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jaygeorge1979
11-04-2005, 03:48 PM
I am trying to figure out how you know when to use seperate chambers inside a box for the different drivers....

http://www.partsexpress.com/projectshowcase/unicc/enclosure_design.html

this link shows dimensions for a 3 way center channel speaker project...i cant figure out what they mean by mid enclosure, and i dont know what baffle means...can someone explain this to me?

JimJ
11-04-2005, 03:50 PM
The baffle is simply the front panel...

jaygeorge1979
11-04-2005, 03:57 PM
awesome...good to know....how about creating a seperate chamber for the midrange? when is it a good idea to do that? and what is that vent thing they put in the back

thylantyr
11-04-2005, 04:52 PM
I am trying to figure out how you know when to use seperate chambers inside a box for the different drivers....

You have to analyze the scenario in detail to determine what is best for a particular design.

For instance, you install a woofer, midrange and tweeter in a common
chamber. When the woofer moves it will push the midrange driver cone
and if you have a vented tweeter it too will move. Not sweet so you create
isolation chambers.

What if your tweeter and midrange driver are sealed ? Then it won't matter.
What if there is an air leak in the tweeter and midrange install? Then you have
another problem to deal with.

What if you have planar tweeter that is sealed but later you notice the diaphram
moves when the woofer moves, confused you analyze the tweeter and found
a build quality problem where the gasket used to create a seal on the tweeter
is not working right. Another problem to deal with.

What if you need the air place for the woofer and can't chamber the design?
Then you have a compromised design unless you solve the other issues.

What if you want two woofers in a box, do you chamber the design or not?
If one woofer fails, the sound is different. If the design was chamber the individual woofer is still performing to spec as it doesn't see the other woofer
in it's own chamber.

What if you can't make a multi-woofer chamber because the port size requirement is too big and won't fit? Then don't make a chamber design :)

What if you make a tall line array with midwoofers sealed? Do you chamber or
do a single box ? midrange frequencies are the nasty ones that have standing
wave issues. A midrange in a small box will have nasty reflections on walls,
if you were to make a non chamber design and fully stuff the box with polyfill,
this gives the sound waves a chance to disperse and 'get lost' in the thick
polyfil to offer less coloration to the sound. On the other hand, by not have
a chambered design here, you have not extra cabinet bracing for a such a large
tower so you have to solve that issue another way.

The general rule is..> DWYW DIY
Do What you Want Do It Yourself

If you make product to sell, then do esoteric things to justify the higher cost
in spite that it may do nothing at all ... ie, we sprayed popcorn material on
the internal walls conforming to Fibonacci patterns to break up standing waves ->
cha-ching -> product sells for 2x more. :clap:

jaygeorge1979
11-04-2005, 05:25 PM
:crazy: thank you

thylantyr
11-04-2005, 05:49 PM
Other reasons to make a chamber.

*A secret stash for drugs
*An S&M hideout inside your loudspeaker .. whip/// crack /// more please.

PV Audio
11-04-2005, 08:14 PM
i want to try a pulp chamber one of these days...

jaygeorge1979
11-04-2005, 09:26 PM
whats a pulp chamber?

thylantyr
11-04-2005, 11:39 PM
whats a pulp chamber?

fiction :)

jaygeorge1979
11-05-2005, 12:27 AM
haha

PV Audio
11-05-2005, 10:41 AM
fiction :)
:eyebrow:

it is kinda like fiberglass in the way that it is used, but it isnt. u ever made "paper" by blending newspapers in water and using the PULP to make stuff? well picture that glop and u then make a small "bowl" out of it that is the correct size of air for the midrange. if i could get a pic right now i could....

jaygeorge1979
11-05-2005, 11:28 AM
i guess that kinda makes sense...how would u get it to be the correct size? seems like it would be hard to get a definate shape out of it...

jaygeorge1979
11-09-2005, 12:10 AM
I have a new question...about tweeters...cuz in the projects i find on zaphaudio.com, i cant see anywhere where it says to use seperate chambers for the tweeter and midwoofer...thylantyr earlier said that if you have a vented tweeter, then you need seperate chambers....how do you know if the tweeter is vented? do you buy em like that or do you have to check it out to see? do you ALWAYS have to seperate chambers if the tweeter is vented?

thylantyr
11-09-2005, 02:22 AM
http://www.mordauntshort.com/content.php?COID=9

If you don't have a chamber air pressure cause by other drivers will push the tweeter's dome.

jaygeorge1979
11-09-2005, 01:30 PM
so if i buy a vented tweeter, then i DONT need a chamber...but if i have any other type of tweeter then a seperate chamber is essential?

i am just trying to figure out how these projects are done...i know that certain drivers need a certain amount of internal airspace to operate appropriately...so you cant just decide that the midwoofer is affecting the tweeter after the box is built and try to chamber it cuz this will decrease the amount of air space availible for the midwoofer to operate right? therefore, you need to take chambering into account prior to box construction...is a vented tweeterthe only tweeter that allows you to not chamber? is having the air pressure pushing the tweeters dome a big deal, or is it something we can get away with...?

thylantyr
11-09-2005, 01:39 PM
so if i buy a vented tweeter, then i DONT need a chamber

A vented tweeter would have the voice coil exposed to air pressure and it needs
it's own chamber to prevent the other drivers from physical destruction. ie,
get an air gun and inject the nozzle in the back of a vented tweeter and watch
your dome come off :crazy: :eek:

i am just trying to figure out how these projects are done

You are the designer, you can do anything you want. But to prevent headache,
there are some basic rules to follow.

Another example, you have a large high excursion woofer in the same
box as a open back midrange. Before turning on the music, push the woofer
cone in/out and watch your midrange cone move. Not sweet. Imagine what
happens to the little poor midrnage at high excursion.

Even some planars have gasket material to seal off the diaphram but in some
rare instances there may be an air leak. Air pressure will destroy your planar.
It's better to make a small chamber to isolate it from the rest of the drivers.

jaygeorge1979
11-09-2005, 04:25 PM
so what your saying is, whether or not i need chambers is directly related to the physical build of the drivers involved...i need to make sure i know whether or not the drivers need seperate chambers prior to box building...in some cases, in a 3way system, i might need 3 seperate chambers, small one for a tweet, medium size for mid, and the rest left to the woofer...which, when i calculate total volume, should be at the acceptable internal volume for each driver.....i think i understand