Major update to system. Now gone active! Wasn't a sudden decision, but gradually built up to it (see Speaker Blog here )
Still partnered with a pair of reversed Dayton UM18 woofers (updated from 15"). Reversing the
woofers adds directivity and reduces room modes.
Integration with the subs simple. Problem using passive speakers is no control of the bass roll-off. The Navis have high pass filter DIP switches. I find using the 80hz cut-off with UM18's & 65hz gives best result.
Went though a few stages to get to where I am now. The 18" AE (Acoustic Elegance) Dipole woofers were replaced by the Dayton 15" 390s a few years back, and now UM18's. These have much heavier fiber-glass cones and a more powerful motor. Arranged in series, they give more depth and slam, take more watts and yield higher SPL's without complaining. They generally take more abuse and dont bottom out as easily as the AE's. I found I get REAL deep bass (20hz) with heavier inefficient woofers vs lighter more efficient designs.
In this F.A.S.T. configuration
(FullRange Assisted Subwoofer Technology) or WAW (Woofer Assisted Wideband) there is no crossover to sap
efficiency and resolution. The Navis having built in amps now connect directly to the SMSL M400 DAC via XLR connectors p &
handles from 80Hz up to 20k.
I have found the UM18's need no eq to compensate for for bass baffle losses. This was a surprise to me as these units seem to deliver bass down to 20hz with amazing slam!
The disadvantage of using inefficient woofers is they need a lot of power, but watts come cheap with the Behringer NX6000D's. The built in Digital Signal Processor makes setting the crossover point a breeze & also iron out room modes.
A pair of Behringer NX6000D's power the 18" woofers. This is primarily PA concert venue Class D full range amp. Not sure what it sounds like full range, but from 20 - 100Hz & it sounds great! Delivers effortless distortion free power, control & resolution..........everything you want in a sub amp.
The DSP section just plugs into a laptop via USB & uses software available from the Behringer site. All relevant parameters can be adjusted in real time from your listening position. The crossover page allows seamless integration with the full range unit. There is a choice of 4 variable slopes, plus crossover point & gain. There is also an 8 filter Parametric EQ page to set compensation for room modes & baffle deficiencies.
I would describe the sound from this system as dynamic, musical, but full of detail.
Using active speakers has taught me the sum of the parts amounts to more in sonic terms. Rather than having an amplifier driving passive speakers, here the manufacturer is driving their own speakers with an amplifier they specifically engineered for the job. The Navis are 3-way, and in the passive version of this speaker, the crossover was huge involving many components. They were an effort to drive with subdued dynamics. All that was rectified by going active. These things go loud, but maintain composure.
The woofers driven by the Behringers integrate seamlessly with the Navis aided by the built in HPF. They go floor-shakingly deep when the signal is present but there is no boom from room resonances such is the control from the PEQ. For serious bass I believe the woofer needs to be actively driven with PEQ. Control of the room modes is a necessity.
I can play a wide range of music on this system from softer acoustic jazz material to pumped up Level 42 playing at realistic levels. Modern electronic music which I was never too keen on makes sense now that I can hear/feel that bottom octave. Kraftwerk, Depeche mode never sounded so good not to mention the more modern Junior Boys and London Grammar. The system delivers it all in a musical, fatigue-free fashion.