Disappointed...

[deek]

I don't know how I missed it, but beware if you're buying a refoam kit from Simplyspeakers, it does NOT come with replacement dustcaps.

Whether you use the cap on or cap off (and shim) method, there's a pretty high likelihood your dustcaps are toast. I know mine are and it was my mistake, but it's disappointing nonetheless.

The Parts Express kit does.

The MSound kit does.

So I ordered new ones from Parts Express today; cheap but that's another shipping charge I could have avoided.

-deek

[oldarnut]

Let us know if the PE foam is equivalent to the Simply Speakers surround. I bought the PE surround for my large Advents, but have nothing to compare it to for compliance.

[deek]

I've done several sets in the past, all 8" drivers, for AR 17's, 18's and the midbass drivers in my 9's. All of these were done with Parts Express kits. The surrounds from Parts Express appear to be identical in thickness, density and flexibility to the Simplyspeakers pair I just got.

I just ordered dustcaps, not the whole kit, so I won't have any to compare directly. One thing I did notice was that Parts Express doesn't offer an angled-edge 12" kit where the inner edge is angled down. The photos appear to be flat on the outside and inside, which would be wrong for these woofers. They do offer this variance in the 8" size. (The correct type for the midbass drivers in the 9)

The Simplyspeakers surrounds are angled properly. I have no idea if this would make a bit of difference in the sound of a woofer this large, but I wasn't willing to risk it with the 8" midbass drivers.

-deek

[deek]

Started on the woofers yesterday... I gotta say, I'm not impressed.

The surrounds themselves aren't sized just right; the ID is slightly smaller than OE so the cone actually portrudes into the roll slightly on the inside. The OD seems to be fine, no issues there.

The glue supplied makes an unholy mess. The consistency is about that of hair gel. The instructions say to put a 1/8" bead on one surface but a 1/8" bead on the cone will drip and run almost instantly and become a sticky mess. The glue may be stronger than the "elmers" variety used by PE, but I have to say this stuff is a pain to work with.

The glue also has no instructions for cleanup and neither soapy water, mineral spirits nor acetone will clean it out of the brush I used to wipe up the drips. (All the more reason to supply disposable foam applicators which PE and MSound both do, but Simplyspeakers does not)

So Simplyspeakers is getting a 3 out of 10 for me... this experience has not been good to say the least.

-Deek

[deek]

An update...

On the card for the second tube of adhesive I opened, there is cleanup information. Nail polish remover is recommended. I haven't tried it yet, but I'll see if it affects the glue or the surround later tonight.

-deek

[Mexicomike]

Acetone is the active ingredient in just about any brand of nail polish remover

An update...

On the card for the second tube of adhesive I opened, there is cleanup information. Nail polish remover is recommended. I haven't tried it yet, but I'll see if it affects the glue or the surround later tonight.

-deek

[michiganpat]

I've never removed a dustcap and shimmed. I glue the surround to the cone with a white PVA glue like PE supplies, or aileen's tacky glue, let it sit overnight. then I use the same glue to glue the surround to the basket, running a 30hz test tone, applying clothespins as clamps around the circumference to hold it in place as it dries once the 30hz test tone has centered it.

used the PE 8" kit (both surrounds) to refoam 2 pair of AR18's, sounds like the best foam to get are actually spec'ed for 8" boston acoustic speakers from msound, they thin and more compliant like the originals, and have an angled inner flange to better mate with the AR woofer.

[deek]

I used that method (sans the test tone) on the first pair of 17's I did and they turned out alright. The second pair I did, I noticed an anomaly that convinced me never to do another that way again...

On one speaker, the cone, it appeared, was glued to the spider off-axis. (Tilted) This made the cone line up to the basket off-center. The original surround was glued on in such a way that it was centered properly on the cone, but off center (less than 1/4") of the basket. I noticed it during disassembly but thought it was a poor former foam job but no, when you measure from the edge of the cone to the spider, one measurement was three full millimeters shorter than the opposite side.

I thought someone was playing tricks on me so I tore off the new surround (Glue wasn't dry yet) zipped the dustcap off and shimmed the voice coil. Sure enough, the cone was out of alignment with the basket.

Had I used my normal method of centering the surround on the cone, then the basket, the voice coil would not be parallel to the gap and could have rubbed. I always shim now, and I also always measure from the edge of the cone to where the spider attaches. I have noticed variances up to 4 millimeters in the 8" drivers I've done since. (Mostly in the 18's)

On a larger cone woofer with quite a longer Xmax, I'm just not willing to risk it.

Forgive me, but I don't see how a test tone could counter an axial force on the motor assembly; anyone who has worked at length with low-tolerance solenoids and servo equipment knows that the bearings and seals are of the utmost importance to maintain parallel motion... the magnetic field simply has very limited force perpendicular to the direction of travel. (or at least that force is well outside the boundary of the motor itself)

-deek

[genek]

I don't think anyone is suggesting that a test tone will center a driver that has any real axial force pushing it out of alignment. Any forces pushing things off-center will still be there after repair if the driver is just temporarily forced into alignment. The tone is merely an alternative means of centering something that needs to be free to be centered. If the tone won't center, there's probably something else wrong with the driver that needs to be fixed besides a rotted surround.

