Menu
Forum
General Car Audio
Subwoofers
Speakers
Amplifiers
Head Units
Car Audio Build Logs
Wiring, Electrical and Installation
Enclosure Design & Construction
Car Audio Classifieds
Home Audio
Off-topic Discussion
The Lounge
What's new
Search forums
Gallery
New media
New comments
Search media
Members
Registered members
Current visitors
Classifieds Member Feedback
SHOP
Shop Head Units
Shop Amplifiers
Shop Speakers
Shop Subwoofers
Shop eBay Car Audio
Log in / Register
Forum
Search
Search titles and first posts only
Search titles only
Search titles and first posts only
Search titles only
Log in / Join
What’s new
Search
Search titles and first posts only
Search titles only
Search titles and first posts only
Search titles only
General Car Audio
Subwoofers
Speakers
Amplifiers
Head Units
Car Audio Build Logs
Wiring, Electrical and Installation
Enclosure Design & Construction
Car Audio Classifieds
Home Audio
Off-topic Discussion
The Lounge
What's new
Search forums
Menu
Reply to thread
Forum
Car Audio Discussion
General Car Audio
should i chamber these?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
<blockquote data-quote="thylantyr" data-source="post: 1226360" data-attributes="member: 560358"><p>Sealed box: [Midrange sound] - sounds better in a over sized box with polyfill</p><p></p><p>or whatever recipe to let the sound inside diffuse through thick layers before it</p><p></p><p>hits the hard surface of the wall where it will reflect again.</p><p></p><p>If you chamber it you reduce the box size for each driver so the standing waves</p><p></p><p>will have to be diffused better. Usually it's better to make a deep box so the backwave gets to travel farther through these thick layers before hitting the</p><p></p><p>backwall which likes to reflect back. You can make both work just think about how</p><p></p><p>the sound is being diffused and if it's sufficient enough for your liking.</p><p></p><p>Do the echo test. Make the box, cut the driver holes, with empty box yell inside..</p><p></p><p>you will hear echo/reverb/etc. Add polyfill until you are satisfied that it's 'dead'</p><p></p><p>when you holler in a burst. No need for fancy test equipment, yell and listen.</p><p></p><p>Ported box: [Midrange sound] - same thing as above but it's not sweet to place</p><p></p><p>alot of loose polyfill as you affect port tuning. If you can only lightly stuff the box</p><p></p><p>then it's harder to diffuse that midrange sound. You need denser polyfill perhaps</p><p></p><p>attached to the walls leaving the inside chamber open for the port to breath</p><p></p><p>better. Ideally, double/triple the backwall polyfill as long is it doesn't block the</p><p></p><p>port.</p><p></p><p>Sometimes if you do chambers design you can model the woofers to see what</p><p></p><p>port size requirements are, maybe the scenario favors non chambered due to</p><p></p><p>port requirements or maybe you can do it in a chambered design too.</p><p></p><p>Run the numbers for both to see what you like. Chambered design is good for bracing as it is a brace too.</p><p></p><p>If you tune higher in a ported box, try to model for a large diameter hole with</p><p></p><p>very little port length, the standing waves exit the hole so there is less</p><p></p><p>reflections.</p><p></p><p>You can also try AcoustaStuf polyfill from PE. More expensive than ordinary</p><p></p><p>Walmarkt polyfill but the material is more dense, good for higher priced projects</p><p></p><p>where you want the best. You can make some excellent sound absorbing pillows</p><p></p><p>with this mated to ordinary poly battling, roll your own pillow and use 3M glue</p><p></p><p>to attach to the walls of ported boxes. For sealed box, no pillows needed.</p><p></p><p>You can go deeper into esoteric sound conditioning inside the box. For homes,</p><p></p><p>they sell this 'popcorn' type stuff that sprays on walls to make it course [chunky</p><p></p><p>foam type particles]. You can spray this stuff to the inside walls so the surface isn't flat to force these waves to take random paths on reflection. Add the poly</p><p></p><p>to the walls, thick.</p><p></p><p>This is all esoteric ideas, most people probably wouldn't notice but if someone</p><p></p><p>paid you top dollar to make a project do these things to justify the extra labor</p><p></p><p>costs so the customer feels special.