PLAYBACK: BG Radia BGX-4850 THX Ultra2-certified subwoofer system

Breaking All the Rules

Ratings (compared to other top-tier subwoofers):

• Bass Extension: 10
• Bass Pitch Definition: 10
• Bass Dynamics: 10
• Value: 7

FEATURES

• The BGX-4850 subwoofer system consists of five main components: four SM-1250 in-wall woofer modules (with grilles), and a standalone, rack mountable, remote controlled BGA-2104 subwoofer amplifier.
•  THX Ultra2 certification guarantees low frequency extension down to 25 Hz (or better) at -3dB, and assurance that the sub is capable of THX Reference Level output in rooms up to 3000 cubic feet.
• Billed as “the world’s first THX Ultra2 in-wall subwoofer,” the BGX-4850 system’s compact woofer modules comfortably fit within the stud spaces of interior walls framed with 2” x 4” studs. Alternatively, the woofer modules could be mounted in a ceiling, or even slipped under couches or shallow cabinets.
• BG’s SM-1250 woofer enclosures use proprietary THX Balanced Bass-line technology to cancel out woofer cabinet vibrations. Fincham’s ingenious, “boxer-style” enclosure features two sets of six drivers that are horizontally opposed and arranged so that their diaphragms pump inward and then outward in unison, so that vibration forces exactly cancel out. Sound is output through a forward facing slot that measures roughly 2” x 22.5”. Even when the woofers are playing loud and low, the enclosures housings exhibit virtually no discernible vibration.
• BG’s multi-woofer module format allows modules to be positioned within as many as four wall surfaces for exceptionally even and well-balanced in-room bass response. (Example: in the Playback lab the system delivers bass response of 18Hz to well over 100Hz, ± 2-3dB, across multiple listening locations at once).
• The BG Radia system uses a total of 48 small-diameter 4-inch drivers (12 in each woofer module) that are light, fast, and responsive—yet that offer bass extension below 20 Hz. The upshot is a subwoofer that is powerful and goes deep, yet that sounds audibly “faster,” more nuanced, and more transparent than most. Interestingly, BG’s 48 small drivers have the combined radiating area of two conventional 18-inch woofers, so high output is never a problem.
• BG Radia offers separate in-wall mounting kits for both new construction applications and retrofit applications. Recognizing, however, that some customers will require an in-room solution, BG Radia has teamed with acclaimed industrial designer Allen Boothroyd (co-founder of Meridian Audio, Ltd.) to develop a combo on-wall/in-room enclosure for the SM-1250 woofer modules. The in-room enclosures are slated for release later this year.
• The electronic “heart” of the system is BG Radia’s BGA-2104 Subwoofer amplifier with provides 2200 watts of power, extensive control functions including DSP and a remote control.

SONIC CHARACTER

Not long ago, I met with BG Radia National Sales Manager Tony Weber to talk about (and install) the BGX-4850 subwoofer system, and one of Weber’s first comments was that it was a “subwoofer that doesn’t sound like one.” By this Tony meant that the system does all the things you would normally want a subwoofer to do (i.e., it goes very low, plays loudly without distress, and offers good, smooth in-room bass response), but without incurring any of the undesirable side effects most subwoofers typically impose. What side effects are those? 

Well, to be blunt, many subwoofers impart a subtle (or perhaps not-so-subtle) quality of sonic “thickness,” as if the system is becoming progressively less nimble and articulate as frequencies drop lower and lower. Many listeners, in fact, describe this as a problem with “slow” bass, or complain that there are audible discontinuities between their main speaker system and subwoofers—especially in terms of transient speed (that is, the ability to respond rapidly to fast-rising bass notes) or textural definition.

For obvious reasons, the “holy grail” of subwoofer performance is to be able to play loudly, smoothly and with terrific bass extension, yet without introducing any problems with bass “sluggishness” of any kind, and in a nutshell this is precisely the balance point that the BG Radia system addresses as well if not better than any other subwoofer system I’ve heard. The BGX-4850 can do the “loud-‘n’-low” thing with the best of them, but where it really shines is higher up in the crossover region where output transitions from the sub to the main system. The BG Radia system is easily one of the (if not the) fastest and most articulate subwoofer systems I’ve heard at any price. In fact, in the critical upper bass region, it is one of the few subs that might actually sound clearer and more articulate than some of the main systems with which it could be used.