Recommended cabinet lining for fullrange?

This is probably a loaded question, but what is the recommended cabinet damping, lining, fill for a fullrange BR enclosure?

It seems like no fill and a few sheets of felt on 3 walls? Would bracing help inside the cabinet? I am looking at around a 35L size cabinet. Probably use golden ratio for dimensions.

I did use some felt on all the walls, but have found the speaker a little lacking in midbass. (Dual 10p).

Thank you for any help!
ok so some specifics. My current cabinets are 8"x13"x20.5" ID. This is 35L. The internal walls are all lined with 1/2 " felt. The walls are 3/4" plywood.

Currently i have 2 possible ports. 3"dia x 5.5" or 3"dia x 4". Testing out which sounds better. The port is on the front.

There are 2x A10p drivers per cabinet. One is run full range, the other is run with a 3mH 1.38ohm air inductor. Both drivers are wired in parallel.

The width of cabinet for BSC is therefore 9.5" as the drivers are mounted on the smaller width. Using Edge software on this looks like a slight 2db hump between 500-1000hz.

i have the Spectroid ap for my phone... and based on running some pink noise through it... it is remarkably flat frequency response... maybe this is the problem... too flat.

Thoughts? Should i remove the felt on 3 of the walls? Do i need to adjust the inductor? Increase to 4mH?

Thanks for any help!
A BR — no matter FR or not, is lined, not filled typiclly. We like using natural felt, like cotton or wool.

A 35 litre enclosure will need significant bracing. My 35 litre CGR (unreleased as of yet) has 3 braces, front to back (driver(s) on the wide side).

Also, dual drivers, wired as you have will need to be brought well into the room or you will have excess bass (you might well like that).

Midrange issues could be time-smear stuff coming back thru the cone, or it could be the large passive radiators on the large unbraced panels.

felt on all sides internally or just 3 sides?

Is there a recommendation for bracing? where to brace on the panels? I am thinking that if i keep the drivers on the smaller width panel then i would need a couple of braces from left to right and one from top to bottom? i could also do a couple front to back i guess.

I have the drivers at least 2 feet from the back wall... and the port is on the front... not the back.
I like to line all the sides, but often alternate sides is recommended, but it will need to be twice as thick at a start. I also have the option to place less dense damping on my holey braces (works best if that brace is near centre), as the wall is actually the least effective place to put it.

As to bracing you can look at many of mine & Scoot’s designs for how i have implemented bracing.

The main rules:
1/ the resulting subpanel from a brace should have a higher aspect ratio than the panel being braced (means braces should be oriented 4-ways.
2/ braces should be continuous and attach to 4 sides (or 3-sides & the driver magnet in small boxes, and 4-sides + driver magnet)
3/ braces should not be placed symmetrically,

We like to brace the driver against the back wall (and usually the top & bottom), so that the weakest panel (the baffle with the big hole(s) in it to the rest of the box and distribute (and reduce the total on any panel) the reactional load across more box.

Our braces are sometimes more wotrk than the rest of the box.

Here an example of a big box (still small for the given driver):


Thank you for the detailed reply.

Could you explain what you mean that braces need to be orientated 4 ways?
4 sides as in left,right,top and bottom?

What would be your recommendation for a 35L enclosure?

I appreciate any help as my last speaker was an OB and no need for any of this stuff... lol.

4 sides as in left,right,top and bottom?

That is 4 sides. Bur most often the preferred orientation is top bottom back baffle. The baffle needs bracing. On my full-on miniOnkens, the unbraced sides are a composite of inner and outer panels with vent spacers sepaerating them so are fairly well braced inherently.

If your drivers are mounted on the skinny side, you will need a brace front to back to brace the drivers/baffle, and then bracing from side to side to deal with the wide panels. I would avoid a brace parallel to the baffle and right behind the driver.