View Full Version : Shoot! Infinity Quantum 2 Blown Tweeters and Pots Question.


Kencat
01-15-2006, 12:08 PM
:tears:

Finally getting around to installing the refoamed woogers. Got the 1st one done last night, and while trying it out I found the upper Emit tweeter has no sound. (used a full paper towel roll as an earphone, and can distinctly hear the sound from the other two, but the top one has none).

I haven't done a search here yet for other info, but wanted to get this post out for any help I get on what the next steps are to repair these if that's possible. I want to get the other speaker running now to see if any others may be dead.

Another question I have for other Infinity owners is how much effect do the attenuating pots normally have? I've sprayed the 3 pots with contact cleaner and have worked the shaft back and forth. While testing the 1st one, it doesn't seem like they have much effect on the tone. The midbass coupler can be killed completely when the shaft is at both extreme positions, and as soon as the shaft is moved off this position it kicks in the midbass but their seems to be no adjustment range.

The tweeter and mid adjusters seem to make a little bit of a difference, but barely perceptible. Is it possible for these pots, if corroded, to still function by sending the juice to the drivers, but not function as attenuators?

OH, on the sound. I asked my wife to come listen to the one speaker last night on a particularily bassy section of music.......she said it gives you goosebumps.....nuff said :D

Inspiribomb
01-15-2006, 12:45 PM
The tweeter and mid adjusters seem to make a little bit of a difference, but barely perceptible. Is it possible for these pots, if corroded, to still function by sending the juice to the drivers, but not function as attenuators?

I had two pairs of Infinity RS-6000's, and both the tweeter and midrange L-pads barely made a noticeable difference. Regarding the tweeters, I am not sure about repairing them, the etched foil is pretty delicate. I am sure they can be repaired, GordonW would probably know better than me. I have seen replacements on ebay before, wouldn't hurt to look there.

Kencat
01-15-2006, 01:31 PM
I had two pairs of Infinity RS-6000's, and both the tweeter and midrange L-pads barely made a noticeable difference. Regarding the tweeters, I am not sure about repairing them, the etched foil is pretty delicate. I am sure they can be repaired, GordonW would probably know better than me. I have seen replacements on ebay before, wouldn't hurt to look there.

Thanks Inspiribomb, Good to hear what you say about the pots. It would make more sense to me that if there was a bad corrosion problem, they would tend to cut out or not work at all....but I could be wrong on that, and hence the question to get a few informed opinions.

I'll definitely be keeping track of the Ebay auctions now, and other spots (AK :yes: ). These can be quite dear on the $$ I've heard. :sigh:

Should have the other mate fired up here in about an hour....hope she's 100%.

Charivari
01-15-2006, 01:31 PM
Finally getting around to installing the refoamed woogers. Got the 1st one done last night, and while trying it out I found the upper Emit tweeter has no sound. (used a full paper towel roll as an earphone, and can distinctly hear the sound from the other two, but the top one has none).
That’s not good. The three EMITs on the front are wired together and so if the others work, then the problem lies with that one EMIT vs. some place else easier to fix. Just to be sure, try carefully removing it (the EMITs are wired together with very short lengths of wire, some of which is held in place with silicone, so be careful not to break anything), disconnecting one lead, and measure for resistance. If you don’t measure anything, ie open, then your EMIT is indeed bad, but there is hope. Army (http://audiokarma.org/forums/member.php?u=1872) knows of someone who capable of repairing these drivers, so get ahold of him for the contact information. If you want to do the repair yourself, there’s some info here (http://www.bobbyshred.com/emit.html) about how to fix burnt traces using a rear window defroster repair kit, but I can’t vouch for the quality that will lead.

This is a common issue caused by amplifier clipping thanks to how power hungry these speakers are. Just yesterday, I read some comments by a former Infinity dealer who said he’d refuse to sell the models with EMITs to the headbangers as he was sure they’d clip their amps and blow the tweeters in short order.

Just fyi, if you don’t have enough power just yet even after repair, adjust the tweeter crossover frequency control to the higher. This should help protect the tweeters just that bit longer.

