What is bottoming out?

[Texas Tech]

I would like to know what bottoming out your subs actually is? what causes it?

Technically, the physics behind it. An explanation.

[Mike Grice]

I'm no technical genious, but I have experienced my fair share of bottoming out. It is when the coil hits the top of the motor. The coil slides down into a round slot in the motor and there is so much room for the coil to move. There is a technical term for this slot, but i dont know what it is, lol. Well, when the amount of room the coil has to move i think is what the xmech is. Bottoming out occurs when the sub is moving past its limits. This can occur when playing under the tuning of the enclosure, or when you are over power a sub by a good amount.

[Railrocker]

Basically exceeding the mechanical limits of the sub. I believe its xmech.

[Ford302Redneck]

Bottoming out is more than just the coil hitting the backplate. It could also be cone hitting the spider, or the spider hitting the landing. This could be cause by overpower, leaky box, or playing below tuning without a subsonic filter.

[J31Rob]

Originally Posted by Ford302Redneck

Bottoming out is more than just the coil hitting the backplate. It could also be cone hitting the spider, or the spider hitting the landing. This could be cause by overpower, leaky box, or playing below tuning without a subsonic filter.

Not tha coil, tha former that tha coil is wrapped around.

[J31Rob]

Originally Posted by Kyle

Weak impacts are not too bad, but strong impacts can dent formers and break cones, and send dust caps flying.

x2. Dented/bent former = scraping on tha inside of tha motor, which we all know is bad.

[Texas Tech]

thank you very much for the replies and fast.

[Xander]

Originally Posted by Mike Grice

There is a technical term for this slot, but i dont know what it is, lol. Well, when the amount of room the coil has to move i think is what the xmech is.

I believe it's just called the voice coil gap...too simple, haha

And it's Xmax, not xmech.

And to reitterate the answer to the questions...bottoming out is pretty self explanatory. It is when the cone moves to far in one direction that a physical part of the speaker prevents it from moving any further. This could be a hard physical impact or a soft one. Either way it is damaging. So listen carefully.

[Supa_c]

Originally Posted by T/S parameters

Xmax/Xmech - Maximum peak linear excursion of driver, in meters. "Short for Maximum Linear Excursion. Speaker output becomes non-linear when the voice coil begins to leave the magnetic gap. Although suspensions can create non-linearity in output, the point at which the number of turns in the gap (see BL) begins to decrease is when distortion starts to increase. Eminence has historically been very conservative with this measurement and indicated only the voice coil overhang (Xmax: Voice coil height minus top plate thickness, divided by 2). Xmech is expressed by Eminence as the lowest of four potential failure condition measurements times 2: Spider crashing on top plate; Voice coil bottoming on back plate; Voice coil coming out of gap above core; Physical limitation of cone. Take the lowest of these measurements then multiply it by two. This gives a distance that describes the maximum mechanical movement of the cone."

Its xmech
Dangit chevy is fast and danger

[Xander]

Oh, right. I'm an idiot. Sorry, I tend to browse forums when I'm really tired. I guess I shouldn't open my mouth unless I actually have something intelligent to say...