[deek]

Like a worn or sagging spider, for instance? I definitely see how the test tone would help that situation.

To each his own, of course. I just don't have confidence in my ability to get things in alignment without the shims. And I'm probably being overly-anal about it!

-deek

[Pete B]

Like a worn or sagging spider, for instance? I definitely see how the test tone would help that situation.

To each his own, of course. I just don't have confidence in my ability to get things in alignment without the shims. And I'm probably being overly-anal about it!

-deek

How do shims fix a sagging spider? In fact if the VC is off center

without the shims, they force it back into center but only while

they are in place, it returns back off center when you remove them.

You either need to replace the spider or do the best job possible,

then mount the woofer so that gravity pulls the spider the other way.

I'm of course talking about a spider that has deformed due to the

weight of the cone. There are really no simple solutions other than

a full rebuild including the spider which is no longer available.

You mention one woofer where the cone was glued off axis to the spider,

actually I think it is glued to the voice coil, but in any case a

rebuilder needs to watch out for these things and decide if the best way

is to duplicate any deliberate compensation done originally or to just

find a replacement driver.

The test tone is simply to run the driver over the full excursion to

be sure that there is no scrape. It will also tend to pull the foam

more on any side that is tighter.

[deek]

How do shims fix a sagging spider? In fact if the VC is off center

without the shims, they force it back into center but only while

they are in place, it returns back off center when you remove them...

I didn't say the VC is off center in the gap, and I'm not suggesting that the shims would fix a sagging spider.

What I have experienced is that the cone edge (to which the surround is glued) is not centered to the basket opening when the voice coil is shimmed. Given the rigidity of the magnet/basket (as compared to the "soft" parts) and the shims holding the voice coil parallel (and centered) in the gap, the cone/coil relationship is comprimised in some way if the basket opening and cone edge are not concentric.

This suggests to me that the cone is either glued to the voice coil in a way that is angled or the cone was not cut properly. Whatever the case, following the method I used prior to this experience would have resulted in a voice coil that travels through the gap in a way that is not parallel to the gap opening.

I'm guessing what I assumed was a poor former foam job was exactly what you describe; a manual adjustment to that misalignment by gluing the surround off-center of the basket.

-deek

[xpat]

I've done several sets in the past, all 8" drivers, for AR 17's, 18's and the midbass drivers in my 9's. All of these were done with Parts Express kits. The surrounds from Parts Express appear to be identical in thickness, density and flexibility to the Simplyspeakers pair I just got.

I just ordered dustcaps, not the whole kit, so I won't have any to compare directly. One thing I did notice was that Parts Express doesn't offer an angled-edge 12" kit where the inner edge is angled down. The photos appear to be flat on the outside and inside, which would be wrong for these woofers. They do offer this variance in the 8" size. (The correct type for the midbass drivers in the 9)

The Simplyspeakers surrounds are angled properly. I have no idea if this would make a bit of difference in the sound of a woofer this large, but I wasn't willing to risk it with the 8" midbass drivers.

-deek

Hello,

I've done surrounds on a pair of AR5s (and also the 4 woofers and 2 midbass speakers on my AR9s). I actually was very pleased with the results using Simply Speakers kits. I've also used the Speaker gasketing material from Parts Express and was very pleased with that product - what a difference in bass output.

[dynaco_dan]

An update...

On the card for the second tube of adhesive I opened, there is cleanup information. Nail polish remover is recommended. I haven't tried it yet, but I'll see if it affects the glue or the surround later tonight.

-deek

Hi there

I would think that any petro based solvent would disolve the surrounds.

I also believe that most suppliers on the internet sell a white polymer adhesive.

The 3M material that is used by most service repair shops would not eligible for any standard delivery because it is legally classified as an explosive.

The polymer likely is not in that same league for it to be able to be mailed via USPS, etc.

Here in Vancouver, I paid a premium surcharge, under the explosive act, for special transportation for my supplier, I only bought a 1 litre can.

One gram or one gallon, it doesn't matter, a licence ia required to transport.

Irregardless, read the MSDS? (spel) Information sheet before using and have eye protection, ventilation and a fire safe work area!

Another thought I have is the rotation of our car tires, perhaps we should turn our speaker cone drivers 180 degrees every 5 or 10 years or so.

At least those that are in the typical vertical mounting position.

Just a thought or two or so for tonight.

[JohnHeubel]

I've ordered all my foams from this vendor: http://stores.ebay.com/GeoAli-Vintage-Stereo-and-More?_trksid=p4340.l2563

No affiliation, just a very satisfied customer. The glue is nice and tacky, cleans up with water. They'll quote you all the dimensions of the surround if you want to make sure. They also supply shims and brushes for the glue and make "custom" kits if you're ordering several sets of foams.

I've never replaced the dust caps, I just carefully cut them almost all the way around, leaving just a little "hinge" that it folds back on. After everything is dry, I check out the speaker and then carefully glue the dustcap together. Once that has a chance to set, I run a final bead of glue around the seam and brush it flat.

John

[JKent]

I've ordered all my foams from this vendor: http://stores.ebay.c...sid=p4340.l2563

No affiliation, just a very satisfied customer.

....and while we're at it, don't forget m-Sound.

http://stores.ebay.com/M-Sound

Kent