Another question I have for other Infinity owners is how much effect do the attenuating pots normally have?
Not much, these are high-end speakers and so the controls are only there to fine tune the sound for accuracy, not as with other speakers where the controls are designed to make huge swings in the sound. In fact, the TOTL Infinities had controls that adjusted the levels by only 1 dB. With these particular speaks, though, the pots should cover a range between 0Ω to 5Ω, but I do now know how much of a level adjustment that works out to be after the crossover.

I've sprayed the 3 pots with contact cleaner and have worked the shaft back and forth. While testing the 1st one, it doesn't seem like they have much effect on the tone. The midbass coupler can be killed completely when the shaft is at both extreme positions, and as soon as the shaft is moved off this position it kicks in the midbass but their seems to be no adjustment range.
You might want to pull these pots and open them up to clean them. The midbass seemingly dying is due to the construction of these pots, they’re a spirally wound wire positioned in a ~270 degree arc inside with the ends held in place with brass rivets. These rivets in turn feed through to the two connections on the side. When the wiper, connected to the shaft and the center connection, swipes beyond the wire coil and onto the brass rivet, it loses continuity thanks to the corrosion guaranteed to be on the brass – I tore mine apart last week and they were really corroded, a fault of the design.

Just remove the pots, making sure you mark where the two wires connect to, jic. There should be a U-shaped wire that connects the back ceramic half to the front rusted metal component. With a pair of needle nose pliers, carefully pull the bent tab on one of the sides out of the hole and remove this wire. The pot will fall apart in your hands if you’re not careful. Set the front aside and clean the resistance wire in the ceramic half by first blowing the crud out and then carefully wiping it clean with some DeOxit on a q-tip. Next clean the center contact, the thing that looks like a mini-pizza cutter, as this is another place of corrosion issues – may look nearly black instead of the silverish color before. I used a piece of crocus cloth to get rid of the bad stuff and finished up with. Now, you’ll want to clean the wiper which is surely covered with corrosion from the brass rivets. I did the same with the tip of this as I did with the center contact (crocus cloth and DeOxit). I also very carefully bent the end that contacts the wire of both metal pieces down a tiny bit to adjust for ~27 years of wear and tear. The wiper plates will want to fall off, but the pins on the shaft are differentially sized, so it’ll go on the right way again. On mine, the front metal half with the shaft was badly rusted on a couple, so I cleaned mine up with some Corrosion Block (great stuff, exponentially better than WD-40) to prevent more rust that might flake down onto the contacts again. Once done, just reassemble the same as you took apart.

The tweeter and mid adjusters seem to make a little bit of a difference, but barely perceptible. Is it possible for these pots, if corroded, to still function by sending the juice to the drivers, but not function as attenuators?
It is possible, as the spiral wire that composes the resistance element can be shorted by flecks of corrosion, as I found in mine. So, you’ll want to do the above and clean them up.

OH, on the sound. I asked my wife to come listen to the one speaker last night on a particularily bassy section of music.......she said it gives you goosebumps.....nuff said
Told ya. ;)

Don’t worry; we’ll help you through getting these back up to spec.
- JP

Kencat
01-15-2006, 01:50 PM
Howdy JP,

Might be a stupid question here.....but.....what's the best way to get those pots out ? I'm not experienced yet with soldering. DO you use the solder gun to pull the wires off or just snip em and resolder later ? Looks like a b...h to have to solder within the box. Good chance to burn up a bunch of wires or something.

What you say about cleaning up the pots makes sense, especially after looking at someones "step-by step with pics" article on the AR pots (Greyhouse I think ?)

Worst part looks like the extraction of them though.

Also, with one tweeter of the 3 blown, does that make it more likely the other two will go ? Depends if they are in series or parallel I guess. If so I better not play them.

Charivari
01-15-2006, 01:57 PM
Howdy JP,

Might be a stupid question here.....but.....what's the best way to get those pots out ? I'm not experienced yet with soldering. DO you use the solder gun to pull the wires off or just snip em and resolder later ? Looks like a b...h to have to solder within the box. Good chance to burn up a bunch of wires or something.
You just pull the knob off the back and using a small crescent wrench or socket remove the nut. The pot'll pull right out. About the wires, I'd prefer to desolder the wires, with a gun or iron, though I prefer gun for this application as it's quick and I'm less likely to burn or melt something while waiting. Since there should be plenty of wire in there, you could cut the wires off and then solder them back on. Probably better that way as you're less likely to have to fiddle with the wires and iron trying to get the wrap through the hole in the pin to come loose.

