Building an Amp Cabinet

15 WATTS IS SCREAMING LOUD!!!!!
 
 
that said, the ta-15 is a great choice, and has a great master volume setup, you'll be able to get any tone you want at any volume.
 
the ta-15 does not have fx loop...
the ta-30 does, but twice as expensive.
 
12" is the norm.
having one open back, and one closed back, covers a lot of good sonic territory
 
if you have different guitarists coming in, each will have a preference.
i like closed back.
 
 
 
for the cost of the materials, i think you could buy a cab as cheap as you could make it nice.
 
AVATAR comes to mind
 

http://www.avatarspeakers.com/
 
 
 
 

avatar:
 
Complete but SpeakerlessSlip Covers Now Available $29
Celestion  Vintage 30, G12H30, G12T75,  Greenback, Classic Lead 80, Hellatone 30, Hellatone 60, G12K100 
Eminence Governors, Wizards, Private Jacks, Swamp Thangs
Celestion Heritage G12M, G12H, G12-65
 
i have a heritage g12-55 in mine...
 
 
but for 279 with a greenback, that's hard to beat
 
 
i know my own time is worth a LOT more than 279
 
 
my rig:

well gentlemen this is excellent info.
Bat that is a nice looking rig you have there, indeed!
 
Ampfixer, really appreciate the detailed info.
 
Guess I really had it stuck in my head this would be a fun project to make the cab.
I love working with wood and making stuff.
I built all the work surfaces in my studio, speaker stands, etc.
So just fun, you know.
However.... one must not overlook the obvious when presented.
 
Are those avatar cabs closed or open back?
I really could not tell by the website. Must dig deeper..
 
 

on the avatars: just do some research, you can get them open, closed, semi open, or a cool alternative is one that has a removable panel in the back, so you can do it either way...
 
my avatar is closed back, but i can turn both of my trusty old roland cabs into open back by removing the panels on back.
 
the demeter, is shown open in the pic, but it is a isolation cabinet in practice.
 
building cabs that are worth having is a bit of an art..
 
the design of the soundboard is key,
along with the interior dimensions, type of wood used, the way it is jointed, you dont just build a piece of furniture, it has to be tuned.
 
 
 

batsbrew
on the avatars: just do some research, you can get them open, closed, semi open, or a cool alternative is one that has a removable panel in the back, so you can do it either way...
 
my avatar is closed back, but i can turn both of my trusty old roland cabs into open back by removing the panels on back.
 
the demeter, is shown open in the pic, but it is a isolation cabinet in practice.
 
building cabs that are worth having is a bit of an art..
 
the design of the soundboard is key,
along with the interior dimensions, type of wood used, the way it is jointed, you dont just build a piece of furniture, it has to be tuned.
 
 
 

I like the removable panel idea. In fact I was considering doing that if I built just one.
off to do some research.

So far beyond anything I would ever consider. You guys who build amps and cabs are like mad scientists! (in a good way, not the evil ones)

Ya, maybe without an acoustic engineering book, perhaps you be wasting your time building a speaker cabinet. To give you an idea, first you build a 2 ft. square box (2ft.x 2ft. x say 8" forget exactly) and measure the speaker in that box facing in the box for resonance frequency (where the speaker move in and out the same usually around 35Hz or so) then you build a cabinet for the speaker according to specs given by the manufacturer for internal volume of the cabinet and then - the hard part - how loud, what sound you want out of it, and all of that.
I have JBL 10" speakers (well actually more - 15" and bullet ring radiators) and at the time got a readout kind of instructions on what cabinet the speakers were made for. Say like the 10" speaker can fit in a 1-1/2 cubic foot box, if you want, it also can fit into anything size wise like 0.5 cu. ft. (12"x12"x6") to 3 cu. ft. type box. Now what are the dimensions you want, what kind of sound for the speaker enclosed in the box, will it be ported or anything like that, open back (if the speaker is made for it or enclosed back) - that is what sound you get when you are done. Now, you will have to imagine how the cabinet will help the speaker and what sound (tone wise ) you will end up with.
 
Tight sound - smaller cabinet - bassier sound - bigger cabinet. All plays into it, so try and imagine how the finish cabinet and speaker in the cabinet will sound.
 
Well, good luck!
 

Here Dave.
 
Everything you need to find out just what it would cost you.

Thanks for the link Spacey.
 
Herb, yeah it's the tonal characteristics of the different speakers that I need to address.
Guess I need to see what cabs Sweetwater and (gasp) Guitar Center has in stock, see what speakers are in each and go play thru them.
This is one of those times where you really need to be able to hear what it sounds like and when
you have other people playing in there it becomes almost impossible.
Never-the-less... still a good way to spend an afternoon.
 
