Open Baffle vs Box Speaker Question - Page 2 - diyAudio
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 21st May 2005, 07:21 PM   #11
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally posted by dmason
could comment abit on his Visaton B200 experience, as this driver is ~ideal for OB with a Q=7, it is reasonably priced
My experiences were very pleasant. Used on a baffle about 1.2 x 1.1 m made from donated plexi from ICBC (saved from the dumpster). I still might get the opportunity to go back to them, but will need to come up with something a bit more room friendly (or get someone to buy me a big flat panel TV of projection screen -- so i can flip my room 180 degrees)

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 21st May 2005, 07:23 PM   #12
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Default Re: the reason I ask

Quote:
Originally posted by Robert McLean
miscellaneous, inexpensive, unknown drivers I have lying around. Some are pulled from old console stereos, some are from ebay, one is 3 way car speaker
Rob

Got pictures... maybe we can turn them from unkown into at least knowing a bit about them.

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 21st May 2005, 08:02 PM   #13
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
Actually many car speakers will work quite well for OB applications, since most are intended for IB type scenarios and feature high Qts. I suggested as much in a previous post and was scolded by someone - shall we say - less informed.. Another thing is that cardboard IS a great material to work with for baffle shape. Use a wood baffle just wider than your (mounted) driver, then add cardboard in every shape and direction to get your final shape. Measure away. Then build it in wood.
I'm working on an inexpensive OB/monopole modular speaker that will use computer, car and ceiling speakers. Thats right. Ceiling speakers!
I also have plans for a folding wing dipole PA speaker. Literally a fold-up speaker! Ah yes, the fun never ends.

Enjoy

AJ
  Reply With Quote
Old 21st May 2005, 08:47 PM   #14
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
I should have posted this link as well.
http://home1.stofanet.dk/troels.grav...ndex_b/OBS.htm

And remember, the high Qts only means you dont have to apply as much eq (if any). You are still limited in the bass (SPL) by excursion. Again refer to the bible on OB
http://www.linkwitzlab.com/spl_max1.xls

Read, then re-read that site.
There is MUCH there to be learned.

Cheers,

AJ
Attached Images
File Type: jpg orionsservosub 011.jpg (64.4 KB, 1394 views)
  Reply With Quote
Old 21st May 2005, 08:49 PM   #15
dmason is offline dmason  United States
diyAudio Member
 
Join Date: May 2004
Location: Republik of Kalifonia
AJ

Ceiling speakers are a many splendored thing; the Radian 508, and Beyma 8agn among others are all "ceiling" speakers. The Radians sound ALOT like Lowthers. (the good parts)

The Ciare CH250 is a "car" speaker. If so, it is the King Of All Car Speakers...

I like your idea about using cardboard to shape a baffle. Sonotube and plywood cylinders also need be mentioned here as one could work that into a very sweet looking curve using a fraction of a half-cut tube.

Which ceiling and computer speakers, inquiring minds wish to know...
__________________
"Pilau Buggah, Big Islan Mo Betta!!"
  Reply With Quote
Old 21st May 2005, 09:17 PM   #16
diyAudio Member
 
Join Date: Apr 2004
Location: Costa Rica
Send a message via AIM to johninCR Send a message via MSN to johninCR Send a message via Yahoo to johninCR
I have to side with AJ over DMason regarding cardboard for OB testing although the best is the foam filled posterboard used for architect's models (but it's not free). A narrow wooden baffle to mount the drivers, tape, and cardboard and go to town. While almost anything will work as a flat baffle, almost anything not very heavy and/or well braced is going to flap in the wind, so use something easy to work with since bass extension is what you are testing.

Hinges to join the wings to the front baffle give you flexibility, but unless you make them very heavy you will feel vibrations in them if folded. I opt for permanent folded and braced wings.

A compromise never mentioned of big flat baffles is the large reflective surface you create which is directed at your seating position and also blocks reflections from the rear wall. I believe this is a major cause of OB's not imaging as well as a tall narrow boxed speaker. I prefer to sacrifice pure dipole radiation for better imaging.

