Introduction: Making a New Speaker Grill for a Guitar Amp or Speaker Cabinet
Breaking or losing the grill to your speakers can really expose your "sound" investments to all sorts of evils. This Instructable shows you one way to fabricate a new grill for your speakers.
The frame/grill needs to be fairly sturdy and be removable to access the speakers. It's ok if the frame takes some effort to get off after it's attached. You don't want it falling out unexpectedly.
I think the key requirement on this project is to use a single piece of plywood for your frame. Everything else is negotiable. A Negotiable Instructable - that should be a new category!
Step 1: Safety, Materials and Tools
Safety: For the grill shown here, a number of power tools were used. These included: table saw, router, drill with hole cutter, and a medium duty staple gun. Each one of these has their own unique set of safety hazards - be sure to be familiar with any safety precautions for each before you proceed!!!!
At a minimum, ALWAYS wear eye protectionand use hearing protection when power tools are in use (including your shop vac). A snug pair of mechanics gloves are a great thing to have around anytime there are splinters or if you need a little extra non-slip grip.
Materials: 1/2" plywood, black speaker grill cloth, medium duty staples, paint primer, black paint, small nails, Velcro, Legos
Tools: Tape measure, table saw, router with 1/8" straight bit, electric drill with 4" hole cutter, medium duty staple gun, 45/90 degree square, misc clamps, paint brushes
Step 2: Measurements
Measuring can be be iffy depending on the type of cloth you end up using. Since I didn't have any grill cloth sitting around, I waited for my cloth to come in before I started the critical measurements. I used an acoustically transparent speaker grill cloth from Parts Express. But realistically, you can use just about any fabric you want. I wanted it to somewhat resemble the original, so I used black speaker grill cloth.
The issue with the fabric is that depending on how thick and stiff it is, it can affect your final height and width measurements of the grill frame. For this project and the cloth I was using, I guessed about 1/4" (1/8" per side) would give me the extra room I needed to maneuver the completed frame into the opening and not tear up the cloth.
The end measurements were:
Width: Actual - 24 - 11/16", frame 24 - 5/8"
Height: Actual - 16 - 5/16", frame 16 - 1/4"
I was worried about the how the speaker baffle leaned back in the cabinet - but this did not turn out to be a problem. I'm just a worry wart.
Step 3: Frame Material Selection and Cutting
There's really not a lot of choices for wood on these. Plywood is pretty much a given and quality plywood is better than bargain bin discards at Lowes. I was lucky and had large piece of 7 ply 1/2" birch plywood from a previous speaker cabinet project to use.
I used a table saw to make the final cuts. But just about any saw will work if you take your time and watch what you're doing.
Here's the final piece cut to the frame measurements from the previous step:
Width: 24 - 5/8"
Height: 16 - 1/4"
Do a "dry fit" by actually inserting this into your opening to make sure you have the correct measurements. Sometimes things will be out of square or tighter that you expect.
Step 4: Measuring and Cutting the Frame Inside Corners
I like rounded corners and this project was no exception. The first pic show the final end product of all the sub-steps. So if you are not that concerned about what your corners look like, you could just make this a big square-edged rectangular hole in the frame.
The key point here is to make the edge wide enough to not break from the stress of stretching the speaker grill cloth across it. I figured 1 - 1/2" all the way around would be safe.
Note about this part: You only need to do all the marking and measuring for one corner. Once you get the reference point figured out, you can transfer it to the other three corners using the 45/90 combo square.
Step 5: Complete Cutting the Inside of the Frame
For this step I used my router with a 1/4" straight bit to get some nice, tight square cuts. But you could use something like a jig saw, or even a back saw, to get the inside cut out.
I take the router at about 1/8" incremental cuts until the entire cut is made.
Step 6: Paint the Frame
Sand down the sharp, splintered edges. Prime and paint as desired. I used a flat black brush on latex for the final finish.
Step 7: Add the Speaker Grill Cloth
Upholstery! Personally, I hate doing this. But it always seems to come out OK. The basic rules are to start in the middle of a set of sides and work your way out. The hard part is to keep the fabric taught, but not to the extent that the sides of the frame will bow in or break. Plus you need to keep the grain consistent (and parallel).
I used a medium duty staple gun with 1/4" deep staples.
For purposes of this instructable, I defer to any number of people that are much more adept at this technique than me. Do a search on "Upholstery" .
Step 8: Attach the Frame to the Speaker Baffle Board
There are any number of ways to do this part. I wanted this to be something someone could easily undo in the future. The solution ended up being Velcro and a "single wide" Lego.
I tried both the normal "double wide" Lego and the thinner "single wide" Lego to see which would work better. The thin one worked better.
The final attachment was a snap. Just take the backing off the Velcro strips and push everything into place.
The goal here is to attach the frame to the baffle in a manner that is removable and does not rattle when you turn the volume up. In addition, if the frame or the attachment method is too thick, the frame will stick out of the cabinet.
Step 9: Final Thoughts
This turned out to be a fairly clean installation when I got done. The black paint on the frame and the black cloth look reasonably stock. Although Peavey enthusiast will immediately note that I'm not even close on what the grill REALLY should look like.
No rattling was noted as I went up to 3 on both the clean and distortion channels. This thing is 130 watts, and I already broke some china a few weeks back testing a 100 watt bass amp at 5. So 3 worked for me :-) You can play with a flat blade screwdriver to work it back out - so it's removable. And it does not fall out as you lean it forward or generally fiddle with the grill.
So met all my requirements.
The only thing I don't like about this is how visible the speakers are. Just my personal opinion. This is actually how transparent the originals are.
Next steps - clean up the Tolex a little, spray the pots and on to Craigslist!
Any comments/suggestions/improvements are always welcomed.