Also, with one tweeter of the 3 blown, does that make it more likely the other two will go ? Depends if they are in series or parallel I guess. If so I better not play them.
That I don't know as I was lucky enough to have all my tweeters working (knock on wood) when I found my Quantums, the only things in them that were. Normally, I'd say it'd be alright if you cross them over higher and don't push the volume. However, as the three are hooked together, having one not working may adjust the impedance and thus swing the crossover point to someplace where these weren't designed to go. So, I'd not run them until you can get the one repaired, though, it might be possible to stick a 10w resistor of the same impedance in place of the bad one as a place holder. :scratch2: I'd ask someone who knows, such as GordonW.

- JP

Kencat
01-15-2006, 02:12 PM
So, I'd not run them until you can get the one repaired, though, it might be possible to stick a 10w resistor of the same impedance in place of the bad one as a place holder. :scratch2: I'd ask someone who knows, such as GordonW.

- JP

Man, do you know how hard it is not to want to play these things.....AH Well, step by step and I'll be there someday. Dang !!

I'm going to hook up the next one to at least know what all needs doing. I don't think I've tested this at all yet. Cross your fingers for me.

GordonW
01-15-2006, 02:16 PM
Last time I checked (about 3 months ago) Harman/Infinity had a VERY FEW EMIT elements left in inventory... and the "word from above" was that there would be no more once they're gone. So, I'd recommend contacting them, and ordering an element ASAP, unless you happen to luck up on one online elsewhere...

I wouldn't try to "jumper" the bad tweeter. Just don't play 'em until the tweeter element is replaced. One missing tweeter will upset the impedence balance of the crossover, which may cause a dip in impedence at crossover (which will cause an INCREASE in power to the tweeter at the crossover point) and possibly damage to the other tweeter as a result...

Regards,
Gordon.

Kencat
01-15-2006, 03:09 PM
Last time I checked (about 3 months ago) Harman/Infinity had a VERY FEW EMIT elements left in inventory... and the "word from above" was that there would be no more once they're gone. So, I'd recommend contacting them, and ordering an element ASAP, unless you happen to luck up on one online elsewhere...

Regards,
Gordon.

Thanks Gordon, I will do that. Hope there are some left.


I wouldn't try to "jumper" the bad tweeter. Just don't play 'em until the tweeter element is replaced. One missing tweeter will upset the impedence balance of the crossover, which may cause a dip in impedence at crossover (which will cause an INCREASE in power to the tweeter at the crossover point) and possibly damage to the other tweeter as a result...

Regards,
Gordon.

That does seem like the most prudent thing to do. Don't want to blow any more of them.

I just tryed the second one, and luckily all three tweeters are working. Both mids aren't making sound though. The leads look ok, so hopefully this is the pot that is the culprit. I'll check the resistance on each though to be sure; although, when putting the woofer back in, I looked at the pots and there is quite a bit of rust and corrosion evident from the outside.

Looks like some more disassembly and surgery is necessary here.

It's only a hobby....It's only a hobby......(my new Yoga mantra) :D

Charivari
01-15-2006, 03:24 PM
I just tryed the second one, and luckily all three tweeters are working. Both mids aren't making sound though. The leads look ok, so hopefully this is the pot that is the culprit. I'll check the resistance on each though to be sure; although, when putting the woofer back in, I looked at the pots and there is quite a bit of rust and corrosion evident from the outside.
If one midrange were bad, the other would still work, so it does sound like a crossover issue. The pot is the obvious culprit and pretty much a given to be in need of cleaning if you can see visible rust. I found with one of mine that the rust flaked off into the coils of the wire and onto the contacts inside the pot causing it to cease to work. Go ahead and clean them up as I wrote above and if you want to avoid the rust issue, try treating the metal housing with this stuff (http://www.nocorrosion.com/corrosion-control.htm). Growing up in a port town, I know from experience that WD-40 and its kin just doesn't cut it when it comes to corrosion/rust, but this stuff is great. Just be sure you spray it from a distance and wipe off the excess, Corrosion Block is an insulator and might interfere with the contacts.

