Is A Super Pensil 12.2p Width of 11.25" Okay?

[tlarwa]

If I maintain the 35.5" internal height and adjust the depth to 15.6" to maintain the same internal volume as the original design? I am not a fan of exposed ply edges, so I am planning to use nominal 12" wide red oak (which is actually 11.25" wide) for the baffle and the top. That way the only exposed ply edges will be at the back and on the bottom, which is fine since I won't be looking at them. The rest of the cabinet will be 3/4" red oak hardwood ply. If changing the overall cabinet width .75" is going to adversely affect performance I'll just rip down the red oak to 10.5". But it's already at 11.25, so I thought it would be easier to leave it alone and adjust the size a bit.

The other thing it would change is the vent size (slightly). My plan is to cut the vent "window" out of the solid oak baffle board. So if I make the vent 9.75" wide (which is what the new internal width of the cabinet would be), I'll adjust the vent height to 2.34" to maintain the same vent area. Is this acceptable? The vent sides will still be in line with the inner surface of the cabinet sides, and I'll round the recommended edges, as shown on the plans.

And by the way, Mark, in case you read this ... I sold my W8-1808's and am using the Alpair 12p drivers instead!

Any issues with this slight dimensional change, given that the internal height (which I've read is the critical dimension) and internal volume stays the same?

Tom

 

[planet10]

As long as you maintain the cross-section area, height, driver offset, and vent area you are fine.

dave

 

[Scottmoose]

What Dave said.

 

[tlarwa]

Thanks, guys. I thought I was safe as long as I kept those critical attributes the same, but wanted do be sure before I started cutting today.

Tom

 

[chrisb]

Tom - remember as Dave said to also maintain the total vent area - so adjust the height correspondingly

Of course another solution to exposed edge plies would be ironed on veneer edge banding - either pre-glued or raw tape/ scraps of paper backed

Either way, do post some pictures of the final results, and enjoy

 

[tlarwa]

Thanks, Chris. And yes, I am narrowing the vent height to offset the increase in width. Overall vent area will remain the same.

I got all the boards cut today, and started gluing them up tonight. I don't have as many clamps as I'd like (who does?) so it'll take a little while to glue them up. I am using solid red oak for the baffle and top, and both panels will run the total width of the cabinet so there will not be any exposed edge ply (except on the back). I am going to route out the vent using a flush bit and a template. One question on that ... Since the flush bit/template method will leave a small radius in each corner, can I leave it like that? Or do the corners need to be square? I think it might look nice to have a small radius in each corner, but I will make them square if it will affect the performance.

Tom

 

[chrisb]

The radius won't hurt, be aware that with solids as dense as oak you'll likely encounter some burn marks that will take some careful sanding to remove without cross grain scoring of the veneer side gables.
A scrap of Postform grade plastic laminate or tin could act as a sanding shield for that.

Attempting to square off the inside corners is not without risk of cosmetic damage to the veneer either.

And, nobody, probably even Norm Abrams, has enough, much less one too many clamps