1/4 wave, 1/2 wave, full wave? - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #11 of 19 Old 12-11-08, 10:42 AM
Elite Shackster
 
Mike P.'s Avatar
Mike
 
Join Date: Apr 2007
Location: Chitek Lake, Sask.
Posts: 19,397
Re: 1/4 wave, 1/2 wave, full wave?

Now that we got the spelling correct, what does it mean?




We're all in this together!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Mike P. is offline  
Sponsored Links
Advertisement
 
post #12 of 19 Old 12-11-08, 04:23 PM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
Mike P. wrote: View Post
Now that we got the spelling correct, what does it mean?
That you're apparently a bachelor.
Bill Fitzmaurice is offline  
post #13 of 19 Old 12-11-08, 05:27 PM Thread Starter
Banned!
jordan powell
 
Join Date: Sep 2008
Location: 18th and bahnson! sfsd
Posts: 361
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
Bill Fitzmaurice wrote: View Post
Horns are considerably less expensive than direct radiators, as they get far better results per driver. My 8 cubic foot HT sub is loaded with a $35 eight incher, and goes as low and loud as SHMBO will tolerate. Commercial horns are expensive due to their high labor costs to build. That's not a factor in the DIY realm.

pics/vids/links??
kryptonitewhite is offline  
 
post #14 of 19 Old 12-11-08, 05:31 PM Thread Starter
Banned!
jordan powell
 
Join Date: Sep 2008
Location: 18th and bahnson! sfsd
Posts: 361
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
Bill Fitzmaurice wrote: View Post
Oops, SWMBO.
she wears my b____ no, not it...
kryptonitewhite is offline  
post #15 of 19 Old 12-11-08, 06:02 PM
Elite Shackster
 
Mike P.'s Avatar
Mike
 
Join Date: Apr 2007
Location: Chitek Lake, Sask.
Posts: 19,397
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
Bill Fitzmaurice wrote: View Post
That you're apparently a bachelor.
I've been married 28 years. A Google search turned up "She Who Must Be Obeyed". Apparently I don't have that problem.




We're all in this together!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.

Mike P. is offline  
post #16 of 19 Old 12-12-08, 08:31 AM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
kryptonitewhite wrote: View Post
pics/vids/links??
On my website.
Quote:
I've been married 28 years. A Google search turned up "She Who Must Be Obeyed". Apparently I don't have that problem.
Have submitted your name to Ripley's 'Believe It or Not' !
Bill Fitzmaurice is offline  
post #17 of 19 Old 12-14-08, 10:46 AM Thread Starter
Banned!
jordan powell
 
Join Date: Sep 2008
Location: 18th and bahnson! sfsd
Posts: 361
Re: 1/4 wave, 1/2 wave, full wave?

So I am using this lazy day to finally do some much needed research....and I've already found some info that surprised me. Toward the top, I am being told a transmission line loudspeaker is merely an infinite baffle, where the sound is absorbed... basically to make it run "free air" yet isolating the rear wave. I assume this refers to midrange speakers, not subwoofers, as toward the end it speaks of the rear wave emerging "in-phase" to enhance low frequency output. While speaking of the loudspeaker, though, it did say it will extend low frequency below 1/2 wavelength....

http://en.wikipedia.org/wiki/Acousti...smission_lines

The difference between a transmission line loudspeaker and a vented loudspeaker system is clear: the rear wave is audibly absorbed and the cavity does not form a tuned system.

Transmission Line Loudspeakers have:

1. minimal acoustic output from the enclosure except from the driver;
2. accurate bass, without 'boom';
3. excellent transient response;
4. typically, extended bass below a half wave frequency of the reflected line length e.g. 30Hz=8 foot length;
5. typically, smoooth impedance curves, possibly from a lack of frequency-specific resonances;
6. low efficiency.








"Transmission line" is also the name of a specialized audio speaker enclosure topology, in which sound from the back of the bass speaker chassis passes along a long (generally convoluted) path within speaker enclosure and emerges from the open end of the path "in-phase" with the sound radiated from the front of the driver, enhancing the output level at low frequencies.



It all makes sense, the only new news to me is that it is saying for upper range it acts as an IB of sorts, until the 1/2 wave is reached, then it reinforces... which is really the whole idea, right?
kryptonitewhite is offline  
post #18 of 19 Old 12-14-08, 11:34 AM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: 1/4 wave, 1/2 wave, full wave?

Quote:
kryptonitewhite wrote: View Post


It all makes sense, the only new news to me is that it is saying for upper range it acts as an IB of sorts, until the 1/2 wave is reached, then it reinforces... which is really the whole idea, right?
It all makes sense, but much of it is incorrect. The problem with wikipedia is that anyone can post anything, and accuracy is not guaranteed. The definitive work on TLs was done in the late 1990s by George Augsperger, his results were published in the JAES and AudioXpress Magazine. As to who he is, should you ever submit a treatise on loudspeakers to the JAES chances are it will be George who passes judgment on it.
Bill Fitzmaurice is offline  
post #19 of 19 Old 12-14-08, 12:51 PM Thread Starter
Banned!
jordan powell
 
Join Date: Sep 2008
Location: 18th and bahnson! sfsd
Posts: 361
Re: 1/4 wave, 1/2 wave, full wave?

I went to walmart, glanced at pillows on the way, probably should have looked in the fabric/hobby section for pillow stuffing? Didn't see any by the actual pillows. How much should I use? Does it need to run throughout, or just a section?
I'm guessing my massive 4" with 6mm p-p won't warrant chicken wire and stapling...
kryptonitewhite is offline  
Reply

Bookmarks

Tags
full , wave , wave?

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome