keeping another pair of QLS1's alive

[banffskiing]

cdfac
I really can't say what it will take for you to notice a differance in amplifiers because I have no experance with different amps. I can tell you this, this bass is unreal low but at the same time sounds very tight. I listen to old music all of the time and here things that I never heard. Even today I was in the garage working and the wife was inside cooking and lintening old 80's tunes. She walked outside and was amazed at what was coming out of the big infinitys. Need i say anymore. Oh yes I Changed all of the wiring in both speakers and even doubled it up going to the Watkins woofers.

 

[cdfac]

tested the tweeters out today and it was mostly good news. all of them worked in the first speaker, but in the second speaker the pots are a little more finicky. at first the rear EMIT didn't work, and it took some jiggling of the dial to get it to turn on. the midbass was the same story. i deoxited the pots (from the outside) before i hooked them up and they were noticeable smoother, but i obviously need to take them apart to do a better job. one pair of EMITs on the front don't work, and i'm pretty sure it's because one of those has a half-inch magnet fragment loose and covering half the racetrack. maybe it shorted it out or something? since each pair is in series, i'm hoping the other one is still ok. anyone have experience with this?

banff, what kind of wire did you use?

 

[cdfac]

i've started to keep an eye out for a major amp score, as i can't really afford fair prices at the moment. i'm on the lookout for adcom 555's, halfer DH500's, yamaha m-80/85's, and, after reading more about them, various soundcraftsmen models.

those that are currently vertically biamping QLS1's (or 2's), do you find yourself needing to adjust the gain between the mids/highs and lows? it seems like most amps that i've seen used vertically with infinities don't have that ability, yet i've never seen anyone complain about it. trial and error with different amps would be ideal, but in my neck of the woods i don't really have that luxury.

 

[cdfac]

here's a couple close-ups of the problem EMIT. you can easily see the magnet fragment in the first, and in the second you can see what looks like it might be a puncture that goes straight through that leg of the racetrack. whaddya think? i will try to test the resistance of the possible tear in the next few days to see if it's actually testing open. can full line EMIT diaphragms still be had these days? or should i just look for a whole new tweeter given the magnet issue? advice much appreciated as always!

-chris

 

[kmanusa]

here's a couple close-ups of the problem EMIT. you can easily see the magnet fragment in the first, and in the second you can see what looks like it might be a puncture that goes straight through that leg of the racetrack. whaddya think? i will try to test the resistance of the possible tear in the next few days to see if it's actually testing open. can full line EMIT diaphragms still be had these days? or should i just look for a whole new tweeter given the magnet issue? advice much appreciated as always!

-chris

I have bought a number of EMITs off Ebay recently so they are available. Of course, it is "caveat emptor" in terms of what you get. Given that the diaphrams are no longer available new, this is the only recourse right now, other than fixing them. You have to be careful when buying them because Infinity used several types of EMITS on their speakers through the years and you will need to buy the type appropriate for your model.

 

[banffskiing]

The diaphragm is no longer available. I had no luck in trying to repair the coil race track. I used it for soldering practice but then again mine, the went completely though the Mylar. I really do wish they were available since the problem with a lot of used emits seems to be that they were overdriven (clipping) which causes the mylar to wrinkle. As long as the meter probe tips are not to sharp, you can touch the meter leads directly to the track and measure resistance there thus eliminating the thru connections.
Can’t remember where I read but someone suggested that all the infinity fans call infinity
On the same day and ask for quantum parts. Would be nice if that would get them thinking about producing more emits and mids. I know it’s just wishful thinking but guess there is nothing to lose.
As for the broken magnets there north south poles are not at the ends of the magnet but rather along the sides. You must pay attention to get all of the magnets aligned as they were designed. As long as you are not missing a section you could probably put it back in place with some glue and it would still work fine.