Maybe I'll come down with something over the next few hours, be forced by peer pressure to leave the office, then stop at Sweetwater on the way home.
That is not a bad plan for a Friday, eh?

 
 

spacey
"Building" I thought was the keyword.
If so and the woodwork is not an issue -as you stated then
you're left with only three major decisions to make;
Cabinet design
Cabinet materials
Speaker selection
 
*cost is a factor but things change when the desire to create is the driving force. Nobody can
determine what that is worth to you.
 
"I built it" is what I would think is at the heart of it...and being the best you can do to achieve the
results you desire.
When I read opinions about points that aren't relevant to "building" I wonder if I'm understanding
your OP.
I also don't understand or agree with ignoring details. Especially in a closed back design or cabinets
containing the amp with the speakers.
I've heard many backyard cabinets what weren't worth the effort...more or less the cost.
 
If you were wanting opinions which would be better- to build or buy - in cost comparison
then the link I provided will help determine build cost and built if their offerings fit.
 
Speaker selection is personal.
Depending on how much I wanted to invest I would want to know my options and they'd probably
be;
One 12" cabinet and two different speakers so I could determine sonic preference.
Two cabinets each to hold one 12" and use two different speakers for same goal.
One cabinet for two 12" speakers- both being the same with plans to get others to hear.
One cabinet for 4-12" and one "tilt" cabinet for 4-12".
 
Size of speakers?
Many different sizes can work based on the design and number of speakers.
I've had cabinets with 6-8" that were fantastic.
 
Whatever it is you're wanting to do...good luck and have fun with it.
 
 

Yeah Spacey, 'building' still is the keyword here.
Admittedly what Avatar has to offer looks very good and if I choose to buy rather than build
I could find what I want there, for sure.
 
But the building project intrigues me. It's the "I did it" factor...
 
I do know I want 2 different speakers for flexibility.
2 small cabs good for flexibility, but 1 cab with selectable input jack for one or the other speaker or both would be acceptable in a larger cabinet.
 
Absolute worst case if I build something and it sounds like crap, I buy a cab and move the
speakers into it.
Wasted the cost of some material... not the end of the world.
As for my time, well if I'm out working in my shop then no matter the outcome, it is never
wasted time to me.
 

dxp

spacey
"Building" I thought was the keyword.
If so and the woodwork is not an issue -as you stated then
you're left with only three major decisions to make;
Cabinet design
Cabinet materials
Speaker selection
 
*cost is a factor but things change when the desire to create is the driving force. Nobody can
determine what that is worth to you.
 
"I built it" is what I would think is at the heart of it...and being the best you can do to achieve the
results you desire.
When I read opinions about points that aren't relevant to "building" I wonder if I'm understanding
your OP.
I also don't understand or agree with ignoring details. Especially in a closed back design or cabinets
containing the amp with the speakers.
I've heard many backyard cabinets what weren't worth the effort...more or less the cost.
 
If you were wanting opinions which would be better- to build or buy - in cost comparison
then the link I provided will help determine build cost and built if their offerings fit.
 
Speaker selection is personal.
Depending on how much I wanted to invest I would want to know my options and they'd probably
be;
One 12" cabinet and two different speakers so I could determine sonic preference.
Two cabinets each to hold one 12" and use two different speakers for same goal.
One cabinet for two 12" speakers- both being the same with plans to get others to hear.
One cabinet for 4-12" and one "tilt" cabinet for 4-12".
 
Size of speakers?
Many different sizes can work based on the design and number of speakers.
I've had cabinets with 6-8" that were fantastic.
 
Whatever it is you're wanting to do...good luck and have fun with it.
 
 

Yeah Spacey, 'building' still is the keyword here.
Admittedly what Avatar has to offer looks very good and if I choose to buy rather than build
I could find what I want there, for sure.
 
But the building project intrigues me. It's the "I did it" factor...
 
I do know I want 2 different speakers for flexibility.
2 small cabs good for flexibility, but 1 cab with selectable input jack for one or the other speaker or both would be acceptable in a larger cabinet.
 
Absolute worst case if I build something and it sounds like crap, I buy a cab and move the
speakers into it.
Wasted the cost of some material... not the end of the world.
As for my time, well if I'm out working in my shop then no matter the outcome, it is never
wasted time to me.
 

