Floor-standing Speakers

BG Corp Z-92 Planar-Ribbon Speakers and 210i Subwoofer

ARTICLE INDEX


Introduction

BG Corp is a speaker company known for their innovative designs incorporating planar-ribbon drivers of their own design. The company was founded in 1994 and has headquarters in Carson City, Nevada. BG Corp is sometimes referred to as BG Radia.

The company produces a complete line of planar-ribbon speaker and subwoofer products from moderately priced up to their $6,995 in-wall subwoofer, the BGX-4850.

This review will be on the Z-92 floor standing speakers and their recommended companion subwoofer, the 210i.

Specifications

  • Z-92 Speakers
  • Design: 3-way, Ported
  • Drivers: One 2.5" x 3.5" Ribbon Tweeter, One 10" x 5" Planar Midrange, Two 6.5" Aluminum Cone Woofers
  • MFR: 32 Hz - 25 kHz
  • Sensitivity: (2.83v/1m) 91dB
  • Nominal Impedance: 4 Ohms
  • Crossover Frequencies: 500 Hz, 2.3 kHz
  • Power Handling: 200 Watts RMS
  • Connectors:: 5-Way Gold Plated Binding Posts
  • Dimensions: 44.25" H x 7.7" W x 14" D
  • Weight: 70 Pounds/each
  • Finish: Light Maple or Black Ash Real Wood Veneer
  • MSRP: $1,250/Each USA
  • 210i Subwoofer
  • Design: Sealed enclosure
  • Drivers: Two 10" Kevlar Woofers
  • Amplifier: 500 Watts RMS Class D
  • MFR: 20 Hz - 150 Hz (- 6dB Half Space)
  • Features: Line-level Inputs, Variable Crossover, Gain, 00-1800 Phase Selector, Auto-On
  • Dimensions: 14.7" H x 16.25" W x 17.5" D
  • Weight: 62 Pounds
  • Finish: Black (Matte)Warranty: 5 years parts and labor
  • MSRP: $1,500 USA
  • BG Corp

Design

The BG Corp Z-92s are floor standing speakers just under 4 feet tall with the included spikes. The speakers are a 3-way design with anodized black aluminum 6.5" low mass woofers in their own separate enclosure. BG Corp claims that these woofers have redesigned voice coils and motors to reduce the mass from the previous design and allow the speed of the new woofers to more closely match the speed of the planar-ribbon midrange and planar-ribbon tweeter.

The planar-ribbon drivers are very thin and light weight diaphragms that are printed with an aluminum conductor overlay and these diaphragms are suspended between two very powerful magnetic assemblies in the front and rear of the suspended printed diaphragms. Therefore, the midrange and tweeter drivers are push-pull devices and completely under the control of the amp at all times. The planar-ribbon tweeter is mounted directly in front of the planar-ribbon midrange.

I assume this configuration is to maintain proper phase coherence and as close to a point source as possible.

Z-92 without grill

Close-up of midrange and tweeter planar-ribbon drivers

The two 6.5" aluminum bass drivers are in their own ported enclosure and cross over to the planar-ribbon midrange at 500Hz and the planar-ribbon midrange crosses at 2.3 kHz to the planar-ribbon tweeter.

The Z-92s are available in a real wood finish of either maple or black ash. They are furnished with rubber feet or metal spikes. I only used the metal spikes on my carpeted media room floor and all listening was done with the spikes in place. They also can be bi-wired by removing the gold-plated jumpers on the back of the speakers.

The 210i subwoofer consists of two 10" Kevlar drivers (equivalent to a single 15" driver in surface area) in a sealed enclosure that is a cross between a cube and a cylinder with a 500 watt rms power amplifier to drive the woofers.

The woofers are configured so that their in and out motion is reactively canceled and the cabinet has little to no vibration of its own because of this configuration. I don't know of any other subwoofer that looks like this, the cylindrical shape is not only functional but a refreshing departure from so many other subwoofers in the market place. Although this subwoofer is relatively small in footprint it still weighs 62 pounds and because of its unusual shape you need to get a good grip on it if you are going to move it.

