What is the problem with this 2235h driver [video]?

[macaroonie]

Yup, I laid it on the spinning IKEA pizza table, put my finger inside with a 90 degree angle, then rolled it around to get the dirt into the dust cap, then I vacuumed it out very gently. The noise was there before this though. I bought it knowing about the noise and got it fairly cheap. Like 80 bucks (which is cheap for a 2235h here in NO).

Good , but remember that you are only getting the stuff that is on the face of the pole piece.
If you think about it if a driver is installed in a speaker typically it stays in the vertical position for years. Imagine that this foam crud starts to fall to bits , it will drop down to the lowest place it can , ie. the part of the VC that is lowest , and of course it will work its way into the gap at that point.

I have encountered this before with a non molested driver. The junk is on the inside of the VC and can only go one of two ways , forwards or backwards. If it goes backwards it will fall into the cavity at the back and do little harm.
Anyway here is my ad hoc method that has worked for me on a few occasions.
With the speaker on its back hold the cone with each thumb and index finger ( at 180 deg on the cone ) and move the cone in and out. Work your way around 45 deg at a time till you get your noise. Then you deliberately offset / tilt the cone to make the noise worse and work the cone back and forth for 6-10 times then relax the cone and move up and down without any deliberate tilt. If it gets better bit not completely gone then do it again. till it's OK.
You can be quite rough with these cones , think about what they do when they are working for a living.

[DingDing]

macaroonie

I did as you say, and there is something that seems to be a metallic rubbing sound, so I guess the cone is misaligned. Tried to adjust it with your method, but to no avail.

I guess the next step is to get new surrounds and try to align it, then measure the frequency response and compare it to one of my other drivers to determine if this is a genuine cone or not.

Found this video, must be my lucky day.



Any advice on supplier for dustcap, shim(?), glue, surround and mounting gaskets?

[Odd]

Surround kit. Contact Rick C. [email protected]
He is looneytune2001 on eBay

[DingDing]

Thank you Odd. Will contact him for supplies. Hopefully it's not a cheap knockoff cone. Even though Martin is pretty sure it is, I'm still hoping that the extremely dirty spider indicates an original cone that has been refoamed poorly.

Made this video just now. This has got to be the VC rubbing, right?



Since pushing it into place is a no go, I guess I can remove the dustcap and surrounds just to do further inspections if this is a genuine cone or not? Anything in particular I should be looking for? Can upload videos and pictures for future reference of course.

[grumpy]

check the pictures in this thread:

http://www.audioheritage.org/vbullet...rsion-question

[SEAWOLF97]

This has got to be the VC rubbing, right?

IMHO , I think that the surround is not centered. Cut it out, so that it's NOT misaligning the top of the cone and retry to see if any more rubbing. At this point, nothing to lose by doing so.

If no more rub, then easy , install another surround, carefully.

If it still rubs, then new cone time.

[DingDing]

check the pictures in this thread:

http://www.audioheritage.org/vbullet...rsion-question

Thank you.

IMHO , I think that the surround is not centered. Cut it out, so that it's NOT misaligning the top of the cone and retry to see if any more rubbing. At this point, nothing to lose by doing so.

If no more rub, then easy , install another surround, carefully.

If it still rubs, then new cone time.

Thank you, and I think you're right, because I removed the dustcap to see if there was a mass ring underneath (if not, it would surely not be a genuine cone). Luckily there was one there, but it's black and not silver/metal colored like I see in google images.

When I look closely at the VC, it looks to be misaligned. We see some markings on the inside in this video, and I'm nut sure if they are scratches or just goo from the foam infront of the pole vent, but it absolutely rubs at one point.



Sorry about the intense breathing, I get that way when I'm focused and have a cold, lol. The sounds around 15 seconds is just the table, and not the driver.

I'm going to use a shim to set the surround anyways, and also going to clean out any dirt I'm able to get rid of, hence why I removed the dustcap.

