Invisible Speaker Installation: Fitting the Amina Sapphire Series in Plaster.
Invisible speaker installation is a skilled trade in its own right, and getting it right is the difference between audio that vanishes seamlessly into the wall or ceiling and a finish that gives the speaker away. This video covers a plaster-in installation, where the top coat can be plaster, micro-cement or Venetian plaster, finished to around 2mm over the panel. Amina’s Keith walks us through a full cut-in and finish of a Sapphire speaker, from finding the studs to handing the wall over to the plasterer. The same method applies across the Sapphire range (the Sapphire 250, Sapphire 375 and Sapphire Dual share the same cut-in approach with a separate back box, in this case the CV345), so it is a useful reference whichever model you are specifying.
Introduction and tools
Hi, I’m Keith from Amina, and today we’re going to be cutting in and mudding in a couple of our invisible loudspeakers. For that we’re going to need some tools, so I’ve brought some out and put them on the bench to go through them.
A template is always good, because that allows us to cut properly. Then we need to measure where we’re putting the template, so a tape measure is useful. We can also measure from the inside how far the studs are from the hole we’re going to cut. Then, for cutting the hole itself, a saw or a utility blade. Both work well. Wire cutters, wire strippers, a hand screwdriver, and our little helper (the screw gun). Some extra drywall screws too, just in case: if you hit the wall and hear a little rattle, an extra screw or two can get rid of it.
When we get to the mudding stage we’ll need some drywall tools. A small blade (a 6-inch, about 12cm) for pushing the compound in, and a large blade to finish the compound off. And then we tape it off. Let’s go for it.
Stage 1: Measuring and cutting
We’ll be installing the Sapphire 250 with the CV345 back box. As you can see, it uses WAGO connectors, so it’s an easy install on the wiring. We’re going to cut a hole, find out where the studs are, put up the template and get ready to install.
We’ll put it in this bay, slightly high, on the basis we might be putting a TV here. First I need to find the studs, so I’ll cut a little hole. There we go, some insulation in there, that’s good, it’ll help deaden it. Now we grab the tape measure and find out where the studs are, because that’s important before we cut a hole.
We transpose that across so we know where the first stud ends. We’ve got about 13cm, so let’s transpose that to the surface, which gives us about 14 or so in between. We know where the studs are, and we have to hope they’re straight. The back box comes with a template and all the screws we need, so let’s get cracking. The instructions show you how to install it.
We did the little cutout and found the position, so now we put up the template with a bit of masking tape. The template is the size of the loudspeaker itself. Then we grab a level (we couldn’t find a small one, so we’re using a really big one, but a level is a level). I’m a little bit crooked. That’s better.
Let’s check where the studs are against the template. There’s the stud on one side, and over here we’re right on the edge of it, so we’re good. That should give us the perfect 345 x 450 cutout.
Now there’s a lot of insulation in here, so let’s make sure we can fit the back box. Find our cable, take out some of that thick insulation, and leave a little behind the back box to dampen it. If we leave too much, the back box won’t fit. And there’s the cable we pulled previously. Always good to pull your speaker cable before you drywall.
Stage 2: Fitting the back box
Take the back box out of its plastic. It comes with all the drywall screws you need. There’s a grommet at the top to insert the cable through, then align the box using the tab.
Take the screws from the packaging (there are plenty to fit the box), put them in temporarily and align the top right first, make sure it’s centred, and drive the first screw. Then the opposite corner. Make sure your fingers aren’t behind where you’re screwing, so you don’t put a screw through them. All the screws are in, and we’re ready to fit the speaker.
Stage 3: Fitting the speaker
We’re ready to put the speaker into the back box. In the packaging there’s a small bag with specific stainless screws, so they can’t rust, plus the WAGO connector that’s already on the speaker. We’ll use the screw gun and the screwdriver, because we don’t want to set the speaker to level just yet. First we make sure the speaker is screwed right in.
