Wayne Parham Messages: 18783 Registered: January 2001
Illuminati (33rd Degree)
I never apply any damping material to the horns. The bell mode frequency is well below the passband and it is highly damped by the horn's mass, so I don't see any need to damp it further. The plastic is really thick.
That said, it doesn't hurt anything. Lots of our friends here do it, probably as a perfectionist move. I don't see any difference in measurements, but if it makes 'em feel better, there's certainly no harm in doing it.
rkeman Messages: 78 Registered: March 2010 Location: Florida
Viscount
The now absolete Eminence H290 had hollowed areas that were filled with electrician's putty on my 3 Pi and 6 Pi builds. Adhesive backed 1/2" acoustic foam insulation cut into four roughly triangular shapes were used to cover the remaining flatter areas of the horn flares. The narrow end of the throat (hollows filled with putty) was additionally wrapped circumferentially with a 2 1/2" strip of the same acoustic foam and secured with a few passes of nylon twine. The resulting horns were incredibly well damped and produced only the dullest thud with a strong tap of the horn mouth. The new H290C may not benefit as much from such treatment if the native structure is sufficiently inert.
mantha3 Messages: 72 Registered: May 2012 Location: Lino Lakes, MN
Viscount
Right on.
I saved a copy of this detail. I'm running the Emmenance H290. I'm thinking I'll run these for a couple months or so without this tweek. I like many on this forum do DIY stuff so sooner or later curiosity will get the better of me and I'll try this.