Question for speaker builders out there

[newbsterv2]

I had a question refarding the foam material used on the insides of speakers. What audible effect does having too little or too much foam make on the sound of the speaker. I read somewhere that too much foam makes the bass "looser". Thanks for any info.

[Garrardman]

Generally speaking, if you put too much in the speaker will start to sound "dead" but if too little it may become boomy and the bass sound somewhat resonant.

A good starting point is just a single layer around the inner sides, top and bottom of the cabinet, and then have a listen and add or remove according to what your ears tell you.

Adam.

[newbsterv2]

Thanks for the info Garrardman. The reason I'm asking is because recently I assembled the Dayton BR-1 speakers kit from parts express and the manual states that each wall should be lined with foam. On the more expensive models however the manual states that of two opposing walls only one should have foam because the system will be overdamped and sound hooty because it's a much smaller enclosure than on the BR-1. I always thought that an overdamped alignment is "tighter" than an underdamped alignment. Anyways to make a long story even longer I figured that decreasing the foam would "tighten" the bass but maybe not. Thanks for your info I appreciate it.



Generally speaking, if you put too much in the speaker will start to sound "dead" but if too little it may become boomy and the bass sound somewhat resonant.

A good starting point is just a single layer around the inner sides, top and bottom of the cabinet, and then have a listen and add or remove according to what your ears tell you.

Adam.

[kexodusc]

There's really too much at play here to try to sum up what "foam" does inside a cabinet. There's tons of foams too, poly fil, acousta-stuff, dacron, nylon, cotton, etc... Some foams alter the physical properties of the cabinet, warming the air when sound energy is present, effectively increasing the volume of the cabinet...some do the exact opposite. Sometimes foam is used to cut down on reflections and interior standing waves, etc. Not all foam is used for dampening.
I believe the foam in the BR-1 kit is more of a deadening/damping type, however.
When a speaker is designed, the amount of foam, the foams material, and placement are all integral parts of the speaker design. Some very good speakers also choose to do with out...Audio Note is a prime example. There isn't a best way, just different ways of accomplishing pre-defined objectives.

[RGA]

Kex

I actually mispoke way back when - AN does use carted sheep's wool as a damping material - they do damp their speakers - they are selective as to where. The original Snell speakers were stuffed with Dacron.

I should imagine that there would be some differences with the Kit versus production AN speakers as a result of this.