Page 1 of 1

Baffle Board in a Twin.

Posted: 1 Sep 2017 12:04 pm
by Bobby Nelson
Has anyone experimented with replacing the chipboard baffle board in a Twin? I took mine to my amp guy today, and a guy there said that he'd had a cabinet maker change his out (for a good wood I assume, he didn't know and thought it was plywood but, it probably isn't) and was amazed at the difference in tone and loudness it made. He also said it made it heavier which, is not a good thing, but hey, in search of tone ya know. I always heard that old yellow pine made for great sounding cabinets.

Posted: 2 Sep 2017 5:16 am
by Ken Metcalf
Older cabinets are pine and baffle is I think ply.
There are differing grades of ply.
The cabinet wood definitely effects the sound.
Particle board is dead sounding and gets worse with age.
A good cabinet will improve with age.
I have had Rick Johnson build a few Twin cabs.
Good luck

Posted: 2 Sep 2017 8:44 am
by Paul Sutherland
I've used Finnish Baltic Birch ply, 1/2 inch, in several cabinets. I've liked what it sounds like in each case. I bought the best grade I could find from a woodworking/hobby shop nearby. It was expensive. About $30 for enough to do one baffle as I recall.

Posted: 2 Sep 2017 9:06 am
by Jack Stoner
Some Twin baffle boards are glued in. Not sure how to replace one of those.

I installed a 15" K-130 in the Twin I had. I think it was 3/4" plywood - if not it was whatever thickness the Fender board was. The Twin I had was screwed in (it was an AB768 chassis).

Baffle

Posted: 2 Sep 2017 11:06 am
by Brett Robinson
I just went through this while putting a D130F in my '73 Twin. Take it apart, kick/knock the glued in baffle out (I did this by standing on it with the cab face down.) I took three lengths of 2x1 and glued in new pleating. Drilled holes through the pleating and screwed in the new 15" baffle. Glue, C-Clamps, some screws and an afternoon cursing and sweating haha.

Image

Posted: 2 Sep 2017 12:51 pm
by Bobby Nelson
I'm now thinking that if I do anything, I will probably have a new cab made. At the moment, I'm having the new K-120s put in - they seem to be twice the weight of the original Fenders. This thing is gonna be a beast to carry around and, I'm going to be 56 this yr (and not getting any stronger haha)so, I'm actually thinking about having the head and spkrs separated.

Ken, you said that you had Rick Johnson build some cabs and liked the work? I'll goggle him. I emailed Larry Rodgers yesterday but it didn't seem to want to go through.

Again, thanks for the info fellas.

Posted: 2 Sep 2017 2:11 pm
by Jack Stoner
Rick Johnson is the man for cabinets.

My Twin came with JBL D-120F's. I was 29 so I could carry it. Over 90lbs. The one K-130 didn't make a lot of difference in the weight.

Posted: 3 Sep 2017 1:20 am
by Tony Prior
3/4 ply would be best. The glued in baffles are a bear to remove, but like seen above, can be done. Using the proper tools of course and working very S L O W L Y

The glued in baffles are indeed fiber board, I think the glued in period started around 71 or so, that era.

Posted: 3 Sep 2017 4:09 am
by Chris Boyd
Bobby.... Larry Rodgers passed away a year + ago...very sad..a wonderful guy who built a few birch ply/aged grill cloth baffles for me and countless others..

Posted: 3 Sep 2017 11:56 am
by Bobby Nelson
Boy, I'm sorry to hear that Chris. Yeah Tony, mine is a '73. I've got an email into Rick Johnson. Thanks guys.

Posted: 3 Sep 2017 9:20 pm
by Steven Paris
I am curious as to why the change from 2 x 12" JBL D120 to 1 x 15" JBL D130. What is the difference in sound?

Posted: 3 Sep 2017 10:52 pm
by John De Maille
I had a 72' Twin, that, I replaced the front baffle with a piece of 3/4" Marine Plywood.
I didn't pay for the piece, I had it laying around my shop at the time. I installed a 15""
JBL E-130 and it never sounded better.

Posted: 4 Sep 2017 1:21 am
by Godfrey Arthur
change from 2 x 12" JBL D120 to 1 x 15" JBL D130. What is the difference in sound?
Pine does lend itself to a tone on a cab but the best thing you can do is get the baffle board the stiffest it can be where the practical thing is multi-ply void-free birch or apple wood.. 13-15 plies is about right.

Press board used during the cost cutting days at Fender did not improve the sound of the amp. MDF is a better choice over press board as there are grades of MDF.


Image

You can see that press board (particle or chip) looks like oatmeal compared to MDF.

MDF is said to be Radiata Russian pine powdered and mixed with adhesives.

Ideally slate would do a great job of the speaker not doing acoustic work on the cabinet, sort of like a high jumper using a board that had loose screws for lack of a better analogy, the launch would be sloppy.

But slate is heavy.

Another good ply is phenolic which is used for boats and cement molds. It's waterproof. The resin used in between plies is actually denser, sticky and lasts longer than basic Finnish birch. Cutting phenolic will dull blades in a jiffy.

Image

Phenolic water proof ply


Using a 1x15 gets a composite sound, more lows, not canceled out by two speakers (2x12) sitting next to each other. Works for steel.

And actually with more than one speaker you get a shift of frequencies from one speaker to the other, meaning each speaker does not react the same way, not unless you match them choosing from dozens that sound close to the same. That said you can use two different model speakers in a multiple speaker cab to get different responses from the different speakers.


I built a custom Twin type cab out of pine for my Dual Showman Reverb amp head and mounted a new Fender 15".

Posted: 8 Sep 2017 3:04 pm
by Bobby Nelson
That's a lot of good info Godfrey - Thanks. I just picked up my Twin w/the JBLs from my amp guy and, it is a beast! I Talked with Rick (a very nice guy!) and, when I get a little paid down, I'm definitely having him make two cabinets for it - for tone and weight. Thanks for all of the replys fellas - Ya'll gave me the info I needed.