Tube Amp Archive

I'm working on a 2x12 version of the 806 and looked at the actual volume of the cab to refine a design. The EV plans state 1.3 cuft but the internal dimensions are 1.284 cuft before factoring in all of the bracing. So some questions -

Has anyone crunched the actual volume with the bracing?

Anyone know the effect on sound waves the bracing has?

How much does the depth of the cab contribute to the 'magic' or is the volume the key?

Thank you for all of your knowledge!

Russ

1.3 cu feet - 1.284 cu feet = .0016 cu feet difference.

Are you really concerned about this?

Is there some concern that the bracing will lessen good tone by making it even less then 1.3 cu feet? I see this as a very insignificant factor and would view wood material, tolex, glue etc.... to be more of a factor on tone.

With respect, 10thtx

Check this thread out:
https://tubeamparchive.com/viewtopic.ph ... 2b98eee79f

It's 40 here today and I am sitting in front of a fire chewing on details so I only have to cut the wood once.

My intent is to replicate the performance in a 24"x 24"x 12" 2x12 ported cab based on the volume of a 806 cab x 2. The depth will be adjusted to hit the volume - I want to 'nail' EV's spec as I will use at least one EVM12L.

The reason for my question is the EV design is over built internally and I will not be putting that much bracing into the cab. I am not an acoustic engineer but I believe the speaker 'sees' only the open air volume bounding box left by the walls and bracing.

I ran the numbers on the bracing which leaves 1.116 cu/ft of volume out of EV's stated 1.3 cu/ft [1.284 actual]. Does the reduction of 290.0625 cu/in [13%] make a difference? I believe it does - just wanted more data.

Russ

With all due respect...you say you are not an engineer...so understand that omitting the bracing because of your erroneous idea that it is overbuilt will have a much more negative effect than the slight reduction of internal volume will make. Besides...all this concern over exact volume is misplaced. It only matters for low frequency extension(which is below a guitar's low"E" anyway). Remember the "TL"series cabs were designed as Sound Reinforcement cabs...to get the best performance for a 2-way system using their EVM style drivers. I've hear EVM's installed in old 2x12" Fender cabs, and there was no lack of lows!

RCGPNY1 wrote:With all due respect...you say you are not an engineer...so understand that omitting the bracing because of your erroneous idea that it is overbuilt will have a much more negative effect than the slight reduction of internal volume will make. Besides...all this concern over exact volume is misplaced. It only matters for low frequency extension(which is below a guitar's low"E" anyway). Remember the "TL"series cabs were designed as Sound Reinforcement cabs...to get the best performance for a 2-way system using their EVM style drivers. I've hear EVM's installed in old 2x12" Fender cabs, and there was no lack of lows!

Exactly.
The thing about the TL806 is the phenomenal bass response and efficiency out of a very small cab.
The heavy bracing is a major part of that.

All good answers - thank you. It is somewhat relieving [and annoying] to know that the volume is not critical.

Russ