BeZo
Well-known member
Been doing this as a side job for years now, and there's 3 things I do to improve the response and quality of a guitar cab. I figured I would share and see what my beloved Rig-Talk community has to say about it.
1) Wiring.
I rewire most cabs that come with crappy 20g wire and clips. I don't trust that stuff. I personally use 16g oxygen free copper speaker wire and solder them right to the tabs. Soldering the wire to the tabs makes a better electrical connection and a better mechanical connection that won't rattle loose over time. As for the wire, any heavy wire made to carry electrical current will work. I've heard plenty of people say they use lamp chord with great results. Mainly, as long as your wire is thick enough for the current, you're good.
This is where I will mention removing switches and PC board. If you run your cab stereo, wire it up stereo with good wire and good jacks. If you only use it mono, than just wire it up mono. There is no need for switches in most cases, and it's a choking point for current trying to make it to your speakers. The PC boards in cabs (especially Marshall cabs) are bad news. They blow and take amps with them. The whole point of rewiring a cab is to help the flow of electricity to the speakers. Better wire, better components, and better connections help accomplish that.
2) Air Movement
People use open back cabs to get air movement on both sides of their speakers. This allows them to travel farther, and allows sound to escape the back from the speakers return movement. This usually results in more bass response and a fuller sound. That is why 1x12 and 2x12 usually come with this option. If you have a closed back cab, like most 4x12s, you don't want air to move in or out. Controlling air pressure in the cab can lead to a stiffer speaker response and a tighter tone. You can do this by sealing up your cab.
If you open up a Mesa cab, you find that everything has a gasket. This is to stop air flow. If you never want to remove parts (handles, castor plates, etc...) you can use RTV to glue them into place. Automotive grade RTV is a silicone based gasket material that is designed not to be corrosive to metal parts. If you use regular silicone to seal the inside of the box or the hardware, you have to let it dry away from the speakers for a few days, because the silicone is corrosive to the speakers. RTV on the other hand won't damage components.
Now, you don't have to glue everything in and seal it with RTV. Just making a gasket out of electrical tape and screwing it down good is enough. That is what I do to jack plates. Another option is getting a foam padding to line the back panel. A thin strip will do the job. The rest of the box should be constructed well enough, but if there's doubts, just run a strip of silicone or RTV around the joints. Make sure to check out the casters at the bottom too. Seal any point where air might get out through the wheels.
This is the other reason why wiring it mono or stereo and removing switches comes to benefit. If the only place air has to enter or exit the cab is the jack hole, and you plug the cab in with a cable, it's sealed. You can use electrical tape on the jack plate to seal up any other holes from where the switch was or the other jack hole. Also, make sure the speakers themselves are sealed well. Most speakers have a gasket on their face to seal when they are rear loaded. Front loading speakers on the other hand, may require an extra gasket. You can get 12" speaker gaskets online to put between the back lip of the speaker and the face of the cab, or you can glue them in if you never want to get them out again. Personally, I would opt for the foam, because trying to get a speaker out that you glued in with RTV is a total bitch!
Make sure everything is screwed in tight. All the handles, hardware, jack plate and speakers should be snug. Rear mounted speakers shouldn't be torqued down though. If you over-tighten the rear mounted speaker, you can warp the frame and ruin the speaker. You should get them hand tight and then give them a little turn to snug them. Use lock washers to make sure they don't come loose, and you're good.
3) Baffling
Some cabs need to have the baffling. Some cabs don't. There's only one way to find out. Go get some fiberglass insulation and line the back part of your cab. When the speakers bounce back, it produces sound that bounces off the back panel and might cause phase cancellation on certain frequencies. Sometimes it tames the high end and sounds great. Sometimes it muffles the speakers and doesn't help. Using fiberglass to insulate the back turns sound into heat by vibrating the fiberglass. It kills waves inside the cab that might otherwise cause phase cancellation. Sometimes, doing the sides or the top and bottom makes a difference. Sometime, you find that you like it better without and you wasted your money on insulation that you now can't return. Only one way to find out if it works though, right?
With these 3 things, you can tighten up and really fine tune most cabinets. Mesa cabs already come with good wire and gaskets to seal them up, and that is why they sound better and tighter. They also use better speakers and different cab dimensions too. Not all cabs are created equal, but most cabs can get a bump in the standings with these little tricks. Marshall cabs especially benefit from this stuff (baffling depending on the speakers). If you rewire and seal up a Marshall, they are tighter and more responsive. Maybe this will help some of you. Maybe some of you already knew most of this stuff. Either way, there you go!
