4th order bandpass, wheel well design :) (design inside) - Page 2 - diyAudio
Go Back   Home > Forums > General Interest > Car Audio

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th January 2008, 06:47 PM   #11
TWOJZ is offline TWOJZ  Australia
Account Disabled
 
Join Date: Sep 2007
ok, the other issue I have, is that I want to put a round port through the rear deck, but I want to have a rectangle port coming out of the box...

is there any real issues with having a round port coming out the side of a rectangle port, assuming they are both the same crossectional area?

edit: for those of you who have no imagination...

Click the image to open in full size.
  Reply With Quote
Old 7th January 2008, 06:59 PM   #12
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
In a bandpass box you are likely to get better performance with a driver designed with more common sense (I mean no donut surround, no bulky cosmetic motor not to be seen by anybody, no ultra heavy cone and voice coil, etc...)


With this approach you are likely to get 2 cavities tuned to 2 different frequencies, and as a result, very very low Q. Bends in a port also hurt efficiency badly because the moving air mass has to change direction and some energy is lost in the process.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 7th January 2008, 07:01 PM   #13
TWOJZ is offline TWOJZ  Australia
Account Disabled
 
Join Date: Sep 2007
Quote:
Originally posted by Eva
In a bandpass box you are likely to get better performance with a driver designed with more common sense (I mean no donut surround, no bulky cosmetic motor not to be seen by anybody, no ultra heavy cone and voice coil, etc...)

umm... donut surround?

what exactly are you trying to say? lol

that it wont get loud?
  Reply With Quote
Old 7th January 2008, 07:33 PM   #14
TWOJZ is offline TWOJZ  Australia
Account Disabled
 
Join Date: Sep 2007
anyhoo! the sub will be here tomorrow, and I'm reading, but not really paying much attention to "Eva's" posts

nothing against you, but, maybe could you stop posting in this thread? lol
  Reply With Quote
Old 7th January 2008, 07:36 PM   #15
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
Sorry, it's just more wise to quit.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 7th January 2008, 07:40 PM   #16
diyAudio Moderator
 
pinkmouse's Avatar
 
Join Date: Apr 2002
Location: Chatham, England
Quote:
Originally posted by TWOJZ
...but not really paying much attention to "Eva's" posts
Why not? It's good advice.
__________________
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 8th January 2008, 12:42 AM   #17
ppia600 is offline ppia600  United States
diyAudio Member
 
Join Date: Jun 2007
Location: Louis y ana
Quote:
Originally posted by TWOJZ



not really... although mounting it at an angle may reduce the height needed for mounting the basket, the basket will then stick up higher... if that makes sense?

http://www.mtx.com/caraudio/products..._slideshow.cfm
Yeah, mounting it at an angle would help a couple of things including height, which you'll need to try and save if you want it as low as possible in the well.


Quote:
Originally posted by TWOJZ
ok, the other issue I have, is that I want to put a round port through the rear deck, but I want to have a rectangle port coming out of the box...

is there any real issues with having a round port coming out the side of a rectangle port, assuming they are both the same crossectional area?

edit: for those of you who have no imagination...

Click the image to open in full size.
Eva was partially correct in that if you use a design exactly like the picture (we know its not to scale) the transition from the square port to the round tube will cause issues.... BUT if you are creative and can negate turbulence by a creatively designed port with smooth transistions, you can increase the lowpass rolloff and keep the efficiency.


Quote:
Originally posted by Eva
In a bandpass box you are likely to get better performance with a driver designed with more common sense (I mean no donut surround, no bulky cosmetic motor not to be seen by anybody, no ultra heavy cone and voice coil, etc...)


With this approach you are likely to get 2 cavities tuned to 2 different frequencies, and as a result, very very low Q. Bends in a port also hurt efficiency badly because the moving air mass has to change direction and some energy is lost in the process.
Whatever.. Mtx makes great speakers and amplifiers. They are some of the most technologically advanced woofers out there. Sure they make some low line models that are marketed for penny pinchers, but the 9500 series is a very well designed woofer.


Quote:
Originally posted by TWOJZ



umm... donut surround?

what exactly are you trying to say? lol

that it wont get loud?
He's probably trying to hate on the large surround because some cheap companies have woofers with huge surrounds. What he's failing to mention is that the cheapo companies try to emulate designs of better companies to sell their flea market stuff. Mtx just happens to make nice woofers with good xmax. The large surround just happens to help achieve this.


Quote:
Originally posted by Eva
Sorry, it's just more wise to quit.
Negative much??


Quote:
Originally posted by pinkmouse


Why not? It's good advice.
TWOJZ is doing what many people have given up on.. some because some think they've learned everything there is to know.. and others because they've lost the energy and motivation to try. He's experimenting and trying to be creative. Why not be positive and give some helpful positive suggestions. Some people here brag about using cheapo woofers to get awesome results. Why mock an excellent woofer that has the capability of making excellent spl and sq if used in a properly designed system. Who knows? He might hit the sweet spot his car and speaker like with that box and impress a lot of people. I wish I still had the spare time and motivation to play around with my system like that.






(I love Mtx. I'll be first in line when they come out with their shallow subs. I just hope its soon!!! )
__________________
Don't worry... you can always turn the gain down!
  Reply With Quote
Old 8th January 2008, 02:43 AM   #18
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
There are probably far more happy owners of my custom bandpass enclosures out there than there will ever be of yours.

You are going to fail. No more free advice, except that I find everything that MTX and other classic brands are currently making of very little use.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 8th January 2008, 04:54 AM   #19
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
The first example that came handy...
Attached Images
File Type: jpg subaru_001.jpg (87.7 KB, 264 views)
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 8th January 2008, 04:56 AM   #20
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
So that nobody can think that I lie...
Attached Images
File Type: jpg subaru_004.jpg (97.6 KB, 258 views)
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
6th order bandpass design - TheWacoKid Subwoofers 5 2nd August 2006 03:02 PM


New To Site? Need Help?

All times are GMT. The time now is 12:17 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2