- JP

rstsgsas
01-23-2006, 02:24 PM
I Have 2 sets of Q3s and have had the same problems.1 set was fixed by cleaning with deoxit.Mine also has very small effect on sound.The second set had serious corrosion and worked intermitantly so I jumpered them out when I set them up for biamping.I have not been able to find a suitable replacement for the pots.1 set is driven by my Sansui g-22000 and souds excellent,although the protection will trip at about 12 oclock on the vol.Yes it is loud.The 2nd set is driven by Bryston 6b mono amps rated at 500 watts into 8 ohms and 800 into 4 and 1000 watts ea into 2 ohms.This set up really makes em sing.Bass response is unbelievable.Finest speakers I have ever heard.keep at it ,in the end you will be most happy.

Charivari
01-23-2006, 02:51 PM
1000 watts per channel? I take it you're into low-level listening. :thmbsp: Please, if you have some pictures of what sounds to be an incredible setup, post them up here for the rest of us to drool over.

As to the bad pots, try pulling the bad set and pull them apart for manual cleaning. As good as DeoxIt is, it was insufficient to clean the center contacts on my bad pots. The crocus cloth (real name that it's sold under) and a bit of manual labor is necessary to clean both the center contact and the wiper. Jumpering those pots means you're running the mids and tweeters full-level which is not the most accurate or balanced setting unless you're listening in a rather dead room. Though, you might not notice the ~3dB of level difference the pots do affect.

- JP

rstsgsas
01-23-2006, 06:12 PM
This is one of them ,and the set up is different now but shows 1 amp anyway.

clifselina
01-23-2006, 06:31 PM
Not affiliated

Quatum EMIT on the Bay (http://cgi.ebay.com/TWEETER-PAIR-INFINITY-QUANTUM-EMIT-TWEETERS-QLS1_W0QQitemZ5857618326QQcategoryZ61376QQrdZ1QQcm dZViewItem)

Several pairs, $114 BIN price.

Charivari
01-23-2006, 07:26 PM
rstsgsas, there's just something right about seeing one of the bigger Quantum speakers getting all the juice they can take. Must really be something to hear when the music cuts loose.

Clifselina, that auction makes me rather angry. First, EMITs rarely go for that amount of cash, but that's nothing. The fact that some greedy powerseller took otherwise perfectly repairable, rare QLS-1s in good condition and parted them out piecemeal for the greatest cash inlay is outrageous. There's not too many of these TOTLs out there and to see this destruction ... :tears:

- JP

newoldguy
01-23-2006, 07:42 PM
OMG what kind of a man parts out a pair of QLS'S.I am about to cry.Well,I will keep looking. :no:

Regards
Mike

rstsgsas
01-23-2006, 07:43 PM
I have never been able to clip these amps .They drive the Q3s to complete house vibrating exctacy.The speakers never miss a beat either.No distortion of anykind .The music just gets louder and louder.I do not listen near those levels ,just putting both amps and speakers thru some workouts to see where the limits were.I folded before they did. :D

Charivari
01-23-2006, 11:29 PM
I agree, newoldguy, there's something seriously wrong with that guy or his greed is more than the already high level in the average human. Wonder if we could petition the seller to cease the piece-meal destruction of these fine speakers and sell the unit as a whole for restoration? I've the crossover schematics, so repair should be possible after driver removal. Or, we could find a bunch of wise guys to do some convincing on the seller's part.

rstsgsas, I've read that the tinsel leads on the midrange domes are supposed to suffer from the weakness of acting as fusable links at higher (500 watts+) power levels. Have you encountered this problem? How about bottoming out the Watkins? I've not been able to do that with mine, but I'm sure it could happen.

- JP

clifselina
01-24-2006, 03:30 AM
rstsgsas, there's just something right about seeing one of the bigger Quantum speakers getting all the juice they can take. Must really be something to hear when the music cuts loose.