1) Wiring.
I rewire most cabs that come with crappy 20g wire and clips. I don't trust that stuff. I personally use 16g oxygen free copper speaker wire and solder them right to the tabs. Soldering the wire to the tabs makes a better electrical connection and a better mechanical connection that won't rattle loose over time. As for the wire, any heavy wire made to carry electrical current will work. I've heard plenty of people say they use lamp chord with great results. Mainly, as long as your wire is thick enough for the current, you're good.
This is where I will mention removing switches and PC board. If you run your cab stereo, wire it up stereo with good wire and good jacks. If you only use it mono, than just wire it up mono. There is no need for switches in most cases, and it's a choking point for current trying to make it to your speakers. The PC boards in cabs (especially Marshall cabs) are bad news. They blow and take amps with them. The whole point of rewiring a cab is to help the flow of electricity to the speakers. Better wire, better components, and better connections help accomplish that.
2) Air Movement
People use open back cabs to get air movement on both sides of their speakers. This allows them to travel farther, and allows sound to escape the back from the speakers return movement. This usually results in more bass response and a fuller sound. That is why 1x12 and 2x12 usually come with this option. If you have a closed back cab, like most 4x12s, you don't want air to move in or out. Controlling air pressure in the cab can lead to a stiffer speaker response and a tighter tone. You can do this by sealing up your cab.
If you open up a Mesa cab, you find that everything has a gasket. This is to stop air flow. If you never want to remove parts (handles, castor plates, etc...) you can use RTV to glue them into place. Automotive grade RTV is a silicone based gasket material that is designed not to be corrosive to metal parts. If you use regular silicone to seal the inside of the box or the hardware, you have to let it dry away from the speakers for a few days, because the silicone is corrosive to the speakers. RTV on the other hand won't damage components.
Now, you don't have to glue everything in and seal it with RTV. Just making a gasket out of electrical tape and screwing it down good is enough. That is what I do to jack plates. Another option is getting a foam padding to line the back panel. A thin strip will do the job. The rest of the box should be constructed well enough, but if there's doubts, just run a strip of silicone or RTV around the joints. Make sure to check out the casters at the bottom too. Seal any point where air might get out through the wheels.
This is the other reason why wiring it mono or stereo and removing switches comes to benefit. If the only place air has to enter or exit the cab is the jack hole, and you plug the cab in with a cable, it's sealed. You can use electrical tape on the jack plate to seal up any other holes from where the switch was or the other jack hole. Also, make sure the speakers themselves are sealed well. Most speakers have a gasket on their face to seal when they are rear loaded. Front loading speakers on the other hand, may require an extra gasket. You can get 12" speaker gaskets online to put between the back lip of the speaker and the face of the cab, or you can glue them in if you never want to get them out again. Personally, I would opt for the foam, because trying to get a speaker out that you glued in with RTV is a total bitch!
Make sure everything is screwed in tight. All the handles, hardware, jack plate and speakers should be snug. Rear mounted speakers shouldn't be torqued down though. If you over-tighten the rear mounted speaker, you can warp the frame and ruin the speaker. You should get them hand tight and then give them a little turn to snug them. Use lock washers to make sure they don't come loose, and you're good.
3) Baffling
Some cabs need to have the baffling. Some cabs don't. There's only one way to find out. Go get some fiberglass insulation and line the back part of your cab. When the speakers bounce back, it produces sound that bounces off the back panel and might cause phase cancellation on certain frequencies. Sometimes it tames the high end and sounds great. Sometimes it muffles the speakers and doesn't help. Using fiberglass to insulate the back turns sound into heat by vibrating the fiberglass. It kills waves inside the cab that might otherwise cause phase cancellation. Sometimes, doing the sides or the top and bottom makes a difference. Sometime, you find that you like it better without and you wasted your money on insulation that you now can't return. Only one way to find out if it works though, right?
With these 3 things, you can tighten up and really fine tune most cabinets. Mesa cabs already come with good wire and gaskets to seal them up, and that is why they sound better and tighter. They also use better speakers and different cab dimensions too. Not all cabs are created equal, but most cabs can get a bump in the standings with these little tricks. Marshall cabs especially benefit from this stuff (baffling depending on the speakers). If you rewire and seal up a Marshall, they are tighter and more responsive. Maybe this will help some of you. Maybe some of you already knew most of this stuff. Either way, there you go!
