imaging and stage depth - 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 7th January 2008, 01:05 PM   #1
peterr is offline peterr  Netherlands
diyAudio Member
 
peterr's Avatar
 
Join Date: Apr 2002
Location: Amsterdam
Default imaging and stage depth

Hi All,

I have been using a pair of Fostex 168ESigma BIBs for the best part of a year now and generally I am quite happy with them.

If you read the giant BIB thread you will see that is almost exclusively about low frequency reproduction and how well the BIB does this. I agree they do very well in this respect but I find I am less impressed with what they do in other areas. Especially imaging and stage depth (of MY pair) are not as good as I hoped. I built them as a first entrance into the world of full range drivers so I am unsure about what is BIB related and what isnít.

I have experienced a lot with placement and damping but although it makes a difference it doesnít bring what I am looking for. Is this something others have experienced too? And if so have you been able to improve things?
When I started this project I thought (perhaps wrongly so) that full rangers generally image very well. Is this true at all?
Would a different box (MLTL?) be any better at it?
I really hope somebody can shed some light here.
Thanks,
Peter

My BIB:
Click the image to open in full size.
__________________
Keep an open mind. It helps.
Peter
  Reply With Quote
Old 7th January 2008, 01:11 PM   #2
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Well, looking at the picture, you need to get them positioned right. For a start, they're corner horns, so they need those to work properly. Imaging is very much a strong point with these cabinets in my experience, so it could be that there's something wrong elsewhere in your system or room.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 7th January 2008, 01:21 PM   #3
peterr is offline peterr  Netherlands
diyAudio Member
 
peterr's Avatar
 
Join Date: Apr 2002
Location: Amsterdam
Quote:
Originally posted by Scottmoose
Well, looking at the picture, you need to get them positioned right. For a start, they're corner horns, so they need those to work properly. Imaging is very much a strong point with these cabinets in my experience, so it could be that there's something wrong elsewhere in your system or room.
Thanks for the quick answer, Scott. I have tried them in the corner but if I do that they are 4 meters apart and I get a big empty hole in the middle.
__________________
Keep an open mind. It helps.
Peter
  Reply With Quote
Old 7th January 2008, 03:58 PM   #4
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
I hate to say this, but you might have picked the wrong boxes for your situation I'm afraid. Therein lies the problem with speaker design / choosing what to build: there is no one-size-fits-all solution, and everything comes into play -system, preferences and the room (particularly the latter in the case of something like a corner horn, which uses the room as part of the cabinet).

You might want to look at one of the double horn cabinets like Chili. Currently the curved front version is not on the site, but drawings have been completed. For the 168, the throats will need changing to 0.75in long (thickness of the build material) and 0.5in deep (each) front-back. Won't go as low, but it'll probably suit your room better.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 7th January 2008, 04:27 PM   #5
rdf is offline rdf  Canada
diyAudio Member
 
rdf's Avatar
 
Join Date: Jun 2004
Location: big smoke
Hi peterr. If that picture is any indication I'ld start by moving the equipment rack. Another experiment is checking the impact on imaging of moving the speakers forward of the rack. In my experience the strong interference and reflections caused by having so many obstructions between listener and speaker will be a major factor.
__________________
Ears aren't microphones.
  Reply With Quote
Old 7th January 2008, 04:53 PM   #6
hm is offline hm  Europe
diyAudio Member
 
hm's Avatar
 
Join Date: Feb 2004
Location: near Hamburg Germany
Hello,
or it might be:
to much mids 300 - 400 Hz coming
through the horn to late with to much area,
this can be a lost of soundstage.
__________________
http://www.hm-moreart.de
  Reply With Quote
Old 7th January 2008, 05:06 PM   #7
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
There shouldn't be any coming out. If there is, the cabinets haven't been damped right. The bend attenuates a lot, but not everything. As a general rule, the front of the internal baffle & one side-wall (1st half of the horn) need lining with damping material from the top to roughly 6in below the driver. And the internal base needs a nice layer of the same. Final tweaking can be done with a pennant of material hanging down the 2nd half of the horn flare.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 8th January 2008, 12:40 AM   #8
kirbyt is offline kirbyt  Canada
diyAudio Member
 
Join Date: Dec 2006
I recently made some bibs housing fostex 168 sigmas and my initial impressions are quite good, especially given that I've heard these drivers need a bit of time to loosen up, i only have maybe 60+ hrs on them right now. My cabinets are not in an ideal room (large open area in my house) nor right in the corners (right tight to the wall though) but I find the imaging to be pretty decent. Previous to the bibs, I've been listening to klipsch cornwalls, had some coral flat 10's (placed in cabinets not well suited so no real comparison here) some hammer dynamics and my tannoy monitor golds (which I have not listened to for awhile) all on the same equipment. My bibs are based on the latest measurements on the bib sight And I have supra baffles, as well my front baffle of the cabinet is two layer which pulls the driver almost completely out of the horn throwt. I dont know if this helps at all but I thought I'd share it.
Attached Images
File Type: jpg 000_0171.jpg (60.4 KB, 1060 views)
  Reply With Quote
Old 8th January 2008, 12:58 AM   #9
diyAudio Member
 
Godzilla's Avatar
 
Join Date: Nov 2005
Location: New York
Those look really nice! I feel BIBs produce a large and involving image. But i also realized when i moved my BIBs from one room to another that imaging suffered due to very bad room acoustics. Treating walls with sound absorbing materials prevented major echoes and minimized a lot of wall reflections. Maybe you have some room issues that might be a problem for any speaker in that space. Since the BIBs fire a lot of sound upward you may consider treating your ceiling above the BIBs or the side walls where you can. I think once you figure how room accoustics are making things worse you can then focus on making it better... and getting back your imaging!

Godzilla
  Reply With Quote
Old 8th January 2008, 04:16 AM   #10
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Default Re: imaging and stage depth

Quote:
Originally posted by peterr

I really hope somebody can shed some light here.
Thanks,
Peter

My BIB:
Click the image to open in full size.

2 Things:

1. They are way to close to your front wall. This seems to be a pertinent thread to your dilemma:

http://www.audioasylum.com/cgi/vt.mpl?f=hug&m=130282

2. Make sure there is no "stuffing" near the driver itself. See my #19 post here:

My Fostex FE 108EZ project, Part 2
__________________
perspective is everything
  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
what's depth, transparency, imaging? kevinkuang Multi-Way 38 7th April 2005 03:22 PM
socket mounting depth tenderland Tubes / Valves 10 17th March 2005 01:55 PM
Depth of Peerless CSX 10inch? macky888 Multi-Way 3 23rd May 2004 12:45 PM


New To Site? Need Help?

All times are GMT. The time now is 10:22 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