Cabinet Experiment (lots of pics)

[NTBluesGuitar]

A little history...

Had one of my friends here selling their Hot Rod/Tweed Pro that I did a re-build on, and in an effort to help, I made myself available for all questions about the amp (since I did the work on it). Ended up getting an e-mail from someone who said "Everything in the build seems to be first rate. My concern is the (cheap?) cab. Wouldn't you agree that a solid pine cab would greatly enhance the tonal quality of this or any amp?"

Well, I don't subscribe to the cabinet tone-wood theory, personally; my belief is simply that the only component that affects any sound significantly is the baffle, since it holds the speaker. That, and shape/size/backing of the cab, but not the actual wood.

But in the spirit of experimentation, I went about in testing my own theory.

Got with a co-worker/buddy of mine who loves to do woodworking on the side to see if he'd be interested in the cabinet build. Having a musical background as well he was more than excited to try. So we set out and did some in depth measuring and replicating of a stock Hot Rod Deluxe cabinet with true-to-form Tweed Era Narrow Panel construction.

Started with the standard 1/4" box-jointed cabinet assembly:







Finished off all the parts with the appropriate birch ply baffle, narrow panels, and rear panel:





Drilled the holes and did a dry-fit of the chassis:





Paint the baffle black:



...continues in next post.

[NTBluesGuitar]

...continued:

Tweed it up and do some grill cloth (yeah I have some of the tweed cut wrong and the stripes go in the wrong direction...but it's a prototype and I didn't want to use more than one piece of tweed for this):







Some shielding on the back panel and put it all together:







And the finished product:







So far, I have found that a solid pine build shaves off a full 8 pounds off the stock MDF cab. It weighs in at 15 pounds, where the stock cab comes in at 23 pounds. Also, we ended up with an extra 1/8" in interior width, so theres a bit of a gap, but it's the only error, I'm sure it's not going to hurt anything.

Soon, I'll give it some play time and see if I notice any sound changes/improvements.

Thanks for checking this one out...I'll report back when I get some time with it.

[Kap'n]

8 pounds! Very nice indeed. I await the tone report.

[FrankJohnson]

Holy Schnikey!

I know A guy who wants to talk to you about discussing cabinet assembly methods - speaker only - not for the Amp! How would be the best method to put this together? Same finger joints? I am ignorant about cabs......

and with the baffle, what part does it play other than actuall holding the speaker?

[Gris]

Absolutely will make a difference. The cab is part of the 'instrument.' How much of a difference depends upon what cabs you are comparing, what volume you are playing at and how good your ear is. With non-pedal tweed type amps I like a thinner baffle.

'Frank' the baffle vibrates like a speaker cone - IF thin enough.

[phantomman]

and with the baffle, what part does it play other than actuall holding the speaker?

Theoretically there will be some residual resonant undertones as a result of the mechanical coupling of the speaker to the baffle via the flange gasket (the cork stuff at the edge). These undertones will be transferred to a lesser extent to the cab itseff. Thus the cab's resonance will play some small role in determining how the amp and speaker sound in combination.

It's sorta like the same principles of a guitar's material composition determining how "bright" or how "dark" it sounds. Thus, maple on a fretboard generally sounds "chimier" than a similar instrument with a rosewood slab. Lotta factors in the sonic footprint of an instrument or an amp.

HTH

[jfab]

Gorgeous looking cab, NTBG! Excellent craftsmanship and beautifully done. I wouldn't even have noticed the tweed's direction had you not mentioned it. Kudos!

[Offshore Angler]

It's sorta like the same principles of a guitar's material composition determining how "bright" or how "dark" it sounds. Thus, maple on a fretboard generally sounds "chimier" than a similar instrument with a rosewood slab. Lotta factors in the sonic footprint of an instrument or an amp.

HTH

Ya'know, I've never experienced that. In fact, rosewood is harder than maple and we would tend to believe it would be brighter and snappier. The fact that rosewood is unfinished tends to make me believe that people think it is softer and warmer.

I think it's purely psychological. Did you ever notice people don't say rosewood sounds fuller, deeper, or warmer. They say it sounds "darker". I always chuckle at that.

[phantomman]

Uh Jeff......who's the "goliath" with the smurf-sized guitar in yer avatar?

[FrankJohnson]

It makes sense.....like an acoustic body resonates.....

[Mesotech]

Just curious (beautiful work on the cab BTW), but why would you bother to tweed and grill cloth a prototype cabinet just to see how "construction and build material" affects the tonal sound quality?

