8

Through ceiling, really.

I've set up my new "office" in a 2nd floor room with accessible (insulated, blown-in) attic space above. At some point I'd like to set up my 5.1 computer speaker system, with the surround speakers attached to the ceiling. Getting speaker wires through the office wall to the attic is no problem. Wondering the best way to get speaker wires through the ceiling to the speakers though, in as minimally invasive and as minimally obvious a manner as possible.

If I didn't care about "minimally invasive" I'd just get some in-wall speakers and cut holes in the ceiling, but I'd prefer not to have to deal with that. Is it as simple as just drilling a small hole and poking the cable through? Hoping for something a little more "finished" looking, like maybe some kind of small grommet.

11
  • 1
    Low voltage speaker cables will not fall in code, so stuff like junction boxes not needed. Depending on the speakers, a small hole should be all that is needed.
    – crip659
    Feb 27, 2023 at 20:59
  • 8
    Code does apply, but it's fairly minor - i.e. you need "in-wall rated" (CL2 or CL3) speaker wire, not just any speaker wire.
    – Ecnerwal
    Feb 27, 2023 at 21:28
  • 1
    If (some of) the speakers are ceiling-mounted, why does their cable or its hole need to be visible at all? Can't it be obscured by the speaker or its bracket? The only stated goal being "finished looking".
    – jay613
    Feb 28, 2023 at 11:36
  • 3
    @E-Riz and where would the wireless speaker get its power from? Bringing in power thus will still require a cable but ironically, that cable will require to follow (more) code...
    – deroby
    Feb 28, 2023 at 15:31
  • 3
    Do you have crown moulding? If so, you can often run the cable behind the moulding and hide both the cable and the drop-down, with only a small exit hole right behind the speaker (easier to drill and disguise a small, clean hole in wood than in drywall/plaster).
    – bta
    Mar 1, 2023 at 3:07

6 Answers 6

19

A small hole is totally adequate for this purpose.

If you drill neatly then a grommit is not needed. A ~3mm hole might be sufficient, just measure your wire first. A small beauty plate may help to cover any tearout in the plaster.

You might choose to fit some binder posts in a plate, or a pair of RCA plugs in the ceiling for convenience and neatness, though its another joint in your wire and generally unneeded. Smaller plates may be more suitable too.

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You can also arrange your rear speakers such that they sit in front of the holes, or if you choose to use mounting brackets then they can straddle the hole and hide the wire as it comes down any internal channel. Although these brackets need to mount into something structural in the ceiling, not just into the drywall/cladding.

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4
  • 1
    I'm probably going to end up using a binder post plate for the wall where the wires will go up to the ceiling, but a plate like that is too high-vis for what I want on the ceiling, so I'll probably end up just drilling a hole. The brackets won't work for me—I should have mentioned that the speakers need to clear above a ceiling fan, which they do if mounted directly to the ceiling, but won't if I use a bracket like that.
    – Huesmann
    Feb 28, 2023 at 13:37
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    @Huesmann Keep in mind that if the fan blades are between you and the speaker, the sound will be very distorted when the fan is on due to the movement of the blades. (As little kids, it was very cool to speak through a running box fan so our voices sounded distorted, but you probably don't want that sound from your speakers.)
    – Moshe Katz
    Mar 1, 2023 at 19:26
  • 1
    I'm aware. The fan is infrequently used, and even when it is I have the option to just use headphones :)
    – Huesmann
    Mar 1, 2023 at 19:53
  • @Huesmann those plates are generally available in black, and you can get "architrave plates" which are smaller. I once painted a white blanking plate with blue/purple speckle to hide something in plain sight, which worked well. Finally, you could even 3D Print a plate to hold small connectors or a wire-pinch-block. Or do without power and use some kind of wireless+battery powered speakers though that means periodic recharging and potential lag.
    – Criggie
    Mar 1, 2023 at 21:12
10

Simplest standard approach would be to locate a "low voltage ring" (looks like a junction box, size-wise, but has no box) directly above your speaker locations so it's mostly hidden, and then you can have a nice finished plate for the pass-through (or terminals, if you want.)

Drilling a hole and caulking once it's done is also perfectly acceptable.

