This is a great observation and I'm happy that you brought this up.
I agree with you, the different models sound different.
As I'm reading this, I'm in a room where I have L1® Model IIs, Compacts, and F1 Stacks (F1 Model 812 with F1 Subwoofer) set up so that I can switch between them, and I do switch between them as I'm doing other things. It's part of how I tune my ear and my expectations.
They all sound different, although at low volume and for music without a lot of bass, the Compacts are a good stand-in for the L1® Model IIs. And at mid level volume the Model IIs are just fine in a head-to-head comparison with the F1s. But they do sound different.
I don't expect to hear the same output from the same input when switch between these systems. And the differences become more apparent as the volume goes up and when source material is demanding. For example: When I run the Compacts full out, it sometimes seems as though the mid-highs outpace the bass, especially as you get farther away or outdoors. You have to be running a LOT louder to have the same sense with a Model II (with one or two B1s) and louder still if you have a B2. Do the same with the F1s and it's hard to have the mid-highs outpace the bass. Having said all that, I could have expressed it that the Compacts sound brighter than the Model IIs and the F1s. It depends on the volume and the source.
To varying degrees you can change the overall voicing of the units.
- With the Compact run into Channel 2, there's no EQ. You have to control everything at the source.
- With the L1® Model II with the T1® we have the Presets and lots of EQ control.
- With the F1 Stack (F1 Model 812 with F1 Subwoofer) we can balance the bass with the mid and highs (F1 Subwoofer and F1 Model 812) by adjusting the F1 Subwoofer Volume, and by changing the setting on the F1 Model 812 EQ.
"But with the f1's I noticed I really have to play with the Eq settings for the highs to come out. If I leave it flat it seems to be just lows and mids."
If you want the F1s to sound more like the Compacts you can dial back the Subwoofer and set the F1 Model 812 EQ to WITH SUB. But at least for me, I don't want the F1s to sound like Compacts. They are a different tool for a different application. So I expect to use them differently.
What do you think Joe?