Until Friday, when Todd and I can get back to work, they will be getting much play time. Sitting down for the Bourne Supremacy now

Oh man, I'm really enjoying this kind of threads. This really turns me on as quoted by another member

Todd, excellent start with the master as your tutor

Hey Leslie!

Soon, I think tomorrow, we will be changing the fret cloth!

Looking forward! Is Todd gonna do the job

Forgot to ask. Embossing of the logo is also part of the job?

Todd has done a lot of work so far, we are each doing one speaker. We only had a little bit of time yesterday, so I did have to step in and hurry things.

The logo is molded into the resin cabinet, yes? I was going to use spray adhesive to get the new cloth to stick.

That's the way but don't put the cloth on to soon or else the glue comes through. Use a sort of rubberized roller after (e.g. what you use for wallpaper) to press it in.

What I did was stretching the cloth first horizontally (for the printed area only) and at the same time press it on the embossing. You need 4 hands to do this. After that use some good quality ds thin tape (or glue) to put on the surrounding of the cabinet and the 2 straps areas. The rest is clear I guess....

I hope I have made myself clear in my dutchenglishamerican Good luck and if you have better ideas please let me (us) know! Always willing to learn...

Evan and Todd, pics please, Leslie gets turned even more on with detailed pics

BTW did you change the resistors, and did you get the midrange OK.

Søren Mexico:

Evan and Todd, pics please, Leslie gets turned even more on with detailed pics

Not to many please, btw I miss my Eugene, where is this person....

Leslie:

I hope I have made myself clear in my dutchenglishamerican Good luck and if you have better ideas please let me (us) know! Always willing to learn...

Me too! I appreciate the tips Leslie.

BTW, your English is just fine

Leslie:

Søren Mexico:

Evan and Todd, pics please, Leslie gets turned even more on with detailed pics

 

Not to many please, btw I miss my Eugene, where is this person....

I have one pic to add from today.

I have also noticed Eugene's absence, I should go check on him!

Here is one of the speakers on my drafting table just after measurments. Todd has been at work today and I was too excited to wait for him! Plus, this is a problem that needs fixing ASAP, school starts in a few weeks.

I measured everything and found some interesting results;

I'm starting to think that the brighter upper-midrange is due to the driver having lower impedance. The resistors between both speakers are almost identical.

What can you all make of this?

Oh and does anybody happen to know exactly what the original dampening material is made of? It has a very unique smell - has me wondering if it is harmful or not

I don't think it's harmfull, it's a sort of isolation material made of glass wool and can be very itchy when the inside touches the skin. 

Leslie:

I don't think it's harmfull, it's a sort of isolation material made of glass wool and can be very itchy when the inside touches the skin. 

Yes, fiberglass does itch. I'm suprised to hear it is fiberglass, I've never been able to smell fiberglass before.

EDIT: Just noticed that in the service manual, the material is defined as "rock wool"

Just made an interesting discovery, although I shouldn't be hugely suprised considering my above data, the speakers overall impedance is vastly different.

Factory Spec:   8 ohm
Good Speaker: 3.7-3.8 ohm
Bad Speaker:   7.8 ohm

Anyone want to start a brainstorm?

Søren Mexico:

BTW did you change the resistors, and did you get the midrange OK.

Didn't change the resistors, don't really think I need to.

And in short, no. The midrange problem persists. I've been exercising the new caps and they came even closer together but still - one speaker is a little brighter (for the better) in the vocal department.

However the gap is not wide enough to keep them from being enjoyed. Last night my parents watched two episodes of 24 and were impressed. I've been listening to them play music during many of these posts in this thread.

Hey Evman, I'm Baaaack

 I've been trying to catch-up on your. "not waiting on Todd too excited to wait busy little fingers at work. Nevertheless I'm

provoked in wanting too know what you or Leslie or Soren think what is causing the higher impedance in the bad speaker and is it relatively

simple to fix and in cost? BTWY do I have the understanding correct in my question....that the impedance being higer is a block so to speak to the bad speaker not being able to project equal levels of soud as the good one but as you say. that not withstanding it is still Terrificly

Enjoyable as your family R expieriencing

There he is!

Yes, fundamentally it seems there is a impedance issue. Looking at the numbers, I am suprised the first hand audible difference is so subtle! Your understanding is spot on.

I just took another measurement and the good speaker holds its 3.8ohms while the other has dropped to 7.3 ohms from 7.8. This time I measured at the spring terminals with the speakers disconnected from the amp. The previous measurement was done on the DIN connections on the corner. Still a BIG difference.

O.K. 7.8 to 7.3 diff. Yesterday you seem to be ready to change the resistors but it seems after further meter testing you have come to the

conclusion that the diff between the 2 speakers as it relates to the resistor reading were not great enough so what was that reading? will you

re direct me in your answer by referring back to open speaker picture in the post just where the resistors are located? I cannot recall if they

r on the circuit pannel or placed in side the drivers! Why does Soren seem to think 10% of'em need to be changed as a standard?

TC

The last 2 measurements I have made are that of total impedance. The entire speaker's impeadance - the load ultimately felt by the amplifier.

Here are the actual resistors (circled in red), on the crossover board.

Regarding the solution..

Earlier when I was taking the more detailed measurements of the individual components. All but the inductors, probably a good idea to check them, but since these crossovers haven't been toasted by some disco central party host, they will probably check out fine.

I think the root problem is the actual impedance of the drivers - plain and simple.

O.K. I'm understanding this a little better now. Thanks for the circling of the resistors.

 love that' however I do have some follo-up questions but they will have to wait  till I see ya tomorrow. I'm at Panera Bread and need too Take Off ! see ya later

TC

Leslie:

I don't think it's harmfull, it's a sort of isolation material made of glass wool and can be very itchy when the inside touches the skin. 

Rock wool, made from stone and wooled at very high temps used as termal insulation in houses mainly in northern Europe, has more less the same termal quotient as Glass wool, and is more itchy than Glass wool