Subwoofer rattle (BIC F12)

[Kelly Rankin]

BIC replied and they want a copy of the sales receipt. I do not have this and its not an option to get it.

 

[Seth=L]

So you're basically saying you really want to put that infernal Infinity woofer in the box?

 

[Kelly Rankin]

So you're basically saying you really want to put that infernal Infinity woofer in the box?

If it is not a terrible idea..yea..since it seems like I'm Sol with Bic

 

[markw]

BIC may not honor the warranty due to the lack of a receipt, I'm pretty sure they will sell you a replacement.

 

[KEW]

I think his real question is will the other driver work.
I don't know.
But it wouldn't hurt to price the BIC driver.
In the mean time, you can tighten the screws and/or pull the driver out to see what you can!

 

[markw]

I think his real question is will the other driver work.
I don't know.

As was mentioned earlier, I'm sure it'll fit and respond electrically. The question remains is how well it will mate with the enclosure and whatever adjustments have been bade to the amp to assure the best performance.

So, we know both will fit and respond to a signal but only one is guaranteed to get the most out of the enclosure and amp.

 

[KEW]

Yeah, I don't know if the BIC amp is sophisticated enough to have any "hard wired" EQ to optimize for the BIC driver or not.

 

[markw]

Yeah, I don't know if the BIC amp is sophisticated enough to have any "hard wired" EQ to optimize for the BIC driver or not.

Perhaps, but they are likely sophisticated to match the driver to the enclosure.

 

[KEW]

That is a good point. Seems like Hsu was involved in the design of one of the BIC subs.

Maybe the H-100?

 

[TLS Guy]

If it is not a terrible idea..yea..since it seems like I'm Sol with Bic

Well you might be able to use that driver.

I have looked into it, and the outside volume of your enclosure is 2.4 cu.ft. So I suspect the internal volume when you subtract wood volume driver volume and port volume will be very close to 2 cu.ft, which is the volume required by that driver..

The port needs to be 4" in diameter and 10" long. The ports specs are critical. If the port is not 4" in diameter and 10" long, you will have to change or modify the port when you change the driver.

As far as I can tell the 3db point will be about the same at 35 Hz.

That BIC sub as far as I can tell is designed to maximize output and not low frequency extension

 

[Kelly Rankin]

I removed the plastic ring on the enclosure and the screws that were under it as well, but I get the feeling that thing cannot be taken out of there without coming to a point of no return.

I don't see any obvious damage from that perspective.

If I place my finger on the bottom middle of the surround and then tap another part of the surround, there is no rattle. If I remove my finger from the bottom part, and tap I get a fairly obvious rattle. If I place my finger on the top of the surround and tap the bottom I still get the rattle. The same result if I place my finger on the side and tap anywhere else.

Thoughts?

Is there a way to remove this thing from there without damaging parts or is it expected that when you remove a driver from the enclosure that you'll have to redo something?

 

[KEW]

So are you now looking at another set of screws holding the driver in place?

The greatest risk is having the speaker fall out after all of the screws have been removed. Sometimes they are a tight CNC fit, sometimes they use a sticky gasket between the driver and the cabinet. Either way, the magnet on the driver is relatively heavy, so when it comes loose, it moves fast unless you control it.
First thing I would do is lay the sub with the driver up (sometimes you may need to rig some support if this means laying it on the back panel, but usually the back panel is not fragile and your sub is fairly light). Next loosen each of the screws so that there is about an 1/8" gap between the bottom of the screw head and the driver. Now, flip the sub so the driver is upright - often the weight of the magnet will cause it to "fall" against the screw heads. If it doesn't come loose, tilt it forward and it should come loose. If it still doesn't, you may need to pry at it, but understand this may scratch/dent the cabinet.
Once you get it loose, with it vertical, the driver should press against the lower screws from the weight of the magnet. Loosen the lower screws as required to allow you to insert something like a butter knife under the rim of the driver. Now flip it back on its back, holding the butter knife in its place as you do. Remove the screws, then use the knife to lift the driver so you can grab it. Lift it out gently until you can see the wires. Unplug the wires from the back of the driver and the driver can be lifted completely free.