 

[kmanusa]

The diaphragm is no longer available. I had no luck in trying to repair the coil race track. I used it for soldering practice but then again mine, the went completely though the Mylar. I really do wish they were available since the problem with a lot of used emits seems to be that they were overdriven (clipping) which causes the mylar to wrinkle. As long as the meter probe tips are not to sharp, you can touch the meter leads directly to the track and measure resistance there thus eliminating the thru connections.
Can’t remember where I read but someone suggested that all the infinity fans call infinity
On the same day and ask for quantum parts. Would be nice if that would get them thinking about producing more emits and mids. I know it’s just wishful thinking but guess there is nothing to lose.
As for the broken magnets there north south poles are not at the ends of the magnet but rather along the sides. You must pay attention to get all of the magnets aligned as they were designed. As long as you are not missing a section you could probably put it back in place with some glue and it would still work fine.

Interesting, I thought a bit of wrinkling in the diaphram was just from long-term use and should be expected. You say wrinkling is from the EMIT being overdriven-- I wonder what the negative sonic effect of the wrinkling is? Some of my EMITs and EMIMs are slightly wrinkled; no sharp folds, just gentle waves.

 

[cdfac]

thanks, banff and kman. i will take it apart once i get a chance to build a jig for it.

it will probably have to be some pretty strong glue to hold the fragment in place. but the more i think about it, i don't think that could kill the sound completely, so i figure that dark spot must be a break in the racetrack. i should be able to test that without opening it up.

perhaps tonight i will type up some kind of form letter to infinity regarding our desire for new parts. i could post it in a new thread and on bobby shredd, and everyone could email it separately with some of their own words to the infinity parts department. it's hard to say whether it would make any difference, since they might have to build new equipment to handle it, but it's definitely worth a shot.

 

[Army]

Hey Chris
A buddy of mine uses the silver contact repair pen from parts express to repair emits and emims. As long as the mylar is intact use an eraser at the break to clean the contact surface and apply the repair pen drawing a line to the break. Once that drys paint the repair with two coats of clear finger nail polish. My 2.5's that you heard Saturday, all four emims were repaired using that method and that was about three years ago. He likes the repair pens because they us liquid silver verses copper and are only about $10 and one pen goes a long way.

 

[banffskiing]

cdfac
If I’m not mistaken, it was Bill Watkins that informed me about the wrinkling of the Mylar. Best way to destroy an emit is to connect it to a 25wpc amp and really crank it up. The dc voltage quickly heats up the race track as if it were a resistive element and causes the mylar to expand. I had a couple of emits that were wrinkled which I place in the bottom of the line array but I can’t here any audible difference from one to the next.
As Army mentioned, the silver pin also works well for the repair. Best way I have found to get it across the broken junction is to dispense some of the silver solution and use a tooth pick to apply it across the trace. Just make sure that it is mixed up very well before you try it, since the components tend to separate if the pin sits around for a long time. Also good idea about the letter to Infinity

 

[cdfac]

thanks banff and army, i will try that method if i can make sure the mylar isn't punctured at that point. i will definitely try this on a spare half-line EMIT i have sitting around that's measuring 14.8 ohms as i can see a hairline crack in the trace.

the previous owner and his dad (original owner) only used decent amps of at least 100 Wpc, and the EMITs aren't wrinkled that badly. they sounded pretty darn good when i tested then on a 50-Wpc sansui.

in terms of a little update, i sent in 4 of the dome mids to Around the Sound in seattle to see how good they are at tinsel fixes - i've heard good things and the fee is very reasonable. the watkins refoams are being done by Army as we speak. the midbasses are in order, so if i can fix this tweeter, i'll be able to do a decent test of them (minus 3500 Hz or so of midrange!). i just picked up a nikko alpha 440 amp last night after doing some research and being impressed by Army's smaller alpha III on the mids and highs of his RS 2.5's, so i have some power on hand.

 

[Army]

the watkins refoams are being done by Army as we speak. the midbasses are in order, so if i can fix this tweeter, i'll be able to do a decent test of them (minus 3500 Hz or so of midrange!). i just picked up a nikko alpha 440 amp last night after doing some research and being impressed by Army's smaller alpha III on the mids and highs of his RS 2.5's, so i have some power on hand.

