Fortunately yes (unlike the OB where I don't seem to have one at the listening position).chris661 wrote: ↑Wed Dec 30, 2020 2:42 pm Simon, did you, by any chance, take some measurements of the 285 at the listening position?
IME, once you get below a few hundred Hz, you need to be treating the room + speaker as one, and acting accordingly. The sealed box will be activating a different set of room modes compared to the dipole version, and of course will be operating without dipole losses. It's possible there's some cancellation (there appears to be one already showing at 1m) which could be eliminated with careful positioning.
There does appear to be something odd going on around 100Hz. It's not something that's obvious to me listening, though I suspect if there is an issue it would be fairly obvious if corrected.
I had thought about this as an option, a little "shaping". The 3116 are barely working so there's plenty of scope. But I don't see the sealed boxes as the long term solution, only if I need some help low down that an OB can't manage in my room.chris661 wrote: ↑Wed Dec 30, 2020 2:42 pm I haven't checked out your LF amp, but if you've got some spare gain available (via turning the volume control up a bit, changing resistors or whatever), you could probably put together a shelving cut with some caps and resistors to drop the level above 50Hz. Totally passive, just put it on the input of the amp. Add the required gain back in, and the <50Hz range should be boosted.