Help with Sub Plans - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 29th April 2004, 07:27 PM   #1
diyAudio Member
 
Join Date: Apr 2004
Location: Kalifornia
Default Help with Sub Plans

I have a single 12" sub that only has a recommended sealed box specs at 27L. But I'm curious as to what makes a speaker sutible for a ported enclosures, and what would work well in my case in wanting good low freqency extension with high SPL capability.

All the specs I can find are listed below:

RE 2x 3.2
QMS 9.09
QES .39
QTS .37
FS 33.5
VAS 60.5L
CMS .16mm/N
sens 86db
Xmax 8.99mm


WinISD gave me a ported Enclosure of 45.5L with a 4" dia port, 12.6" long tuned to 36Hz.
  Reply With Quote
Old 29th April 2004, 10:13 PM   #2
diyAudio Member
 
Timn8ter's Avatar
 
Join Date: Jul 2003
Location: Seattle, WA
Would I be right that this is a driver typicially used in auto sound? I think the low Vas and somewhat short Xmax is what gets you here. If you put it in a vented enclosure your power handling will go down but it'll work ok. Your enclosure numbers seem ok. Depends on what your goals are.
  Reply With Quote
Old 29th April 2004, 11:20 PM   #3
diyAudio Member
 
Join Date: Apr 2004
Location: Kalifornia
Thanks Tim!

You know I used to live in Seattle during the .com days. Boy I sure miss the great north west. I was just there recently to see some friends and stop by in Whistler and Vancouver for some shoippingand snowboarding, and boy do I miss the cool, crisp, clean air. I don't have that in San Diego.
  Reply With Quote
Old 30th April 2004, 05:01 AM   #4
diyAudio Member
 
Timn8ter's Avatar
 
Join Date: Jul 2003
Location: Seattle, WA
Don't tell anybody but it's hardly rained here this month and the temps will be in the upper 70's this weekend. It'll be our secret.
  Reply With Quote
Old 30th April 2004, 09:22 AM   #5
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Reflexing is not a problem. In fact the lowish Vas (so not ultra low Fs) makes it ideal for
reflexing, as subsonic power handling will be far better than a driver with much higher Vas.

Power handling will go down over sealed, but maximum SPL will
increase considerably in the low bass, equivalent to 4 12" sealed,
and it will take less juice to get there, high power handling only
by the fact there is no low bass to speak of is pointless.

sreten.
Attached Images
File Type: gif unknown.gif (60.0 KB, 219 views)
  Reply With Quote
Old 30th April 2004, 05:05 PM   #6
diyAudio Member
 
Join Date: Apr 2004
Location: Kalifornia
Fantastic, thank you Streten.

Ported it is!
  Reply With Quote
Old 30th April 2004, 09:01 PM   #7
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
I was curious as to why 27 litres sealed is recommended and
then I noticed the Re is quoted as 2 x 3.2R, 4 ohm per coil.

Hmmm......

A dual voice subs parameters are usually given with the coils
in parallel. Fine for a passive sub with each coil driven by each
channel of a 4 ohm capable amplifier, but 2 ohm is not a good
load for the huge majority of plate subwoofer amplifiers.

Is 27 litres sealed for the coils in series parameters ?

sreten.
  Reply With Quote
Old 30th April 2004, 09:17 PM   #8
diyAudio Member
 
Join Date: Apr 2004
Location: Kalifornia
I'm sorry. This is a car woofer that is from MB Quart. It's a dual voicecoil 12" sub rated at 4 ohm per coil. Model DWE304 I think.

I have this sub and a Dayton 10" MKII sub as well. MB Quart only recommends a sealed enclosure of 27L, and never mentions a ported enclosure.

I'm kind of curious based on recommended enclosures and predicted graphs which would be better and where. I figure I'll put the Dayton in my home in a recommended enclosure based on Parts Express's designs, probably using a sonotube. And the MB Quart maybe better suited in my car it seems.
  Reply With Quote
Old 30th April 2004, 09:35 PM   #9
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Well you do get 2 ohm rated car amplifiers, but not home sub
plate amplifiers. You can always use a stereo 4 ohm amp to
drive each voice coil (paralled inputs) for in car use.

For in car use its quite simple - nearly every 12" sub is designed
for a ~ 1 cuft sealed box and it would be fine in this application.

For in-car use box volume is a major issue. Sealed with a amplifier
with a bass boost feature is probably better in car, though the
blue line with a flat amplifier probably would be a good choice.

sreten.
  Reply With Quote
Old 30th April 2004, 11:19 PM   #10
diyAudio Member
 
Join Date: Apr 2004
Location: Kalifornia
I have a Chevy Suburban, so box volume is not an issue I can seat 9 passengers, and still haul a bunch of junk in the trunk.

I've never been a fan of bass boosts, they sound terrible and too boomy and artificial.
  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
Has anyone got any plans for a car amp? GW Chip Amps 1 27th May 2004 01:41 PM
Has anyone got any plans for a car amp? GW Tubes / Valves 4 27th May 2004 05:27 AM
Plans Miha Multi-Way 1 21st April 2004 11:25 PM
VTA plans someone? Zen Mod Analogue Source 7 31st January 2003 01:56 AM
Plans and changes Andy G Multi-Way 4 30th September 2002 02:30 PM


New To Site? Need Help?

All times are GMT. The time now is 12:23 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