Building a Speaker Cabinet

[Andre S]

I plan to use white pine, and build 2 212 cabs. I will base the plans on the Marshall 1936 cab. I picked up some tools to aid in the finger jointing by hand.

 

How important is internal volume in the sound for a closed cab?

Are dimensions less important for an open backed cab?

[surfpup]

I plan to use white pine, and build 2 212 cabs. I will base the plans on the Marshall 1936 cab. I picked up some tools to aid in the finger jointing by hand.

 

How important is internal volume in the sound for a closed cab?

Are dimensions less important for an open backed cab?

 

Not sure what you mean? If you are modeling the dimensions after the model 1936, why are you asking about internal volume?

The 1936 is a pretty large 2-12 but not massive. Or are you wanting to make them smaller? You can build a smaller 2-12 and have it be a sealed cab, if that is what you are asking.

[Thundergod]

You should at least leave 2 inches between speaker and speaker and between speaker and cab wall. That's as small as you can get.

[Andre S]

Not sure what you mean? If you are modeling the dimensions after the model 1936, why are you asking about internal volume?

The 1936 is a pretty large 2-12 but not massive. Or are you wanting to make them smaller? You can build a smaller 2-12 and have it be a sealed cab, if that is what you are asking.

Sorry, I should have clarified.

 

I am planning to use the 1936 dimensions unless I can find a smaller set.

 

I was asking about the internal volume, speaking generally, just wondering how it affects the speaker, for my own knowledge.Although I was hoping to find a slightly smaller size because I want to make two. From what I hae seen though, the Avatar cab is similarly sized.

 

Funnily enough a 412 would be smaller, if the two 212's were stacked ontop of another or even set out side by side.

This is kind of me trying to start the foundations for my dream rig.

[MrNylon]

Go to the Mesa Boogie site. Look at the the cabs there. They off-set the 12' speakers.

[cornflake]

You need to ckeck the specs on the speekers for enclosure size and weather you need sealed, ported, or free air(open back)

[Andre S]

Well in that case, I am unsure of which speakers to buy. I know I should buy speakers with at least twice the wattage of my amplifier. However is there a standard ohm rating for the bigger tube amplifiers? Are they all 16 ohms? or does that vary between amps?

 

As I said, this was the beginning to my dream rig, and the way I want to run it, is one amp to one speaker, so two amps to one speaker cabinet (or some slight variation on that)

The maximum wattage of amplifier I would buy is 50W. So that means I need at least a 100W speaker. Of course I wanted to use Celestion V30's but they are only 30W.

 

Can't I build it so that the back of the cab is removable, allowing me to convert it from an open to closed back cab?

[damian]

You have a lot of questions here....I prefer sealed cabs..As T-God said, the speakers need SOME room to breathe...Yes, you can build cabs so the back is removable..Two sealed cabs with 2X12s each IMO is preferable to one 4X12 cab...Study up on ohms etc....Series vs parallel wiring..One is preferable to the other...Guitar cabs can be front ported, but, study the science first...V-30 speakers are fine..They can handle much more than 30 watts...Cabba will probably recommend Weber speakers..Good choice....Do a lot of online research before you build....If I had the right folders here, I'd add more....Each aspect of building your project requires in-depth research...It's not that hard....Getting the ohms right is important.......50 tube watts is a lot these days........just some thoughts...There's tons of info online; tons.......

[Andre S]

You have a lot of questions here....I prefer sealed cabs..As T-God said, the speakers need SOME room to breathe...Yes, you can build cabs so the back is removable..Two sealed cabs with 2X12s each IMO is preferable to one 4X12 cab...Study up on ohms etc....Series vs parallel wiring..One is preferable to the other...Guitar cabs can be front ported, but, study the science first...V-30 speakers are fine..They can handle much more than 30 watts...Cabba will probably recommend Weber speakers..Good choice....Do a lot of online research before you build....If I had the right folders here, I'd add more....Each aspect of building your project requires in-depth research...It's not that hard....Getting the ohms right is important.......50 tube watts is a lot these days........just some thoughts...There's tons of info online; tons.......

Its not so much a matter of how many watts I want. I know the amps I want to get, so I have a rough idea of 50W maximum. I am already familiar with the difference between series and parallel wiring and the importance of matching the ohm rating.

The actual construction is not a problem, I have some experience in woodworking.

Why do you say that 2 212s are preferable to a 412? Transport?

[MrNylon]

Jensen and JBL speakers are good 12's also.

[Andre S]

Jensen and JBL speakers are good 12's also.

