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Discussion Starter #1
For building a 1x12 guitar amp cabinet, does it matter what wood I use? Is it worth it using like nice quality hardwood? Or should I stick with what the major companies use, 3/4" birch plywood?
 

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Depends if your going to cover it with Tolex or not. When I've used some nice woods for some of mine: Maple, Oak, Select Pine, etc.. . I just stain and clear coat. It's a lot easier than applying Tolex too. But if you're going to be taking it on the road with you might want to use plywood with Tolex and good corner protectors.
 

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Discussion Starter #3
Im not going to use any tolex :D

I will be doing what you are. I will just join the pieces of wood (I probably will just join them simply. I dont have the equipment to make dovetail joints, etc although I would love to lol). Then I will stail the wood light cherry, and cover with some varnish. I will still go with some corner protectors, but yeah.

Does using good woods instead of the usual plywood make the cabinet sound better? Like will I get a nicer sound? If not, I will just use the plywood, and glue a thin sheet of mahogany on the exterior of the cabinet for looks. Just fyi, I will be making an open backed cabinet.

Any tips for baffle material?
 

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I

Does using good woods instead of the usual plywood make the cabinet sound better? Like will I get a nicer sound? If not, I will just use the plywood, and glue a thin sheet of mahogany on the exterior of the cabinet for looks. Just fyi, I will be making an open backed cabinet.

Any tips for baffle material?
From what I've read (and I collect classic texts all the way back to G A Briggs in the late 40's) perhaps the two most important factors for a guitar cab would be rigidity and no voids in the plywood.

The reason we use thick wood is to ensure stiffness. If the walls of the cab can vibrate with the stronger bass energy they suck that energy up! The bottom end thus suffers.

With plywoods, the cheaper styles often have voids in some of the plys. Again, bad news for the sound. That's why we often use Baltic or Russian birch plywoods.

If you intend to use a tolex or whatever covering you can get away with 1/2" MDF. This is a plywood made of very fine particles and is very dense and heavy as Rosie O'Donnell. It can be a bitch to cut and especially to router. The stuff is so hard that you need good quality router bits and go very slow or you'll burn them out for sure. It's these same PITA qualities that make it such a good choice!

Hifi cabs were all the rage back in the late 40's and 50's. Magazines were full of construction articles giving all the dimensions (not really critical for a guitar cab but important for bass and PA) and info you needed to roll your own incredible cabinets. All sorts of materials were tried to give the rigidity needed, like ceramic tile and even concrete!

To handle those lower bass frequencies there's no substitute for size. Big cabs will have great tone and efficiency. Little cabs will lose tone and will need hundreds of watts of drive. Theatres used cabs half the size of a typical refrigerator. They contained only one speaker and a horn, rated for 75 watts. They could blast the walls out! Compare that with all the power you need for those tiny bookshelf speakers your woman made you buy from Future Shop...

Most home cabinet plans were for units just as big. They would use veneers or solid good looking woods with stains and finishes. The boxes would become furniture in the corners of your listening room. Some guys used plywood spaced a half inch apart for cab walls and filled the gap with dry sand. The unit would weigh close to 200 lbs! The improvement in overall sound though was quite worth it.

Anyhow, for your purposes you want it to be rigid and void free. Any type of wood that accomplishes those factors will do fine. The same points apply to the baffle, with the qualifier that some guitar cabs sound better if the baffle is a bit on the thinner side. You actually get some sympathetic baffle movement that improves the result! This apparently was the secret behind the legendary Fender Bassman 4-10" cab from the late 50's.

:rockon:
 

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Discussion Starter #5
Hey Bill! Do you know if the plywood at home depot here in Canada would be ok? I dont know if they carry Baltic or Russian Birch plywoods though, do you know perhaps? As you were saying a smaller cabinet will need more watts, I do sort of need a "manageable" size of cab, as I want to be able to transport it.

About the baffle being thinner, do you think if I used 3/4" plywood for the cabinet, and 1/2" plywood for the baffle, would that be good? Sorry for the many questions. I do not know a lot about cabinet construction, and the stuff that I have found online at other websites contradicts itself a lot lol. thanks Bill!

