Usually, within a given line of loudspeakers made by a given company, as the models increase in cost, the aspect of their sounds that sees the most change is the bass response. Look at a speaker line from almost any brand and you’ll see, at the bottom of the price hierarchy, a smallish bookshelf speaker, usually a two-way. Above that will be, perhaps, a bigger bookshelf model, followed by two or three floorstanders, the largest being three- or four-way models. Often, all of these speakers will use the same model of tweeter and similar if not identical models of midrange drivers; it’s the woofers that grow in size and number as you ascend the ladder of price and size.
For audiophile shoppers, the directive seems clear: If you want deeper, more powerful, more articulate bass -- in a word, better bass -- you need a bigger speaker, for which you should be prepared to spend more money.
But there’s another way to get better bass: Buy a pair of small speakers and a subwoofer -- or two.
The latter strategy has its pluses: Generally speaking, good subs don’t cost many thousands of dollars; and you can buy two or more of them and put them where they’ll help smooth your in-room frequency response, while placing your satellites so as to optimize their imaging. What’s not to like about those advantages?
If it were only that simple. The advantages I’ve just listed are genuine, but getting the outputs of subwoofer(s) and speakers to seamlessly integrate is not easy to do. There’s a reason really good speaker designers go to great pains to get their crossovers just right: perfect integration between the outputs of disparate drivers at a speaker’s crossover frequencies is critical to achieving great sound. Being able to identify the output of each individual driver instead of a virtual single-point source can ruin the musical experience. The cold truth is that, in setting up a system that includes subwoofers, the average audiophile is faced with significant obstacles.
With the introduction of their CR-1 Active Subwoofer Crossover ($3000 USD), JL Audio intends to make the process of integrating the outputs of your speakers with those of your subwoofers -- theirs or any other maker’s -- a bit more precise. They sent me one to put to the test.
The CR-1
JL Audio’s powered subwoofers serve the different but overlapping markets catering to audiophiles and to home-theater enthusiasts, but the CR-1 is, as best I can tell, their first product designed specifically for audiophiles. Don’t let this worry you. Two things JLA knows well are product design and manufacturing -- for proof, take a look at our February 2011 company tour -- and the CR-1 does not look like a freshman effort. With its black body and silver faceplate, it seems beautifully and precisely made, with perfect joins and high-quality connectors. It may surprise you to learn that the CR-1 is not a digital crossover, and contains no analog-to-digital converter. Instead, JLA says that the CR-1’s circuitry is realized through the use of “two banks of precision Linkwitz-Riley low-pass and high-pass filters. Multiplying DACs with monolithic ratio matching are employed to adjust the analog circuit’s filter frequencies. This offers superior tracking behavior and far more precise left/right channel balance, compared to conventional approaches.” In short, the CR-1 is most accurately described as a digitally controlled analog crossover.
The CR-1’s aluminum front panel has a recessed, slightly rounded central section where the user controls are mounted. Beginning at the left are: an on/off toggle switch; a Crossover Bypass button; and a toggle to switch between stereo and summed-mono (L+R) operation. Next up are five rotary dials, the first two for adjusting the subwoofer(s): Frequency, for setting the low-pass output; and Damping, to slightly contour the response at the crossover frequency. Dead center is Sub/Sat Balance (dB), which works like a regular balance control, except that instead of adjusting the balance of the left and right channels relative to each other, it lets you do this with the levels of the subwoofers and satellites. The remaining two knobs adjust the satellites: Damping and Frequency, just as are available for the subs. As JLA puts it, “These damping controls dramatically improve the acoustic summing through the crossover region, by compensating for each speaker system’s frequency response.” To the right of these five knobs is a toggle for setting the crossover slope to 12 or 24dB/octave, followed by four Output Muting buttons: one each for two subs and two sats.
The rear panel is packed full of high-quality input and output connectors. At far left are the Main Stereo Inputs, which connect to your preamplifier’s main outputs to accept a full-range signal, via RCA jacks or XLR/TRS combo plugs. Next are the Outputs to Satellite Amplifier connectors, with a choice of RCAs and XLRs for connection to the main power amplifier driving your speakers. If you have just two main speakers, you probably won’t use the third set of connectors: the Managed Bass Inputs, on RCA and XLR/TRS connectors, these to be used with a surround-sound processor whose crossover settings you want to use for home theater in addition to using the CR-1 for your two-channel system. But I’m not really sure that audiophiles whose systems already include crossover functionality would want to also spring for a CR-1. On the other hand, purists may want to split the crossover functionality they need for their 5.1-channel system, which would be better handled in the processor, and the two-channel duties for which the CR-1 is more optimized. Either way, at least, JLA has you covered. The rightmost connectors are the Outputs to Subwoofer(s), also with a choice of RCAs and XLRs. At far right is an IEC power-cord inlet.
