Menu
Forum
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Car Audio Discussion
General Car Audio
Car Audio Build Logs
Car Audio Equipment
Subwoofers
Speakers
Amplifiers
Head Units
Car Audio Help
Wiring, Electrical and Installation
Enclosure Design & Construction
Car Audio Classifieds
Car Audio Classifieds
Car Audio Wanted
Classifieds Member Feedback
Gallery
New media
New comments
Search media
SHOP
Shop Head Units
Shop Amplifiers
Shop Speakers
Shop Subwoofers
Shop eBay Car Audio
Log in / Join
Test
Forum
Search
Search titles only
Search titles only
Log in / Join
Search
Search titles only
Search titles only
What's new
New posts
Live Activity
Search forums
Members
Registered members
Classifieds Member Feedback
Menu
Reply to thread
Forum
Car Audio Discussion
General Car Audio
Geting Proper Port Area
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="hispls" data-source="post: 8407240" data-attributes="member: 614752"><p>Round is optimum. Fluid dynamics and all that.</p><p></p><p></p><p>When the coil is centered in the gap it has 100% bl. As it moves up or down from center you'll come to a point where the gap isn't full of coil but only part of the coil is in the gap. The accepted standard for x-max is the point where BL goes below 70%.</p><p></p><p>A lot of the conventional wisdom about box building has gone upside down and the folks who wrote the loudspeaker cookbook certainly weren't considering woofers with a 50 pound+ motor, 27mm x-max, and a suspension stiff enough to stand on. Fundamentals are still the same, but we've gained a bit of flexibility for our ported alignments.</p><p></p><p>If you use winISD and enter correct TSPs it's pretty good predicting port velocity to keep yourself out of the problem areas. I would agree that it's very hard to do "too big" and generally speaking too small will give you a lot more trouble.</p><p></p><p>The ratios of "15 square inches per cube XX inches long" were cookie cutter boxes for a couple different woofer brands (Shocker Mike was big into this and DD uses similar box). The ratio of area to space PLUS the length are to keep a tuning within where that driver wants to tune and does assume you're using the appropriate volume for each size driver. Mostly these "how many square inches per cube" rules will keep you out of trouble.</p><p></p><p>IMO go as big as you feasibly can. It's much easier to shrink a port than to make it wider. Also I've had a long day and am half asleep so if any of this doesn't make sense LMK and I'll clarify or edit.</p></blockquote><p></p>
[QUOTE="hispls, post: 8407240, member: 614752"] Round is optimum. Fluid dynamics and all that. When the coil is centered in the gap it has 100% bl. As it moves up or down from center you'll come to a point where the gap isn't full of coil but only part of the coil is in the gap. The accepted standard for x-max is the point where BL goes below 70%. A lot of the conventional wisdom about box building has gone upside down and the folks who wrote the loudspeaker cookbook certainly weren't considering woofers with a 50 pound+ motor, 27mm x-max, and a suspension stiff enough to stand on. Fundamentals are still the same, but we've gained a bit of flexibility for our ported alignments. If you use winISD and enter correct TSPs it's pretty good predicting port velocity to keep yourself out of the problem areas. I would agree that it's very hard to do "too big" and generally speaking too small will give you a lot more trouble. The ratios of "15 square inches per cube XX inches long" were cookie cutter boxes for a couple different woofer brands (Shocker Mike was big into this and DD uses similar box). The ratio of area to space PLUS the length are to keep a tuning within where that driver wants to tune and does assume you're using the appropriate volume for each size driver. Mostly these "how many square inches per cube" rules will keep you out of trouble. IMO go as big as you feasibly can. It's much easier to shrink a port than to make it wider. Also I've had a long day and am half asleep so if any of this doesn't make sense LMK and I'll clarify or edit. [/QUOTE]
Insert quotes…
Verification
Post reply
Forum
Car Audio Discussion
General Car Audio
Geting Proper Port Area
Top
Menu
Home
Refresh