Clifselina, that auction makes me rather angry. First, EMITs rarely go for that amount of cash, but that's nothing. The fact that some greedy powerseller took otherwise perfectly repairable, rare QLS-1s in good condition and parted them out piecemeal for the greatest cash inlay is outrageous. There's not too many of these TOTLs out there and to see this destruction ... :tears:

- JP

Reminds me of the Taliban destroying the 1000 year old Budda carvings in Afghanistan.

Maybe I could offer to swap some Blose miracle cubes for his Quantums and put my Kappa 6's in the ....

Oh @#@^!!! I don't have a room without a system in it....

rstsgsas
01-24-2006, 08:36 AM
I have a few extra mids that I have repaired.I have not had them act as fuses.It takes several tries to clean off what ever covers the tinsels to get solder to hold.Several times I thought I had one fixed and when driven hard the solder joint was not good and just came apart.I have gotten pretty good now ,last one I did has not let me down no matter how hard it was drive.I have 2 sets of Quantum 3s,and 1 set of the Quantum Jrs ,so all in all I have a total of six of the mids in use.Thats why I have several spares.They have all been repaired by me .That way I will never be without the sound of my babies.I do not know exactly how much power I am putting out from the brystons as the lights in the front are calibrated in dcbls .i know have had them all lighting up without any problems.It does have a clip light in the last bulb green/red but have never seen it come on.

Charivari
01-24-2006, 08:13 PM
clifselina, there's no parallel between a sad thing in a hobby vs. the destruction of such historically important art. Unfortunately, that dances the edge of a political subject and would be against the rules to bemoan more. :nono:

I did contact the seller about the possibility of their selling all the units together so someone could breathe life back into these, but this is what I heard back:
tell about it..i played and enjoyed for 4 hours..the better audio experience i never have..
yes this broke my heart too.
but i was thinking how to ship so heavy speakers 190lbs each...and i have to guarantee not broken on arrival..well that was terrible for me..so i decided to kil my monsters and give chance to other monsters to come alive again with original parts...so other owners can get their speakers fixed with original parts or have spares..so they not died for nothing,,they give new life to others..well i want to think that way..that make me feel better..
no they is no way to put those units back..cabinets was purchased by a friend mine him is a old proffessor of University of san diego him is a engineer..and him told me him going aput some JBL's components and make a prototype for his garage...him take the cabinets with grills today..they was mint..so nice.
so not way back

thanks..
This has raised my perspective of PowerSellers in that at least one is a person of conscience. :yes: This is just another example, though, of how the ignorance of there being enthusiasts like us has caused the destruction of one model. Nevermind the sacrilege of putting JBL components in Infinity cabinets. :no:

rstsgsas (that's a lot of "s"s to keep writing), just curious about how you repaired the mids or rather when. When I did it with mine sometime back, I had been unable to find any information of anyone else doing it successfully. It seemed like there was the possibility that I was first and only, but I held some doubts on it.

- JP

rstsgsas
01-24-2006, 08:41 PM
Initials of me.wife and kids.I used a razor knife like modelers do and a magnifying glass to scrape and remove that infernal coating on the wires.Then its a matter of soldering.I had one that was broke at the edge of the dome where it meets the plastic.I dug the old wire out and soldered in a new piece from the round thru hole.It take a few tries to get it reliable.I have one in 1 of my Q3s that has been working for at least 7 or 8 months.Its tedious and patience is required.But it can be done.

Charivari
01-24-2006, 08:44 PM
Well, that makes sense now. A lot more personal than a random word out of the dictionary like mine. Now, I wasn't asking about how to do it (I've already done it (http://audiokarma.org/forums/showpost.php?p=407666&postcount=13)), I was more curious about a time frame as I did mine the better part of a year ago. Ah well, it is of no matter and inconsequential in the long run.

