Experience with the BG Neo8 PDR

[BoomieMCT]

Does anyone here have experience using the BG Neo8 PDR planar transducer? I'm thinking about making a whole HT setup and using it as the tweeter but I want some info first. Specifically I have these questions;

1) Does a planar this large have any beaming issues at higher frequencies? I do not want to have to have a super tweeter for these designs.
2) How low of a crossover can it really handle well?
3) How well does the BG suggested notch filter work?
4) Any other issues I should be aware of?

[phaseshift]

I have done a few system development projects with the smaller BG drivers and was very pleased with the outcome. Unfortunately, the product line never hit the market with the planars, so I can not point you to a reference other than similarly situated products. This was a mid to higher home theater speaker system designed to compete with stuff like the Snell 700 or 800 (I am terrible with model numbers & names). We had to meet THX Ultra certification, and the planars were my first choice for that project.

What you need to be aware of first is the impedance curve – or lack of it. Most of the time, you are dealing with a lot of impedance issues running a tweeter down below 2K or 3K, but these do pretty well down that low. If you are accustomed to working with LMS, Sound Check, MLSSA or Clio, you can easily see how well behaved the impedance is with a planar driver and as a designer, you need to keep this in mind when doing your network and notch filters you may need.

I would also recommend looking at any application notes that BG has on the device and apply what you learn there to your system. A “one size fits all” notch filter may not work as well as they intend with _your_ system, but then again, it may. The parts are so cheap, just build it and measure or listen and make the choice based on your observations.

The systems with the planar drivers came out great, performed well and met the TXH requirements, but were ultimately killed by sticker shock at the buyer end and we re-did the thing with a high end dome tweeter. It sounded about the same, but I have to say that I actually preferred the planar in that system.

You may read that planar tweeters have issues with impulse response or other acoustic issues- well, some do and some are better than others. Keep in mind that the ultimate ruler by which speakers are measured is the ears of the listeners.

Best of luck with your project.

[planetube]

I have used bg neo 8 in a home theatre for a while now.
everyone compliments on "clarity" in voices , and "presence" especially during acoustic music.

I use a homeade/kit se amp with 6ew7 tubes 1.7 watts set up for 4ohm load, so its not loud but is pure.

homebrew speakers using:
bg neo 8 (didnt like notch filter instead used simple hand rolled 12gauge inductor 10.8khz cutoff
this actually gives fairly flat respose to around 13khz)
(low pass capacitor at 617htz)
(open baffle 9"x 13")
polk 6 1/2" car woofer (used car speaker for 4ohm to match bg neo 8, and 94.5db at 1 watt also
matches bg neo 8)
(crossover high pass machine rolled inductor 12 ga wire set at 665htz cutoff)
seas tweeter (use ocasionally . has on off switch . crossover 12.5khz +)
sub (digital amp dual voice coil 15")

this set up sounds perfect with a movie like oh brother where art thou.
however with movie like matrix I use dennon amp turn on extra tweeter and turn up the sub.

[planetube]

almost forgot my bg neos took three months to break in! so in a multichannel application that sends most of the information to the front, this can make break in uneaven, maybee switch front to rear then back again.