QLS-1 Restoration Project
- Thread starter banffskiing
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Reviews of the performance of the QLS-1 are rare. I don't remember ever reading a review--only comments here and there.
Those of us that have Q2's and Q3's have an idea of the performance the QLS-1, but have no idea of things like imaging and low frequency performance vs. the Q2 and Q3.
It seems to me that since the identical Watkins woofer is used in these systems, the larger cabinet volume would yield slightly extended bass. But, as Mr. Watkins said to me a few years ago, this caused a problem with the woofer bottoming more easily than in the smaller systems. He had advised Infinity against using this woofer with the larger cabinet volume.
Imaging with the Q3 seems to be slightly better than the Q2. I wonder if this is due to fewer drivers. If it is, imaging with the QLS-1 could be inferior to the Q2 & Q3.
Hopefully, you will be able to answer or comment on these questions after completion of restoration.
Good Luck!!
Those of us that have Q2's and Q3's have an idea of the performance the QLS-1, but have no idea of things like imaging and low frequency performance vs. the Q2 and Q3.
It seems to me that since the identical Watkins woofer is used in these systems, the larger cabinet volume would yield slightly extended bass. But, as Mr. Watkins said to me a few years ago, this caused a problem with the woofer bottoming more easily than in the smaller systems. He had advised Infinity against using this woofer with the larger cabinet volume.
Imaging with the Q3 seems to be slightly better than the Q2. I wonder if this is due to fewer drivers. If it is, imaging with the QLS-1 could be inferior to the Q2 & Q3.
Hopefully, you will be able to answer or comment on these questions after completion of restoration.
Good Luck!!
banffskiing
Active Member
To all
Items to be covered for this project will include the following items In this order.
1. Mid Repair with pics
2. Crossover rubuild
3. Emit repair (If needed)
4. Woofer surround repair
5. Baffling material Installation
I have a total of 11 bad mids and so far I have managed to repair 2 of them using the instructions from JP. http://audiokarma.org/forums/showpo...44&postcount=29
I will post a series of pictures so that everyone can better understand the repair process. If your going to attempt this repair, the one thing I will suggest is that you take your time, otherwise you will wind up starting over.
Sincerely
Banff
Items to be covered for this project will include the following items In this order.
1. Mid Repair with pics
2. Crossover rubuild
3. Emit repair (If needed)
4. Woofer surround repair
5. Baffling material Installation
I have a total of 11 bad mids and so far I have managed to repair 2 of them using the instructions from JP. http://audiokarma.org/forums/showpo...44&postcount=29
I will post a series of pictures so that everyone can better understand the repair process. If your going to attempt this repair, the one thing I will suggest is that you take your time, otherwise you will wind up starting over.
Sincerely
Banff
banffskiing
Active Member
Mid range repair
The mid range dome repair is going great. 1st picture is a little hard to see but if you look close you can see where I have removed the orange coating and about 4mm of tinsel wire is showing. I have managed to get almost all of the drivers to this stage. Had to stop at this point because my soldering iron quit working. :tears: 2nd picture is a little easier to see with the white back ground. Last picture is the woofer showing where the surrounds have come loose from the cone. Spoke with Bill Watkins the other day about the drivers and the cabinets. He was very informative about several issues relating to the quantum series. I'll post that info later.
Sincerely
Banff
The mid range dome repair is going great. 1st picture is a little hard to see but if you look close you can see where I have removed the orange coating and about 4mm of tinsel wire is showing. I have managed to get almost all of the drivers to this stage. Had to stop at this point because my soldering iron quit working. :tears: 2nd picture is a little easier to see with the white back ground. Last picture is the woofer showing where the surrounds have come loose from the cone. Spoke with Bill Watkins the other day about the drivers and the cabinets. He was very informative about several issues relating to the quantum series. I'll post that info later.
Sincerely
Banff
Attachments
Charivari
Fighting Naïve Realism
You can find a review at the bottom of this page.bocoogto said:
Banffskiing, those are very unusual looking QLS-1s. I never knew they came in any finish other than walnut, but that looks too well done to be anything but factory (unless a cabinet maker was employed). I look forward to reading this thread as you post updates and pictures on this project.