I placed the order for all the surrounds needed, yesterday, should have them by Friday I would think.

New 440 coming...sweet! Maybe I'll hear yours before mine is done

 

[cdfac]

I placed the order for all the surrounds needed, yesterday, should have them by Friday I would think.

niiice.

New 440 coming...sweet! Maybe I'll hear yours before mine is done

i'll drag it up when i come to pick up the woofers! then you'll get yours back all rebuilt and fancy schmancy, and i'll get jealous about how much better it sounds, and then echowars will be putting that expertise to work again in a jiffy :thmbsp:

 

[cdfac]

update:

4 repaired mids are on their way back from Seattle - hopefully they hold up. i'll probably be sending the next four there soon, assuming the guy is in fact good. he told me to tell people that the cost is now $25 per mid, not $12 or whatever i paid - wish i would've sent them all at once!

Army and i discovered that one woofer had a bad voice coil, so i'm looking for another.

on a GIANT upshot, i'm going to be hooked up with a guy who's supposedly selling a "parts" pair for $80!! there was a thread in "Speakers" about it, and i really hope it works out. a lot of the tweeters are supposed to be bad, but that's one of the areas i have completely covered. the woofers are good, and i'll take whatever functional mids i can get. not sure what i'd do with the cabs, especially considering he's several hundred miles away, but i'm assuming he'd much rather have everything gone. apart from redoing the crossover, this may give me a complete pair much sooner than i expected

now, if only i can pass that darn phd qualifying exam taking place the next three days.... :tears:

chris

 

[Army]

Chris what did you figure out with the amp problem? Was it the pre-amp or did you lose one channel?

 

[cdfac]

it was the amp. it worked again for a while, and then went totally out last week. any word on when your nikkos will be done? i've picked up a few more amps in the meantime, too the onkyo sounds great, and the green lamps are the bomb. the yamahas are both in the repair yard but may be done soon.

chris

 

[Army]

it was the amp. it worked again for a while, and then went totally out last week. any word on when your nikkos will be done? i've picked up a few more amps in the meantime, too the onkyo sounds great, and the green lamps are the bomb. the yamahas are both in the repair yard but may be done soon.

chris

Nope no word lately on the Nikkos, pretty sure they will fall into the rotation before too long. :thmbsp:

 

[cdfac]

question: if the cloth dome on a midrange no longer has any sheen and has some dimples that won't stay pushed out, is it going to sound any different than one that appears more "normal"? my gut says no, since they're pretty flexible anyway, but i wondered if anyone had experience with this issue.

chris

 

[cdfac]

my previous question still stands, btw.

so...i picked up the QLS1 parts in green bay this weekend. the seller, who was very helpful and knowledgeable, helped me completely strip the speakers of everything useful, including the rear EMIT grills and the wood bases with the crossovers. i couldn't take the cabs, i couldn't find someone else to take the cabs, and he was going to get rid of them immediately, so i figured what the heck. it was sad to see the demolition of a giant, but on the bright side i'll be able to refurb one set of crossovers while i still get to enjoy the speakers.

9 full-line EMITS measure good, 3 measure >8 Ohms, and 4 measure open. both rears are good. 6 or 7 of the midrange domes are still intact. the woofers both measure about 2.5 Ohms/5.4 Ohms. here are the EMITs:

for some reason, i had really thought the rear EMITs were just the half-line version found on the smaller quantum speakers, but not so. don't believe i've ever seen a pic of these before:

the woofers are interesting too. now, his pair of QLS1s with the raised black particleboard baffle were definitely a different version than mine, which have the flush walnut baffle. the weirdest thing to me was the thick particleboard woofer gasket that the woofer basket is very solidly glued to - was this stock? he mentioned that the woofers had been "reconed," which can often mean just "refoamed," which these definitely have been. the cones are stamped in white with "776895." the cone looks original to me, does anyone recognize that #?

 

[Grainger49]

That is truly awesome! Give Murphy's oil soap on the wood to start with. It can remove a huge amount of soil with little work.

And post more pictures please. Oh, I see you did. What a find!