BG planar project

[phazer99]

I'm new to speaker DIY, but after reading about BG planars I got really interested in building my own speakers using them. FYI, my room has concrete walls, but I have quite effective dampening in the >100 Hz range. The room is about 12 feet across at the listening position, and about 17 feet wide. I can place the speakers quite freely in the room.

I'm uncertain about which setup I should go for. I'm considering a dipole using either a BG Neo 10 + a BG Neo 3 or a BG RD 50. One obvious disadvantage of the RD 50 is the cost being twice as expensive as the the 10+3 combo. Of course, the 10+3 would require a crossover filter which has its disadvantages.

Some questions:

- What differences are there in sound between the RD 50 and Neo 10 + 3?

- Both the Neo 10 and the RD 50 are speced to go down to 150 Hz. Is it realistic to go this low in a dipole construction? Is one of them better suited for lower frequencies? Would two Neo 10's make it possible to go lower?

- What type of passive crossover filter is recommended for a 10+3 combo? What's the typical cost of the filter components?

- I'm not very familiar with the different mounting possibilities like open baffle, dipole etc. What advantages/disadvantages do they have? Any links to builds are appreciated.

- I've never heard a planar speaker, how does the sound compare to a good electrostat like ML ElectroMotion (which I like a lot)?

Any links to descriptions of builds involving these drivers would be appreciated.

Thanks.

[studiotech]

Depending on what kind of SPL you are looking for, either driver at 150hz MAY work OB, but that is really pushing it. Search around.
google is your friend. There is info out there, by myself and others.

I'd stay above 250-300 for either one personally, but I like to rock out.

Greg

[RogerGustavsson]

Distorsion for Neo 10 raises at frequencies below 200-250 Hz. There is a resonance at about 150 Hz. I think 300 Hz is the lowest suitable crossover frequency.

[StigErik]

RD-50 in OB can easily go to 150 Hz with a proper baffle, no problem. But you should XO with 24 dB/oct. I have the bigger RD-75, using it without baffle at all down to 200 Hz. Works like a dream ...

[Remlab]

The difference between the 10, 3 combo and the RD50 is the same as the difference between a point source and a line source speaker. They both energize the room differently, which translates into two very different experiences at the listening seat..
As far as dipole vs monopole is concerned, it depends on your listening room situation. If your speakers are going to be relatively close to the sidewalls, but have several feet behind them to the front wall, dipoles would be a very good choice. If you have the exact opposite situation (Like mine) you would probably be better off with a monopole setup.
Ultimately though, like Greg said, Google is your friend. Take full advantage of it. Truckloads of info at your fingertips. Learning this stuff is fun!

[phazer99]

Thanks.

Surfing around I found the Martin Logan AMT tweeters for $120/pair, which looks like a bargain. I haven't found any distortion measurements of these. How would these compare to the Neo 3's?

On another note, how does the RD and Neo drivers sound compared to electrostatic panels?

[Remlab]

Originally Posted by phazer99

Thanks.

Surfing around I found the Martin Logan AMT tweeters for $120/pair, which looks like a bargain. I haven't found any distortion measurements of these. How would these compare to the Neo 3's?

On another note, how does the RD and Neo drivers sound compared to electrostatic panels?

An interesting note concerning Martin Logan is that they used BG neo 3's in that product line before switching over to the AMT type. From an objective measurement perspective, I have never seen an AMT that outperforms the Neo 3. There are several reasons why they could have switched, including "flavor of the year" marketing decisions. AMT's are "hot" at this moment.
I believe that this is the Amt model that ML uses.(Without the round faceplate)
http://meniscusaudio.com/airborne-rt4001-p-1201.html

[phazer99]

Originally Posted by Remlab

An interesting note concerning Martin Logan is that they used BG neo 3's in that product line before switching over to the AMT type. From an objective measurement perspective, I have never seen an AMT that outperforms the Neo 3. There are several reasons why they could have switched, including "flavor of the year" marketing decisions. AMT's are "hot" at this moment.
I believe that this is the Amt model that ML uses.(Without the round faceplate)
Airborne, RT-4001

Yes, they look very similar. At least the frequency response looks good for this unit.

[Remlab]

Originally Posted by phazer99

Yes, they look very similar. At least the frequency response looks good for this unit.

If you look closely though, you will notice that some Chinese manufacturers (Like this one) 'squish' the graphs in order to make their drivers appear flatter than they actually are..

[Remlab]

Originally Posted by phazer99

Thanks.

Surfing around I found the Martin Logan AMT tweeters for $120/pair, which looks like a bargain. I haven't found any distortion measurements of these. How would these compare to the Neo 3's?

On another note, how does the RD and Neo drivers sound compared to electrostatic panels?

Typical electrostatics energize the room differently than either BG type. Much wider than the RD50 and much taller than the Neo's..