'86 Cornwall II's have no Insulation in Enclosure

[Frzninvt]

I took a woofer out of one of my Cornwall II's and when I had it open I noticed there is no insulation of any kind inside the enclosure like the older Cornwalls had. I plan to order the pieces of Acoustic foam from Parts Express and spray glue it to the panels inside. Do you do all the sides or only the three non opposing sides when you apply insulation to the cabinet.

The reason I want to do this is to eliminate resonances, if you tap on the side of the enclosure you get a big echo as compared to the '62 Cornwall right below it that is solid as a rock when you tap on the side.

Anyone have any better insulation ideas than the acoustic foam from Parts Express I am all ears.

[D-MAN]

Sounds like a good idea.

The main effect you will notice from cabinet insulation is that the reflections from the back of the enclosure subsequently coming out of the cone will be reduced. This may or may not be desirable, depending on some vagaries like the crossover frequency and the suspension qualities of the woofer and whether you like the sound that you are getting without it.

I would try it first with some stuffing to see how it sounded before I glued anything permanent into it.

It makes quite an effect. Also, the sound absorbtion material will make the enclosure seem like a larger internal volume to the driver. This will be directly proportional to the amount of material used. Start small to test the effects. Too much will cause distortion due to excessive excursion (backwards) - this will sound distinctly bad and muffled. At which point that occurs is dependent on a lot of variables.

But I find it hard to believe that no isulation at all would be a good thing in any box enclosure...so go for it!

DM