BillFitzmaurice.info

Hi All,

I'm going down the dark hole of valve bass amplifiers.
Just purchased a Fender Bassman 135 head, and am now considering cabinets.

It's very big. 26" wide.
It shouldn't matter, but having it sit muffin-top style on top of a narrow cabinet would grind my corn.

So I'm considering building a non-tallboy Omni 12 for it. No tweeter, just a 3012LF woofer and the usual Alpha mid.

Questions:

1) Could I make it an inch wider without drama? If so, would I take an inch off the height?
2) The head is only 135 valve Watts, probably overestimated. So efficiency is a goal. The 3012LF seems relatively inefficient compared to the Deltalite II 2512 for example. Is the 3012LF a good choice for this application? I'm thinking the cabinet design makes up for this, or it might not be an audible difference. Thoughts?

Regards

An inch wider is fine, no need to reduce the height. For maximum sensitivity use two tens. Tube amps don't like 8 ohm cabs anyway.

Bill Fitzmaurice wrote: ↑Tue Nov 02, 2021 10:44 am An inch wider is fine, no need to reduce the height. For maximum sensitivity use two tens. Tube amps don't like 8 ohm cabs anyway.

Thanks Bill. Worth checking.

I take your point on the 8 ohm cabs for tube amps.
This amp has an output transformer with a tapped secondary matched to either 4 or 8 ohm loads.
In fact, it was a Talkbass article to which you contributed a million years ago that pointed this out for this particular amp. Good to know.

So assuming two 8 Ohm 10" woofers, would the relatively efficient (97.3db) Deltalite II 2510 be a better choice than the relatively inefficient (92.7db) 3010LF? (@ 1W/m)

Or am I tilting at windmills?

The difference between those drivers is that the LF goes lower, useful if you run low B, and has more xmax, which matters not with only 135 watts.