Then Mojo is a great place to know about. They have a great selection to help make it a pro looking
cabinet.
I've had beautiful hardwood cabinets (Boogie and Acoustic) that were used for gigging and what a
hassle. I custom made wheeled padded crates to haul and protect them and all the while thinking I
should get a different amp. They would have been better settin' in a studio looking pretty.
So what I planned on using it for would be a major factor in design.
Speakers?...cabinets designed good so that switching them out isn't a problem. ( so front load/rear load considered)
 
I have a mini stack Marshall with 2-10"..and those 10" will sure surprise you in the house.
 
If you do your homework on the speaker (spec's and mounting) and box design it won't sound like crap.
 
 

Dave I think it's popular opinion that you shouldn't build it yourself.
 
 
 
 
 
 

Now I remember more about it (it has been a few years and the book is gone nowadays), and actually Radio Shack had a book out similiar about building cabinets for speakers. The resonance test was for the 15" speaker, and the acoustic engineer (actually like a mechanical engineer or electrical engineer) was talking about building the optimum size cabinet for the speaker. Especially with JBL at the time, there was a range like stated where the speaker in a cabinet would work (without blowing it out or anything like that) and with the 15" speaker at the time I think (I may still have the specs from JBL after buying the raw speaker) it was a cabinet that was at least 1.5 cu ft by 6 cu ft. Imagine a Voice of Theater (without the wood bending horn part of the cabinet) for the 15" speaker. This acoustic engineer said that there was an optimum size cabinet for any speaker. Finding that size would give the best frequency response and of course it was geared more for in that size range of a 15" speaker, a 10" speaker, and bullet ring radiators at the time was a PA system like or even a huge stereo speaker cabinet type cabinets.
 
Anyway, they did print books about any of that, that a person could buy to build a speaker cabinet instead of just - well here it is, hope it works type cabinet.
 
In other words the cabinets they make for speakers are usually just about or at the size needed for the speaker or speakers. Just going by the size of existing cabinets you may turn out with something that sounds good, but then you have to wonder about all the work it involves and getting the speaker grill and whatever that manufacturers can to put it all together anyway. Nowadays it seems as if it is something that is harder to do than it was in the past (unless there are places where they still sell everything you would need.).
 
Wheels on the cabinet to move it around - whatever.
 
Buying a cabinet is usually easier, unless you want to try and imagine or work out what sound from the speaker and cabinet you really want - and some already built cabinets are not going to cut that, and others may be okay, but tweaking the cabinet with the speaker is going to take some engineering work perhaps just learning why cabinets are built the way they are.
 
Using pressed wood to built it, or oak plywood, or whatever wood because density of the wood also plays into the sound of the total package. Wood usually lets through 15% of the sound out the sides and back of the cabinet. Bricks are the about best at 1%. Fiberglass resin hard inside of a cabinet lets out 2% of the sound out the back and sides. That can be found in a Electrical Handbook if a person wants to know about sound propagation and anything like that.
 
What if any of that is necessary to you as a speaker cabinet designer as well as the dimensions of height, width, length of the cabinet and how you want it to look and how functional you want it to be.
 
And then you have to dampen the cabinet with fiberglass and tune the cabinet when it is all done and all of that in the end. Get those little 1.5" D cell batteries to make sure the positive (moves the speaker cone out) is actually what side it is, sometimes those terminal posts are not.
 
Even if you buy a cabinet, it is best (if you want to) to buy the speaker, then do some testing with the speaker and then work out the dimensions of a cabinet suited for the speaker, and then buy the cabinet, unless you want to build a cabinet.

Well, good luck.
 

you know, the beauty of all this is I can build a cabinet and it could be rockin' awesome or it could suk, totally suk, and neither one would really matter because of my lack of talent as a musician...
 
       
 

No matter what you do (after looking at that link provided by spacey) the speaker and cabinet combine to form a system - whether it turns out to be a little Art or exact according to whomever who wants you to caculate these parameters and how it is to sound - it has to satisfy you in the end.
 
Well, good luck!
Here's a link perhaps even good (I did not look at it all the way).
 
The fine art of musical instrument and speaker making, is combining efficiency and power, responding with clarity and evenness, complying within the 3 octave rule, 1 decade.   A musical instrument and speaker may be efficient but uncontrolled which means the sound is colored the notes uneven without clarity.   Many cheap musical instruments and speakers behave this way.   An instrument or speaker may be in-efficient having a flat response the notes even but lacking dynamic expression and responsiveness, requiring to be played harder to be heard.

http://lenardaudio.com/education/05_speakers.html


Musical Education 101 I guess!

 
 
http://www.duncanamps.com..hnical/speaker_cab.html


More links upon searching.