Log in
Register
Home
Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
News
Members
Current visitors
New profile posts
Search profile posts
Features
Log in
Register
Search
Search titles only
By:
Search titles only
By:
New posts
Search forums
Menu
Install the app
Install
Reply to thread
Home
Forums
Low Earth Orbit
DIY Audio
Solution for beaming?
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="Bennett Prescott" data-source="post: 74319" data-attributes="member: 4"><p>Re: Solution for beaming?</p><p></p><p>John,</p><p></p><p>Depending on your crossover point, the dual 15" design (assuming the standard vertical arrangement) exhibits several problems.</p><ol> <li data-xf-list-type="ol">The physical size of the woofer itself begins to cause beaming at a relatively low frequency, depending on your desired dispersion you may be limited here.</li> <li data-xf-list-type="ol">The physical arrangement of the two 15s vertically means you are going to have polar pattern asymmetry, as they are several wavelengths long at the usual XO points.</li> <li data-xf-list-type="ol">Above about 800Hz (give or take, depending on design) the 15" begins to have internal reflection problems. Sound is emitted from the voice coil, travels along the cone, and is partly damped at the surround. The whole cone doesn't move at the same rate, and the wave propagating to the surround isn't perfectly absorbed, so the energy reflects from the surround and travels back down the cone to the voice coil where it interferes and causes time smear with your intended radiation. For this reason using a 15" woofer above about 800Hz usually results in a less desirable midrange character due to time smear from this re-emission.</li> </ol><p></p><p>The device you mention, essentially a simple phase plug, can help with only 1/3 of your problem.</p></blockquote><p></p>
[QUOTE="Bennett Prescott, post: 74319, member: 4"] Re: Solution for beaming? John, Depending on your crossover point, the dual 15" design (assuming the standard vertical arrangement) exhibits several problems. [LIST=1] [*]The physical size of the woofer itself begins to cause beaming at a relatively low frequency, depending on your desired dispersion you may be limited here. [*]The physical arrangement of the two 15s vertically means you are going to have polar pattern asymmetry, as they are several wavelengths long at the usual XO points. [*]Above about 800Hz (give or take, depending on design) the 15" begins to have internal reflection problems. Sound is emitted from the voice coil, travels along the cone, and is partly damped at the surround. The whole cone doesn't move at the same rate, and the wave propagating to the surround isn't perfectly absorbed, so the energy reflects from the surround and travels back down the cone to the voice coil where it interferes and causes time smear with your intended radiation. For this reason using a 15" woofer above about 800Hz usually results in a less desirable midrange character due to time smear from this re-emission. [/LIST] The device you mention, essentially a simple phase plug, can help with only 1/3 of your problem. [/QUOTE]
Insert quotes…
Verification
Post reply
Home
Forums
Low Earth Orbit
DIY Audio
Solution for beaming?
Top
Bottom
Sign-up
or
log in
to join the discussion today!