"Pressure plate"-anyone who knows smtg?

[cerrone 10+ year member]

Hello everybody. greeting from BULGARIA

I found this forum very helpfull, although allmost all the components (excluding Pioneer, Sony, Alpine, Panasonic) you are using for building yours sound system are "very hard to find" here.

I've just finished building a sub box (23 litres, "looking stealthy" closed box - it's small, but I need the trunk for other purposes also) for my car trunk and saw one install that have a pressure plate infront of the speaker and was wondering the meaning and if someone could explain the benefits and howto for that....

I've heard that it brings also some benefits to sound pressure.

Normal closed box works as closed rear chamber of the bandpass box. "Pressure plate" is about 40-60mm away from the box and the space between box & plate works as tuned chamber of the bandpass box.

here is the link:

http://www.kalliojarvi.net/autos&sec.htm

Doesn't anybody know facts?

Click to read more...

 

[matrxx dude 5,000+ posts]

me either

 

[ga12r 10+ year member]

I think they are called "loading walls" by SPL competiters around here.

 

[Mitch86 5,000+ posts]

I dont know about a "pressure plate", but I'm diggin the pic from 1979.

 

[ultimate157 5,000+ posts]

I dont know about a "pressure plate", but I'm diggin the pic from 1979.

lol he looks like a fatter adam sandler

 

[yacob.naif 10+ year member]

dual reflex bandpass, basically

 

[cerrone 10+ year member]

dual reflex bandpass, basically

Please, can you be more specific.

Are there an air gap from all plate sides, or it is sealed everywhere, except the cutted hole infront of the center of subwoofer? where is that small hole on the edge of the plate?

I just can't imagine

 

[skmfkr 5,000+ posts]

from reading the link he only gained 1db...and it just sounds like he used more bracing like a double front baffle?