The 210i back panel has the normal subwoofer controls; Variable crossover, gain, phase and auto on/off switch. Input and output connections and a detachable power cord.

The 210i is finished in a black flat paint (I would call this a matte finish) that is actually quite attractive.

BG Corp 210i with exposed Kevlar woofer

BG Corp 210i subwoofer back panel.


Setup

I first set up the Z-92s to be utilized as a stand alone pair without the assistance of the 210i subwoofer to determine their usefulness without the added expense of the 210i. I first angled the speakers toward my center listening position and the combination of the directed mids and highs plus the fact that the speakers had not been broken in made the speakers sound a little forward. I proceeded to reposition the speakers to fire directly forward and therefore slightly off axis to my listening position. This repositioning solved most of the harshness and after a break-in period that was over 50 hours any issues with harshness were completely resolved. These speakers need to be properly broken in and positioned correctly to achieve their optimum performance. Once I had spent the time to do this the speakers began to show their true capabilities. It is therefore very important that you audition these speakers at a dealer that is willing to work with you in positioning the speakers correctly for your listening environment.


In Use

I listened to music from various artists (Diana Krall, Muse, Rodrigo y Gabriela, Armik, Taylor Swift, Metallica and Lady Gaga) to determine that the speakers could indeed be used stand alone without a subwoofer and concluded that the Z-92s produced more than adequate bass. The bass was very fast and taught with only a hint of hangover on certain musical selections and the bass integration with the midrange planar-ribbon driver was smooth and seamless. The midrange and highs are very smooth and detailed with excellent resolving power and wide dynamics. It appears that BG Corp has achieved their design goal of mating a cone bass driver with a dissimilar planar-ribbon midrange driver with excellent results. The Z-92s stand alone have enough bass output to satisfy all but the really deep bass aficionados.

I then proceeded to place and adjust the 210i subwoofer to augment the low bass output of the Z-92s. I first adjusted the subwoofer manually and set the gain and crossover using test tones and a radio shack SPL meter. I ended up setting the gain at about 10 o'clock and the subwoofer crossover to augment the Z-92s output below 60 Hz. This combination produced a speaker/subwoofer combo with substantial powerful bass without any noticeable hangover and a clean highly resolved midrange and smooth extended high frequencies. The sound stage produced by this combination was wide and had better than average depth. The big surprise to me was the 210i subwoofer's speed and lack of coloration. I have three other excellent subwoofers in various systems and the only one that outperforms the 210i in a two-channel music system is the Sunfire Subrosa and the Subrosa is almost three times the price of the 210i.

As good as this combination sounds on its own; it was further improved by utilizing the Audyssey room/speaker equalization system in my receiver. After equalization the already excellent bass tightened up more with better pitch definition and any remaining vestiges of midrange forwardness completely disappeared. This also improved the believability and apparent depth of the soundstage.


Conclusions

The Z-92s were a pleasant surprise; there are few speakers in this price range that will truly challenge the z-92s. The 210i subwoofer's performance was unexpected. I have listened to many subwoofers in this price range and this is definitely one of the better ones. I liked it so much that I have made arrangements with BG Corp to purchase the review sample.

This speaker needs to be auditioned in an environment where they are properly placed and if used with the 210i subwoofer care must be taken to balance the output of the subwoofer with the Z-92s. This should be easy to do for most customers that are purchasing a speaker in this price range as they probably have a receiver or pre/pro that has the Audyssey room/speaker equalization processor or similar EQ processor. I have found that this type of EQ is put to best use with a quality speaker and makes the subtle differences that transform a really good speaker system like the Z-92s/210i into a great sounding system.

In closing the manufacturer includes a lifetime warranty on parts and labor for the Z-92s. I can't name another speaker manufacturer that has that level of warranty. If your budget allows you to look at speakers in this price range, then the Z-92s/210i system should be on your audition list.