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Infinity RS 4B - Some Questions

FreeOrange

FreeOrange

Well-Known Member
Hey all, I'm working on getting my first infinity speakers. :banana::banana:

I've kinda been dreaming getting somethign with EMITs since happening upon a pair of IRS V Betas in a shop and being blown away by them :D

I don't have them in hand yet, but I had some questions about what to expect.

I'm getting the 80's RS 4B's which apparently don't kill as many amps as its bigger brethren, but I read somewhere that the load does drop below 2ohms at certain frequencies. My plan was to mate these with my B&K ST-140 (105 WPC). Any opinions on whether this will be a good match or not?

The first thing I'll have to do with these is refoam them. I believe these have dual 8" watkins woofers. I've done some refoaming but never a watkins type, does anyone have any tips/tricks for doing this well?

Can anyone comment on what material and finish these will most likely have? Is it a vinyl veneer, or a real wood finish? I'd like to get these looking real nice :yes:

I am jumping into the pool blind here, but I'm really excited about getting these together!

Lat question, are these old enough that a crossover recap would be helpful, or are there crossover mods and other internal mods that can be done?

Thanks!
 
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when I got my 4b's i tried driving them with an amp rated at 150wpc@8 ohms..sounded nice, but I was left wanting, a bit disappointed. On advice found here, I obtained an amp rated at 220 wpc@8 ohms and the ability to dig deep at lower ohm ratings, and discovered what kind of performance the things were capable of. The only reason I didn't keep the 4b's was moving on to Infinity Kappas. Congratulations!

btw: the woofers aren't Watkins, and are a breeze to refoam
 
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Thats a common misconception that all infinity woofers are Watkins.
As far as iv figured out the Watkins are only IN dual voice coil.
(I have learned more sense then)
 
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Yeah, I was hoping to get get clarification on whether these were watkins or not. I wasn't 100% sure they were but I was optimistic. The bass coming out of these is still supposed to be pretty OK. At least good enough where you don't need to run them with a sub.
 
Dont get me wrong there a great set of speakers with verry good bass.
just not amp stressing watkins woofers.
 
Well, I've got the RS 4Bs in my basement and have started the overhaul. So far so good.

I pulled all the drivers out and tested resistance, they all tested between 3 and 4 ohms, and were the same between speakers, so I think my drivers are all good :)

Replacement surrounds are on the way, that should be pretty straightforward.

I have started sanding the cabinets down to smooth the surface, but I'm not going to completely strip them, just sand enough to smooth it out. After that I'm going throw on a couple layers of restore-a-finish followed by feed and wax. I'm not sure how this will end up in the end, but I'll be sure to post pictures :)

Originally I was thinking I was just going to re-cap and be done with the crossover, but now I'm starting to lean towards getting a little bit deeper into it.

I'd like to take the crossover and turn it into a bi-ampable speaker. I was going to use this or something similar:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=260-281

Will this be as easy as just breaking off the woofer and the mid/high circuits and hooking them to the separate binding posts? The schematic I've seen for this implies that this is possible, but I was sure if anyone has done this or has actual knowledge as opposed to my inexperienced gut feel :)

Also are there other components in the crossover circuit that should be replaced? Inductors and resistors don't really degrade, so I'm guessing no, but I'll defer to greater experience.

Here's a real question: The big honking capacitors have come unglued from their original position, what glue would you recommend to keep these big effers in place?

Another crossover related query: I'm going to up the wire gauge used inside the box, probably to 14 awg. Any recommendations for wire type? solid/stranded, brand, etc?

Lets see... also these had lots of cottonny fluffy stuffing inside them, should I swap this out for a poly filling or is the original stuffing good enough?

Any tips on the type of material to use behind the woofers to keep the filling from getting into the woofer without affecting acoustics? The backing material that was factory installed just fell apart in my hands when I was tearing them down.

One last thought: I've got them all torn up, I'll probably wood glue all the seems just in case, are there any other cabinet improvements people have done to these? They are pretty sturdy boxes, but would extra bracing help?

Thanks for your patience if you've gotten this far :) I appreciate any and all input!
 
