@HansW I understand your observation; I suppose I always knew that I would have to compromise. The room determines speaker placement; the s600 like to be close to the wall, and REL’s advice was to fire the unit across the diagonal, but I have tried various positions for the REL within the limitations of the room.
I’ll have more time to experiment once the cricket is over. It’s an enjoyable process, if a touch frustrating.
@opus that’s a good idea about a rug; there is an old, threadbare kilim and plenty of cushions but the floor could with something extra. I must try removing the grill too.
A couple of tunes to rouse the soul and test the sub-bass: Sibelius’s Finlandia and Vaughan Williams’s Rhosymedre. I’m not won over by this recording but it’s worth listening to; but my favourite this evening was something else entirely, a brass version of Rhosymedre: stunning.
So have been looking at MJ Acoustics subs; they have twin independent crossovers…not sure what they do, but it sounds like they make for a better integration into an existing 2 channel system!
Anyway, I downloaded a frequency analyser app and ran a sweep from 20Hz to 20kHzto see what my playback is like (my speakers are spec’d at 28Hz to 33kHz). Hardly calibrated mic/ REW (which I may try), but probably good enough for a starter for 10/ order of magnitude assessment. Here it is (the red trace) in all it’s unsmoothed glory…
Following a few late night sessions rediscovering my music collection, from Bowie to Talking Heads, via King Crimson, Fotheringay, Hawkwind, Thievery Corporation and Jan Garbarek, the sub-bass brings something extra to the experience.
I’ve avoided tinkering, although I’m sure the setup is not quite optimal it’s not far off. In short I’m enjoying my music again. Will the experience ware thin - who knows?
I recorded the spectrum above using my ancient Galaxy S9 and a free app from the Play store, using a frequency sweep I found on Qobuz. Then I managed to get hold of a calibrated mic and spent a lot of time researching REW and recorded this…
Not as much difference as I expected and the cheap and cheerful method would have given me enough to set up some reasonably good parametric filters in Roon. Of course REW provides other info not available on an app.
I also borrowed a REL T9i sub, and set that up. Answering my own question I found that with a bit of messing with the sub I could flatten out some of the low frequency peaks and boost the null in the 100 to 200 Hz region, without any EQ! I also managed to get a pretty flat frequency response down to around 20Hz adding a bit of ambience to my music. Early days yet, but I think I like it.
Audition over … new box in the corner. As advised by REL I’m feeding it music for 24 hours before I attempt to tune it. Any advice on running it in would be welcome.
(A couple of old rugs have been spread around, a throw has come out of the cupboard to soften the furniture, and the REL’s power cable has been wrapped in insulation.)
I ended up buying an open box Kef KC62 and it’s now setup and working. I liked the small from factor compared to alternatives, and it goes deep.
FWIW, this is how I set it up.
Volume matched it to my speakers using test tones at 40, 60 and 80Hz (there is a suitable file on Qobuz).
Took recordings in REW of main speakers and then main speakers with sub to work out xover frequency
Generated convolution file using the method for time, volume, SPL and phase alignment that is on Roon forum
Listened and tweaked a little. Job done.
Here is my result, a bit busy, but red thick red line is my corrected response vs Harmon curve (black) and a good fit right down to low frequencies, thick blue is uncorrected response (all with speakers and sub). Green my main speakers minus sub, rolling off from about 40Hz. Plots at bottom are the correction curves for left and right channels.
I played the test tones (being within the frequency range of both speakers and sub) at my usual listening levels firstly on my main speakers and measured the volume via microphone and did the same for my sub and adjusted the gain on my sub to match. Probably would work accurately enough using a mobile 'phone and sound meter app, or just listening to it.
Don’t know if that’s the recommended method, but that’s how I did it.
Tweaked the beast this afternoon; tried crossover at 35 Hz but clicked it back to 30 Hz. The volume still needs adjusting but will let it run in for a while more as it has had its 24 hrs of solid music.
For those interested I attach the Housecurves and the equalised adjustments for the Roon convolution filters. I’ll revisit these once it has run in for longer.
Not really taken much notice before, but my room measurements show a noticeable improvement from 1kHz to 4kHz with the sub connected, compared to without, despite the sub not operating at these frequencies.
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