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Likelihood of finding an RS 4.5 Electronic Crossover Unit

D

Deogletree

New Member
Hi All,

This is my first post, although I've been reading the forum for some time now. I have a pair of RS 4.5's which were obtained without the e-crossover unit. I have always used them with a single amp through the passive crossovers. Does anyone know how I might locate (or if I would ever be able to locate) just the crossover box for these? I wouldn't have any idea where to check, and I can't seem to find anything for sale on line.

I am so pleased to read about the upcoming EMIM replacement diaphragms. I also have a set of IRS Betas in another room. Does anyone know about repairs to those larger EMIM drivers? One of mine is 'buzzy'. Thanks in advance for any input you can offer.

David Ogletree, Boston, MA
 
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I have a pair of 4.5's now for about 25 years. The electronic crossover works, but is nothing to write home about. I currently use the low pass section to drive the woofers, but use the bypass switch to go straight through on the high side. However, it could probably be improved with some new caps, and updated ic's. Its basic construction and parts quality is not that bad, but there is an electrolytic cap in the signal path that needs to go.

A much better way to go is get an ashly xr1001 crossover, much better than the stock infinity crossover, and it will sound a lot better on the high end. I expect one in today to make the switch. It is also a lot more adjustable. If you google the xr1001 on google, you should find a lot of info, and very favorable user reviews. It is probably the best in class for an affordable analog crossover.

On the ashly, might want to get a made in usa used one, the new stock are I believe coming out of china.

The infinity box will probably cost $400-$600 if you can find one, a used ashly you can probably pick up for $150 range.

IRS Beta's, very, very nice!!! Hopefully long term the replacement deal will make the lemim diaphrams you seek. They might be repairable if they are wrinkled, or perhaps they have a foam layer for centering, or could be the nickel flaking off of the magnets (and all of those can probably be corrected). You would be best off sending it to a specialist that has experience with the lemim's.

BTW, welcome to the forum!
 
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Welcome to AK! :thbmsp:

You have two wonderful sets of speakers there, as I'm sure you know. :music: :yes:
Finding a crossover unit for a 4.5 wil be challenging; just finding the speakers is difficult enough. But you only need ONE unit, so it shouldn't be an impossible challenge.

The first step you've already taken: post here on AK! You'd be amazed at what the members of AK own, and it wouldn't surprise me too much if someone here comes up with an extra one of these they will part with.

Keep haunting eBay; it is one of the most likely places for such a thing to show up. People selling speakers like these often list the speakers and the crossover unit in separate auctions, so you may have a chance to acquire the unit that way (and, unfortunately, probably leave the buyer of the speakers in your current situation!).

Likewise, keep a good eye on CL listings in your area. Not so many people in any one area are likely to be looking for that particular item in your vicinity, so your odds of actually getting any one that shows up are fairly decent.

If all else fails, perhaps you can obtain the schematics and/or borrow one from someone and have a copy made. There are people here who can help you to get a circuit board done, and help guide you through any bumps in the construction process. If this isn't something you can do yourself, then perhaps you can get someone to make a copy for you. Given the work involved in undertaking such a project from scratch, it probably wouldn't be cheap, though.

Other than asking the same question on other audio boards as well, and posting "wanted" ads everywhere you can, I can't think of anything else to add, other than to say, "GOOD LUCK!"

OF course, in the meantime, you can always get by with any active crossover with appropriate settings. It may not be the same, but in a pinch it should do.

{:scratch2: Come to think of it, I'm facing a similar hunt since yesterday, when I got a pair of Infinity Modulus speakers, sans the woofer and crossover unit for them.}
 
I found the RS 4.5 crossover and put it into use. I was not impressed with it. I now bi-amp without it. It changed the sound in a negative way no matter how much i played with it.
 
The Infinity RS-4.5 can either be driven full-range by a single amp or biamped via separate connections for woofers and mid/high drivers. When biamping, you can "passively" biamp without using an external crossover or actively biamp using an active crossover. Infinity provided an active equalizer/crossover as part of the RS-4.5 package.

