Grateful Dead Music Forum

A place to talk about the music of the Grateful Dead 

Chat about Equipment Info
 #28249  by High Peaks
 Sun Oct 28, 2007 5:28 am
Im going to build 2- 12" cabinets for my jbl's. I have 4 e120's (2 for backups) and currently have a 2 x 12" cabinet. The problem is that it weighs more than i care to handle.

My question is what are your thoughts on the advatages in tone for open back, and closed back cabs.
I currently have a closed back.

I know that open backed cabs cut down the longevity for speakers. And at $200 a pop to have them re-coned with JBL parts is pretty steep.


 #28252  by phpbb
 Sun Oct 28, 2007 5:58 am
For anyone who is interested in Building Speakers, I highly recommend the following book:

Loudspeaker Design Cookbook by Vance Dickason.

This book walks you through how to determine the best options for a box for your speakers (from sealed or ported boxes to transmission lines), from simply using the specs of the speaker to measuring the actual responses and designing it from there. Without this reference, you are just guessing.

 #28265  by strumminsix
 Sun Oct 28, 2007 9:12 am
Hmm I just wrote about this the other day either here or on the Gear Page...

Closed gives you a tighter more punchy sound - great for harder and edgier rock. Very focused and directional. Sound moves forward only.

Open gives a fuller open sound. Less focused and directional. Sound radiates around the box.

I prefer all my cabs open and I've tried both ways. Never have I found a closed back that I liked.

 #28290  by tigerstrat
 Sun Oct 28, 2007 2:16 pm
My primary stage cab is an odd little 1x12 half-back I scored at a used gear store about 10-12 years ago. It's a Tubeworks cab but it came with a "Mesa Black Shadow" EVM-12L speaker (I now use a JBL E-120)

A couple of years ago, in the open part of the back, I wedged a 18x18 square of a piece of material that had been part of the packing material from a shipped Bag End replacement speaker: a 1" thick soft-fiber (wool?) cab insulation material, apparently what Bag End uses to line the inside of their cabinets. Anyway, it sits wedged in there nicely and helps keeps moisture and dust etc from entering the back of the cab, but it still sounds like an open back speaker.

 #29507  by betteroffdeadnc
 Fri Nov 09, 2007 7:21 am
My favorite of all cabinets I've used, and unfortunately no longer have, was a Mesa Boogie 2x12 that had a fully closed-backed bottom section and open-backed slant top section. I had a JBL D-120f in the top and a Electrovoice EV12M in the bottom. It was an incredibly well balanced cab and sounded great with all of my amps. Today I use an assortment of combos and Fender cabs. I'm in the process of opening the back of one of my closed-back 1x12s to use along with one of my other closed-back 1x12s, both loaded with JBLs to find that balance again. Due to physics, closed-back cabs have a nice tight, well defined bottom, and open-backed cabs a better high-mid, and high end in addition to the ambience and dispersed sound. The bottom end of open-backed cabs is loose, and weak in comparison to that of closed-back cabs.