Horning Eufrodites - help needed with boomy bass

BTW, I asked Tommy about the damping materials and shutting the bass ports, he said: "all the things you are thinking of doing is against the whole idea of the Eufrodites way of working".

Using absorbent material in the ports isn't the ideal, but if the Eufrodites' way of working isn't working for you and your room, then imo it's reasonable to try to find a solution that is a worthwhile net improvement.

I design speakers too, and most of my designs have user-adjustable ports, because I can't always reliably predict in advance what the room acoustic situation will be like, where the speakers will be positioned, and/or what the output impedance will be of amplifiers they might be used with. I have one customer (a single-ended triode amplifier manufacturer) who went all the way to plugging the ports on his speakers, so they are now sealed boxes. Yeah that theoretically goes against their "way of working", but it's what works best for him, his amps, and his room (speakers up against one wall, listening couch up against the opposite wall, so lots of boundary reinforcement).

As for optimizing the type and amount of damping material, I'm afraid it's a matter of trial and error, and a juggling of tradeoffs.

Duke

Even though Tommy's remark, I agree with your statement, Duke.
I'm continuing the research...

This is a long shot, so consider it just the ravings of an insomniac:

It is possible that the enclosure is a transmission line/tuned port hybrid of sorts, and if so, you might be able to tighten up the bottom end a bit by lowering the tuning frequency. One way to do so would be to reduce the cross-sectional area of the port over its entire length.

Remove the stuffing from the port, then measure how far the port extends into the box (horizontally). Cut several boards that long, and just wide enough to fit into the port. Stack enough such boards in the port to roughly cut its cross-sectional area in half.

If the box functions as a reflex box, we've just lowered the tuning frequency somewhat. And that just might be a better "fix" than stuffing the port with damping material. If the results seem promising, find the optimum number of boards by trial-and-error, and then if you want to, glue and/or screw the boards together to make a solid block, and maybe wrap the ends with electrical tape or some such to give you a snug, rattle-free friction fit.

Theaudiotweak's suggestion of improving the coupling between speaker and floor may work very well, I don't know, I have less experience with that approach. I don't see how it could do any harm (unlike the things I've recommended, which very well could be detrimental, especially in the wrong dosages... but at least they're easily reversible).

Duke

Your first step should be to couple the speaker and then wait a few days for the unit to find ground. Until you do this properly your retuning of the enclosure may lead down a path of continual frustrating results. There are ways to mechanically ground a ported speaker so that no internal damping material is needed but probably not now in your case without serious intrusion. Damping will reduce dynamics coupling will not. Tom