dust - how much of a hazard when you don't have a dustcap?

Until recently, I have never owned, or taken interest in owning, a speaker without a dustcap in the center. Not that I was insistent on dustcaps, just the categories of speakers I was involved with always already had dustcaps.

I've taken an interest in full range speakers, and many of the better ones have a phase plug or other form of open center area, rather than a dustcap.

I live in a 180+/- year old farmhouse that is a perpetual project (and some of the demolition/ rennovation projects are especially dust-inducing, even though I try to contain and control it), with forced air heat (very effective at moving dust around), and I am a divorced guy with a busy schedule... so my home is... uh... very far from dust-free.

As a practical matter, how much of a practical worry is it that a speaker without a dustcap, oriented vertically, will "take on" dust that will lodge in or otherwise be bad for the gap between the voice coil and the center of the pole piece?

Will a perforated metal grille with fairly high % open area do anything at all to partially mitigate dust at risk of entering the speaker's moving area?

Is there anything that you can get that is along the lines of what I have seen on some old (early '80s) ADS metal perforated metal grilles that is a very fine, very thin, fabric, and if it's available, how much of a negative effect would it have on driver performance?

Thanks in advance
 
Last edited:

boswald

Member
Paid Member
2014-06-27 3:32 pm
Where are you? We have a similar situation house-wise, and are next to the world's deepest marble quarry (Danby Marble, now Carrara) and rt 7.

I don't keep a permanent installation of a phase plug speaker without grill cloth.
Our dust is luckily not the red, iron-bearing dust from up north, so not magnetic, but salt dust from the highway will pick up a static charge.


Good quality grill cloth is no problem, many blind tests have shown no detectible change in sound, and if you calculate thread diffraction, 150-180khz is, after all, well away from what any mammal can sense, though we do "hear what we see".

Harmon, B&O, the CBC, used to have papers on their sites regarding this. If you know an IEEE member, there are papers there.


Anyway, welcome and contact me sometime, we cannot be all that far apart in this little state.


Best, David
 
Any grill fabric of fine enough weave to exclude dust is likely to affect the treble response of the speaker.

Synthetic fabrics are more than transparent enough even quite fine weaves. I've tested through multiple layers and never thought it would be noticeable (although I don't have the data to show now).

Just buy a few yards and toss it over the drivers. I use paisley.

B.