@erik_squires wrote:
No one wants peaks or nulls, but IMHO and experience, peaks are worse. Of course, mathematically we can compute power differences for each, but peaks are bad because they tend to force the listener to keep the overall subwoofer level excessively low. OTOH, I’ve never seen a real system where the nulls were so pronounced that they forced an excess in sub volume. Maybe I got lucky.
In my experience, clipping the peaks and then raising the subwoofer level is 2/3rds of the battle.
The highlighted parts are important points I’ve tried to raise at numerous, previous occasions - certainly the aspect that many end up lowering sub(s) gain to suppress not only peak issues in the range here, and thus are deprived of sufficient low end presence and overall quality.
To clarify on the corrective measure of peaks/nulls: it is my experience that nulls, which can be quite severe, require sometimes a fairly prodigious amount of extra power to be alleviated, and this can put a strain on the amp(s). At the same time peaks do the opposite to some degree, which may end up at least partly nullifying the added power demands from peaks, but from my chair this is usually not enough to keep nulls from being a potential power issue correction-wise, to the point even where the driver is also stressed.
The purpose of this thread was to discuss the myth of subwoofer speed, not any particular technology, and it invariably happens that SWARM fanboys show up and turn the thread into "WHY DON"T YOU HAVE SWARM" and take the discussion far afield from it’s intended point.
So, sure, any tech which evens out the peaks and nulls and correctly meshes the response of the subs to the mains is good, including SWARM, but this thread is about dispelling myths that you can’t add a sub to a "fast" speaker, not pushing any particular solution.
First, if dispelling named myth is the goal then be prepared for a variety of suggestions on how proper subs integration can be achieved. I don’t yet SWARM myself (though down the road I’m contemplating a symmetrically set up DBA with smaller tapped horn, similarly tuned variants), and my intention was not to be the "SWARM missionary" here but rather to lay out the challenge with a more limited number of bass sources (say, no more than 2 bass sources). Yes, SWARM presents challenges as well, but personally I find 2 subs a mandatory outset for serious sub integration, and one that lends itself naturally with a main speaker high-pass above the 60-70Hz range (i.e.: where directionality sets in when not using absolute brick wall low-pass slopes) placed symmetrically to and (fairly) close to the main speakers with the subs configured in stereo.
Installing 1 subwoofer correctly is a big deal and a lot more work than most audiophiles want to do. Tripling the number of speakers (from 2 to 6) for SWARM is also a big deal for many. Failing to do either well is what makes for slow, mushy or overbearing sub experience.
Either of these approaches can dispell the myth that big cone subs are slow and unable to keep up with "fast" planar speakers. OTOH, lets be realistic that audiophiles are also unprepared for the work they’ll have to do in many cases to be done.
Indeed they often are.
IMHO, bass should not be "fast." It should be glorious. That is, it shouldn’t sound like you are listening to a bullet traversing the air, nor should it feel like a hammer in your chest.
Excellent bass should be clear like air or water and evidence itself only by the scale and dynamic range of the music being played and seemingly come out of nowhere and ignores the physical size of the room.
When you put it that way (and it’s a very good description of what great bass can sound/feel like) I’ll have to say very few ever get to experience bass like that. Such bass presentation only comes from prodigious effective air radiation area, loads of headroom (i.e.: very low distortion and thus ease) and excellent overall integration.
However, with reference to your second paragraph just above I’d go further and say there is a particular design approach that aids the traits mentioned by you (even though you don’t want to get "specific"), and that’s horn-loading or a variation thereof; that particular "coming out of nowhere," omnipresent and liquid/smooth sense of the lower octaves that swell effortlessly with dynamic swings and don’t call unnecessary attention to itself is a definite quality of large, horn-loaded subs. Direct radiation with larger, or multiple smaller cones (remember, horns are force multipliers that make smaller cones deliver similar or even more total air pressurization) just make themselves and their cones known more predominantly - even to the point of becoming a distraction when you know the difference horns can make. It comes down to cones in horns moving very little to produce even staggering output, as well as the gradual impedance match of cone-to-air coupling of horns, with all that entails, likely in combination with the woofer cones being partly or entirely hidden in the horn path and thus prevents mechanical distortion and upper end harmonics to more readily enter audibility (effectively acting also as a low-pass filter). It’s more of an immersive, musical flow of low frequencies than the more ground-based and differently tactile sense of bass from direct radiators, to my ears.