Looking at that picture of the Watkins, the foam looks in good condition, possibly having been recently replaced. That it's separated from the cone is no big deal and is easy to fix by just gluing back down. If you'll do a search on AK for refoaming information, you should find some good suggestions of what glue to use.
- JP
banffskiing
Active Member
Jp
He had them done by a professional. When I picked them up, I was amazed, Not a scratch anywhere. They have a finish similar to a black grand piano. He gave me the walnut veneer to transform them back but, the black is growing on me.
banff
He had them done by a professional. When I picked them up, I was amazed, Not a scratch anywhere. They have a finish similar to a black grand piano. He gave me the walnut veneer to transform them back but, the black is growing on me.
banff
vintage-yungin
i still really like pizza
my dad and i seen a pair of these go for 300 bucks on the bay and they worked fully
banffskiing
Active Member
Yes I have also seen them on ebay, I searched for 3 years and only saw 2 pairs the entire time. I lost one pair for something like $380 and the other went way out of my price range the last 20 seconds. Both pairs were in CA, a long way from me. Mr. Watkins told me that a fully functional pair would be worth around 1500 to 1800.
I think if you were going to buy something similar today it would be anywhere from
8000 to 10,000 in other words, way out of my range.
Banffskiing
I think if you were going to buy something similar today it would be anywhere from
8000 to 10,000 in other words, way out of my range.
Banffskiing
banffskiing
Active Member
Different mids
Does anyone know why these drivers look different or recognize where the one's without the full magnet cover came out of? Oh yes on the back of the plastic cover the ones without the full cover say 4 ohms. I know they are not 4 ohms because the domes are dimensionally and electrically identicle.
10 have the full cover and 2 do not.
Banff
Does anyone know why these drivers look different or recognize where the one's without the full magnet cover came out of? Oh yes on the back of the plastic cover the ones without the full cover say 4 ohms. I know they are not 4 ohms because the domes are dimensionally and electrically identicle.
10 have the full cover and 2 do not.
Banff
Attachments
Charivari
Fighting Naïve Realism
Well, I'm stumped. Never seen a driver that looked like that being identified as an Infinity Quantum series dome. So, you did use your multimeter to measure the DCR (DC Resistance) and it matched the regular domes? You might want to check the back of the front plate for any stamped numbers and see if they match up with the original Quantum domes and even if they say "Made in Germany" as well. Perhaps these were later Infinity supplied replacements or maybe they were modified with different VCs from the original 4 ohm to the 8ohm Infinity spec?
Sorry I'm no help here.
- JP
Sorry I'm no help here.
- JP
banffskiing
Active Member
The front portion is exactly the same in all 12 mids. Voice coil dia. is also the same in all. They all measure the same dc reistance across the voice coil. The magnet size is also the same. Only diff. I can see is one has a full plastic cover that is held on by 3 screws and the other must be glued on. Oh well guess it does'nt really matter just kind of like for them all to be the same.
banffskiing
Active Member
QLS Restoration
Removed all of the emits form one speaker today. All of them worked fine except for one. The resistance measured ok but there was no sound comming out.
Upon disassembly, I noticed that the diaphragm was stuck to the front side magnets. For those of you out there who speak of reduced high freq output on the emits, this could very well be the cause, especially if they ohm out good. Anyway tried get it unstuck but was un successfull. There are 3 broken spots on the mylar ribbon track windings. Tried to repair them, but to no avail. Did manage to obtain two good midbass drivers (picture) thanks to a tip from JP. Also got a 1ft sample of ultra flex 7 strand 36awg teflon coated wire. I think it is going to do a super Job on the mid range repair. When I spoke with Bill Watkins last week, I questioned him as to whether or not the orange epoxy on the mids was suppose to be hard or soft. he informed me that it was supposed to be fairly soft. I guess that explains why there are so many bad units out there.
JP
Did you say they changed the spec from a 4 ohm spec to 8 ohm? Had a guy email some pics two that he had for sale. Both pictures were the exposed magnet type. One said 4ohms and the other said 8ohms even though he said they both measured 8.
Banff
Removed all of the emits form one speaker today. All of them worked fine except for one. The resistance measured ok but there was no sound comming out.
