"Rotatable" EMIT Tweeter?

dave1701

Active Member
I was browsing the catalog for my Infinity RSb speakers today and I noticed that it says this in the breakdown of the drivers:

"Drivers, each channel: One 10-inch (25 cm) RS woofer with polypropylene cone. One 5-inch (12 cm) midrange driver with polypropylene cone. One EMIT Tweeter, rotatable."

Any idea what it means?

RS_brochure_RSb.jpg
 
It means if you are going to place them vertically ( as shown in the picture you posted and which is probably the normal usage) the EMIT opening should be up and down.
For horizontal speaker placement, remove the 4 OUTER (not the ones closest to the EMIT opening) EMIT screws and turn them 1/4 turn with the EMIT opening running up and down.


Edit---OOOPS, EMIT openings should run up and down regardless of speaker orientation.
 
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Part of the EMIT design was limiting the vertical dispersion to reduce reflections from the floor and ceiling. The Qa (Oops sorry, the Qe, thanks swechsler!), being a "bookshelf" speaker had a seperate, plastic, circular backing plate so you could set them on their sides and still have the tweeters correctly positioned. The first generation of EMITs required a square hole, cutting out a circle is much quicker and therefore cheaper, so the second generation, RS and later, of EMIT faceplates are round. Eventually Infinity changed the design of the EMITs to the EMITr which has spiral traces and disperse in all directions..
 
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Part of the EMIT design was limiting the vertical dispersion to reduce reflections from the floor and ceiling. The Qa, being a "bookshelf" speaker had a seperate, plastic, circular backing plate so you could set them on their sides and still have the tweeters correctly positioned. .

Just a nitpick - it was the Qe that had the rotatable tweeter. All other speakers in the Q/Quantum series were designed to be used upright only.
 
That is true, thank you, I will correct it in the original post. I posted rather early in the first morning cup...
 
Interesting. Why would one set their speakers on their sides? Is it just to save space. It's hard to imagine anyone setting the fairly large floor standing RSbs on their side. At least I know I have the option!

Thanks for the replies.
 
For a while, back in the day, I used my RSM's on their sides.
Had a pair of stands/tables that had rotating tops so playing with toe in and toe out was easy.
So long ago I don't remember how they actually sounded.
 
Interesting. Why would one set their speakers on their sides? Is it just to save space. It's hard to imagine anyone setting the fairly large floor standing RSbs on their side. At least I know I have the option!

Thanks for the replies.

Good point, the aren't "mirrored", if you set them on their sides, one EMIT would be higher than the other. The Qe were symmetrical.
 
Back in the day "bookshelf" speakers could be quite large, but smaller than many of the 15" woofer floor models. I beleive that the JBL L100 was sold as a bookshelf system, so you can see what was a norm of sorts back then. Here's a pic of the Nova 88 from the 1972 JBL catalogue, which is basically an L100 sans LE5 mid.

page14.jpg
 
Back in the day "bookshelf" speakers could be quite large, but smaller than many of the 15" woofer floor models. I beleive that the JBL L100 was sold as a bookshelf system, so you can see what was a norm of sorts back then. Here's a pic of the Nova 88 from the 1972 JBL catalogue, which is basically an L100 sans LE5 mid.

View attachment 1266084
"Back in the day", I'm thinking people must have had some serious bookshelves..lol.
 
I guess so. While looking for pics there were plenty of references to the L100 as bookshelf speakers and I'm pretty sure the AR3a was thought as one also. In fact, years ago I bought an AR2 variant I think in a box that had one long side unveneered; it was first plywood, as that was the bottom for the bookshelf application.
 
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