Does tweed sound better than Tolex, and does grill cloth really make a difference in tone or is it there just to protect and hide the speaker face?

Not dissing the workmanship, it's top notch, but it seems a bit overboard for an experiment.

[NTBluesGuitar]

Just curious (beautiful work on the cab BTW), but why would you bother to tweed and grill cloth a prototype cabinet just to see how "construction and build material" affects the tonal sound quality?

Good questions...all of them. There are a lot of other reasons I'm doing this, but the initial inspiration was to see if a pine cab really affected the sound overall in a really significant way.

Another reason behind this was that my buddy wanted to try his hand at an amp cabinet build and I thought this was a great project to go with as a practice run (he's doing my BF Vibroverb repro cab as well for me). Also, I wanted more practice doing cab covering. Keep in mind that this sort of project is right up our collective alleys and it was a lot of fun all the way through for me and my pal. Wood is cheap, covering and hardware wasn't too bad, so I'll be turning a profit once I sell the original cab off.

This project is really no trouble at all and I'm coming out ahead in all kinds of ways, I believe.

That said, I know that there is going to be a difference in sound, but keeping in context of the original statement: "Wouldn't you agree that a solid pine cab would greatly enhance the tonal quality of this or any amp?" my question is: Would having an amp re-built hand-wired and to classic specs suffer from being in a cheap, MDF cab?

Gris, thanks for what you've said about the baffle thickness. A good point.

Along those lines, the original HRD baffle is birch ply, so we're comparing pretty much the same thing, housed in an enclosure of the same dimensions, but made from pine. I have the same speaker in there and I know the amp, so it will be interesting to see how it sounds to me as I get to know it.

Overall, I thought this experiment is, at the very least, extremely interesting, if not valuable in what is learned from it. Hell, eight pounds off just for the wood treatment? I found that VERY interesting.

There's all that, and I got tired of the black and silver color scheme and wanted a tweed cab for my baby.

Thanks for the interest, guys. Still haven't had a chance to play it yet....

[Cygnus X1]

Outstanding work, NT!

Who can direct me to a good place to learn how to do a box joint?
I get lost...and people say it's "easy".

[cdw2000]

With my project amp currently in a very heavy MDF cabinet, I'll be very interested in your conclusions on the tonal differences (or lack there of) of the pine cabinet versus the MDF.

Great work on the cabinet, BTW!

[Gris]

The original Fender tweed baffles were 3/8 spruce ply. I have an Gibson cab w/ baffle like that. It sings... :-)

[Kap'n]

I'd venture a guess that the depth of the box (front to back) would make a bigger sonic difference than the actual composition of the sides, by increasing the dimensional volume.

But of course, I'd like to hear your opinions once you do some testing.

[Dale]

I have found that box dimensions tend to be most important. I have 3 solid pine cabs I have built and one ply. So I am pretty new at it though. For some reason I have also found I tend to like very solid baffle boards made of solid wood. I use more of a tight butcher block type board 1/2" thick made of 2-3" pieces to keep things from warping. I am not really into vintage though, it is just for what I like. I do not know how much that affects things really. I tend to connect the baffle very solidly to the box as well. My favorite cab is a 1x12 of 1/2" pine (see avatar) that is about the size of a twin. It is white blonde. I used Lock Miter Joints for on it. (http://www.woodcraft.com/product.asp...FamilyID=3596). It seems, in my mind anyway, to transfer the energy more directly to the cab itself.

[NTBluesGuitar]

Hey, Dale, that's some great info.

Nothing wrong with it if you like it! Can't say I've heard of much Lock Miter Joint cabs...so it's really original.

Very cool.

[jfab]

Uh Jeff......who's the "goliath" with the smurf-sized guitar in yer avatar?

Hahaha, been working out a lot lately, so I am HUGE. LOL! That was during a Guitar Hero session at the GF's parent's house. Thought it was good for a chuckle or three...

[phantomman]

Sh*t, I thought it was Pete Townsend in his younger SG/Hiwatt days!

Guess I need to git my bi-fokes checked, eh......?

[LGS]

That's some mighty fine joinery NT. Did you guy's use a table saw for that? If you aren't careful, your gonna find yourself in the amp business!

[NTBluesGuitar]

I wasn't there for this cab build, but I believe that my buddy used a table saw w/box joint jig. Not sure how complicated the jig was, but this is a guy who makes his own furniture pieces from time to time, so I was not surprised just how well his box joints turned out!

