Marty,
I can try to answer a few of your questions:
1) The Ohm sound does indeed sound very similar from model to model. I went from the Micro to the 100 and the difference was room fill. The sound and detail level was the same but they fill my room better. They also play louder obviously. Each model user a larger driver from the previous model I believe. The cabinet is also larger. At least this is the case with going from the Micro to the 100s
2) Even though the lower bass would be off-loaded to a Sub in the HT models, you would still want a larger driver to handle different SPL requirements. If you have a huge room, larger speakers will have an easier time getting to louder sound levels than smaller ones.
3) The Main Ohm's are crossed over to a super tweeter that is directional at the higher frequencies. In my experience the transition is very smooth. I believe they offer true omni's that are designed for use as surrounds.
4) I have used the Mirco's /w a sub in a music only system. This would give you more flexibility in where to set the crossover. 80Hz might be fine for some, but others may choose to cross over a bit lower depending on the application. In my setup, I did not have bass management so the extra bass from the Micros allowed me to cross the sub at a lower level to get a smoother transition.
5) I would recommend e-mailing or giving John a call. He is a great guy and my experiences have been very positive. If you have special needs they can work with you to tweak a model to your needs. Combine that with the great warranty and long audition period and they are definitely something to keep in mind. Someone can chime in and correct or add to anything I may have said but I hope this helps :)
I can try to answer a few of your questions:
1) The Ohm sound does indeed sound very similar from model to model. I went from the Micro to the 100 and the difference was room fill. The sound and detail level was the same but they fill my room better. They also play louder obviously. Each model user a larger driver from the previous model I believe. The cabinet is also larger. At least this is the case with going from the Micro to the 100s
2) Even though the lower bass would be off-loaded to a Sub in the HT models, you would still want a larger driver to handle different SPL requirements. If you have a huge room, larger speakers will have an easier time getting to louder sound levels than smaller ones.
3) The Main Ohm's are crossed over to a super tweeter that is directional at the higher frequencies. In my experience the transition is very smooth. I believe they offer true omni's that are designed for use as surrounds.
4) I have used the Mirco's /w a sub in a music only system. This would give you more flexibility in where to set the crossover. 80Hz might be fine for some, but others may choose to cross over a bit lower depending on the application. In my setup, I did not have bass management so the extra bass from the Micros allowed me to cross the sub at a lower level to get a smoother transition.
5) I would recommend e-mailing or giving John a call. He is a great guy and my experiences have been very positive. If you have special needs they can work with you to tweak a model to your needs. Combine that with the great warranty and long audition period and they are definitely something to keep in mind. Someone can chime in and correct or add to anything I may have said but I hope this helps :)