Oh also, when you say rigidity is key for good tone, would you use glue to join the panels of the cabinet, or just screws? or both? and what type of glue? I have carpenter's wood glue, and a bunch of difference types of screws (drywall etc)
 

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oh another question too,
You said,
"Little cabs will lose tone and will need hundreds of watts of drive. Theatres used cabs half the size of a typical refrigerator. They contained only one speaker and a horn"

Do I need a "horn" in my cabinet? or can I just use a 12" guitar amp speaker? Is this a horn like a tweeter? I have no idea what those things are lol...I only know what a speaker is.
 

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Do you know if the plywood at home depot here in Canada would be ok? I dont know if they carry Baltic or Russian Birch plywoods though, do you know perhaps?

The Depot does carry quarter sheets of Russian birch ply.

I have used 3/4 (or whatever the metric equivalent is) for the cab and 1/2 for baffle with good success. I like to use carpenters glue or foam glue ("gorilla" glue, but only if you have good clamps) and I biscuit joint the corners, and screw in the back and baffles. I find 18in H X 18in W by 10-12in. deep is a good starting point for 1X12. You can go smaller but they sound a bit boxy to my ears.
 

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You can use pickup truck bed liner (the kind in a can like hippo liner or rhino liner) to cover a cabinet. It comes in different colours and will protect the cabinet and it actually looks pretty good. You can also do touch ups in case you do ding it.

The stuff is about fifty bucks a can, but that's still pretty good when you consider the cost and time it takes to wrap it in tolex.
 

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"Ah, nostalgia isn't what it used to be!"

oh another question too,
You said,
"Little cabs will lose tone and will need hundreds of watts of drive. Theatres used cabs half the size of a typical refrigerator. They contained only one speaker and a horn"

Do I need a "horn" in my cabinet? or can I just use a 12" guitar amp speaker? Is this a horn like a tweeter? I have no idea what those things are lol...I only know what a speaker is.
Other guys have chimed in with good advice for most of your other questions, GZ.

To explain further, there's a big difference between the typical guitar cab and one made for bass guitar, PA or hifi. Lead guitar doesn't ask for nearly as low a bass range. To make a cabinet efficient for lower bass frequencies requires size, special dimensions and/or resonant ports, slots and various tricks.

A lead guitar cab is basically just a frame to hold the speaker(s). We don't ask for the cabinet to do anything else. The only real options are to leave the back open or close it. Open back cabs sound louder. They're not really louder but they tend to fill and wash over a wide area. Closed back cabs have some directivity to how they throw the sound and due to the back pressure on the speaker cone(s) they tend to sound "tighter".

A horn is a tweeter that has a wide, flared horn in front of it to throw the sound. In your living room a tweeter is enough. In a large hall or outside venue you need the horn to throw the sound out to fill the required area.

Guitar doesn't go high enough in frequency to need tweeters or horns. They are sometimes put in a cab as a gimmick to get you to buy it but they don't really do anything.

PA, or "public address" amplifier systems have to do a reasonable job with music but mostly amplify the human voice from a microphone, like with an announcer or emcee. The human voice doesn't really put out much energy above 3000 cycles per second but there are overtones (harmonics) in voice and many instruments like piano, cymbals, horns and others that add to the fidelity with music and the clarity with voice, particularly with singing. So cabinets for this application do need horns or tweeters.

Bass guitar cabs used to routinely be as huge as a refrigerator! They were loud as heck with great tone and threw the notes as far and wide as you could ever need. The "suits" began to offer smaller cabs that were lighter and easier to transport. Of course, the tone suffered and you couldn't hear them as well but they had an answer for that. "Your amp is too puny! You have to buy a more powerful amp!" Naturally they had an amp all ready for you, that was gonna cost a bunch of bucks. So they got extra money out of you with a new amp as a solution to having bought their toneless, inefficient small bass cabinets. Do you see what's wrong with this picture?