[NTBluesGuitar]

Oh...and for the initial sound report:

I had about 30 minutes to play the amp this morning while the wife and kids were out at the store. My initial impressions is that some of the muddiness in the lower half of the spectrum has been improved.

Overall, I'm hearing a clearer, more defined high-mids and low mids. There's a slight emphasis on the overall mids, but it could be the muddiness being cleared up somewhat doing this. I'm playing the amp on carpeted concrete flooring with the amp's back about two to three feet away from a wall.

I used my new CV Tele.

I like the bit of added clarity (or shift upwards of the emphasized sound spectrum). Would I drop $250 on a cab like this to attain it? Well, I'm not a recording player, so probably not. However, if I was doing a lot of session work I would do this to gain the difference I heard.

It was a slight difference, but to a really sensitive ear and discriminating player, it could seem more significant. Putting it up against my theory, I'll say that the pine cab did not radically improve the sound. It did change it a bit, as expected, but the original cabinet was not causing the amp to suffer outside of a hair of low-middle muddiness.

Just my pair o' pennies. YMMV.

[Kap'n]

Very interesting. Same speaker used? Was one out of the box, vs. broken in?

[NTBluesGuitar]

Same exact speaker and amp. Just moved everything from the stock cab to the new pine cab.

Again, the difference is slight, and I think it's one of those things that is more significant the more sensitive an ear one has.

[Gris]

You used too thick a baffle for the true tweed combo sound IHMO.

[NTBluesGuitar]

Really? It's about 1/16" thinner than the Hot Rod baffle.

Also, you'll have to consider that this is Hot Rod iron, too. A PT designed for full-wave rectification, etc., that I worked in a Copper Cap.

True tweed was not something I expected with this build, but Tweed-like is. And, I'm doing my best to compare as directly as possible for the pine.

[Gris]

yeah, i understand what you were doing. but i think you should have used a 3/8 (spruce?) baffle with each. i think the pine cab doesn't work the same with a thicker cab. i.e., i think the box and baffle are 'intedependent.' but i agree with your overall assessment - that it a somewhat subtle thing - dependent upon volume, etc.

FWIW, personally i like big monster mag alnico speakers. so i usually end up with 0.5" (or better) baffles.

[NTBluesGuitar]

We did use 3/8" birch ply, but not sure what exact wood it was. I know it's not baltic birch ply, but I ran the idea of spruce birch by my buddy, and we'll see what the cost is.

Another idea I have is to make the same cab, but taller for a 15" speaker.

[cdw2000]

So how does the pine cab differ dimensionally from the original cab? Just curious.

I would also love to know how your buddy did those box joints. If you could get some more detail on how he did that/what jig he used, I'd be grateful.

Thanks for sharing this project/experiment.

[NTBluesGuitar]

Dimensionally, it's as identical as we could make it. I think an erroneous cut line gave us an extra 1/8" width, and not factoring the feet into the height (measured from the floor once instead of turning the cab on its side and measuring the side directly) gave us an extra 3/8" in height.

I'll talk to my buddy again soon (we're on break from the university, so I won't see him for another week), and talk about what he used. Maybe on the next build, we can get some phtots.

[LGS]

I just went through all the joinery stuff on my 5e3 cabinet. I used a table saw, and this jig:

http://www.sawdustmaking.com/Box%20J...xjointjig.html

It turned out okay, but not as good as this example here. I used a 1/2 dado, and a really cheap saw. After seeing this I think I a going to start over again.

[Dale]

Find out what sort of jig was used NT. I would be interested to know on this one. Those joints are amazing.

[stratcat55]

TJ you are truly an outstanding craftsman! Beautiful job.

[NTBluesGuitar]

Find out what sort of jig was used NT. I would be interested to know on this one. Those joints are amazing.

Well, I talked to my buddy this morning, and apparently, the jig wasn't very complicated because he already destroyed it! It was just a simple peg-and-board type jig.

He wants to make a better jig.

[Dale]

I want to be able to be as good with a system as he is! Better how? Have it glue itself? :-)

[gooman]

WOWY

[Wilko]

Pegs are the good old fashion way to make that joint.

Very "new Yankee Workshop"

[NTBluesGuitar]

I want to be able to be as good with a system as he is! Better how? Have it glue itself? :-)

Ha! Better as in more solid, maybe? Different jig material? I'm not sure as I need to see what he used before. I've done a cab before with someone else and we used a real rudimentary box joint jig; it took a long time to dial in, though.

I'll do my best to get a shot of the new jig for the next build he does for me.

[hippiebob01]

lookin good TJ!