Infinity Reference E-L Upgrade

[chrisn]

Got two of these for free, cosmetically in pretty nice condition. The foam woofer surround it gone on one speaker, and completely intact but fragile on the other speaker.

I modeled and simulated different replacement woofers in the small (guesstimated under .20 cubic feet) box. The Dayton ND140-4 matched the cutout and screw holes perfectly, but didn't simulate as well, plus the other ND140 had a dented frame. The MCM 55-3870 pair would have worked with just a thin adapter but really didn't want to make another set after the existing ones disappeared. Eventually settled on the Peerless TPY05WO0088 which also fit the cutout and existing screw holes and has the classic pincushion frame.

The stock tweeters look fine, but are just mylar cone drivers. A Peerless DX20-4 is a close fit, but needs new screw holes drilled. I had these on hand already. For now, blue painters tape holds it in place.

[chrisn]

Schematic of the stock crossover. I don't see a value printed on the inductor. It appears the drivers were connected with the same polarity.



Measured stacked on top of two other speakers, mic at tweeter height about 2 feet away:


Same conditions as above but with the grill removed. I measured these at varying distances heights and angles. The woofer doesn't roll off that much off axis, despite the apparently high crossover. The relative smoothness and evenness was a complete surprise, as I listened to the working speaker before measuring and they sound bright, painfully bright. I measured other known speakers just to make sure something wasn't out of whack.

[chrisn]

Here are the new drivers, connected to the stock crossover. Tweeter level a bit low. This woofer doesn't like a small sealed enclosure, but it will be vented.




Same as above, but without the grill:





Tweeter flange looks thick, will probably try felt treatment:

[chrisn]

Holes cut for the vents. They had to be positioned offset, because the tweeter is deep enough to cause clearance issues with the vents length:










New woofers bolt in place with existing screws and screw holes. The tweeters needed new holes drilled and minor sanding/notching so the tweeter could fit with the wires attached.




One day maybe I'll build a speaker with the crossover components glued all over the outside of the cabinet and connected with jumper wires, similar to the way they appear here. Measuring/listening/tweaking phase currently.

[chrisn]

Some experimenting with F13 felt, 1" width, about 1/2" thickness, here thinned to maybe 3/8".




Yes there is a lot of...room effect..in these measurements. First picture below is with no grill, no felt:




This is the same, with the stock grill in place:





Lastly, grill in place with felt around the grill frame surrounding the tweeter:





Felt was tried on the baffle, closer to the tweeter with varied results. For now I'm content with the felt along the grill frame. It smoothed the response that I was able to raise the tweeters level, whereas before the response was a bit lumpy for an across the board change like that.

[PWR RYD]

Felt for the win! Looks really good.