Go Back   Home > Forums > Loudspeakers > Full Range

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 June 2012, 07:17 PM   #1
diyAudio Member
 
stochastic's Avatar
 
Join Date: Feb 2012
Location: Vancouver, BC, Canada
Default Alpair 10.1 in a car - enclosure design...

Hi, I'm in the slow process of building a car audio system in my new car. I've already built a diffuser into the headliner (doesn't look all that pretty, but doesn't look horrible). I've got a CSS SDX10 sub that'll go into a sealed (I'm pretty sure) enclosure in the rear, and I've got a pair of Mark Audio Alpair 10.1's that I plan on putting in the corners where the dash meet the windshield. I'll probably be crossing the speakers over around 100Hz so low frequency extension on the Alpairs isn't needed - but if I can get the extension then maybe I won't high-pass the Alpairs.

My question is on the enclosure design for the Alpairs - I have nothing built yet so all is flexible.

My current plan (based on the limited space I have) is to create a fiberglass enclosure for each speaker that runs slightly up the a-pillar (about 12" or so) and also runs along the dash just under the windshield. The dash portion of the enclosure will be about 3" wide by about 1-2" tall. It will have either a crescent moon or an eye cross-sectional shape to it and will be about 23" long. I think the general cross-sectional volume of the a-pillar enclosure portion will be in the same ballpark as the dash portion. Directly behind the speaker itself will have a larger volume as it will be mounted on an angle in the corner.

Should I design this as a sealed enclosure or put open holes at the center of the car where the two boxes meet to turn the enclosure into a TL? If it's a TL, should I direct the ports with an angle toward any given direction? Will a center porting of these enclosures loose stereo imaging? Do I even need an enclosure this large if I'm high-passing the speakers at 100Hz - would just the a-pillar portion of the enclosure suffice?

Any other ideas on my design? Am I setup for failure or success? And yes, I know a car is a poor acoustic environment for audio reproduction, but I'm enjoying this project and the challenges that it includes.

Last edited by stochastic; 7th June 2012 at 07:21 PM.
  Reply With Quote
Old 7th June 2012, 08:04 PM   #2
diyAudio Member
 
Join Date: Jan 2012
i put my MA chr-70.3's into small reflex boxes mounted on my cars rear shelf. they do a pretty decent job in a crappy environment.
  Reply With Quote
Old 7th June 2012, 09:45 PM   #3
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Mark should probably address this, but I'd be really careful ( as in wouldn't even thinking about) running any lightweight metal cone drivers in an auto or boat system. CHP or EL70, or Fostex FFxxxWKs, sure - even then I'd want to XO them above 150-200 HZ and tread carefully with the volume control.
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote
Old 7th June 2012, 10:28 PM   #4
diyAudio Member
 
stochastic's Avatar
 
Join Date: Feb 2012
Location: Vancouver, BC, Canada
Quote:
Originally Posted by chrisb View Post
Mark should probably address this, but I'd be really careful ( as in wouldn't even thinking about) running any lightweight metal cone drivers in an auto or boat system. CHP or EL70, or Fostex FFxxxWKs, sure - even then I'd want to XO them above 150-200 HZ and tread carefully with the volume control.

Care to explain why? (consider me a newb to the DIY scene)
  Reply With Quote
Old 7th June 2012, 10:39 PM   #5
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
The metal cones are very very thin, so can be easily damaged where a paper or poly cone might shrug off any accidental collisions.

That said, the comments about crossover points say he's on about too much LF energy getting to the drivers. I don't think that'll be a problem, and I'd expect a 100Hz XO (so the subwoofer's position isn't obvious when you hear it) would be fine: the fact that you're wanting to use MA drivers says to me you're looking for more quality of sound than being able to do hair tricks.

Chris
  Reply With Quote
Old 7th June 2012, 10:49 PM   #6
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
10.1 should be more robust than 10.2 in this environ, i'd build a sealed cabinet and try to get the acoustic roll-off to as close to the intended XO as possible (3-6 litre).

dave
Attached Images
File Type: gif alpair10g1-sealed-sims.gif (21.0 KB, 122 views)
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 7th June 2012, 11:02 PM   #7
diyAudio Member
 
stochastic's Avatar
 
Join Date: Feb 2012
Location: Vancouver, BC, Canada
Thanks Dave.

Chris I sort of doubt that I'll have any accidental collisions with them on the dash behind grill covers. Anything is possible I guess, but I got a good enough deal on them from Bob at CSS (his old stock, mismatched colors) that should anything happen I'll not be too heartbroken. Still sad, just not heartbroken.

So is sealed the obvious and simple choice then? No high-pass filter?
  Reply With Quote
Old 7th June 2012, 11:06 PM   #8
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
I'd still put a 1st order hi-pass on them (PLLXO -- a single cap per channel on the input of the A10's amplifier).

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 7th June 2012, 11:15 PM   #9
diyAudio Member
 
stochastic's Avatar
 
Join Date: Feb 2012
Location: Vancouver, BC, Canada
My amp (Memphis ST1300D) has an optional 18db sloped high-pass on those channels. I'll probably just use that unless there's any reason not to (phase coherence?).

Edit: I'm also going to be running a Rockford Fosgate 3sixty.2 digital signal processor that will digitally EQ everything, so maybe I've already waved goodbye to phase coherence?? Like I said, I'm slightly new to the DIY scene - loving it though.

Last edited by stochastic; 7th June 2012 at 11:27 PM.
  Reply With Quote
Old 7th June 2012, 11:28 PM   #10
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Then i'd go that route...

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  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
Mark Audio Alpair 10 MLTL Design Jim Griffin Full Range 210 5th April 2012 01:11 AM
Cabinet design alpair 10 Ewald Full Range 7 11th February 2011 09:19 AM
Driver/enclosure to complement Alpair 10.2 FR Pensil in a FAST system? southernoise Markaudio 24 7th February 2011 01:04 PM
Alpair-10 - MarkO design from Germany markaudio Full Range 3 23rd February 2010 12:37 PM
Alpair 10 wide bass driver and Alpair 10 Fullrange _henry_ Full Range 71 15th March 2009 11:37 AM


New To Site? Need Help?

All times are GMT. The time now is 12:29 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