</p><p></p><p>I think everything you do add up to make the box not sound like a box</p><p></p><p>for midrange frequencies. Lower cabinet resonance by using thicker walls &amp;</p><p></p><p>bracing, condition the standing waves using those esoteric ideas using popcorn,</p><p></p><p>AcoustaStuf [or wool], fiberglass if sealed, not ported, pillows on walls if ported,</p><p></p><p>otherwise loose polyfill if sealed... etc.</p><p></p><p>People that make subwoofer boxes don't have to deal with these issues</p><p></p><p>except making a good stiff box with lots of bracing. But for midrange it's a new</p><p></p><p>ball game to make the midrange sound more clear and less boxy in sound.</p><p></p><p>Lots of people like open back design because they elimiated the standing wave</p><p></p><p>issue that you have to deal with with box designs. The idea is to make your box</p><p></p><p>design sound more like open back, when you do, then pat yourself on the back.</p></blockquote><p></p>
[QUOTE="thylantyr, post: 1226360, member: 560358"] Sealed box: [Midrange sound] - sounds better in a over sized box with polyfill or whatever recipe to let the sound inside diffuse through thick layers before it hits the hard surface of the wall where it will reflect again. If you chamber it you reduce the box size for each driver so the standing waves will have to be diffused better. Usually it's better to make a deep box so the backwave gets to travel farther through these thick layers before hitting the backwall which likes to reflect back. You can make both work just think about how the sound is being diffused and if it's sufficient enough for your liking. Do the echo test. Make the box, cut the driver holes, with empty box yell inside.. you will hear echo/reverb/etc. Add polyfill until you are satisfied that it's 'dead' when you holler in a burst. No need for fancy test equipment, yell and listen. Ported box: [Midrange sound] - same thing as above but it's not sweet to place alot of loose polyfill as you affect port tuning. If you can only lightly stuff the box then it's harder to diffuse that midrange sound. You need denser polyfill perhaps attached to the walls leaving the inside chamber open for the port to breath better. Ideally, double/triple the backwall polyfill as long is it doesn't block the port. Sometimes if you do chambers design you can model the woofers to see what port size requirements are, maybe the scenario favors non chambered due to port requirements or maybe you can do it in a chambered design too. Run the numbers for both to see what you like. Chambered design is good for bracing as it is a brace too. If you tune higher in a ported box, try to model for a large diameter hole with very little port length, the standing waves exit the hole so there is less reflections. You can also try AcoustaStuf polyfill from PE. More expensive than ordinary Walmarkt polyfill but the material is more dense, good for higher priced projects where you want the best. You can make some excellent sound absorbing pillows with this mated to ordinary poly battling, roll your own pillow and use 3M glue to attach to the walls of ported boxes. For sealed box, no pillows needed. You can go deeper into esoteric sound conditioning inside the box. For homes, they sell this 'popcorn' type stuff that sprays on walls to make it course [chunky foam type particles]. You can spray this stuff to the inside walls so the surface isn't flat to force these waves to take random paths on reflection. Add the poly to the walls, thick. This is all esoteric ideas, most people probably wouldn't notice but if someone paid you top dollar to make a project do these things to justify the extra labor costs so the customer feels special. I think everything you do add up to make the box not sound like a box for midrange frequencies. Lower cabinet resonance by using thicker walls & bracing, condition the standing waves using those esoteric ideas using popcorn, AcoustaStuf [or wool], fiberglass if sealed, not ported, pillows on walls if ported, otherwise loose polyfill if sealed... etc. People that make subwoofer boxes don't have to deal with these issues except making a good stiff box with lots of bracing. But for midrange it's a new ball game to make the midrange sound more clear and less boxy in sound. Lots of people like open back design because they elimiated the standing wave issue that you have to deal with with box designs. The idea is to make your box design sound more like open back, when you do, then pat yourself on the back. [/QUOTE]
Insert quotes…
Verification
Post reply
Forum
Car Audio Discussion
General Car Audio
should i chamber these?
Top
Menu
What's new
Forum list
