Legacy Audio Xtreme XD Subwoofer Review

Features

The XTREME XD comes in similar finishes to the upper end speaker line, including Natural Cherry, Rosewood, and Black Pearl, the finish of the review units. No lightweight, a thousand-Watt Icepower Class D amp powers the active driver, which according to the Owners Manual is in a “6th Order/Back EMF Cancelling Circuit.” This is a steep slope to cut off the high frequencies, allowing the XTREME XD to dovetail with a wide variety of floor standing and bookshelf speakers.

Controls on the oval faceplate sporting an illuminated company logo include an AUTO/OFF audio signal switch, to which the power is controlled by a separate switch in the rear that stops or starts signal flow to the sub. In the Off position, the internal preamplifier stays active, but the amplifier shuts down. If the unit has not received a bass signal after thirty minutes, it will mute. The logo stays illuminated as long as the rear power switch is in the On position. New owners should always check subwoofers with dual switches to ensure the signal control/operating switch is turned off prior to engaging the switch for power.

The other controls are LEVEL, FREQ (Frequency), BLEND and Phase. LEVEL is the volume control for the subwoofer only. The FREQ button allows adjustment of the range of the subwoofer from 45Hz to 150Hz. The BLEND button influences frequencies in the 35-50Hz range. Turning the control counter-clockwise from the 12 O’clock position reduces gain in that region, while turning it clockwise increases it. The frequency at the center position was selected to match the first cancellation node of most rooms.

The PHASE control allows for aligning the mains and subwoofers in phase to each other. If out of phase, the waves from each can cancel, creating nulls at some frequencies. The Owners Manual includes detailed instructions on how to set the PHASE.

There are no readouts on any of the XTREME XD’s controls front or rear, but there are notches in the faceplate showing quadrants, making it somewhat easier to achieve symmetry when setting both subs. Small movements of the dials effect noticeable changes, so watch that you do not overshoot when tuning them; as little as 1/16th inch movement is enough to detect a change.

The connections on the rear include four line level inputs; Right, Left, LFE and Balanced. If your surround receiver, preamplifier or digital processor has an LFE output, connect it to the LFE line level input. Note that the LFE input bypasses the sub’s internal crossover, allowing you to control the sub from your preamp/processor. The Level control on the front will operate as a sensitivity control when set at the 12 O’clock position, allowing the preamp/processor to control volume.

Legacy recommends cables less than five meters long when using the low-level RCA Right or Left inputs, as beyond that length attenuation of the signal can result. The XLR/balanced connection is supplied for use in conjunction with the Legacy Audio Wavelaunch Digital Signal Processor System. Input 4 of the Wavelaunch is designated to control the XTREME XD. However, it can be used with traditional preamplifiers and provides 12dB of gain versus a single L/R RCA input of 6dB gain. If you do not have XLR outs from your peamp you can use an RCA splitter to double the Left and Right outputs to each sub. In such a scenario the Left out from the preamp would be split, or doubled, and both leads sent to the Left subwoofer. The Right output is treated similarly to the right sub, allowing them to achieve the same gain as if using an XLR input!

If you determine to use the High Level/Speaker Level inputs, they should be connected parallel to the main speakers. Legacy warns, “Do NOT use the output from a differential Monoblock amplifier as a parallel input to the subwoofer.” My understanding from a brief discussion with Bill is that a non-differential amp has physical grounding, while the differential amp does not. You will want to check with your amp manufacturer if you are unsure.

Placement and performance pimping

I don’t have a huge room; dimensions are 13’W x 23’ L x 7.5’ H. One dual 15” subwoofer is sufficient. Sufficient, perhaps, but not overkill. I have never in any system preferred a solitary subwoofer, which has more to do with the voicing of the system than the listening level. Always a pair of subwoofers has been easily discernible to my ear as “right.” Only in a most dire shortage of space would I move to a solitary subwoofer. Case in point, in my office I have room for either one huge sub or two smaller ones. The choice was easy, as I use two smallish subs so as to not destroy the stereophonic balance of the speaker system.

Consequently, in my listening room the XTREME XD is placed fairly tight against the walls; both are precisely 1’ from the front and side at the headwall. My initial placement had the active driver in the rear of the unit facing the headwall. However, as I am an inveterate tweaker and perpetually curious, I couldn’t help but wonder if the performance would improve by turning them around such that the active driver faced toward me. I did so, and it did improve – as has been the case with every woofer or sub ever used. The reason is elementary; if a wave is blasted at you it’s going to sound cleaner than if you blast it off a wall first.

While I am making Bill at Legacy gasp, I may as well continue on. I understand the implementation of a passive radiator firing downward, but I don’t care for my thick carpeting to absorb it. I have very thick carpeting intentionally, as I want a studio-grade performance, not a townhouse kitchen performance. I don’t want reflections accentuated by hard surfaces. I want to hear the system more and the surfaces of the room less, so I put in half inch padding and a thick Berber carpet. The downside to this is, well, the down side of down firing woofers which get swallowed up in the carpeting’s depth.

I have learned to overcome the abyss of sound-diminishing floor covering by elevating speakers further. To that end, my trusty hard rubber hockey pucks were once again employed to elevate the XTREME XD about 1.5” higher than its integrated feet. I will admit it’s not terribly Ad-worthy to illustrate a subwoofer backwards, its gorgeously finished face turned away and put up on blocks like a car. I don’t care; it sounds far better in my installation that way. I’ll take an Ad pic with the subs installed pretty, but then I will return them to my configuration. I have zero WAF (Wife Acceptance Factor) considerations, and the wires and power cords long ago stopped bothering me – it’s the performance which counts! You will get better than respectable performance with the XTREME XD set up in its most aesthetically proper positioning, but I get overkill performance with it turned around and jacked up well above the thick carpeting.