| T.R | Title | User | Personal Name
 | Date | Lines | 
|---|
| 1544.1 | Stop Rattling | AQUA::ROST | Subliminal trip to nowhere | Tue Oct 31 1989 07:28 | 10 | 
|  |     
    The fibreglass is used for two things.  One is to help prevent rattling
    of the cabinet.  The other is that acoustically, a cabinet stuffed with
    fibreglass supposedly acts like an empty cab of slightly larger
    dimensions.
    
    Radio Shack will sell you a large bag of fibreglass for a couple of
    bucks.  
    
    						Brian
 | 
| 1544.2 | Sealed cabs should be insulated | STAR::DONOVAN |  | Tue Oct 31 1989 11:22 | 20 | 
|  |     I would put some type of insulation in your cabinets.  I neglected to
    put insulation in my cabinets and the result was a noticeable
    distortion....not the good kind.
    
    A recording engineer told me that, in sealed, uninsulated cabs, the sound 
    waves bounce off of the hard wood insides and actually "slam" back into the
    cone of the speaker.  
    
    The speaker driver is trying to move the cone in accordance with the 
    electronic signals it is receiving, and it is forced to compete with
    all of these extraneous "shock waves" that are literally distorting the
    shape of the cone.  The result is low efficiency and lousy sound.
    
    I insulated my cabinets with builder's insulation and the result was
    pretty dramatic.
    
    Hope this helps,
    
    Brian
    Obviouslyu, in open back cabinets, the sound waves can escape.
 | 
| 1544.3 | Great! | CSC32::G_HOUSE | Hooks in you | Tue Oct 31 1989 17:25 | 7 | 
|  |     Thanks!  I'll definately put it back in (I still have what was in there
    and it's in good condition.
    
    You guys are definately a wealth of information, don't know what I'd do
    without this notesfile.
    
    Greg 
 | 
| 1544.4 | sealed boxes should be | SWAV1::STEWART | There is no dark side of the moon... | Tue Oct 31 1989 23:54 | 14 | 
|  | 
	Don't forget to either caulk the openings or put in some
	weatherstripping. "Sealed" boxes that leak sometimes produce real
	annoying noises.  This isn't so much a problem with ported (or
	open-back) designs. 
 | 
| 1544.5 | a second for sealant | MARVIN::MACHIN |  | Wed Nov 01 1989 04:50 | 6 | 
|  |     RE .-1
    
    Yes, and a slight leak can act as a one-way valve, so the speaker 
    pumps air into the cabinet and the cone gradually emerges until...
    
    Richard.
 | 
| 1544.6 | foamimg at the mouth | DISCVR::JONEILL |  | Wed Dec 06 1989 10:31 | 3 | 
|  |     Does the insulation have to be fiber glass or can foam be used as well?
    
                             Jim (who has a lot of foam awaiting an answer)
 | 
| 1544.7 | I like the foam | RAVEN1::BLAIR | Fan mail from some flounder? | Wed Dec 06 1989 13:30 | 9 | 
|  |     
    My uneducated opinion is that the best is the foam rubber that has
    the "egg carton" sides.  I faced this side toward the sound.  I really
    don't KNOW if it's better than fiberglas but it LOOKS cool.  The Field
    Service guys often have some on hand.  It is real easy to install - I
    didn't even need staples or glue.  You might check the AUDIO conference
    and ask the audiophiles.
    
    -pat
 | 
| 1544.8 |  | OTOA01::ELLACOTT | Freddie's Revenge | Wed Dec 06 1989 15:45 | 7 | 
|  |      	IMO foam (the thick stuff) is almost as good... line all sides
    of the cab...if you use fiberglass pack the cab but avoid letting
    it come in contact with the spkr cone
    
    FJE_who_was_once_very_quiet_but_not_any_more
                            
    
 | 
| 1544.9 | Try it, You'll like it... | CSC32::MOLLER | Nightmare on Sesame Street | Thu Dec 07 1989 14:56 | 8 | 
|  | 	The goal is to stop the sound from bouncing around in the cabinet    
	on the flat surfaces. Foam will work as well as other substances.
	I've used old shag carpeting (it really works) as well as
	fiberglass. Fiberglass is lots cheaper than foam, or pretty
	much any other sound deading padding, hence it's used more
	frequenty. Use the foam, it should work quite well.
								Jens
 |