The WAGO connector makes this easy. Flip them back, strip the wire, check the polarity, snap them and they’re in place. To strip the wire I like to score the outside of the cable with a utility knife, get rid of anything you don’t need, then strip back about 10mm (around 3/8 of an inch) with the strippers. I went a little overboard on that one, so that’s what the cutters are for, and we trim it back. A little twist of the wire and we’re ready to hook on the loudspeaker. The WAGO connection is so strong you can hang the speaker off it. Just make sure no wires are sticking out, so you can’t get a short.
And what do I see in the back box? We almost forgot the extra drywall screws I put in to fix the box. Make sure nothing’s left inside, because there are magnets on the back of the panel. Those screws will stick to the magnet and you’ll have a rattler. You don’t want too much cable in there either, because it can clack on the back, so push most of the cable back before fitting the speaker.
Now the screw gun and the specific screws. All around we have pre-drilled mounting holes, so hit that point and put the screw in, but don’t screw it all the way. Leave it slightly short. There’s always a spare screw in the pack in case you drop one. Do the opposite side, then the last screw at the top.
Now take the hand screwdriver and the level. We’re proud of where we’re supposed to be, so bring the speaker in gently so the corners sit flush with the drywall. Don’t overtighten. Go across the diagonal and the speaker comes down, then the final one. That’s perfect. The speaker is flush with the drywall and we’re ready to mud it in.
Before that, we want to make sure there are no buzzes before we plaster. Take away any tape left from the template. That looks like a problem area, so let’s put an extra screw in to be sure. That brings it tight to the stud, and the rattle’s gone. Now, because we’ve been moving the speaker around, we want to know it still works. Take a tone generator (I just downloaded a signal generator app) and run a sweep so we can hear any problems. Perfect. Let’s get it ready for tape and mud.
Stage 4: Taping and finishing
We’re ready to mud in the speaker. We’ve mixed the compound to the consistency of thick ice cream. This is a fast-set 30-minute compound, so it won’t take too long to dry hard, after which we tape. We want to create a bond between the speaker and the drywall by filling the gap, much like a lath-and-plaster repair. Press the compound right into the gap without spilling it everywhere, using the small 6-inch blade, so it protrudes just past the speaker edge and creates a base to tape over.
That’s the first stage. Now grab the tape (lovely orange tape, for the Dutch football team, of course) so we can see what we’re doing, and tape right over the edge. I don’t overlap, that’s not necessary, just bring it up to the edge of the previous tape and remove the blade. The seam is covered.
Next, more mud. I’m quite generous with this. This is the scratch coat. Take the larger blade, which covers the whole speaker, and put on a little less than a millimetre (about a 16th of an inch) across the whole panel. That’s our scratch coat. We let it dry, then come back for the second and final coat.
To finish
There you have it. We tested the speaker, tone-tested it, took the rattles out of the wall and made sure everything works perfectly. We’ve got it to the point where your plasterer can come in and do the final finishing. We’ve installed the Sapphire 250. I hope you enjoyed it and learned something, and we’ll see you next time.
Invisible speaker installation at a glance
The full process is in the video, but here is the sequence for reference on site:
- First fix: pull speaker cable to each position before the plasterboard goes up.
- Cut a small inspection hole and locate the studs with a tape measure.
- Fix the CV345 template with masking tape, check it with a level, and confirm the studs sit at the edges of the 345 x 450 opening rather than through it.
- Clear excess insulation so the CV345 back box seats, leaving a little behind the panel to deaden the cavity.
- Feed the cable through the grommet, align the back box with the tab, and fix it square to the studs.
- Wire the speaker using the WAGO lever connectors (strip around 10mm, check polarity, no stray strands).
- Clear any loose screws from the back box, then drive the mounting screws and bring the panel flush across the diagonal without over-tightening.
- Run a tone sweep to confirm the panel is clean, then tape, apply a 1mm scratch coat, and hand over to the plasterer for the final skim.
What matters most on site
What matters most on site
Getting an invisible speaker installation right takes focus, skill and experience. Every step counts towards the magic of sound with no visible source, and that is only possible with the right preparation.
The sweep tone test. Once the panel is plastered over, a buzz or rattle means opening the wall back up, so a quick signal-generator sweep before any compound goes on is a step you should never skip. You will need mains power on site and an amplifier in your kit to drive the speaker for the sweep. Most rattles trace back to three things: loose screws left in the back box (they stick to the magnets on the rear of the panel), too much slack cable clacking against the back, or a section of board that needs an extra screw to pull it tight to the stud. If you pick up any of these, sort them and run the sweep again.
