Unless you find an aftermarket seller or something on E-Bay or such selling system parts, no. The HTiB is sold as a set including the inexpensive proprietary speakers. The advice of most on this site for Broken HTiB sets is, and always has been, to throw them out. Most often they are of non-standard design or Ohm average (many 3 ohm or less), making them improper or even dangerous choices for mating with standard receivers. Bear in mind that these are very cheaply made speakers, you can often replace them with better performing ones that operate at the safer standard 6-8 ohms for as little as $60 dollars a pair or less. Such speakers are not something I would recommend normally, but still, better is better.
I'll note that as an alternative, many salvage parts (drivers, capacitors resistors, etc) from these, for use in hobby projects. This does assume some knowledge of how to adjust, or account for , Ohm balance in building DIY, and bear in mind that caps and resistors go bad. Coils (chokes) usually don't though. Caps on woofer / drivers: Often some work is done electronically to limit bass extension on cheap speakers that don't mechanically roll off before they start to rattle. Occasionally, these (usually) small drivers are repurposed as mid-range drivers or couplers in larger DIY experiments, especially where their range is limited to their "sweet spots". - At least for test purposes, so depending, might be reserved.