what "fuses" are used in Ampeg PB212H?

[THC]

Hi. To be brief, I need a "fuse" which looks like a tube type light bulb for an old VW dome light. Anyone know what I mean? I have an Ampeg portabass PB212H powered by an SWR Headlite that I use for practice because it's light & loud. Last night at practice the bottom speaker started distorting, and cutting in & out, I opened the cabinet up tonight and found one of two of these "bulb/fuses" blown. So thankfully it did it's job and saved the speaker. But I have no idea where to get a replacement. Searching everywhere turns up nothing. Can anyone help me?
Thanks so much.

[will33]

I believe many of them are 24volt bulbs but you can use the 12 volt one from the dome light in your car. They work fine. Those bulbs are to protect tweeters. If it was a woofer causing problems, the bulb isn't the only problem, unless it just happened to get caught up in the back of the speaker when it fell down.