Glue Type Used on Woofer Assembly?

Posted by: m_underwood

Glue Type Used on Woofer Assembly? - 08/09/16 10:27 PM

My oldest Axioms (M40Ti) started buzzing, so I took out the offending driver and found this:



Iím guessing the coil is now rubbing. Anyone encounter this before? Any idea what kind of glue it is and how to get it off so I can replace it? Would it be safe for me to swap in the much newer drivers from my seldom used M3v3 for the moment?
Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/09/16 11:06 PM

Hi, I honestly don't know what was used on that but I think back then the drivers came out of the far east. I would suggest something like jb weld , it will get the job done. There are tutorials on youtube about how to center the voice coil when the cone is replace, I believe they use a 50hz sine wave. I think that would be the biggest challenge. There wont be an issue with using the other driver. When Axiom uses 2 driver in a speaker they use 2 drivers in series that are 4ohm's each and since both your speakers are single drivers you will be fine.
Posted by: m_underwood

Re: Glue Type Used on Woofer Assembly? - 08/10/16 01:22 AM

I tried removing the woofer from one of my M3s, no joy. The driver practically fell out of the M40Ti when the screws were removed, this one won't budge and I'm afraid of damaging things if I force it too much. Even tried removing the tweeter and pushing from behind, its completely stuck.

One odd thing I just noticed, the M3s look like they are veneered on both sides of the MDF(!). Not sure what the point of that was.

Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/10/16 10:26 AM

From what I have seen of the factory online, they veneer the sheet of MDF then cut reliefs with a cnc router. The speaker is then folded into its final shape and glued. I suspect the veneer was damaged in some way so they flipped it over and put more veneer on the other side to salvage the sheet of MDF.

As for the driver, what I do is use a wood screw that is larger than the mounting hole and turn it in so it grabs the metal surround , and then leverage it out with a large metal table spoon. The drivers are tough, I have built speakers with Axiom drivers and they can take it.

Richard
Posted by: m_underwood

Re: Glue Type Used on Woofer Assembly? - 08/10/16 02:22 PM

Thanks, I was able to get it with a pair of woodscrews. Unfortunately it looks like they changed the crimp on connectors. The older woofer has two different widths, the newer one uses the same width for both and uses different lengths.

While messing the the M40 woofer, I found that something beyond glue is holding the magnet portion on. It looks like it originally had a pair of rivets at the rear of the basket, but one of those rivets failed, and the 2nd is slightly stretched out from the weight of the magnet. It doesn't look like I can reliably repair this unless I can safely remove those rivets. I may need to find a replacement driver.

The newer woofer feels lighter, even though the basket is much thicker and heartier looking. Perhaps the newer one is cast aluminum and the old one is stamped steel maybe? Also don't see a shielding magnet on the M3's woofer.

Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/10/16 03:44 PM

Maybe a call to Axiom is in order. That's called a bucking magnet and is not really important just a different way of doing things not necessarily better. Are your newer speakers HP's , the cast basket is something they started do for people that feel cast is somehow better. It may aid in cooling the voice coil on a bigger woofer used for bass but on smaller ones there really is no difference. The ones in my car are plastic and I paid 350 for them. I think you will find the rivets are from the inside and to access them will require the cone to be removed, so it will be a big can of worms. Axiom makes their own drivers so call them and see what they can do.
Posted by: m_underwood

Re: Glue Type Used on Woofer Assembly? - 08/10/16 04:28 PM

The M3s are custom VaSSallo Edition units. It would've been just like me to go all out and check all option boxes.

I guess I'll need to give Axiom a call tomorrow. Just a bit hesitant to do so given the largely negative after sales support experiences I've had with them in the past.
Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/10/16 05:15 PM

I have not had a lot to do with Axiom with after sales though I bought some M80 v3 and they came with v4 drivers , Ian sent all the correct drivers on his dime and I got to keep the others. I have had a few other experiences and all were positive. Luck of the draw I suppose.

Richard
Posted by: Mojo

Re: Glue Type Used on Woofer Assembly? - 08/10/16 08:44 PM

That M3v3 driver shown on the left is not shielded because you can clearly see the magnet. Nice basket though.

The only time you have to worry about shielding is if you're going to butt up the speaker against a CRT or a hard drive.
Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/10/16 09:02 PM

Thanks for adding that mojo, more info is always good smile
Posted by: nickbuol

Re: Glue Type Used on Woofer Assembly? - 08/11/16 09:00 AM

Just a drive-by comment here, but if comparing the woofers to see about compatability, if it is the connectors that are holding you back, you can certainly find new ends for the wires and solder/crimp/heatshrink them on. the newer woofer's spade connections ARE different widths (and lengths) from each other, but also (as you noted) different than the older woofer you are looking to repair/replace.

