The TC-Helicon VoiceSolo FX150 is an personal monitor system that attaches to a microphone stand.
The L1® systems were designed to be positioned behind the performer and when used as designed there is no need for a monitors. For more more information on that concept see: The L1® Approach and the History of Amplification .
I have a TC-Helicon VoiceSolo FX150. It is at least as good as the similarly sized personal monitors from Mackie and Behringer. When I use my L1® systems I don't need monitors. However I got my TC-Helicon VoiceSolo FX150 as part of promotional deal and I was glad to have the opportunity to try it first hand.
I've tried using the TC-Helicon VoiceSolo FX150 in various ways and for me, it does NOT improve the monitoring experience I get with an L1® behind me.
As simple as it is to set up, it's more trouble than it's worth. On the microphone stand, I have found it too prone to feedback. I can't get the volume up high enough to be heard over the Model II. I might consider using it in a situation where I had to place the L1® in a position where I could not hear it. But for me, that almost never happens.
After a lot of experimenting I just don't use with it when I have my Model II or Compact. I use it when the L1® Compact would make too much of a visual impact. For example - at an acoustic jam where I've brought my Yamaha Silent Guitar. At these events amps are not welcome, but I can get away with the smaller TC-Helicon VoiceSolo FX150.
I have used it with a wireless microphone for small speaking gigs but I have to be careful about feedback. In small rooms for 15-20 people the TC-Helicon VoiceSolo FX150 has been fine. I had a series of gigs on a walking campus where I had to haul everything I needed in one trip. Even the 30 pound L1® Compact would have been too much to carry and the 7 pound TC-Helicon VoiceSolo FX150 was up to the task.
If you're thinking of buying one, I'd suggest that you rent or borrow one, or try one out someplace where you can run it in front of a Model II first.
If you are thinking of getting one, please see
TC-Helicon VoiceSolo FX150 Application Notes
This has ideas about how you can use it with a Model II, Model 1S, or Compact.
If you have questions about the application notes, please post them here.