- JP

rstsgsas
01-24-2006, 08:52 PM
That was when I got my first set of Quantums together.But took me several months to make it work reliably.First few tries it would come loose after playing music pretty loud.I have 1 in my quantum jrs I fixed,grill got hung on it.1 in one set of quantums and 2 spares that I have done and seem to be reliable now.1 of them I actually repaired on the inside if the voice coil about a 1/4 in from where the windings start.It is a spare although I have measured the resistance and played some music thru it,it hasn't been thru its paces yet.I have 2 more I have not done anything with yet.

Kencat
02-12-2006, 05:54 PM
Hey there, Quantum fans,

I am just reading the last posts about the QLS destruction and gas's monster power. Boo to the former, and Yeehah to the latter. There's actually some Emits still for sale by the boob.

I'm in the middle of trying to get the two mids working in one of my Q2's. I have measured the DCR at the junction points in the crossover where the 2 sets of the white and white/black wires go to the mids. The Mids are in parallel if I understand the wiring correctly. Anyway, the DCR was 3.8 Ohms. If each mid is 8 Ohms, this then would be a close proper measurment indicating that both mids are healthy.

Can anyone confirm what the DCR is for one of these mids from an actual measure of one ???

I did manage to get the attenuating pot out for the mid, and although the steel cup is badly rusted aand looks like hell, the element looks very clean from the side holes. Also the resistance between the center lead to lead 1 and lead 2, varies from 0 to 5 Ohms as the shaft is turned, (each one in inverse to the the other). This would indicate that the pot is OK (??).

So why was there no sound from both mids :scratch2: Will accept any and all theories :D

Well, I'll take the pot apart and clean up what is there and will post some pics for others to see what's in there.

Charivari
02-12-2006, 08:26 PM
I did manage to get the attenuating pot out for the mid, and although the steel cup is badly rusted aand looks like hell, the element looks very clean from the side holes. Also the resistance between the center lead to lead 1 and lead 2, varies from 0 to 5 Ohms as the shaft is turned, (each one in inverse to the the other). This would indicate that the pot is OK (??).
As I recommended before, Corrosion Block will prevent the steel housing from rusting more and will actually reduce some of it. Don't worry about it causing issues as it's electrically non-conductive -- common way to advertise the product at marine product shows is to have a TV running in a tank of it.

Your measurements are correct, just as it should be. I'd still clean it as a precautionary measure, but this does mean something else is up. I'd go through, using the crossover schematics you downloaded a little while back, and test the various components to see what's bad. It could very well be that the crossover cap has gone bad. Um, just to be sure, you did check the fuse, right? It protects both the tweeters and the midrange -- I used mine as stereo subs for a while by pulling the fuse and running just the Watkins.

- JP

Kencat
02-12-2006, 08:45 PM
Hey JP,

I can always count on some feedback from you, appreciate it.

About the fuse - looks like it is protecting the Emits, the mids, and the mid bass, if I'm reading the schematic right. Problem is, the mid bass and Emits work ok, while the two mids don't. Can't be the fuse.

I'll check across the two big honkin resistors for proper Ohms. Without looking up how, how do you check a cap and an inductor ?

I'll get the pot back in and try it out again. Maybe the pot cleanup will have done something.

Any feeling for the mid combined DCR of 3.8 ?

Charivari
02-12-2006, 08:55 PM
Hey JP,

I can always count on some feedback from you, appreciate it.
Well, I did say I'd help you get those Quantums going.

About the fuse - looks like it is protecting the Emits, the mids, and the mid bass, if I'm reading the schematic right. Problem is, the mid bass and Emits work ok, while the two mids don't. Can't be the fuse.
Eh, it was a long shot. Still, sometimes the obvious can be overlooked and cause those infamous "doh" moments. So, I had to ask.

I'll check across the two big honkin resistors for proper Ohms. Without looking up how, how do you check a cap and an inductor ?
Unless there's very obvious physical damage (ie evidence of hammer blows or it looks like it went through a crematorium), the inductor is most likely fine. There is equipment to measure the inductance to verify if it's still good, but a quick check with an ohm meter to verify it isn't open (no continuity) will be a good enough test for your purposes. As to the caps, there isn't a reliable means to check to see if it's good with the test gear you have on hand. So, you can either borrow the caps from the other speaker for a quick check or just straight up replace 'em. A decent 20µf Solens or Dayton and a higher quality 0.4µF bypass cap should put you back into business (if the caps were bad before) or at least serve as a good upgrade for the existing tired caps.

