I bought four AV15s during the recent preorder and one of them is defective. John, at Stryke, has told me to ship it back to TC Sounds for a rebuild and I'm wondering what kind of turn around I can expect. Does anyone have experience under similar circumstances? The problem I'm having is that one of the four drivers makes a very noticable ticking sound in synch with the movement of the cone (no, it is not bottoming out. It is not nearly that loud). It does not show up until moderate excursions (~ .5 - 1.0" p-p). My test setup is all four drivers mounted in my IB manifold sitting on the floor. This is a test setup and the manifold is not installed in the attic so the drivers are acting like OB not IB. I've got all four drivers hooked up in series with one coil driven (the other open)for an effective impedance of ~8 ohms. I'm driving this from one channel of an AudioSource amp rated at 150 watts into 8 ohms. The ticking is very noticeable at very low frequencies from 10 hz to 25hz and only one driver makes the noise. As you raise the frequency it starts to sound like a motor boat. I took the bad driver out of the manifold and drove it alone while I held it in my hands(lower power ~ same excursion) and it is definitely coming from the one driver and not the speaker cables flapping around. I've checked above and below the spider with a flashlight and found no obvious cause. I also looked into the back vent and also saw nothing. The other three drivers work fine. I'm thinking that there is either some foreign object getting in the way of the voice coil or the coil is mounted off center and is nicking the poll piece at moderate excursions. I'm shipping it out tomorrow. Is there anything else I should look for before I ship?