a gross difference is your choice of floor covering, which you might be thinking about already. The large area presented by a carpet-covered floor provides a huge amount of absorbent surface affecting the critical midrange sound, and with a suitable underlay reduces impact noise for free. Reflective surfaces - tile, wooden flooring etc - throws this away, requiring that you will almost certainly need to add more absorbent surfaces in the room and may need to address impact noise (though probably not over a utility room/garage).

None of the above necessarily implies added cost; it all comes down to an eye for detail. Tell your architect everything you can about the intended use(s) and your concerns - you're paying, so exploit his technical knowledge and you'll then be more likely to get a pleasing outcome.

M.

BTW the link for UK building regs is http://www.safety.odpm.gov.uk/bregs/brads.htm Don't worry about the changes TC hints at, they're not onerous.

This is of interest to me too since I'm now thinking about extending rather than moving. I'm looking for advice rather than giving but the things I've thought about so far are:

Try and ensure internal dimensions that minimise standing waves i.e avoid proportions of 3*4*5 etc and square rooms - does anyone know of any ideal proportions to aim for?

Ensure the floor is as rigid as possible.

Ensure walls are solid i.e. concrete block or brick and avoid the modern practice of lining the walls with plasterboard sheets laid on batons or dobs of plaster - get them rendered the old fashioned way. Avoid stud walls.

Consider putting coving in - especially the cheaper polystyrene type. I'm led to believe it helps quite a bit.

Think carefully about siting of equipment and get at least one dedicated spur - ensure a common earth and equal length cables for multiple spurs.

If you have to have a wooden floor make sure it is screwed down far more securely than 'normal'.

If you are a non ferrous believer go for an aluminium or copper radiator. Even if you're not, make sure it is damped in some way and can't rattle.

Try to design non hifi power cable runs so that the don't go near the kit.

If you are having low voltage lighting keep the transformers as far away from the kit as possible and definitely on separate power circuits.

Try and arrange the room so that speakers are on a clear wall without windows, doors alcoves etc - Even with non boundary effect speakers it should make setup easier. The wall with the speakers against it is usually the one that responds best to accoustic treatments - I have a sound absorbent panel above and between the Kans which has made quite a difference.

Consider putting the cabling for an alarm in at the build stage!!

The extra insulation in new building regs is a good thing - anything you can do to help keep the room at a constant temperature will help, especially with vinyl systems since tracking force is temperature dependant.

Would be grateful if anyone cares to add to this list.

Regards
Steve

Do not forget that you need ventilaton /cooling as well as heating.

If you are not into wireless networks or DECT phones put the cables for lan and phones in at build time.

Put in cable ducting to carry signal for HT projectors attached to the ceiling or elsewhere in the room.

Consider the positioning of kit so that is close to a solid supporting wall - so as to minimise vibration

If you have windows and they are double or triple glazed see if the air gap is wide enough to stop the booming echo you can get from transmitted traffic sound.

Even consider the size of the glass panes so that do not resonate to the sounds (if this is a possibility)

Add 30% to the estimated price to allow for late additions.

Do not allow feature creep of the extension once you have started work.

Before you start - think about whether you ae likely to change job location in the next few years.

The more customised a dwelling is the harder it will be to move

Ensure that the access to the room is sufficient to allow easy import and export of DBLs, WB Bishops etc and heavy electronics and comfortable seats.


Derek

Steve,

how about a photo when it's finished?
Great bike!

Christian

Thanks for all the advice so far - keep it coming!

I've got the preliminary plans now - my house is a mirror image of one the architect had already done so it didn't take him long to do them.

The overall room size is longer than I though at 24' but quite a lot of width is lost due to the shape of the roof. With the space lost to a small ensuite it looks like the listening part of the room will be about 18' x 12' (wider into the bay) which sounds reasonably well proportioned, especially as the ceiling will be quite high.

The speakers would be on the end wall, with no obstructions other than perhaps a small window and I'd probably put the kit right at the back of the room.

Looks promising so far, and I'll discuss the points mentioned above at the next meeting with the architect.

I need to have a look into a budget for a decent AV setup as well - I told Fiona about £10K but that was just a guesstimate. I've got quite a reasonable DVD player already but my existing AV amp is crap and I'd want either a plasma screen, projector or back projector tv. Say £2K for the AV amp and another £2K for the speakers leaving £6K or so for a screen. Does that sound realistic?

Regards
Steve

Anyone considering building a new room for their hi fi should start by reading these articles on Stereophile's web site:

"Building the Hi Fi House" by Tom Norton

"In Search Of The Audio Abode-The Hi-fi House" by J. Gordon Holt

F. A. Everest's Master Handbook of Acoustics is considered the standard work on room acoustics and has a lot of information on optimum room dimensions for distributing bass modes. Your architect should definitely read that chapter before fixing the room's size. If you're using frame construction you might consider doing staggered stud framing to reduce noise transfer into and out of your room. Hang the sheetrock on resiliant channel rather than mounting it directly to the studs. A good introduction to these techniques can be found in the "Acoustics 101" document at www.auralex.com (click on "literature" on the main menu). Lastly, ASC's (the Tube Trap people) Iso - Wall system may be of interest to you. It's a complete soundproofing wall system for hi fi rooms and home theaters; if I had a bare room I think I'd use this approach. Details at: http://www.asc-soundproof.com/

[This message was edited by Rob Doorack on FRIDAY 09 August 2002 at 21:16.]