Infinity Qb Transformation

[mjalazard]

Greetings,
I've started my Qb project and I wanted to show some initial photos:
The originals:

The drivers:

The original crossover:

Bracing the cabinet

Gorilla glue seal:

Sound coating slurry:

To be continued...

 

[mjalazard]

The drivers pt 2:

The slurry:

The coating:

Primer:

I touched up the light spots.
Tomorrow: textured black base paint and semi-gloss urethane coating...

 

[chigger]

great deadening idea , how much extra weight is that? couple lbs , waiting for the ta da

 

[tjohnusa]

Pretty curious to find out how they sound. I had a set of Qb and loved them!

 

[slimpikkins]

Sand and paint, very good idea. I bet those are dead as a door nail (in a good sort of way)

 

[chef free]

Replace that 12.5 cap. That should improve the mid range response. When I re capped my Qb's I increased the stuffing by about 25%. That tamed the bass boomy-ness.

 

[chigger]

after deadening coat are you going to restuff or trial and error ?

 

[madmonda]

I'm patiently waiting. I have a pair myself. They were my eye opening speakers. The tweeter is really something special. And the woofer takes some good abuse! They bring out detail in the music. I have a cd that sounds terrible on all my speakers...except the QBs.

Hurry up and finish already. Report back ASAP!

 

[mjalazard]

Sorry progress has been a little slow. I had to drive out to LA last weekend...
I have used the sound coat mix on previous speaker projects.
I am replacing all the crossover components with new ones, thanks to Parts Express:

Making the 12.5 uf midrange bundle:

I'm not too neat with the glue gun:

I also took apart and cleaned the L-pads as I did last year on the WTLC's:
http://www.audiokarma.org/forums/showthread.php?t=487987

 

[audiomagnate]

I bet they'll sound great when you are done. I would have gone with an air core inducter in series with the woofer.

 

[telemike]

Can you list out what you ordered from parts express? I need to redo my crossovers too

Sent from my XT907 using Tapatalk

 

[mjalazard]

Can you list out what you ordered from parts express? I need to redo my crossovers too

Sent from my XT907 using Tapatalk

2 AUDYN CAP PLUS 0.1UF 1.2KVDC DOUBLE LAYER MKP FOIL CAPACITORS
2 AUDYN CAP PLUS 5.6UF 800V DOUBLE LAYER MKP FOIL CAPACITORS
4 AUDYN CAP PLUS 6.8UF 800V DOUBLE LAYER MKP FOIL CAPACITORS
2 JANTZEN 1.0MH 16 AWG COPPER FOIL INDUCTORS
2 ERSE SUPER Q 1.5MH 16 AWG 500W INDUCTORS
2 Dayton Audio DNR-8.0 8 Ohm 10W Precision Audio Grade Resistors
2 Pair Dayton Audio BPA-38SN HD Satin Nickel Binding Posts

I also ordered a bunch of silver wire for several different projects from seller: "navships" at the 'bay...
Mike

 

[telemike]

Cool, thanks. Will you show how your wired them up? Hoping to do this around Christmas

 

[Kahoona]

Whoa!! Those are some really fine speakers and you are pulling out all of the stops to get the max out of them! I am intriguer by the slurry. What are you mixing the sand into and what proportion? I have never seen this. Does it reduce reflection also or is it primarily to reduce vibration? Will it replace bracing? I cannot wait to hear about the results. The tweeter is the star of the show IMHO but that mid is some serious stuff too. Thanks for sharing this.
ROb

 

[madmonda]

Any more progress? No pressure. Just report back with impressions.

 

[mjalazard]

I assembled one full crossover, but when I tested it the Lpad was sticky and sound from the mid only came out at one position of the dial. Some glue had seeped into the potentiometer, gumming up the works. I'm too embarrassed to show the pictures. I ordered a new pair of 5 ohm 5 watt L-Pads from Mouser. I hope to get a little more progress this weekend. I have to get the house ready for the Thanksgiving relatives...

 

[Arkay]

Very interesting project. Will be following it with interest.

 

[mjalazard]

Thanksgiving is over; relatives are all gone; mass quantities of food consumed. Now back to silver wires.
I completed the crossovers. It's funny how the second set comes out much neater than the first:

Little touch up cleaning is due:

I'm going to test them right now.
I should have the Qb's completed over the weekend.
Cheers!
Mike

 

[mjalazard]

Here are the final steps to the Qb transformation:
Xover mounted in the cabinet. I used small wood screws in the corners:

Acousta-Stuff:

Installed drivers:

Re-painted stand:

Everything installed. I used a pair of newer EMIT tweeters. They have a larger magnetic structure and sound smoother to me. Also, one of the metal wire clips on the original EMIT had broken off:

I have to glue together one of the speaker grill frames and route out a curve on the upper left side to accommodate the flange of the new EMIT's. I purchased some dark black grill cloth to cover the modified grill frames. More pictures to follow...
So far, I'm very happy with how they sound.
:thmbsp:
Mike

 

[chigger]

good job , I used black cloth also , didn't care for the brown. looks nicer