WRT testing, do it in room from your listening position. Also, very high Qts drivers are a little harder to work with because you have a rising bass response down to Fs. If you get just the right match of dipole bass rolloff due to baffle size with the increasing bass response of the driver then you can create magic, but it's tricky. I stick with Qts's below 1 and usually determine the baffle I want, then test to see what the actual bass extension is and figure out how to improve from there. Then final tuning is simplified with variables of placement, rear wave attentuation, and crossover changes all of which are very quick and easy without a closed box.
__________________
Everyone has a photographic memory. It's just that most are out of film.
  Reply With Quote
Old 21st May 2005, 10:16 PM   #17
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
Default Cheapo dipole

Hi dmason,

I've heard the Radian. I have not heard the Beyma. The Radian was nice sounding, but 1mm Xmax makes not an OB speaker. Too many compromises. Both will cost more than the ENTIRE speaker system I'm building. I'm going to call it the SCAD. Simple Cheap Active Dipole. I'll use them in the rear of my theater and bring them to DIY events. Dipole, well sort off, since dipole bass = $$$. A cheap large dia. woofer and a huge baffle can circumvent this, but defeat the purpose. These will be small (11"x11" footprint). Monopole sub. Dipole on upwards. Logitech Z-2200. Here it is:
http://www.tomshardware.com/consumer...and_to_the_ear
Same sub, the Z2300 satellites are smaller. $65 with shipping!
The ceiling speakers are these: http://www.jbl.com/home/products/pro...HTI&sCatId=IWO
OB off course. I like the 2k XO on the tweeter. Shows good design. Diffuser will be chopped. Aluminum midbass driver too.
I've found them on ebay for just over $100/pr.
Probably $250 for the whole mess (1 sub/ch). That will be version 1.
Believe it or not that's a decent little amp in the Logitech. 200w RMS might be a stretch, but numerous reviews have measured peaks of 110+db from that little TB driver, which can't be more than 90db efficient (if that!). So somethings going on there. I can't beat that for 65 bucks even if I built it myself. Version 2 will use sonotube and .....
Well, we'll see

Cheers

AJ
  Reply With Quote
Old 21st May 2005, 11:11 PM   #18
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
A really good car speaker for OB use s the GM/Delco 6x9 whizzer cone driver. Found in 4 ohm & 10 ohm versions. Keep your eyes out at garage sales... invariably somebody has replaced theirs with $100 plus triaxials and the better FR is going for a pittance.

Tannoy ceiling speakers are probably one of the least expensive sources of new dual concentrics.

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 21st May 2005, 11:45 PM   #19
AJinFLA is offline AJinFLA  United States
Banned
 
Join Date: Feb 2005
Location: Tampa
That is correct Dave!
You will find suitable OB drivers in the least likely places. I comb ebay lurking for such items. Ceiling speakers by Tannoy, KEF, Paradigm, etc. Car models too. High Qts and decent Xmax wanted. I picked up a pair of brand new Dynaudios about a week ago for about $220 with shipping! These actually
http://www.dynaudio.de/eng/mobile/driver/mw180.htm.
Shhh, don't tell too many people . I hate bidding wars
I have way too many drivers sitting around right now, so I'll probably stay off ebay for a while now. Unless of course something tasty comes along......

Cheers,

AJ
  Reply With Quote
Old 21st May 2005, 11:49 PM   #20
Illusus is offline Illusus  Canada
diyAudio Member
 
Illusus's Avatar
 
Join Date: Sep 2002
Location: Prairie Wasteland, Canada
Delco's - you can also get them for a song or smile from your local auto-graveyard.
Ford 5x7 with whizzers sound great too, I've tried them on open baffles and they sounded pretty good. The Ford speakers have a glued on grill though, kind of a pain to remove without wrecking the surround but it's doable. I don't worry about destroying them though, I get as many new ones as I want for free through my work. I use them for experimenting.

Anybody want some?
__________________
Fighting the program since 1976.
  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
My first Open Baffle Speaker audiojoy Multi-Way 197 2nd September 2010 10:29 PM
Open Baffle Speaker Positioning wixy Multi-Way 2 9th January 2009 11:45 AM
Open Baffle Speaker Design using BG Neo-8? Matt MacBeth Multi-Way 2 24th December 2002 03:44 AM


New To Site? Need Help?

All times are GMT. The time now is 07:23 PM.


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