Converting a closed back guitar speaker cabinet into an opened back Cab

Posted by Guy Capuano - October 21, 2011 - Classroom, Gear Reviews - 1 Comment


The difference in tone between an opened back cabinet and a closed back cabinet can be very dramatic. An Opened back cab gives more of an airy, full, opened type of tone, but can lack a strong bass presence. A closed back cab can give a very strong, chunky tone with a strong bass response, like a good kick in the chest. Of course these statements are just generalizations and can vary with different situations as anything may when talking about tone. Whether one is better than the other is completely a preference issue, but I prefer opened back cabinets. Recently I came into a situation where I scored a very nice cab off Craigslist in a trade for some pedals that I was not using. The cabinet happened to be closed back, so I decided to modify the cabinet and make it an opened back.

Bugera V212 Vintage Guitar Speaker Cabinet

The Cabinet is a “Bugera V212 Vintage Guitar Speaker Cabinet.” This cab comes with the same speakers as the Bugera V22 amp, and I know I really like the speaker in the V22 so I knew I would love this cab. The V22 is an opened back combo that has some HUGE tone. I would still own a V22 had it been built a little more reliable. Mine failed the second week I had it. But the tone was so sweet I literally thought of paying a tech hundreds of dollars to tune it up for me. My wife thought that a crazy idea as it was a brand new amp. Long story short I ended up returning it.

This V212 cab was basically new when I got it in trade. The guy purchased it to play with a cover band that he did not end up joining. So it literally was new! The tone had a very strong bass presence in its stock closed back state, very Marshally, like a good kick in the chest. I was going for more of a opened, clear and mellow tone. I am sure the cab stock would totally KILL it with a Marshall style head banging out some AC DC!

How to Make a Closed Back Opened Back

Now for the DIY (Do it Yourself) stuff! What I did was remove the back panel. Then I peeled back the black protective covering material. I used the Vox AC30 V212HWX extension Cabinet as my reference point both structurally and tonally. I tried to get the same amount of speaker exposure as the V212HWX cab. Basically because that cabs feel and presence seems to be ideal for what I am looking for. I then made my marks and cut each panel as desired. To make this cut you will need a scale saw with a wood blade. After that I put down some crafts glue, let it set up for a few minutes and then re applied the black protective covering as firmly as possible. Then I re installed the input jack panel and screwed both pieces back on!

Huge Tones

The tone now is HUGE and just what I was looking for. Also if you don’t already know, Bugera makes all there own speakers, and they are of a high quality, believe it or not. I have heard things that these speakers, Bugera 12G70J8’s, are clones of Celestion Vintage 30’s. I have no experience with Vintage 30’s so I cant really say one way or the other. What I do know is these speakers sound GREAT! Please drop me a line if you know more on this situation. The speakers do seem to benefit heavily from breaking in time.

One comment

  • Ron says:

    I don’t know anything about the speakers but I ordered the cabinet on faith for the price, weight and wireing options. I was a bit dissappointed at first by the low end output but tried it with the back off . The low end blossomed and compared quite favorably with the sound of the stock celestions in my mesa lone star. I intend to make a new back with a large oval cut out as in the Avalon style and replace the plastic jack plate with a metal one.( two corners broke when removing it) thanks

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