You don't have to worry about all this stuff for your lead guitar cab, GZ. However, if you're interested in building something for your stereo or a bass guitar just do some googling. There are still a lot of guys that make their own sawdust for some great DIY cabinets! There's a great deal of pride to be had in making something yourself, especially when it outperforms so much of the store-bought gear.

Have fun!:food-smiley-004:
 

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Lots of info for a guy that's going to butt-join a few pieces of wood together.Solid pine sounds best for guitar speaker cabinets.Cheaper than baltic birch too.Go to Home Depot,Rona or Totem and get them to cut the wood to the sizes you need and glue away.Use some screws and internal braces in the corners.A 2x2 will do fine.Use the baltic birch for the speaker baffle.Done. Pine may not look as nice stained as hardwood,but it is about 1/5th the cost of good hardwood.
If you are in Calgary,I'll dovetail the panels for a reasonable price for you.

www.claramps.com
 

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Good tips guys but you missed the most important one..

Volume as in air, look up the specs for your speaker or call the company that provided the speaker to find out how much air you need.
Think of it as a spring, the strength of the speaker can only compress so much air..more air is easier to compress than less.. a 12 that moves 1/4 inch in a 1 sqft box may work ok but a 12 that moves 1/2 may only move 1/4 in that same box loosing all bottom..now add 1/2 sqft of air and you have a totaly different sound.

Closed back and open back cab speakers are specific to that style, to cross over is not a good idea.

Every speaker is different in the specs..
Thick surrounds = bigger volume
Small coils/magnets = bigger volume
Big coils/thick surronds/big magnets = smaller volume

So just from looking at a speaker there is no way to know what volume works.
Once you do have the spec you can make the box a bit smaller to increase mids and highs, or bigger to increase bottom and roll off the highs.
Tuning can be done with rock wool, increasing the wool makes the box a bit bigger.

hope that helps.
Bev
 

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Good tips guys but you missed the most important one..

Volume as in air, look up the specs for your speaker or call the company that provided the speaker to find out how much air you need.
Think of it as a spring, the strength of the speaker can only compress so much air..more air is easier to compress than less.. a 12 that moves 1/4 inch in a 1 sqft box may work ok but a 12 that moves 1/2 may only move 1/4 in that same box loosing all bottom..now add 1/2 sqft of air and you have a totaly different sound.

Closed back and open back cab speakers are specific to that style, to cross over is not a good idea.

Every speaker is different in the specs..
Thick surrounds = bigger volume
Small coils/magnets = bigger volume
Big coils/thick surronds/big magnets = smaller volume

So just from looking at a speaker there is no way to know what volume works.
Once you do have the spec you can make the box a bit smaller to increase mids and highs, or bigger to increase bottom and roll off the highs.
Tuning can be done with rock wool, increasing the wool makes the box a bit bigger.

hope that helps.
Bev
Absolutely true Bev but as our friend A2T reminded me this thread started with a question about lead guitar cabinets. I stand by my point that these cabinets are little more than a frame to hold the speakers. You can make mistakes such as too thin/flexible woods but resonance, tuned ports or whatever just don't apply. Lead guitar has little or no energy below 100 hz or above 4-5 khz. Cabs built for this application invariably seem to be just big enough to house the speaker(s) and not much more. No manufacturer sees value in any extra wood costs as far as the delivered sound. Hifi cabs of course are a totally different animal.

You might find this interesting, if you haven't seen it already.

http://www.aikenamps.com/

Go to "tech info" and you'll find a FAQ about the frequency response of a Marshall 4-12" cabinet.
:food-smiley-004::rockon:
 

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more advice

Check out the great little article on the Celestion site on guitar cabinet design/construction. Another site that I like for almost any idea you can imagine is Shavano Music. Great "practical" (i.e. useful, rather than theoretical and/or interesting) advice, plans etc.
 

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Discussion Starter #16
aah ok guys! thank you very much for the information, especialy Wild Bill :)

I will get back to you on the project soon. I have another week of school after this one, so it wont start till then anyway.
 
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