Sub for single-driver desktop speakers

The Submini and Arche system now works fine in my home office. Complaints minor.

The Submini was first placed under my desktop, but the bass integration with the FR2 speakers (on short stands on the desktop) was not optimal. It sounds better on the desktop, firing towards me, more or less in line with the speakers. My goal is not to get the most bass, but the best bass, sounding like it comes from the speakers not the sub itself. The bass now sounds clearer, better articulated and coherent with the midtone and treble. Interesting how "small" things like sub placement can mean big improvements. Ideally the sub should probably stand in between the speakers, but my pc screen makes that impossible. So it now stands to the left of the speakers, and is maybe a bit louder to the left, but not much, provided I tune the sub volume and crossover "just so" (low-moderate) to help the system along. The sub is small and simple, but does a good job now.

I naively thought a a sub crossover set at - say - 100 hz  - meant that the sub would reproduce the sound below this point, not above it. I should have known better. The Fostex submini 2 comes with a manual with an informative graph (p 12) that shows the output above the crossover point. Even if I set it to the lowest point, 60 hz, there will be audible output up to somewhere in the region 500 to 800 hz!

Even if this is lower than the output below 60 hz, it is very much there, at least to 2-300 hz. I have confirmed this by listening. The sub, playing by itself (speakers muted), offers quite a bit of lower midtone, even (somewhat ghostly) voices. I suspect that this is a general feature of subs, not just this one (dependent on the slope of the filter etc). Therefore, to my ears, the idea that you can place subs almost wherever, since you wont hear where the bass is coming from, is flawed - since you don't just get the deep quite omnidirectional bass, you get higher frequency sound also. Correct me if I am wrong.

Therefore, it is nice to be able to play around with this small sub, easily pushed around on my desktop, so it sounds perfectly in sync - time coherent - with my desktop speakers. This was never easy to do with the big subs I had in my main system. It is also interesting that the new results resemble what I found in my main listening room (regarding front-firing subs).

Namely: 1) get the sub placed and tuned so you dont hear it (you think the bass is coming from the speakers), and then 2) micro-tune the sub - small changes of position - so the time alignment becomes optimal. My result now is in line with what I heard with the big Velodyne DD18 sub in my main system: the sub woofer should be a little bit in front of the speaker driver(s), to "lock in". At that point, at my desktop, I hear added energy, voices sound more coherent. I don't like a sub staring at my face at my desktop, I would rather push it to the back of the table. But it seems that this forwards position, ca 2 cm in front of the plane of the desktop speaker drivers, actually gives the best sound.

For further discussion of my Arche desktop system with Fostex sub, see