At 17.4"W x 3.8"H x 15.67"D and weighing a solid 22 pounds, the CR-1 is about the size of your average high-end preamp. As I’ve said, its build quality is outstanding, especially given the price. In that sense, the CR-1 would fit into a system with, for instance, Simaudio components, without skipping a beat in the fit’n’finish department. The CR-1 has no remote control, which makes sense -- most users will just set it and forget it. Still, you should take some time to read and digest the very thorough owner’s manual -- the CR-1 has a lot of functionality, and the owner will need to follow JLA’s directions to get the most out of this product.
Where I started
I firmly believe that a proper wedding of a subwoofer(s) to satellite speakers requires acoustic measurements. You just can’t efficiently assess a sub/sat blend with pinpoint accuracy by listening to recordings of music. Yes, an ultimate evaluation of the quality of the musical result must depend on the listening -- but just as an automobile manufacturer can’t design a car based on test drives alone, you can’t dial in subwoofers only with listening tests.
My tools: FuzzMeasure Pro 3 speaker-measurement software installed on my Apple MacBook Air, a Behringer ECM8000 microphone, and an MXL Mic Mate. The Mic Mate, a line-level XLR-to-USB adapter, provides phantom power for the microphone, and interfaces with the computer without requiring additional drivers. I used a pair of Triangle Magellan Cello speakers for this review, their positioning in my room already optimized for flattest frequency response and best imaging before installation of the CR-1. JL Audio also sent me, to use with the CR-1, a pair of their excellent E-Sub e112 subwoofers, which I reviewed for SoundStage! Hi-Fi in October 2013.
I placed the e112s to either side of the Triangles and adjusted their positions from there, based on the measured room response. This didn’t take long -- I’ve often had dual subwoofers in my Music Vault, and so have a good idea of which positions yield the flattest, loudest bass. There were no surprises with the e112 setup.
I inserted the CR-1 between my Ayre Acoustics KX-R Twenty preamplifier and MX-R power amplifiers, using Nordost Valhalla XLR interconnects. The CR-1 was then connected to JLA’s E-Sub e112 subwoofers with Nordost Valhalla RCA cables.
Dialing in
Anyone who’s successfully installed subwoofers in a high-end system knows that the process can take a while. Figure a half-day investment. With the mike in place and my system fired up, I began with some initial settings on the CR-1, based on my prior experiences: 80Hz crossover Frequency for subwoofers and satellites, Damping set to 0, and Sub/Sat Balance set to dead even. I summed the two subs to mono because, in my experience, stereo operation is not as important below 80Hz as the response-smoothing benefit that multiple subwoofers can provide.
I first took nine measurements in at nine different mike positions that described a fairly tight grid at and surrounding my listening position, and averaged them using FuzzMeasure Pro 3. It looked pretty good overall. Some initial listening impressions told me that the integration was generally decent, but I still heard bass that seemed a bit thick. I listened to bass-guitar virtuoso Jonas Hellborg do his thing on The Silent Life (16-bit/44.1kHz ALAC, Day Eight Music), a disc I know well and often use in reviews. Unlike the low bass on a lot of recordings, this album’s deep, powerful bass is also extremely articulate and textured. The thickening I heard with my initial settings by no means ruined my experience, but I knew improvement was possible. The articulation was just a touch concealed, robbing this album of its magic.
I next experimented with the crossover frequencies of the sats and subs. I first lowered both frequencies, in an attempt to achieve a flatter frequency response and a less thick sound. Going too low, however -- down into the 50Hz range -- yielded a slightly opaque sound in the midbass, although the measurements weren’t all that bad. I finally settled on a 70Hz crossover frequency for subs and sats, which provided basically flat measured response and articulate bass. For purposes of experimentation, I then toggled the slope from 24 to 12dB/octave and remeasured. I didn’t even need to listen to this one -- the gentler, 12dB slope led to significant cancellation at the crossover frequency that produced a deep null, whereas the response at the 24dB slope was dead flat. I switched back to 24dB/octave, and the sound of the Hellborg album was now much better: linear and lithe, but still deep and powerful. That was more like it.