Getting the panel flush. The panel should sit fractionally proud of the board (around 1.5mm, a 16th of an inch) so the plasterer can feather it in, and it should never be overtightened. Bring it down evenly across the diagonal with a hand screwdriver rather than a drill, so you keep control of the last turn.
Plan the timing. The fast-set compound gives roughly 30 minutes of working time, and the scratch coat needs to dry before the plasterer returns for the final skim, so the finish is not a single continuous job.
First fix or retrofit? The sequence above is a first fix, which is always cleaner because you can run cable before the board goes on. Retrofitting into a finished wall or ceiling is possible but adds extra steps and disruption, so it is worth flagging to the client early.
One process, three models. The Sapphire 250, Sapphire 375 and Sapphire Dual all use the same separate CV345 back box, so this is your reference for the whole range. The Sapphire 250 also has an integrated back box variant, the Sapphire 250iB, which removes the need for a separate back box.
If you are specifying invisible audio for a project and want to see the finish quality in person, request a demonstration, or use our specification service to get the right model and back box onto the drawing.
If you are specifying invisible audio for a project and want to hear the finish quality in person, request a demonstration, or use our specification service to get the right number of speakers, and the right model for your project.
Invisible Speaker installation FAQ’s
For a plaster-in installation, invisible speakers are cut into a plasterboard wall or ceiling and finished flush so no grille is visible. The installer locates the studs, cuts an opening to the template, fixes a back box, wires the panel (Amina Sapphire models use WAGO connectors), screws the speaker flush with the board, then tapes and skims over it. The plasterer applies a final finish of around 2mm over the panel.
Invisible speaker installation is best handled by an experienced AV integrator working with a skilled plasterer. The cut-in, back box fixing, wiring and flush alignment all affect the final sound, and the panel then has to be taped and skimmed to a plaster finish. Amina supplies templates and back boxes to make the process repeatable, but the finish quality depends on trade skill.
You need a template(included with the speaker), a tape measure and a level, a saw or utility blade for cutting the opening, a screwdriver and screw gun, wire strippers and cutters, and drywall screws. For finishing you need fast-set jointing compound, jointing tape, and 6-inch and larger finishing blades. You also need mains power on site, an amplifier and a tone generator app to run a sweep test on the panel before you skim over it.
Yes. Invisible speakers are designed to be covered by around 2mm of finish, plaster included, so they disappear into the wall or ceiling. After fitting, the installer presses jointing compound into the gap, tapes the seam and applies a thin scratch coat of around 1mm across the panel. Once dry, the plasterer applies the final coat and skim flush with the surrounding surface. Aim for about 2mm of finish over the front of the panel for the best results. Plaster is not the only option: the Sapphire range can also be finished into wood, stone, veneers, BASWAphon, Dibond and many other materials.
Rattles usually come from loose screws, cable or an unsupported panel. Before finishing, clear any loose screws from the back box (they can stick to the magnets on the rear of the panel), push excess cable back into the void, and add a screw to pull the board tight to the stud if needed. Then run a tone sweep to confirm the panel is clean before you skim over it.
Both are possible. On a new build or renovation you can pull speaker cable to each position before the plasterboard goes up, which makes cutting in and wiring much simpler. Retrofitting into a finished wall or ceiling can be done but is more disruptive, since cable has to be routed after the board is on.
Amina Sapphire speakers use WAGO connectors, which make wiring quick. Score the cable sheath with a utility knife, strip back around 10mm, twist the strands and check polarity before clicking the connector closed. Make sure no bare strands are left exposed, as these can cause a short. The connection is strong enough to hold the weight of the panel.
The Amina Sapphire 250, Sapphire 375 and Sapphire Dual all share the same cut-in installation method and CV345 back box. The measuring, cutting, back box fixing, wiring, tone testing and finishing steps are the same across the range, so one process covers whichever Sapphire model you are specifying. If you prefer an integrated back box (iB) version such as the Sapphire 250iB, see our iB installation guide.
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