Recently purchased the Radia Series 420 loudspeaker which is a planar-hybriddesign utilizing a 40" planar-magnetic, line source driver that operates above
a passive crossover point of 325 Hz. In each speaker, a pair of 6.5" high-power mid-bass drivers operate below this crossover point. Each speaker
has an impedance of 4.0 ohms, bi-wireable, a sensitivity of 88db/1w/1m,
a power rating of 250 watts and weighs 48 pounds.

Found the build quality and construction of the gray model of the Radia 420, which retails for $2,290/pair, to be exceptional. The speakers are bi-wired
in a system utilizing a Classe Audio CA-100 power amplifier, Audio Research
LS-3 preamplifier, and a California Audio Labs Icon Mark II CD player.
On well recorded CDs, the sound was astonishingly realistic because of the
very large soundstage that the speakers projected along with a very clear,
open midrange. On vocals, the performers had an almost spooky presence.
Unlike other planar-magnetic designs (e.g., Manepans-which I have owned in the past), the speakers did not appear to be as placement sensitive nor as limited in were the listener had to be sitting in order to obtain the proper imaging.

The downside of this design, however, was in the bass. Because the speakers
have a specified cuttoff of 80 Hz, a subwoofer is definely required. Without
a subwoofer, the bass was tight and controlled--but definely not extended.
I found that a "properly adjusted and placed" Paradigm PDR 10 seemed to work well with this design. If it were not for the lack of extention in the base, these speakers in my opinion would rate 5 stars since they appear to do most
everything else right. So four stars is our rating--but a very satisfying
four stars.

Transparent sound!!; Looks; Little vertical dispersion

Low frequency response (80Hz cutoff)

I was looking for speakers with sound and style. Listened to some Bang & Olufsens, but didn't want to cough up the $3k to $5k. Then saw these at UBid and jumped on them (perhaps a little too quickly). I've noticed them between $520 - $550.

They sound fabulous, the first word that comes to mind is Transparency. The sound is understated and unintrusive - planar ribbons do a wonderful job from 325Hz to 16/18Khz. The 2 mid-ranges sound a little muddy to my ears, perhaps bi-amping will help. Also, they're still in the break in period.

Also, they aren't very sensitive or it might be the planar design that makes the volume level deceiving. So make sure you have plenty of power on hand to drive these.

Vocals are very clear, so also instruments. The dipolar design (with sound from the rear reflecting off the walls), helps with the soundstage, feels like you are in the concert hall. To allow for the reflection, they need to be at least 3' from rear wall, and at least 3' feet from side walls.

So they kind of stick out from the walls. But the finish and the looks (with polished aluminium) are so good that my wife doesn't mind :-). They look almost as good as the B&Os for better sound and much cheaper.

The mid-range
Highly recommended - the 520DX is also available on ubid for a little bit more, same specs, only 10" taller but too imposing in my medium sized family room.

I give them 5 stars for value, esp. if you get a pair for around $1100, sound is fantastic, but lack of bass means a subwoofer, so I'll give it a 4.

My system:
HK CD FL8550
Harmon Kardon AVR10 - used as a preamp, shopping for a preamp
Harmon Kardon Signature 2.1 - 5 channel amp - good buy at onecall.com
B&G 420DX main
Audiosource SW-15 subwoofer - great buy

Similar Products Used:

First planar/electrostatic; Other point source spkrs

Ribbons are Ribbons! BG makes no attempt to reproduce deep bass resulting in clean mid-bass that meshes seamlessly with my subs.

No manual, which would be beneficial to first time ribbon users for speaker placement.

I am running a 7.1 HT configuration using The 220DX Center, four 520DX (front and side surrounds) and two 420DX (rear surrounds). I also have two Talon Audio Roc subwoofers.

Having owned Carvers before these, I consider the 80Hz cutoff a big plus. The Carver AL-III's I owned used 10" woofers to attempt full range bass. The result was muddy mid-bass. The BG design delivers much cleaner mid-bass than the Carvers and leaves the deep bass to subwoofers. This results in a speaker system that is uncompromised when coupled with quality subwoofers.

The ribbons are discussed in detail on previous posts. They are very similar to those made by Carver, since one of the BG owners (I forget which one) designed the legendary Carver ribbons too.

Those who knocked a star off for the 80 Hz design need only compare the mid-bass of these speakers to the Carvers (when using the same sub with both). You would add the fifth star in a hurry.

Similar Products Used:

Carver AL-III, Carver Amazings

Good Transparant speaker with pure sound quality

expensive

The best speaker I ever heard

Similar Products Used:

Martin Logan

Transparency as expected from all electrostatics but DYNAMIC RANGE as well!! Excellent balance and soundstage. Craftsmanship was great, but then again there aren't alot of parts either. Don't need much power...extremely linear response across entire range with more than adequate power handling

Live with the bomb, die with the bomb. Linear design makes power diffusion great for soundstaging and transparency, but non-point source makes volume very deceiving. Cut off at 80hz makes need of seperate low end a no-brainer, so you're pretty much stuck with a 5 ft sub-sat system.

Excellent pair of speakers...especially for only 3 grand/pr! Needs to be tweaked for room dimensions and reflections more than others, but well worth it when done correctly. Still can't believe the dynamic range considering design...

In my opinion the best improvement in speaker technology in a long time..now we'll wait for dynamic drivers for comparable transparency, and then we'll have a contest.

oh..they look cool...but $300 more for 2 pieces of wood platforms for feet? oh well....

Similar Products Used:

Maggies, Carver ribbons, b&w's, Infinity EMIT's, dyne's, martin logans, etc.,