Repairing a speaker isn't impossible by any means, but like Socky mentions, it can become a can of worms if you have never done it.

As for Axiom support, the biggest thing lately seems to be long delays in responses, not that they won't help people out with great service, just that things are slow going lately... VERY slow going. Be patient, and they will offer solutions to your problem.
Posted by: Mojo

Re: Glue Type Used on Woofer Assembly? - 08/11/16 03:25 PM

The Thiele-Small parameters for those two drivers are not equal. Obviously, by just looking at the two drivers, you can tell FS, VAS/CMS, VD, MMS, XMAX/XLIM and SD are not equal...LOL! smile

I'd be very careful if I were you. If you replace the old driver with the new one, you might alter the flux quantization within the magnetic gap and cause your entire house to get sucked into never-never land smile.
Posted by: bridgman

Re: Glue Type Used on Woofer Assembly? - 08/11/16 07:22 PM

Originally Posted By Mojo
...you might alter the flux quantization within the magnetic gap and cause your entire house to get sucked into never-never land smile.

Even worse, it might not sound right.
Posted by: m_underwood

Re: Glue Type Used on Woofer Assembly? - 08/13/16 09:24 PM

Well, I heard back from Axiom and now have pricing for a new driver. In the mean time I decided to experiment. I moved not only the M3's woofer, but it's tweeter and crossover as well. Drivers from the M3 are ever so slightly larger, so the seals around the speakers are not quite perfect. The result? In a word, horrible. Detail is reduced, bass is gone. Double checked that it's not a wiring issue. It's probably due to crossover tuning. In fact it almost sound like my M3s, which never worked very well in that room. Undoing now.

Very different crossovers in the two speakers. The woofer is directly powered in the M40 (on the left), the tweeter has a resistor and two electrolytic capacitors which are not board mounted:


Can also now confirm that my M3v3 is completely veneered on the inside, almost makes it look like plywood if you don't look at the speaker cutouts!
Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/14/16 12:04 AM

how bizarre. Can they provide an exact replacement driver?
Posted by: Mojo

Re: Glue Type Used on Woofer Assembly? - 08/14/16 12:44 AM

Veneer on the interior will change the speaker's response.
Posted by: Gr8_White_North

Re: Glue Type Used on Woofer Assembly? - 08/14/16 12:59 AM

that ugly ass veneer in there certainly changed mine .
Posted by: bridgman

Re: Glue Type Used on Woofer Assembly? - 08/14/16 02:19 PM

AFAIK the woofer has always been directly driven on M3/M40... and at first glance that still may be true. The crossover on the right (assuming that's from your M3 ?) only seems to have one additional capacitor, so it's likely that the woofer is still directly driven. Might be worth tracing out the circuit, probably just a one layer PCB...

Definitely if the cabinet doesn't seal that is going to mess up your bass pretty seriously.

If you lived a bit closer I could drive over with my M40s and try some mixing & matching, but Richmond is a fair haul even without the hassle of going through customs.
Posted by: Mojo

Re: Glue Type Used on Woofer Assembly? - 08/14/16 05:28 PM

Richmond...BC!
Posted by: bridgman

Re: Glue Type Used on Woofer Assembly? - 08/15/16 10:18 AM

Yep... first thought was "hey he's in Canada too, no customs/immigration" but that didn't last long.

Besides, IIRC the fastest route out west is supposedly cutting through Michigan anyways, even with two trips through immigration. I guess the trick is to cross the border at the smaller crossings where you don't have 8000 trucks lined up ahead of you.
Posted by: Mojo

Re: Glue Type Used on Woofer Assembly? - 08/16/16 09:11 PM

I once went from Cape Town SA to Calgary AB via Yakutsk because that was the fastest way.
Posted by: bridgman

Re: Glue Type Used on Woofer Assembly? - 08/17/16 12:39 PM

Yikes. Did the plane have skis ?
Posted by: m_underwood

Re: Glue Type Used on Woofer Assembly? - 08/20/16 06:53 PM

Originally Posted By bridgman
AFAIK the woofer has always been directly driven on M3/M40... and at first glance that still may be true. The crossover on the right (assuming that's from your M3 ?) only seems to have one additional capacitor, so it's likely that the woofer is still directly driven. Might be worth tracing out the circuit, probably just a one layer PCB...


You're right, the M3's woofer is direct. In fact the crossover component values are identical except for the addition of what appears to be a 2.7ohm resistor. I'm going to have to try shorting that extra resistor out afterwords - the weaker tweeter output may be why I feel the M3s are dull sounding compared to my other Axioms.