Although I now had good linearity, I also tweaked the Sub/Sat Balance on the CR-1, with the expected results: I could easily tilt the response, in very fine increments, one way or the other. A setting of 2dB on the +Sat side of the dial tilted the balance toward the satellites and proved best in my setup -- despite a depression in the Triangles’ midrange between 1 and 2kHz, they now had a touch more output there. I found this control intuitive in use, and greatly preferred it to using the level control on the subwoofer alone. Finally, the CR-1’s Damping controls allowed me to work the responses of sats and subs precisely at the crossover frequencies. I could see some slight variation in the measurements right at the crossover frequency of 70Hz. Although in my setup the output was dead flat at 70Hz, I could see where this control could be of critical importance in getting a perfect blend of sats and subs in some systems. Remember, getting that crossover point to sonically “disappear” is the goal, and having the Damping control to assist in that is a really nice feature. My room response ended up being about +/-4dB across the entire audioband, with the exception of a room-related 6dB null at 40Hz and an 8dB peak at about 25Hz. The sound was now just what I’d hoped for: balanced, integrated, deep, fast, controlled -- all the hot buttons were being pushed!
As a last test, I wanted to hear what the CR-1 had added to and/or subtracted from the sound of my system. After all, no matter what else it does or doesn’t do, adding the CR-1 adds more circuitry and interconnects that the audio signals must pass through. I turned off the subs and set the sat crossovers as low as possible -- 30Hz -- to listen to the Triangles running essentially full range (their frequency-response spec bottoms out at 30Hz), but with the signal still running through the CR-1. I listened to “Goodbye Is All We Have,” from Alison Krauss and Union Station’s Lonely Runs Both Ways (16/44.1 AIFF, Rounder), then removed the CR-1 from the signal chain and listened to the track again. I can only conclude that the CR-1 was very transparent. It didn’t add any noise that I could hear at my listening position, nor did it change the tonalities of the voices and instruments one iota. My system still sounded neutral and clear, just as I like it. With the CR-1 back in the loop, the soundstaging did seem very slightly softened, the image of Krauss’s voice ever so slightly more diffuse -- in the grand scheme of things, an extremely minor problem.
The takeaway: Perfectly integrating a good subwoofer(s) into a system with the CR-1 far outweighed any concern about transparency. This is not even to mention the increased dynamic range and concomitant lower distortion satellite speakers can have when relieved of deep-bass duties. Many audiophiles claim that subwoofers are mandatory in a high-end system that aspires to the state of the art. I see their point.
Conclusion
Those who want to perfectly blend a powered subwoofer(s) with topflight main speakers in a high-end stereo system should consider as mandatory JL Audio’s CR-1 Active Subwoofer Crossover. It’s flexible, transparent, and intuitive to use. So grab an audio buddy, spend a few hours with a CR-1 to dial in your system to the nth degree, and you’ll surely be rewarded. If the rest of your components are up to snuff, when all’s said and done you’ll have a full-range system that can approach the sound of those big, superexpensive, multiway loudspeakers you can only dream of owning. The CR-1 puts incredible sound within your reach.
. . . Jeff Fritz
jeff@soundstagenetwork.com
Associated Equipment
- Subwoofers -- JL Audio E-Sub e112 (2)
- Speakers -- Magico Q7, Triangle Magellan Cello
- Amplifiers -- Ayre Acoustics MX-R monoblocks
- Preamplifier -- Ayre Acoustics KX-R Twenty
- Sources -- Apple MacBook Air running OS 10.9.4, iTunes, Amarra 3.0.2, DSDPlayer for Mac
- Cables -- Nordost Valhalla interconnects, speaker cables, power cords; Siltech Explorer speaker cables, interconnects, power cords
JL Audio CR-1 Active Subwoofer Crossover
Price: $3000 USD.
Warranty: Three years parts and labor.
JL Audio, Inc.
10369 N. Commerce Parkway
Miramar, FL 33025-3962
Phone: (954) 443-1100
Fax: (954) 443-1111
Website: www.jlaudio.com