Modifying a speakers frequency response

[rocket]

Can I lower the resonant frequency of a speaker by coating the membran?

Will I get a better bass response then?

I am talking about a 5" Speaker from a squier sidekick amp that I am converting to 2W tube amp (ecc83/ecl80).
So I am not afraid of ruining the speaker because at the moment it sounds rather useless.

Loss of efficiency would not be a problem.

Will the (small) cabinet allow a useful bass response? It is closed and has 2 holes of 40mm as "bass reflex" ports.

I have also though about using a 6x9" speaker but I am not sure if that will work in a small cabinet (which I would like to keep).

[Rob Mercure]

Hey Rocket,

I'm not sure what the dimensions/volume of the cabinet you're referring to are so I can't comment but there's lotsa information available on the web and in print about sizing cabinets/ports to tailor response - mostly for HiFi but useful enough for guitar.

But as to coating the speaker, while you would theoretically increase the mass and lower the resonant frequency you would probably wind up stiffening the cone and raising it. Or you could use something flexible to increase the mass with out stiffening it and probably increase the damping to the point that "mud" is all you'll get.

You're already on the right track of just testing every small speaker you can lay your hands on to find one that sounds good with guitar. Generally I've had good luck with the 4-6" "institutional P.A." speakers that are ceiling mounted - the ones with a nice stiff paper cone that gives a nice ring when tapped. The other source, which is probably a long shot, is military surplus film projectors. I bought 5-6 of these about 8 years ago for around $10 each and each has a great little 12W PP 6005 (JAN 6AQ5) amplifier and a 4" Jensen alnico speaker with the magnet being almost as big as the basket And even these are a bit "anemic" when used solo but two in a small cabinet really sound great. It's the old "TANSTAAFL" (there ain't no such thing as a free lunch - Robert Heinlein - "The Moon is a Harsh Mistress") effect -it's really hard to make a small MI speaker so you have to adapt to what you've got.

Rob