Yet another 4x12 angle cabinet project | Warehouse Guitar Speakers

Yet another 4x12 angle cabinet project

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Wm Anderson
02/10/2018 11:37am

Hi Vaughn,
I’ve scoured the WGS archives, and I’m ready for your feedback on my project.
After procuring detailed plans off of the web, I’m building a Marshall 4x12 angle cabinet.
I snapped up the brief Sweetwater DSL100HR $749 deal before they raised it to $899. I knew that was coming.
After all of the WGS archive reading I've done, I have 3 ideas for the project:
- Either HM75/Retro 30 or ET65/Retro 30 in an X-pattern
- Make a 5 piece back, with 7” openings horizontal across the speaker magnets similar to my Fender Twin Reverb. This would also allow me to open it completely or close it completely.
- You’ve also mentioned many times that a multiple speaker set up with each speaker in its own cabinet sounds great. What about a divider inside of the 4x12 to create such an effect?
Thoughts? Please influence me before it’s too late!! :^)
Bill A

Wm Anderson
02/20/2018 5:42pm

So any thoughts on having a divider in an open backed 4x12?

06/13/2018 1:50pm

internal dividers will alter the early reflection comb-filtering effects and the cab resonance. Four cubical chambers with a center-mounted speaker each will likely reinforce only one early reflection delay time heard as a resonance freq equal to ~2x the distance from the speaker cone to the cab rear, and one cancellation freq equal to ~4x the distance. Whether it's better or not is anyone's guess and depends on the speakers, the cab depth, etc. Maybe try one removable horizontal panel and experiment with dividing the top and/or bottom speakers with removable panels. You'll probably want some foam or silicon on the panel edges to damp audible vibrations. Account for the edge sealant in your panel measurements. You could screw/glue blocks to the panel sides to anchor the rear panel to.

Openings at the cab edges will reduce internal ER's more than across the magnets. High pressure air moving in/out of the very thin spaces between panels may cause asymmetrical cone movement. FI, air could be more pushed out than in creating an intermittent vacuum causing audible pitch/volume modulations as the pressure changes. That might even damage the speakers. I'd try one closed panel, maybe with set of "pressure equalizing" holes tuned well below the guitar range, and use two thinner panels you can affix either at the cab edges or across the center that leave the back ~1/3 open.

Wm Anderson
02/21/2018 12:37pm

Thank you Narcoleptigon_47048 for the very informative reply. While making the mods for the changes and experimentation is to me easy and well within my wheelhouse, it sounds like any possible success would most likely be minimal and far more trouble than the effort is worth, and most likely a waste of time.

In this case thinking outside the box about inside the box may not be worth it.!! ;^)

02/21/2018 3:35pm

Okay, definitely go with the ET65/Retro 30 combination. Since you'll be running it semi-open back (good!!) don't bother with the hassle and weight of dividing the cabinet internally :-)

02/22/2018 1:12pm

Agreed. Seems like a waste of time. The 4x12" cab concept is not a smart design. Have you considered a 3x12" cab? A tight triangle configuration disperses high end essentially the same as a single speaker. You should be able to hear up to ~4kHz at 20d off-axis compared to half that with a 4x12". Perhaps you can configure the cab dimensions for an Rs of 140Hz like the infamous 1x12" "AX84" cab? You could use three different speakers that mix well and flip the cab depending on which you like on top. You would of course need one 16 Ohm and two 8 Ohm speakers.

Wm Anderson
02/22/2018 4:55pm

Narcoleptigon_47048, I've already started the 4x12, but plan on building others. I'll try your suggestions and play around. I'm spending my kids' inheritance!!

VAUGHN, I already bought 2 each of the HM75, Retro 30, and ET65 to play around. I'm spending my kids' inheritance!!

VAUGHN, you ever run into my daughter Elise ( She also worked at The Tracking Room years back for Dan Mitchell.

02/22/2018 7:57pm

Well, you don't want the bill's to get stale do you? ;)

On second thought, I'd use all the same Ohm speakers in a 3x12" cab so the power is distributed evenly. It may balance well with a slightly higher Ohm 4x12", and with better high end dispersion placed on top.

02/25/2018 6:01pm

Hummm ... don't think so ... but I did work at the Tracking Room a lot from about 1990-1994 so I might have ran into her...

Wm Anderson
05/12/2018 10:13am


I got the cabinet completed, here's a link to some pics (I added the last 2 screws in the jack panel and plugged into the speakers after shooting the pictures, oops)


05/14/2018 5:11pm

Bill! Is this what you do as a profession? That looks flawless. Man ... a 1/3-open back vintage Marshall cab with basket weave grill ... who DOSN'T want one of those??!!??

Let us know how it sounds. As I've stated before, the HM75's never worked for me ... but in that particular combination, I could see good things...

Wm Anderson
05/14/2018 5:45pm

Thx for the compliment!!!

Nope, my first cabinet build. I built the middle piece for the back just in case as well. It really was a lot of fun.

But, I've been building things my whole life: models and balsa wood airplanes as a kid in the 60's, street rods & drag race funny cars, 8 years in tool & die in the 70's, 35 years as an electronics engineer, and on and on...

I think it sounds great, but then that's me...