Modified Cornwall cab for 604??

[mondonitro]

Hey everybody a real newbie hear but here it goes. I have some Cornwall cabs ( no drivers,I was going to put 511b's on top, but thought I'd try this first) that measure 25.5 W x 36 H x 15.5 deep. The 620 measures 26W x 40 H x 18 D Can I add about 4.75 inches to the front and get about the same volume as a 620. If I did my math right it seems like it may work. What are the downsides to doing something like this? Would that make it too square? Does that matter? What port size sHould I use. The same as a 620 right? Any reason to leave the port shelf and vent like the cornwall? I'll be using 604-8h and maybe talk to GPA about some crossovers. Any thoughts would be great.
Thanks in advance

[Mr. Widget]

The Cornwall cabinet is built much like many cabinets of the '50s and '60s... it is very poorly braced. It could be reworked, but it is also a very shallow cabinet. I suspect this was done for domestic acceptance. In general cabinets that are deeper than they are wide tend to sound better.

I think I would start from scratch.


Widget

[speakerdave]

. . . . Can I add about 4.75 inches to the front . . . .

I did something like this to build the test beds I'm using for my current project so I wouldn't have to throw some existing cabinets in the landfill. They were competently joined diy triangular cabinets about 40" high that I cut into unequal parts horizontally because I needed four cabinets of two different sizes, and then roughed out the existing baffle, leaving enough around the edges to brace the cabinet at that point, trimmed the width at a slight angle, made new sides to add displacement onto the front, and cut new baffles. They work really well, and I'm not sorry I did it, but I had to make many many little pieces, and jeez it was a lot of work! I certainly wouldn't want to try to make a finished cabinet of something like that. I guess it depends on how much your frugality or resource/environmental consciousness can animate your moral stamina--and whether you have skills to match. Making speakers is often a much more involved project than is initially foreseen. Adapting cabinets is probably not a short cut unless you are just adding bracing and making a simple modification to the baffle, and if you are thinking of doing this because you are not sure of your cabinet making skills or equipment level, it could easily founder the whole project.

David