Which Speakers?

strat84

They're quite easy to make if you have access to a jigsaw? Some decent plywood (I use 12mm) and 4 T nuts and screws to suit ;-)

SunDevil

@strat84 - I do have a jigsaw - results usually look like I actually used a shotgun to make the hole

How easy it is it do (or more specifically, how round does the hole have to be not to risk the speaker cone?

dcg

a Scumnico SC75 is a truly wonderful invocation of an early Celestion, and totally worth the money (he said modestly)...

ICBM

SunDevil said:

@strat84 - I do have a jigsaw - results usually look like I actually used a shotgun to make the hole

How easy it is it do (or more specifically, how round does the hole have to be not to risk the speaker cone?

Very easy. It's not usual for the speaker cone to be able to move far enough forward to contact the baffle even if it's not round, or substantially smaller than the speaker - that's the purpose of the thick gasket round the edge, as well as to make the gap fairly airtight. Many amps have non-round speaker holes where a logo plate crosses the speaker, or on something like an old AC30, a bar right across the hole to protect the speaker a bit better.

strat84

Haha! It's quite easy if you take your time - the last one I did I actually ordered a round piece of plywood the exact size I needed from a shop on ebay, then it's just the hole in the middle to cut. 

 You can always sand the edge of the hole if it's not completely round. Don't worry about the cone as that shouldn't touch the surface of the plywood