8

There are wall plates available with RCA jacks, 1/4" phono jacks, etc. (just listed as examples). As mentioned by @crip659, they do not require junction boxes.

Some have plaster ears, the tabs on corner shown in this AC outlet to allow mounting the outlet itself flush with the wall (or ceiling) surface, to be covered by a plate. Others may have metal tabs or cross-bars that fit through a cutout in plasterboard, and "sandwich" the plasterboard between the tabs on the inside and the outlet, outside.

As for drilling a hole from the wall into the attic, the easiest way is to use a long drill bit (e.g., this 18" bit or this 24" bit), or even a 72" bit), drilling carefully from the wall up into the ceiling. Carefully includes checking your between studs, that there are no wires or pipes in the way, and being cautious to drill close to vertically, so as not to go through the opposite wall.

It is also possible to drill from attic down to the wall, if there is sufficient space in the attic.

In either case, stiff wire must be pushed down from the attic and "fished" out at the opening for a wall plate.

6

All of the speakers in my house just have a very small hole through the ceiling or wall with the wire coming through and attached directly to the back of the speaker and mounting the speaker over the hole. I just used a small Phillips screwdriver to make the hole through the drywall. If a few cases where I later on wanted to move one or two of them, a small dab of spackle was all that was needed.

6

Assuming those speakers are passive (that is, don't have a mains plug and the amplifier built in), then you're going to have a relatively long cable run. It's worth using thicker than normal cable for this.

On the plus side though, this is a permanent install. So if you use Criggie's idea of binding posts at each end, you can use regular mains solid-core wire. Contrary to what you may hear from hi-fi nuts, speaker cable only affects the sound if it's too thin. Myths about special oxygen-free cable are just that. (I say this as an electronics engineer with some experience of getting very small signals from place to place very accurately!) A nice thick bit of copper will see you right - and coincidentally that's exactly what mains wiring looks like.

4
  • Stranded wire is normally used for speakers because (being an EE you'll realize this is true with a little thought) higher frequencies travel only on the outside "skin" of the conductor (I think through self-inductance, but it's been a long time, so I have little confidence that's right). Using stranded wire provides a lot more "skin" so the impedance at higher frequencies is more similar to that at lower frequencies. I would expect a noticeable roll-off at higher frequencies using solid speaker wire, though I've never tried it.
    – Jeffiekins
    Feb 28, 2023 at 17:21
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    @Jeffiekins I'm afraid that's not correct. The reason for using stranded wire is solely because it's flexible, and nothing else. Stranded and solid wire of the same diameter will behave basically the same (at least to well past audio frequencies). Skin effect is certainly a thing, but it's not significant here.
    – Graham
    Feb 28, 2023 at 19:40
  • @Graham According to this site, the largest wire for 100% skin depth for the entire audio band is 19AWG. The 12AWG that is often used for mains wiring starts "skinning" around 4.1kHz. So maybe a HF boost on those channels to compensate, or it might actually work out nicely if you or your speakers are extra sensitive to sibilance. But you're right in that solid or stranded doesn't matter. If you want to make that distinction, you need Litz wire.
    – AaronD
    Mar 1, 2023 at 5:23
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    @AaronD It still doesn't really matter though. The point of a nice chunky bit of copper is that the resistance becomes negligible and its effect can be discounted. (At least to orders of magnitude past the accuracy of the electronics and the ears anyway! :)
    – Graham
    Mar 1, 2023 at 7:22
4

However you make the hole, make sure to air seal (e.g. with caulk or expanding foam) around the penetration. If you make a small hole just to pass the wire through, you can seal directly around the wire. If you make a larger hole for a low voltage ring, you can make a little box out of rigid foam, and seal around the edges of that.

You want to minimize the air leaking from your conditioned living space into your attic. Especially if you live in a colder climate. See also https://www.youtube.com/watch?v=Nw-b6up7kjE

2
  • I was thinking to glue a panel of foam above the ceiling—the rubbery kind of foam they use for insulating around outlets and light switches.
    – Huesmann
    Mar 1, 2023 at 14:05
  • That would probably be fine, as long as the foam is tight around the wire. Mar 1, 2023 at 17:57

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