The Infinity crossover is just a simple two-way active crossover with the capability of providing first order (6 dB/octave) slopes at 110, 156, 220, 312, and 440 Hz. The high and low pass crossover frequencies are individually selectable from the set of 5 listed above. The crossover can be used as an equalizer as well as active crossover; it also has a bypass switch so that it is possible to use the device as an equalizer on the low end and simple pass-through on the mid/high end of the RS-4.5.

As others have noted, there are other active crossovers with similar or greater capabilities on the market so you do not have to use the Infinity device for biamping. I have Marchand and Bryston crossovers in addition to the Infinity. These units offer additional slopes and crossover frequency choices not provided by the Infinity.

I have replaced the power supply caps in the Infinity and this appeared to perk up the sound of the unit. However, I would not spend a lot of money on buying an Infinity crossover on the used market if I did not have one, given the other choices available.
 
Thanks for the help!

Hi everyone,

Thanks for all of the help and input on this. From the sounds of it, I shouldn't spend a lot to get the Infinity xover based on its sound. It's amazing to me that Infinity would make speakers as fine as these and include a substandard xover with it! The passive units sound great, I think.

Also, any suggestions about lemim repair people/factilities for me to contact? Thanks again for you help. I look forward to being a part of the forum going forward.

David Ogletree

p.s. Augy, I'll be in touch and thanks!
 
keep in mind the infinity crossover came out about 9 years past drinking age at this point! I'm sure some basic mods would help it quite a bit.

I will chime back in when I get to try the ashly, the seller did not ship it until last friday, after paying him the week before.....eerrrr...

I would think that just going with the 24db slopes would have to be a big improvement over the mentioned 6db slopes above, to remove maybe a little too much ovelap betweem the bottom and top ends. has always just seemed to me when you get the bass slam you want, that the upper bass/mid just starts craping all over the emim's lower mid, not in a smooth good sounding fashion.
 
Deogletree said:
Hi everyone,

Thanks for all of the help and input on this. From the sounds of it, I shouldn't spend a lot to get the Infinity xover based on its sound. It's amazing to me that Infinity would make speakers as fine as these and include a substandard xover with it! The passive units sound great, I think.

Also, any suggestions about lemim repair people/factilities for me to contact? Thanks again for you help. I look forward to being a part of the forum going forward.

David Ogletree

p.s. Augy, I'll be in touch and thanks!
Click to expand...

Welcome from one Boston area guy to another.

I have Betas as well. I wish you luck finding a LEMIM panel anywhere. It is possible that one of the magnets came unglued over time and this may be the cause of your problem.

I have seen LEMIMS come up once in many years of Ebay watching, and like a fool I did not bid. I've never seen them available anywhere else for many years now.

Best,

Paul
 
initial listening to the ashly xr1001 crossover is pretty positive, believe the sound has improved quite a bit from the infinity crossover. I did not consider the high pass really useable on the infinity, and ran bypass. that was allowing too much low end to the emims, as you could see bass notes (like kick drums) move the diaphrams. they don't move on bass now. need to protect that unobtainium if nothing else. lets hope the apogee boys fix that soon.

currently running unity on all gains, crossover at 300hz, and the notch deal at 6. (on the ashly)

24db slopes vrs 6db is really helping too, I believe.

will report back once have a few more days to see where it is at, and try more adjustments.

a couple of years ago I upgraded the emim and emit crossover caps to solens, and that is probably one of the best mods to date to really clean up the sound quality. going thourgh a electrolytic cap to an emim just is not a good idea. and not through a 30 year old one at that.

Brian
 
beemer said:
Welcome from one Boston area guy to another.

I have Betas as well. I wish you luck finding a LEMIM panel anywhere. It is possible that one of the magnets came unglued over time and this may be the cause of your problem.

I have seen LEMIMS come up once in many years of Ebay watching, and like a fool I did not bid. I've never seen them available anywhere else for many years now.

Best,

Paul
Click to expand...

Occasionally you see them on the German ebay site.

www.ebay.de

do a search for infinity and select hifi category ;)

regards
david
 
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