 

Yea, I was looking at Eminence, Weber, Celestions and Jensens.

 

I'll check out JBLs too.

 

I guess I don't need to make the final speaker decision till after the cab is constructed if I make it with a removable back.

 

I believe my JCA12S has a removable back.

[damian]

Its not so much a matter of how many watts I want. I know the amps I want to get, so I have a rough idea of 50W maximum. I am already familiar with the difference between series and parallel wiring and the importance of matching the ohm rating.

The actual construction is not a problem, I have some experience in woodworking.

Why do you say that 2 212s are preferable to a 412? Transport?

 

I might get slammed here from a techy angle, but....IMO two speakers in a cabinet 'play' nicer together than four speakers in a single cabinet...The sealed air in a 2X12 cab is going to give a nice tight sound...Unless one is really loud, there IMO is too much air in a sealed 4X12 cab...The speakers end up fighting each other..So the sound muddies up quicker, and is less definded..This is somehow scientifically correct, but I don't know or how why..Transport as well, but I'm talking strictly sound wise..Two 2X12 cabs will also let you use two types of speakers in the seperate cabs for a fuller sound as well; in addition to angling them differently per show requirements..If the object is tone, two 2X12 speakers pushing nice tight controlled tone is IMO more definded than a single 4X12...IMO, a 4X12 cab at lower volumes can muddy up, as the sealed air doesn't make them work hard enough to produce CONTROLABLE tone..This is from years of experience, and is only IMHO...I find my homemade 2X12 cabs pushed loud sound much better than any of my 4X12 cabs; once again, IMHO...If I understand your plan, you want to use two tube amps; if this is the case, running each amp driving it's own 2X12 cab opens you up for an incredible variety of tone options, as well as running one set cleaner than the other; mixing a cleaner set with an overdriven set of 2X12 speakers IMO solves many of the problems of 'Am I too distorted?' and related issues..Strictly in my opinion...The other school of thought is to allow speakers to breathe via an open back, or semi open back...Perhaps it's all a question of personal taste...A common mistake is also not angling speaker cabs up at an angle at gigs...The sound one hears onstage being close to one's amp and speakers is a lot different than it sounds some feet away in the audience..Anyways, that is IMHO...

 

Another thought; maybe you find your Jet City a bit bright because it's a single 12 in a sealed cab...SOMETIMES a single 12 in a cab likes to breathe, producing more bass out the backside.......

[cornflake]

If your going to use white pine for the box and you want a removable back try Lexan for the back if you want more low end punch or MDF if you like more mid. I beleave if you make the whole box out of pine your highs will scream but the lows will be muddy

[damian]

If your going to use white pine for the box and you want a removable back try Lexan for the back if you want more low end punch or MDF if you like more mid. I beleave if you make the whole box out of pine your highs will scream but the lows will be muddy

 

I think his plan is white pine.......I use strictly birch plywood myself....but, ...

[Andre S]

I might get slammed here from a techy angle, but....IMO two speakers in a cabinet 'play' nicer together than four speakers in a single cabinet...The sealed air in a 2X12 cab is going to give a nice tight sound...Unless one is really loud, there IMO is too much air in a sealed 4X12 cab...The speakers end up fighting each other..So the sound muddies up quicker, and is less definded..This is somehow scientifically correct, but I don't know or how why..Transport as well, but I'm talking strictly sound wise..Two 2X12 cabs will also let you use two types of speakers in the seperate cabs for a fuller sound as well; in addition to angling them differently per show requirements..If the object is tone, two 2X12 speakers pushing nice tight controlled tone is IMO more definded than a single 4X12...IMO, a 4X12 cab at lower volumes can muddy up, as the sealed air doesn't make them work hard enough to produce CONTROLABLE tone..This is from years of experience, and is only IMHO...I find my homemade 2X12 cabs pushed loud sound much better than any of my 4X12 cabs; once again, IMHO...If I understand your plan, you want to use two tube amps; if this is the case, running each amp driving it's own 2X12 cab opens you up for an incredible variety of tone options, as well as running one set cleaner than the other; mixing a cleaner set with an overdriven set of 2X12 speakers IMO solves many of the problems of 'Am I too distorted?' and related issues..Strictly in my opinion...The other school of thought is to allow speakers to breathe via an open back, or semi open back...Perhaps it's all a question of personal taste...A common mistake is also not angling speaker cabs up at an angle at gigs...The sound one hears onstage being close to one's amp and speakers is a lot different than it sounds some feet away in the audience..Anyways, that is IMHO...