Low loft polyester batting works well to replace the fabric behind the woofers. It is white, thin, and does not block sound waves. I used it in my RSIIb rebuild; you can find it in craft stores such as Michaels.
 
hey FreeOrange - how are things turning out with your 4bs? what amp did you end up using... sounding good?

i've got my eye on a pair also. would be my first serious Infinity set so i'm eager to see how your adventure has gone.

cheers!
 
I'm still in the final steps of refinishing the cabinets, and just starting the crossover work. Things have been coming along, but this project got sidetracked for some time while I helped a friend with a construction project.

I have all the important parts and have good momentum to finish sometime soon. Unfortunately it'll be a busy week and I'm gone this weekend, so I'm not sure when I'll actually get done.

I am really impressed with the finish quality of the howards restore-a-finsh and feed n' wax, Once the cabs get their final coat I'll put some pics up of them.

Those little flutes on the corners sure are a pain in the tuckus to sand/steel wool and finish!
 
freeorange.....you will be glad you rebuilt your crossovers.....when I bought my 4b's I listened to them for 6 months and kept trying to talk myself into that I liked them....but something was lacking....after a deal fell through to sell them I decided to have the cross overs rebuilt...and I am glad I did....they are sonic bliss now:music:.....I am no audiophile so its hard to explain the difference...but my ears know.......and by the way I am pushing them with a sansui G7700 and that 120 wpc is all they need ......good luck with your project...be careful picking them up around the flutes....they will break easy.....
 
Bump!

Well, eons have passed and the earth has gone cold, but at last there has been PROGRESS! :banana::banana:

I finally got some time and finished with the... finish :)

The veneer cleaned up really well with some elbow grease and some time, the toughest spot was the flutes on the corners, that took some time. I redid the crossover with limited new components and a new topology to hopefully allow for bi-amping.

The original crossover and the new layouts are shown in the pics below.

Thanks for all the advice and help, I've got some work on placement and matching electronics, but so far so good :) :thmbsp::thmbsp:
 

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Thanks, I'm wondering if there is anything I can do about the yellowed woofers, and there is one gouge that is visible on the side of one that I'd like to do a bit more work on. Aside from that my main goal is to break 'em in :D
 
FreeOrange said:
Thanks, I'm wondering if there is anything I can do about the yellowed woofers, and there is one gouge that is visible on the side of one that I'd like to do a bit more work on. Aside from that my main goal is to break 'em in :D
Click to expand...

Try that anti yellowing lotion made for auto headlamps... works on all plastics
 
Funny, a friend of mine noticed my headlights were getting pretty scuffed up and loaned me some of that polish not too long ago. I've been procrastinating on that while I worked on some other projects (any guess what?) :) So I actually have some of that stuff sitting around right now! Too cool, I guess procrastinating can pay off. Thanks for the tip!
 
FreeOrange said:
Well, eons have passed and the earth has gone cold, but at last there has been PROGRESS! :banana::banana:

I finally got some time and finished with the... finish :)

The veneer cleaned up really well with some elbow grease and some time, the toughest spot was the flutes on the corners, that took some time. I redid the crossover with limited new components and a new topology to hopefully allow for bi-amping.

The original crossover and the new layouts are shown in the pics below.

Thanks for all the advice and help, I've got some work on placement and matching electronics, but so far so good :) :thmbsp::thmbsp:
Click to expand...

Absolutely Beautiful :thmbsp:
 
FreeOrange,

I've collected all the drivers and the crossovers, needed to build a pair of RS-6B's. But, I don't have the cabinets! And I haven't had any luck in finding suitable cabinets either. :tears: So, after seeing how well your RS-4B's turned out, I might just collect another set of woofers, and see if I can find RS-4B cabinets instead... :scratch2:

Nice Work! :thmbsp:
 
StimpyWan said:
FreeOrange,

I've collected all the drivers and the crossovers, needed to build a pair of RS-6B's. But, I don't have the cabinets! And I haven't had any luck in finding suitable cabinets either. :tears: So, after seeing how well your RS-4B's turned out, I might just collect another set of woofers, and see if I can find RS-4B cabinets instead... :scratch2:

Nice Work! :thmbsp:
Click to expand...

Well, if you need any info about the speakers I'd be happy to take measurements or dig up part numbers for you. Thanks! :thmbsp:
 
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