Sure bass horn loading is a different case…. i’m flat to 20 in a regular room without resorting to cutting down every tree in the mythical forest… Enjoy the music ;-)
Subwoofer speed is in the room, not the box
First, if you like swarm, that’s fine, please start a thread somewhere else about how much you like swarm.
I want to talk about the impression that subs are fast or slow compared to planar or line sources.
The concern, and it’s correct, is that adding a subwoofer to say a Martin Logan or Magneplanar speaker will ruin the sound balance. That concern is absolutely a valid one and can happen with almost any speaker, not just speakers with tight dispersion control.
What usually happens is that the room, sub and main speakers aren’t integrating very well. Unfortunately for most audiophiles, it’s very hard to figure out exactly what is wrong without measurements or EQ capabilities in the subwoofer to help you.
So, there’s the myth of a small sub being "faster." It isn’t. It’s slower has worst distortion and lower output than a larger sub but what it does is it doesn’t go down deep enough to wake the dragons.
The biggest problems I’ve heard/seen have been excessively large peaks in the subwoofer range. Sometimes those peaks put out 20x more power into a room than the rest of the subwoofer. Think about that!! Your 1000 W sub is putting out 20,000 watts worth of power in some very narrow bands. Of course that will sound bad and muddied. The combination of sub and main speaker can also excessively accentuate the area where they meet, not to mention nulls.
A lot is made about nulls in the bass but honestly IMHO, those are the least of our worries. Of course too many of them can make the bass drop out, but in practicality is is the irregular bass response and the massive peaks that most prevent any good sub from functioning well in a room.
Bass traps are of course very useful tools to help tame peaks and nulls. They can enable EQ in ways you can’t do without it. If your main speakers are ported, plug them. Us the AM Acoustics room mode simulator to help you place your speakers and listening location.
Lastly, using a subwoofer to only fill in 20 Hz range is nonsense. Go big or go home. Use a sub at least at 60 Hz or higher. Use a single cap to create a high pass filter. Use EQ on the subwoofer at least. Get bass traps. Measure, for heaven’s sake measure and stop imagining you know a thing about your speaker or subwoofer’s response in the room because you don’t. Once that speaker arrives in the room it’s a completely different animal than it was in the showroom or in the spec sheet.
Lastly, if your room is excessively reflective, you don’t need a sub, you need more absorption. By lowering the mid-hi energy levels in a room the bass will appear like an old Spanish galleon at low tide.
Showing 10 responses by tomic601
@avanti1960 got it right…. and building an inert cabinet for those massive low THD but high IMD woofers is not trivial…. but then cabinet movement = trash = output = “ efficiency “….. funny how systems engineering just creeps in….. |
One should not confuse my argument as support for anything less than a systems engineering approach to the sub / room problem. The solutions i mention in a previous post include MUCH more than 3 x 8” drivers in a domestically attractive 90# box….. Obviously, i’m a Vandy owner and fan…. I’ve owned the big block gear, starting w Hartley … Infinity servo….Beveridge, etc ( i am…an old bastard… )carry on….and enjoy the music gents !,,,,,,
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Making a large diameter stiff structure is so easy…. i listen to two vastly different engineering solutions to the same problem…. 3 x 8” vs a push pull titanium honecomb bespoke Scanspeak driver…. like i said prove that big 15” paper cone stays in pistonic in the bandpass…. send it to germany….laser scanner does not lie…..
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@clio09 no fair, you attended the Roger Modjeski skool of great listening AND Engineering….. Best to you I miss him |
Much of the benefit of a high pass before the mains amp is the loafing it enjoys….. The problem w servo is input signal is compared w voice coil movement, NOT cone movements which are rarely pistonic….. But y’all like those big paper woofers flapping in and out of phase….. Vandy powered bass: high pass the mains before amp, high level connectors to sub amp to provide identical transfer function, VERY linear pistonic drivers ( The sub 3 use 3x8”, the 7’s use a Titanium honeycomb core push pull dual voice coil driver ), 11 bands of ANALOG EQ below 120 hz to address room issues, and the 11 bands are NOT 1/3 octave for a reason…. An excellent “ learning engineer “,,,, would ponder on that seemingly unorthodox approach…… |