Sub for single-driver desktop speakers

Thanks all for interesting suggestions. Especially to @atmasphere – maybe I hear some Doppler effect, yes. At least, so far, these small speakers sound much better with well-recorded ‘sparse’ music than with high dynamic multi-instrument rock. Like Shelby Lynne: Just a little lovin’ (though I have yet to hear a system where this album sounds bad). However I realize that my initial post may be premature. The FR2 speakers need some weeks to open up, according to reviews.

BTW, these speakers will eventually replace my trusty old Sony SRS-ZX1, that are even smaller than the FR2, and yet go down to 60hz or so. This is due to a C-formed channel at the back that Sony calls a «Mobius duct», leading to the bass port below the single driver. I like this analog domain type of modification, avoiding electronic equalizer glare, but I don’t think Sony ever developed it further. However, even if the Sonys go lower, the FR2s are better from midtone upwards (clearer, more air, space), so I hope they break in, over time.

Good to see you are trying the Arche's.

Don't know if they are still in production but years ago I tried/liked a small Gallo sub (TR2) with various widerange single drivers (including 3"-4.5" Japanese drivers).

Also tried it with their little "ball" speakers.

Think the sub's crossover defaulted to 100Hz when using the speaker cable connections (adjustable when using the low level connection).

DeKay

The Gallo Tr2 (also Tr1) is an interesting suggestion , thanks.

A sub should not go high - agree with Atmasphere - just up to 80hz, or if possible, even lower. The lower, the less problems with integrating with the main speakers.

I am not sure, if the gap between the low 100hz end of the speakers, and the top 80hz of the ideal sub, is a real problem. According to John Parks at Arche, the Fr2 system works well with an added sub.

Raised almost to ear height with 19 cm alu stands, plus more break-in, the Arche system now sounds better. Very clear and detailed.

If you need to know, which of your streaming albums should you invest in, on vinyl, this system offers good orientation.

Regarding the gap between the low range of the speakers (on paper, 100hz) and the high point of a sub (no higher than 80, or maybe 70) - is there an easy way to measure this? I could use the REW program, or Audacity, I think, but I am looking for some easy-to-use phone app that can tell me about the output in a specific range (like 80-90-100 hz). Ideas welcome.

Another way would be to use test tones, and our trusty old friends, the ears. I found some sine wave tones on my pc. The FR2 plays tones down to 125hz very loud and clear, no problem. They play a 100hz tone clearly also, providing I turn up the volume (confirming what reviewers have said). Surprisingly, they play 80hz and even 63hz tones also, still clear, at the same louder level. It is only when I play 50hz that they give up, I hear ca nothing. So this would suggest, I think, that the "gap", on paper, between speaker and sub limits may not actually be a problem. My general impression, using subs and main speakers, is that the main speakers should not be cut off at the bottom end, unless there is dire need for it. I think this goes for the FR2 also. Maybe I am too tolerant of "colorations", "doppler effects" and other suspects, but I find that full range speakers should be given a full range signal, to sound best.

Perhaps the ideal, in my context, would be a small sub that has speaker level connections - avoiding crossover/equalizing - that helps the speakers along in the 100 or so hz to ca 60 hz range (or however low it goes). I have some flexibility and can position the sub so it just helps the speakers along, adding some more deep mid and upper bass tone, without disturbing the clarity of the speakers. Positioning + subtle use of sub volume (so it stays "invisible") may do the trick.