I'll get the pot back in and try it out again. Maybe the pot cleanup will have done something.

Any feeling for the mid combined DCR of 3.8 ?
Never did measure mine together, but that sounds about right.

- JP

OMI
02-12-2006, 09:47 PM
FYI reference the diaphragm kits ...

RE: Infinity Quantum As tweeter diaphragms

Hello Omi, Thank you for contacting Infinity.
We do have some diaphragm kits available, however they are only supplied
to our licensed service centers.
You can find a service center in your area by visiting
www.infinitysystems.com.
Thank you and please advise if you have any further questions.

Sincerely,

Kelly

Parts Department

Kencat
02-12-2006, 10:15 PM
FYI reference the diaphragm kits ...

RE: Infinity Quantum As tweeter diaphragms

Hello Omi, Thank you for contacting Infinity.
We do have some diaphragm kits available, however they are only supplied
to our licensed service centers.
You can find a service center in your area by visiting
www.infinitysystems.com.
Thank you and please advise if you have any further questions.

Sincerely,

Kelly

Parts Department


Thanks OMI,

Infinity was kind enough to forward my request to a distributor here in Canada who had a few diaphragms for the QLS series Emits. I picked up some and repaired the bad tweeter. Works A-ok now.

The current battle is to get the two mids singing in the one speaker. Looks like a strange issue at this point.

Nat
02-13-2006, 08:31 AM
I had two Emit tweeters that didn't work and the problem was not the diaphragm, it was the connection to the diaphragm -- it was corroded, and so even if the two leads were together tight, no current flowed. I cleaned the connection (which requires taking the speaker apart, and there is a real possibility of pinching fingers or tearing diaphrams) and it worked fine. Its possible that when diaphragms are replaced, its simply that the new one has no corrosion that makes it work.

Kencat
02-19-2006, 10:39 AM
I had two Emit tweeters that didn't work and the problem was not the diaphragm, it was the connection to the diaphragm -- it was corroded, and so even if the two leads were together tight, no current flowed. I cleaned the connection (which requires taking the speaker apart, and there is a real possibility of pinching fingers or tearing diaphrams) and it worked fine. Its possible that when diaphragms are replaced, its simply that the new one has no corrosion that makes it work.

Nat, I agree with what you say. The old emit that didn't produce sound, actually measured a high resistance...it was not "open" I kept the diaphragm figuring it is probably repairable working on the connections as you say.

How were the wires attached to your Emits?? Mine were soldered. The crimped on leads were soldered (with a major amount of it as well) to the diaphragm. This area on the diaphram is a large flat conductive surface.

I had a near impossible time to get the solder to take to the diaphram. I don't think the connection is good even now. It was like the surface would not heat up (too much of a heat sink?) enough.

Which Connection to the diaphram are you referring to? The soldered leads or the "buttons" at the foil ribbon? See the pics.

Nat
02-20-2006, 09:03 AM
Its been close to twenty years since I did the repair, so my memory is hazy. But it seemed to me that the wires made a compression contact, rather than being soldered. With yours I'd resolder all the solder joints to see if that solves the problem.

Kencat
02-25-2006, 04:04 PM
Well, I got some time to dig into the "lack of sound in the midrange drivers" problem. I was actually going to put the cleaned up pot back in, but before doing so I thought I'ld check the two resistors in the mid circuit while they were disconnected.

The 8.1 Ohm 25W er measured good. Quess what ?

The 2.7 Ohm 25W er does not measure - yup- she appears to be open. :sigh:

Good and bad news I suppose, would explain the problem, but now I have to fix it. I reconfirmed the drivers themselves and got about 4 Ohms across each set of leads at the junction where they come off of each resistor. So the drivers are still good.

I know everthing can fail, but is it likely for one of these ceramic-looking type resistors to go open???? Is it possible the multimeter leads aren't getting contact? It worked on the other one though, so I'm probably grasping at straws.

Anyone know of a good source for these resistors in the south-eastern Ontario area? Well, better crank up Google.