On rare occasion the above was not successful and I needed to remove the amp plate from the back in order to push the driver from inside the cabinet.

 

[Kelly Rankin]

So are you now looking at another set of screws holding the driver in place?

On rare occasion the above was not successful and I needed to remove the amp plate from the back in order to push the driver from inside the cabinet.

I also removed those screws, not realizing it might fall out. It seems to still be in there fairly firmly so I will have to pry it out.

I had considered removing the plate amp, but I wasn't sure what I would find.

 

[Kelly Rankin]

So, I got the driver out. One thing that I noticed is that it looks like the the small circle in the center is not fully glued to the bigger piece behind it. Is it supposed to attached completely?

 

[KEW]

I gotta call it a night, but see if you can identify the small circle:

Ideally it would be the dust cap, lol!

 

[Kelly Rankin]

It was the dust cap. As it turns out I think i was incorrect though. Once I got the thing in the light I was able to see the glue.

 

[TLS Guy]

It was the dust cap. As it turns out I think i was incorrect though. Once I got the thing in the light I was able to see the glue.

This is your driver on the left.

Now the center piece is the dust cap. This covers the part where the voice coil is glued to the cone.

Now look in behind the cone and push the cone forward, gently probing all the way around the cone, a section at a time, and see if the cone separates from the voice coil former at any point.

I'm pretty sure at some point the VC former has become detached from the cone.

If it has, then this can only be fixed by a complete recone.

I have looked to see if there is a recone kit, and I can't find one. This is not unusual in these days of Far Eastern manufacture.

See if BIC will sell you a new woofer. Manufacturers usually will sell you a new driver, but sometimes will require proof of purchase.

If not then you can use the driver you suggested. You may need to do some carpentry to make it fit.

One thing you will need to do most likely is to change or modify the port. The port must be 4" X 10" for that replacement driver to work in that cabinet.

 

[Kelly Rankin]

I checked pretty carefully by reaching in and pulling the cone outwards lightly (but with enough force to move a bit) and I don't see any detachment

 

[TLS Guy]

I checked pretty carefully by reaching in and pulling the cone outwards lightly (but with enough force to move a bit) and I don't see any detachment

Well they can be hard to find until the cone is removed.

When you push the cone in and out, do you hear a rubbing or grating sound?

The fact is that when a speaker has a buzz or rattle, that is not due to a rotted surround, or a surround that is partially or totally unglued, then the cure is always reconing.

So you need a new cone with VC, spider and surround. You also need a new dust cap and a set of factory shims to align the voice coil in the gap. You will also need loudspeaker glue.

So you need to desolder the wires of the VC from the chassis terminals and remove the cone. It is no use, so it does not matter how much damage you do.

Now put masking tape over the VC gap.

Now all the glue has to be removed from the chassis. This can be done with acetone, or alcohol and a paint scraper. Alcohol is slower but I like it better. It takes longer, about 20 min to soften the glue, but I find you get a better peal. You need to remove all the glue from where the surround and spider attaches.

Now blow out the VC gap with compressed air. Now fold a piece of masking tape back on itself so there are two sticky surfaces outwards. Now wipe it round the gap to make sure there is absolutely no dirt in the gap.

Now place the new cone in the speaker. Put the factory shims between the VC and the pole piece and leave them there.

Now glue the spider to the chassis with no stress.

Now do the same for the surround.

Now leave everything alone for at least 12 hours until the glue is fully cured.

Now remove the shims and glue in the dust cap.

Resolder the VC lead in wires to the terminals.

In 12 hours your speaker is ready for installation.

Check with BIC, for a recone kit or new driver.

You can also check with Orange County Speakers, or Simply Speakers and see if they have a recone kit.

If you can't get a new driver or recone kit, then you will have to use the driver you suggested in your original post and to the mods already outlined in the post above.

 

[jinjuku]

Make sure the speaker basket isn't deformed or warped before you put any effort into the existing driver.