And this was a personal set of Steven who has been involved in Quad ESL for over 35 years?
The more I read here, the more I doubt the whole story. Sorry.
Just as I am amazed about the speed and conviction of conclusions drawn from "measurements" made.
It started out as a phase questioning/problem and all conclusions are in phase, out phase panels.
The more I read here, the more I doubt the whole story. Sorry.
Just as I am amazed about the speed and conviction of conclusions drawn from "measurements" made.
It started out as a phase questioning/problem and all conclusions are in phase, out phase panels.
He may have had them at home but not listened much, just intending to sell them.
Probably it is best to avoid this person in the future.
Probably it is best to avoid this person in the future.
I'd love to see pictures or a description of where the four treble panels wires go from the audio transformer to the treble panel. Pay attention to where each wire goes into the treble panel (front or back). Also I'd love to see the bass wiring from the audio transformer to the bass panel right in front of it. Also check the bass panel wiring that they are in phase. IE the left wire on the left panel goes to the left tag on the right panel.
Here's how it should be: http://quadesl.com/origRefs/quad_audio_wiring.pdf
Also just because someone has been involved with something for a long time, doesn't mean a) they know what they are doing. b) if they do know what they are doing, that they never make mistakes. But this was sent back if I read this thread correctly, and the mistake should have been fixed.
Any photos you are willing to share would be great, I'm very interested in the workmanship.
Sheldon
Here's how it should be: http://quadesl.com/origRefs/quad_audio_wiring.pdf
Also just because someone has been involved with something for a long time, doesn't mean a) they know what they are doing. b) if they do know what they are doing, that they never make mistakes. But this was sent back if I read this thread correctly, and the mistake should have been fixed.
Any photos you are willing to share would be great, I'm very interested in the workmanship.
Sheldon
Hi everyone, after putting the Quads close together and running pink and white noise and listening carefully between the Quads I came to the conclusions that the bass panels were out of phase when the speakers were connected electrically in phase. This morning I revered the black and brown wires on the transformer. Doing the same test again seems to have solved the issue as expected.
Is it normal to get a slight phasing effect when swinging the head from side to side? (even now)
The attached graph shows the response at 1m. Green trace with bass panels reversed. You will see that, the treble end has drop down a bit. Brown trace same speaker as measure yesterday before the change. Still the curve is no way as smooth as my right-hand speaker.
I have also attached a photo of the transform with the black and brown wires before I changed them round. Also, including some other photos of the left speaker.
Rodney.
Is it normal to get a slight phasing effect when swinging the head from side to side? (even now)
The attached graph shows the response at 1m. Green trace with bass panels reversed. You will see that, the treble end has drop down a bit. Brown trace same speaker as measure yesterday before the change. Still the curve is no way as smooth as my right-hand speaker.
I have also attached a photo of the transform with the black and brown wires before I changed them round. Also, including some other photos of the left speaker.
Rodney.
Attachments
Hi Sheldon, I think that you were a bit shocked when you saw my crossover photo? Tomorrow I will remove the back of my right speaker and make a comparison. I think this speaker will be ok.
But this was sent back if I read this thread correctly, and the mistake should have been fixed.
Yes, correct and you can see that a replacement bass panel was fitted in September last year. The other one is much older.
Yes, correct and you can see that a replacement bass panel was fitted in September last year. The other one is much older.
Sheldon, going on your crossovers, mine are a bit dated. I notice there are more resistors in the newer version?
You have the older style tag-board with the extra modification piece as quad suggested. So your circuit is electrically equivalent to the more modern tag-board. The resistors look a bit small, they could be the lower wattage series of vishay HV resistors, but I'm not convinced of that. if you are still on speaking terms with OTA, you might want to ask.
you mention phaseyness still, that could be the beaminess of the speakers in which case that is normal. But as you can see it would be super easy to get one segment of the treble panel backwards (I mark the rear wires with black bands). Did you trace out each wire to the treble panels too? Given how much of a rookie mistake the bass panel wiring was (even after a return), I would want to trace out EVERY connection.
Sheldon
Hello, I annotated the photo of your trafo bottom. Please check if each wire goes where it should. And where does the thick red wire go from the RT turret? (RB = rear bass, FB = front bass, RM = rear middle, FM = front middle, RT = rear treble, FT = front treble)
Attachments
Last edited:
Just want to confirm that you are using true mono noise, precisely identical signals sent to both speakers?
Hi Sheldon, I am pleased to hear the circuit is ok.
Although I am very disappointed with the work done by OTA, there is no point in being upset with them. I don't have a problem going back to them but at the same time I have lost confidence in there work!
Ignore my comments on the phaseyness for the time being. It really is only noticeable on a mono signal.
You mention "super easy to get one segment of the treble panel backwards" I don't understand what you mean by segment? Isn't that just changing the connection to the tweeter?
No, I have not traced the wires from the crossover. But I think it's all in phase now.
How can I get a smoother frequency response as I have on my right speaker?
Tomorrow after leaving them to discharge overnight I will take a look inside my right-hand speaker to check for differences,
Rodney
Interesting question. It is some pink noise I downloaded ages ago from the internet.
As I understand it, there are three distinct tweeter segments, one large segment at each side,
and a single one that is thinner at the center. It's actually a three-way speaker, since the center
segment operates beginning at higher frequencies than the other two.
Last edited:
Right, that rayma said, the treble panel has evectively two channels (brown and blue) you could have the blue out of phase or the brown out of phase. That's why everrybody is asking you to trace the wires back to where they go into the treble panel to see if the identically colored wires are going in the front or the back. So you can put the question of phase inversion to bed.
Sheldon
Sheldon
Sheldon, do you have a drawing that clearly shows which wires go where,
for both the HV supply and the audio transformer?
Was Quad consistent at using certain color wire for each location?
for both the HV supply and the audio transformer?
Was Quad consistent at using certain color wire for each location?
I have the transformer wiring guide, that shows where everything on the left side goes: http://quadesl.com/origRefs/quad_audio_wiring.pdf
I should add something for the HV side, but there are just three wires, the ground goes to the EHT block or to the tag on the power supply chassis, and then there is the tweeter and bass panel power.
Quad was very consistent with wire color in these speakers; brown to the treble panel center section, and blue to the outer sections (in parallel). This is tragic, because they are identical colored wires, so it's super easy to get phase screwed up. They should have made those 4 distinct colors. The ground wire is black and thin. The bass panel wiring is thick, and the rear stator is a thick white wire, and the front stator is a thick black wire. The treble panel has a thin red wire to the HV supply, and the bass panels use a thick red wire to the HV supply.
Sheldon
I should add something for the HV side, but there are just three wires, the ground goes to the EHT block or to the tag on the power supply chassis, and then there is the tweeter and bass panel power.
Quad was very consistent with wire color in these speakers; brown to the treble panel center section, and blue to the outer sections (in parallel). This is tragic, because they are identical colored wires, so it's super easy to get phase screwed up. They should have made those 4 distinct colors. The ground wire is black and thin. The bass panel wiring is thick, and the rear stator is a thick white wire, and the front stator is a thick black wire. The treble panel has a thin red wire to the HV supply, and the bass panels use a thick red wire to the HV supply.
Sheldon