[DingDing]

The mass ring of the 2235h driver in the earlier posted video tutorial of the chap who does the refoaming is also dark grey or black, so I guess it indicates that the current cone is genuine.

Time to see if it's possible to cut off the surround and have it centered without any rubbing, then buy supplies and test my surgical skills.

[DingDing]

The surround has been removed. Is it safe to play a test tone at 10 or 25-30 Hz to see if it self centers through the spider?

If it isn't the spider will be removed to check if the VC is dented into an elliptical shape, in which case I will recone it.

[macaroonie]

Yeah just run it like that gently , cone facing up. Perhaps use a few tabs of electrical tape to stop the cone from tipping , ersatz surround.

[DingDing]

Thanks again, I could not have done this without your help.

When the surround was removed I noticed the old surround was not completely removed from the frame, but I cleaned it up real nicely now. I also removed the inner glue where the foam piece preventing dust into the pole vent was.

As can be seen in this video the cone seems to be misaligned around the leads of the VC. (PS: The cone is not wobbling, it's an artifact of progressive video recording at 24fps, when the cone stops it's playing @ 24 Hz, hence the cam only see the same position 24 times a second).

NOTE: The volume in this vid is a little loud.



The loud metallic noise @ 1:15 is not the driver, but the heatsink on my amp, lol.

It's not easy to see that the VC is not centered properly in the video because of the shadows, but it's visible with the naked eye. I guess the spider will not self center the cone which is weird as the spider looks very old. Also, I don't believe the VC is dented, as it would rub in two places, not one if it were elliptical. Do you guys agree?

So here are some (crazy) ideas:
(1) The noise is not as evident when I play low frequencies, at 125 Hz like in the beginning of this video it's clear as daylight. If the cone was misaligned due to the refoam job that has been done and the spider has been there all along but been bent out of center due to the foam, then I could let it sit for 1-24 hours and play a tone in hopes the spider would realign the VC back into place.

(2) Gently use a heat gun on the spider and try to re-liquify the glue in hopes of realigning the VC back into center position.

(3) Tare away the spider, rip out the cone, measure the diameter of the VC to make sure it's not dented. Cross fingers it's genuine and reassemble.

[macaroonie]

Spiders can sag , think of a driver sitting in the same position for 30 years , gravity has an effect.

[DingDing]

Spiders can sag , think of a driver sitting in the same position for 30 years , gravity has an effect.

Ok, then I guess it's recone time unless some of the ideas work out. I think I want to try to do the recone myself, not to save money, but to gain some experience.

Not sure how to ask this properly, but are the original 2235h recone kits partly assembled like this?



If this is correct, it looks like I only have to clean out the old frame, solder the leads, glue the spider and surround, then gaskets and dust cap, right? With a kit like this where the spider is pre installed it doesn't look that hard to get the VC set at the proper depth into the gap.

Also, do original recone kits come with all the glue needed to do the job? I know a place where I can get genuine recone kits.

[DingDing]

Ladies and gentlemen, the cone is out and there is no turning back.



Do you guys think this is the genuine article?

When measuring the voice coil, should I measure the windings only?

According to spec, VC winding depth is 191 mm (3/4 in), so I guess that is the windings only?

Sorry about the silly questions.

[ivica]

Ladies and gentlemen, the cone is out and there is no turning back.


Do you guys think this is the genuine article?

When measuring the voice coil, should I measure the windings only?

According to spec, VC winding depth is 191 mm (3/4 in), so I guess that is the windings only?

Sorry about the silly questions.

HI DingDing,

1.
It seems to me that the coil and the sider are original,
2.
unfortunately You have cut the spider so, I think that it would be very difficult, (may be impossible) to remove it and put the new one without the VC destruction. As I remembered ther was a kind of suggestion to carefully remove the spider (without its destruction).
3.
You have to check is the VC almost perfect circular in order to be placed in the gap.

regards
ivica