I added a second Rel this weekend and I'm very pleased with the improvements in in the depth and smoothness of the bass. Seems like the whole soundstage is more cohesive. I was going to sell my speakers and single sub and buy speakers with built-in subs but what I was interested in weren't available to listen to. Good for me. Too bad for them.
Help with choosing sub-woofers please
Having survived more than 30 years using full-range electrostatics @clearthinker has finally decided to get sub-woofer(s). Previously he was put off by the well-known difficulty in setting the cross-over to allow a seamless integration. Modern sub design and electronic aids seem to have fixed that.
@clearthinker is pretty knowledgeable and experienced in most aspects of two channel audio. He has spent some hours researching sub-woofers but he's having trouble evaluating the benefits of differing design and application approaches. Such matters are not dealt with qualitatively or comparatively in most postings and videos. He has yet to listen to any and will be trying contenders in his system. But it needs to be narrowed down as he can't try them all.
His Martin Logan CLX Anniversaries are -3dB at 56dB and driven by vintage Krell 200 KRS References. The room is 23 x 15.5 x 8.5 feet, carpeted, plaster ceiling, All walls are deadened with French style fabric covering and 25mm of wool behind. Symmetrical, no windows. No furnishing save equipment, two chairs and a small side table. Subs will be spiked to concrete floor. @clearthinker listens to two channel stereo all genres, no theatre in this room. Cost is not the most critical issue.
Some of the issues that need evaluating (in no particular order) are:
* Benefit of subs using two opposing drivers to reduce vibration, rock and roll
* Floor firing vs. side firing
* How much does size matter? Small is better if all things are not too unequal
* Benefit of two subs to create stereo image. Many say bass isn't very directional below about 50Hz. But bass heard above that on the MLs is certainly directional
* To what extent will the sound deadening deal with room modes? Some say bass waves go straight through wall treatments back to the hard surface behind and bounce right out again
* Benefit of two subs (or more?) optimally arranged to cancel room modes. The unlamented Miller who was rude but knew a fair bit about audio used to mention six and eight. There is freedom to locate.
* Taking unit price into consideration, is it better to have one hi-end sub, two decent ones or multiple smaller cheaper subs to deal with room modes?
* Do wireless feeds work well or is good old wire better? How much does wire choice matter in feeding subs (that may be a long way from the amp. Incidentally the Audio Research Ref 6 is fully balanced.
* Is the KEFKc62 too good to be true?
* Does it make sense to keep it simple and just to use ML subs and digital set up systems with ML main speakers? If so, is it worth spending more to get the Balanced Force series?
* What about REL?
* Anyone else?
Thanks in advance for all your posts. I'm hoping a discussion of qualitative and comparitive issues will help others get to the bottom of optimal sub-woofer applications.
- ...
- 35 posts total
@danager Thanks. Yes near the beginning of his talk he said he has an acoustics PHD. Most of what he said makes sense, but he was totally contradictory on the benefits of conventional room boundary damping for low frequencies. My room is built so I can't alter it now. Looking into constrained layer damping, it is said the effect is gained by attaching two different materials to each other, even though these may be relatively thin. Other vids have suggested that short of mounting walls on springs (not very practical, it is impossible to damp low frequencies. One said you need 5 feet thick material to damp a rear wall. Not very practical either. @dalims4 Noted. Did you wire the two RELs separately for stereo or wire both sides into both? And where did you site them in the room? |
@clearthinker you are correct regarding passive bass dampening it's not a practical strategy. Nelson Pass made an active dampener that would listen and then apply a 180 degree phased mirrored sound to compensate much like noise cancelling headphones but it either didn't work or was never marketed correctly but I like the concept as it could easily be place in the rear of the room without the hassle of running wires or futzing with wireless connections. |
I now read in an REL spec that their wireless has’ delivery latency’ of 16-20 milleseconds. Wonderful term ‘delivery latency’. Might sound benign but it just means ‘delay’. A 20ms delay is the equivalent of the length of a 50Hz wave, or around 25 feet. So the sound takes 20ms to get to the speaker and then perhaps another 10ms before it gets to my ears. The kind of digital tech we don’t need thank you. OK perhaps for the end of the world on a video extravaganza; I don’t mind if the end of the world is delayed 20ms. But not for a symphony thanks. Not just with REL who are honest enough to give this spec; the tech’s all the same so I guess they’re all like that. Pity, I had been thinking of the benefits of losing the wires/cords to 3 or 4 subs around the room. But a signal travels along a wire at nearer the speed of light. As someone said, no such thing as a free lunch. Especially with digital, I said that. Hell, this is even more complicated than I thought. |
- 35 posts total