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New score, Infinity Quantum 4 :)

Amplifierz

Amplifierz

Active Member
I just acquired these gorgeous Quantums.
One thing that i noticed right away is that they have the later 'Polycone' woofers. I checked immediately that they were Watkins and not a standard 12 inch woofer. Fortunately the first was the case, they are Watkins 902-1180 woofers.
They sound real nice.



Also, i noticed that the silver faceplates for the Emits were fairly scratched up so i decided to wet sand them and give them a nice coat of flat black.
But in my infinite wisdom when rebuilding one of the tweeters i had a big old magnet slap and one of the 3 magnets on the faceplate side of the assembly has shattered and broken of the faceplate. I removed the broken magnet and carefully continued the assembly process, the tweeter works... But with reduced output.
So that was one silly move.. Now i need to search for replacements. Do i really need to use the old style square silver emits or are those newer round types equally suitable for my Q4's?

Cheers,
Ben
 
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You can use the round tweeters if you're going to replace both, but why? The chrome versions can usually be found on eBay fairly cheaply.
 
The chrome ones do seem to be cheaper. Make sure you get offset ones if you do decide to go with chrome.
Matter of taste, could play a part if you ever decide to sell. While the woofer is an "ok" replacement, round face EMITs would not be correct.
 

Thx for the replies. I managed to straighten out the sound difference by imitating the missing magnet on the right tweeter to the left tweeter. Now they both play at the same output. I increased treble a bit with the pots on the back of both speakers. But, i'm in search for replacements anyway. I found a set of QB's being parted out and i saw those use the same emits. Seems like a good drop-in set.
 
Amplifierz said:
I just acquired these gorgeous Quantums.
One thing that i noticed right away is that they have the later 'Polycone' woofers. I checked immediately that they were Watkins and not a standard 12 inch woofer. Fortunately the first was the case, they are Watkins 902-1180 woofers.
They sound real nice.



Also, i noticed that the silver faceplates for the Emits were fairly scratched up so i decided to wet sand them and give them a nice coat of flat black.
But in my infinite wisdom when rebuilding one of the tweeters i had a big old magnet slap and one of the 3 magnets on the faceplate side of the assembly has shattered and broken of the faceplate. I removed the broken magnet and carefully continued the assembly process, the tweeter works... But with reduced output.
So that was one silly move.. Now i need to search for replacements. Do i really need to use the old style square silver emits or are those newer round types equally suitable for my Q4's?

Cheers,
Ben
Click to expand...

Those look nice but you need to either get magnets or replacement EMIT's so the drivers are more properly balanced.
Pretty sure I've seen posted on here about magnets that are the right size but don't remember where. EDIT/ADDED here are the magnet dimensions They are 50mm x 5mm x 3mm and fit right on the frame. You would want Samarium cobalt magnets. Might be available on ebay or other places.
You might want to build a jig, maybe info in this thread... https://www.audiokarma.org/forums/index.php?threads/emit-emim-tweeter-diaphragm-repair-how-to.65571/
or even easier watch the video in this thread if you decide to obtain magnets and need to install them https://audiokarma.org/forums/index...ragm-i-am-no-longer-afraid-to-replace.885392/
 
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Thx for the links to the other threads. I got a line on a set of replacement units, i will replace their diaphragms when they arrive. The video from Bobby sure is helpful. I'll need to get to the hardware store to get the right screws to reassemble the emits carefully. Not in the mood for more magnet slap.
 
paint it black
thumbnail.php

 
Amplifierz said:
...Do i really need to use the old style square silver emits or are those newer round types equally suitable for my Q4's?

Cheers,
Ben
Click to expand...

I am not 100% sure, but some of those "round" types look like the same driver as your original square type, only mounted to a different shape faceplate. If correct, then you could swap the faceplates.
 
Yamahalic said:
I am not 100% sure, but some of those "round" types look like the same driver as your original square type, only mounted to a different shape faceplate. If correct, then you could swap the faceplates.
Click to expand...

I already sold those speakers a while ago. But, you are right. The round EMIT is technically the same. The only difference is the front part of the assembly is round. It isn't really a faceplate eather, it is one half of the magnet assembly. The magnets used are the same. Samarium cobalt magnets, strong but very brittle.
 
Essentially all emits can take the place of all emits...it’s just a matter of styling....


Wtf is that metal face on the baffle...?
 
Bkphoto said:
Essentially all emits can take the place of all emits...it’s just a matter of styling....


Wtf is that metal face on the baffle...?
Click to expand...

Yes, all standard rectangilar EMITS can be swapped out for one another. That thing was there to hide the ugly silver woodscrews that the previous owner used. It was one of the first things i did. Remove that cover and replace those ugly screws with nice black bolts and t-nuts.
 
Amplifierz said:
Yes, all standard rectangilar EMITS can be swapped out for one another. That thing around the woofer was there to hide the ugly silver woodscrews that the previous owner used. It was one of the first things i did. Remove that cover and replace those ugly screws with nice black bolts and t-nuts.
Click to expand...

Ohh and yes.. That metal ornament thing was immidiately removed aswell. The previous owner thought that looked rather classy.. I just thought that it made the speakers look cheesy.
 
Amplifierz said:
...the silver faceplates for the Emits were fairly scratched up so i decided to wet sand them...
Ben
Click to expand...

Ben,
Question, when you sanded the silver faceplates, did you begin to see below the silver coating (like pitting that extended below the plating, so when you sanded it all off you could see the base metal)? I presume these are not solid polished metal plates that can be heavily polished several microns deep. When I have sanded plated metal in the past down to the point of removing pitting, I have quickly learned the error of my ways and began to see a bronze colored base metal. I will at least try a simply polish on my pitted silver plates, but not sure about going deep.
 
Yamahalic said:
Ben,
Question, when you sanded the silver faceplates, did you begin to see below the silver coating (like pitting that extended below the plating, so when you sanded it all off you could see the base metal)? I presume these are not solid polished metal plates that can be heavily polished several microns deep. When I have sanded plated metal in the past down to the point of removing pitting, I have quickly learned the error of my ways and began to see a bronze colored base metal. I will at least try a simply polish on my pitted silver plates, but not sure about going deep.
Click to expand...

I must say, i am not a professional painter.
Just sanded the oxidation of the plate, and gave it 2 coats of flat black. Worked out fine.
 
Yamahalic said:
I have quickly learned the error of my ways and began to see a bronze colored base metal. I will at least try a simply polish on my pitted silver plates, but not sure about going deep.
Click to expand...

If the silver plates are chrome plated then sanding through them will reveal the copper that is plated on the base metal first. Chrome won’t bond to steel directly and needs another metal, usually copper, to bond to. Once you scratch the chrome by sanding it can’t be “repolished” to it’s original finish. The only way to correctly fix it is to have the plate re-chromed which is not cheap and it’s difficult to find a shop that does good quality work all the time.
 
If you need to replace them I’d go up the ladder to the ones used in the RS 2.5 and 4.5

I am using those in my RSII’s
 
I was thinking that it looks like your QLS-4s were updated at some point, not only with the Watkins polycone woofers, but also the mids were installed in a rotated 90 degree orientation (usually the tinsels are installed vertically, but on yours installed horizontally. Not sure what that emblem was that was installed on the bottom front of the initial photo, but it looks like you removed it in the second photo. Also, you can use the method suggested by American Vintage Audio to take the EMITs apart more safely and avoid magnet slap, it worked for me. Here is a link to the video:
 
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