Adding a small subwoofer for music in 2020


I see a few old posts considering small subwoofers, but I wanted to resurrect this topic for 2020.

I have a small office (8x10). I have zu cubes, and a heaven11 billie and small tube amp I like to switch between.
The cubes need a sub but I have limited space. The Billie has a pre out, the small tube amp only has speaker output.

Ideally I would get something that has both high level as well as low level inputs. I haven’t found a lot of truly small units that offer this. So far the only thing jumping out at me is the Velodyne microvee. I like the features of Rythmik, but their 12" units seem too big. JLaudio discontinued their d108.

Anything else in a small sub to round out music I should consider?
m_j_d
Sounds similar to my rock and roll office I just revised a few months ago. I am very happy with my results.

You need a Low Pass or High Pass Filter SOMEWHERE, and a self powered sub.

Send only the low bass to the sub; or, send only the upper bass/mids/highs to the bookshelf speakers. Separate prior to the amp, so amp does not need/try to make power hungry low bass (which is why you want/need a self powered sub).

In cases like this, 2 channel, sub is always on, always doing as much bass as you ask it to do (via an adjustable crossover, via the sub’s volume control).

Adjustable crossover can be built into the sub (common) or, a separate crossover before the sub (usually in a larger system).

Placement flexibility: Separate crossover, another piece, another expense, can be small, on the shelves near the amp. Doing that, then a sub, same size output, without built in crossover, might be a bit smaller enclosure, and a bit less expensive.
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Where will it go? Vibration? Direction of sound waves? How much bass? Volume? Access to adjust controls?

In this case, using only one sub, you do not want to be aware of it’s location, just add ’extra’. Typically not even be aware it is working unless you turn it off. Makes those small bookshelf speakers seem amazing.
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Imaging. My desk faces the bookshelves, chair/monitor dead center on speakers, wonderful imaging, and, center channel images from the monitor when watching music videos, playing Pandora ...

My old Velodyne sub (bigger than I need but I had it) is on the floor, in front of the two bookcases, left end, aimed sideways across the front of the bc, out of sight, no hints to it’s location.

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High Pass Filter: line level to sub, built-in adjustable crossover, takes low bass, sends only upper bass/mids/high frequencies, still line level, to your amp. Easier job for amp, amp to bookshelf speakers.

Speaker wires from amp to sub. (My option using my old Velodyne) If the amp has enough power, like my Carver Cube (Small, SS, 200wpc great for bookshelf use), you send speaker wires to sub, the sub has a built in crossover, after it takes as much bass as you ask, via it’s crossover, it sends the upper bass/mids/highs via speaker wires to the bookshelf speakers. Amp still makes power hungry bass, but bookshelf speakers do not have to. Same result, except the amp does not get a break.

I also have a small listening space and was concerned that a large sub would completely overpower the room and make integration all the more difficult. After reading numerous professional and user reviews, I ended up buying a small Rel T/5i sub that paired quite nicely with the Kef LS50s. The T/5i has an 8" driver in a sealed enclosure. It has Low Level (RCA) and High Level (Speaker) inputs. Even comes with a Speakon cable for High Level use. Definitely include the Rel T/5i on your short list.

https://rel.net/shop/powered-subwoofers/serie-ti/t5i/?gclid=Cj0KCQjw7sz6BRDYARIsAPHzrNK8NcjURmxJVl9G...
REL Habitat.  Occupies no floor space, has both high and RCA level inputs.

Velodyne is long gone and there is no support, service, repairs, etc available.