Upon disassembly, I noticed that the diaphragm was stuck to the front side magnets. For those of you out there who speak of reduced high freq output on the emits, this could very well be the cause, especially if they ohm out good. Anyway tried get it unstuck but was un successfull. There are 3 broken spots on the mylar ribbon track windings. Tried to repair them, but to no avail. Did manage to obtain two good midbass drivers (picture) thanks to a tip from JP. Also got a 1ft sample of ultra flex 7 strand 36awg teflon coated wire. I think it is going to do a super Job on the mid range repair. When I spoke with Bill Watkins last week, I questioned him as to whether or not the orange epoxy on the mids was suppose to be hard or soft. he informed me that it was supposed to be fairly soft. I guess that explains why there are so many bad units out there.
JP
Did you say they changed the spec from a 4 ohm spec to 8 ohm? Had a guy email some pics two that he had for sale. Both pictures were the exposed magnet type. One said 4ohms and the other said 8ohms even though he said they both measured 8.
Banff
Attachments
Last edited:
banffskiing
Active Member
To all:
Just in case anyone needs the QLS-1 connection diagram for the tweeters, here it is. Did not show the rear, since it is shown in the schematic. It is basically 4 pairs of 2 in series all in Parallel. This might be good for a quick check to see if the whole tweeter line is in the ball park.
Banff
Just in case anyone needs the QLS-1 connection diagram for the tweeters, here it is. Did not show the rear, since it is shown in the schematic. It is basically 4 pairs of 2 in series all in Parallel. This might be good for a quick check to see if the whole tweeter line is in the ball park.
Banff
Attachments
Last edited:
banffskiing
Active Member
dome repair
Just finished repairing one of the mids using the 36awg ultra flex wire and liquid tape to secure it in place. The liquid tape seems to do a fantastic job at adhearing to the dome. Once I have refined the process a little more I will post the pics of each step. Also used up the 1 foot sample of wire and had to order the min qty of 100ft at $1.20/ft The wire is very hard to strip without cutting into at least 2 of the 7 strands. Ordered a pair of precision strippers for that job. Wow, now I have enough material to repair at least 200 mids.
Banff
Just finished repairing one of the mids using the 36awg ultra flex wire and liquid tape to secure it in place. The liquid tape seems to do a fantastic job at adhearing to the dome. Once I have refined the process a little more I will post the pics of each step. Also used up the 1 foot sample of wire and had to order the min qty of 100ft at $1.20/ft The wire is very hard to strip without cutting into at least 2 of the 7 strands. Ordered a pair of precision strippers for that job. Wow, now I have enough material to repair at least 200 mids.
Banff
Attachments
Last edited:
banffskiing
Active Member
dome repair
Yesterday was a good day, I repaired 6 mids in about 4 hours. That means now I have 9 good and only 3 bad. :thmbsp: The 3 remaining are going to be more difficult since the tinsel wire is broken off flush with the dome. Will have to try JP's method for replacing the complete wire. The 36 awg stranded wire is perfect for the repair. I will post some pics when I repair the last few drivers. I believe I have a good method (solid connection) for repairing the mids as long as the wire is not broken off flush with the dome.
Banff
Yesterday was a good day, I repaired 6 mids in about 4 hours. That means now I have 9 good and only 3 bad. :thmbsp: The 3 remaining are going to be more difficult since the tinsel wire is broken off flush with the dome. Will have to try JP's method for replacing the complete wire. The 36 awg stranded wire is perfect for the repair. I will post some pics when I repair the last few drivers. I believe I have a good method (solid connection) for repairing the mids as long as the wire is not broken off flush with the dome.
Banff
banffskiing
Active Member
I am a lot closer than I was 2 weeks ago. Only have two more mids to repair and it looks as if only one of them is going to be tough. (broken off flush with dome) Trouble is, I have to many other projects going on at the same time such as boat repair home improvement, etc. Reason I was asking about the emit resistance range is, most of mine have a number written on the diaphragm in red ink. It ranges from 5.3 to 5.8 ohms. Almost all of mine are in the 6 to 7 ohm range. They could probably use a little touch up to get the resistance lower. Anyway once I finish all of that, I will probably replace all of the caps and resistors in the crossovers. All that is left then is to re-glue the surround on one woofer, stuff the cabinets with Dacron and put all of the drivers back in the cabs. I would like to have them finished sometime in September. Can’t wait, just hoping my Onkyo M540 will drive them. That amp runs pretty warm from just bias current can’t imagine what it will do with the Watkins woofer.