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maggnepan
10-18-2006, 06:54 PM
i have rebuilt a pair of L-112s and have to say i amvery pleased,except:
these are the only mirror imaged jbl speakers i have ever owned and am unclear if the tweeter should be on the outside or on the inside. I can not find any lit. on the issue and i feel better somehow with the tweeters playing when they are inside , but that could be a esthictic issue. I dont know...any words of wisdom and does any one know what i mean by miror imaged?

Zilch
10-18-2006, 07:05 PM
http://audioheritage.org/vbulletin/showthread.php?t=12583

Measure the polar response.

[I doubt it's published anywhere....]

Titanium Dome
10-18-2006, 07:07 PM
Usually you'll see them with the tweeters and mids on the outside, though in some instances they might be placed on the inside.

Aside from personal preference, reasons to have them on the outside would be to widen the soundstage, to shorten early reflections, and to create more space in a narrow room.

Having them on the inside would produce opposite effects.

Ideally, the room would allow enough space between speakers and walls that you could simply place the drivers to the outside and be done with it.

SEAWOLF97
10-18-2006, 07:46 PM
http://www.audioheritage.org/vbulletin/showthread.php?p=129730#post129730

I think I extracted that my 4410s s/b hf to hf if in horiz. config. In vert, it makes no difference. Which still doesn't answer why produce a mirror image, if all 3 drivers are in a vertical array...???

If you take driver aliment out of the question, the bass port is the only difference. Still dont know L from R :banghead:

Zilch
10-18-2006, 08:54 PM
Which still doesn't answer why produce a mirror image, if all 3 drivers are in a vertical array...???Diffraction effects. Even if the drivers are vertically aligned, you want them off the centerline so that effects from each edge do not reinforce each other....

DavidF
10-19-2006, 01:19 PM
Here is the manual which has a recommendation within it...

http://manuals.harman.com/JBL/HOM/Owner%27s%20Manual/L112om.pdf

David F

Titanium Dome
10-19-2006, 03:24 PM
Here is the manual which has a recommendation within it...

http://manuals.harman.com/JBL/HOM/Owner%27s%20Manual/L112om.pdf

David F

Thanks for making me look like I know what I'm writing. ;)

MJC
10-20-2006, 04:51 PM
Diffraction effects. Even if the drivers are vertically aligned, you want them off the centerline so that effects from each edge do not reinforce each other....
Having mirrored vertical towers increases the width of the soundstage. At least that's what I found to be true with my mirror L212s, compared to the stock "down the middle L212s".