 

Another thought; maybe you find your Jet City a bit bright because it's a single 12 in a sealed cab...SOMETIMES a single 12 in a cab likes to breathe, producing more bass out the backside.......

 

I understand what you are saying and it makes sense.

Initially once the cabs are done and I buy another amp, I will use one amp per cab.However in the long run, I plan to use two amps per speaker cabinet~one amp per speaker.

I did find the JCA20 to be ear splittingly bright, but after some tweaking, it doesn't sound like that again.

[cornflake]

I think his plan is white pine.......I use strictly birch plywood myself....but, ...

Yeah that would be my choice too butI dont know alot about this Ive built a few hundred custom sub enclousers Youknow we mostly use MDF . Im trying to knock the windows out of the guys car there not trying to Rock Out

[Andre S]

I think his plan is white pine.......I use strictly birch plywood myself....but, ...

 

I can't get that type of plywood here. I've checked two places and they don't have Baltic Birch ply. I have one more place to check tomorrow. If I can't get it then I will use the white pine and unknown ply for the back and the baffle.

[Andy R]

I can't get that type of plywood here. I've checked two places and they don't have Baltic Birch ply. I have one more place to check tomorrow. If I can't get it then I will use the white pine and unknown ply for the back and the baffle.

 

 

Hmmm So my question is why build? There are a ton of different 2 /12 boxes out there. Why not try them out and see what you like. One thing about an open back is it will never sound the same anywhere you go as you are depending a lot from the reflection of what is behind the cab and the distance to a solid surface. Come to think of it you coud just buy a decent used 4/12 and cut it in half! If you went with a straight cabinet you could have two matching boxes or if you went with an angle could have a cool little 2/12 angle cab.... Just throwing it out there!

 

 

How many ply is the white pine Plywood your looking at? Or are you talking about building them from solid white pine? Solid woods are definitely not recommended for speaker enclosures. To build something decent and get good finger joints you will need a high ply like 15 ply baltic birch....

 

 

 

[Andre S]

Hmmm So my question is why build? There are a ton of different 2 /12 boxes out there. Why not try them out and see what you like. One thing about an open back is it will never sound the same anywhere you go as you are depending a lot from the reflection of what is behind the cab and the distance to a solid surface. Come to think of it you coud just buy a decent used 4/12 and cut it in half! If you went with a straight cabinet you could have two matching boxes or if you went with an angle could have a cool little 2/12 angle cab.... Just throwing it out there!

 

 

How many ply is the white pine Plywood your looking at? Or are you talking about building them from solid white pine? Solid woods are definitely not recommended for speaker enclosures. To build something decent and get good finger joints you will need a high ply like 15 ply baltic birch....

 

The local music stores, don't have any cabs. They all sell the combo amps, with the exception of one who sells a Marshall 1960A cab. Its the same with the guitars which is why I can't play any model before I buy it.

 

Why build it? When I brought in my JCA12S, freight and duty cost me $200 USD for a cab that: only cost $65 US and weighed about half of, a 2*12.

 

Shipping would be too much.

 

Its not white pine plywood, I'm using solid white pine, like the older Fender amps for the cab, but I am using 1/2" 5 layer ply for the baffle and the back of the cab.

My reasoning for using pine, which can colour your tone, is that it would add slight characteristics, to distinguish my tone. Instead of using ply which would reflect all the sound and not really colour it, I think the cab should make its own subtle differences to the tone.

[Dub-T-123]

If it were me I'd put two different speakers in each cab.

[Andre S]

If it were me I'd put two different speakers in each cab.

 

I may. I may do the whole Eric Johnson thing, and put different speakers in each, or if I am using one cab for one amp, then I will use different speakers to as he said, to fill in the EQ>

[MrNylon]

If you were to use a 4X12 cab, it would sound good. The catch with a 4X12 cab, it needs a pretty good amount of power from the head to keep it clear. That's where you're muddy sound comes in with the 4X12 compared to the 2X12. Try to go with almost any good type of plywood over the white pine too. White pine doesn't even sound that great with bass cabs, and with a bass cab you can get by with a touch of off clarity.

[Andre S]

Really? Any plywood? 3/4 "? I thought that low grade plywood wouldn't be good? I believe its all construction grade, not the nice marine grade birch plywood.

[MrNylon]

Yes of course marine grade plywood. Birch if possible. White pine though isn't really that good. That's what I meant to say, a good grade of plywood. Don't let any one talk you into ply-board instead.

[MrNylon]

Definitely go to the Mesa.com site to see the inner construction of their cabs. They really are some of the best built and designed cabs anywhere.