Just to have a question answered, why crossover at 1800 Hz to BG Neo3 PDR with your OB-5 ?
Where else would I cross it?
The woofers will play flat to 6kHz and is only 5db down at 10kHz. I could have crossed it anywhere, but there are a lot of reasons as to why it is crossed at the 1.8kHz range.
First of all the diaphragm on the Neo 3 pdr is much smaller (only 5/8" wide opening) and its off axis response is much better than that of the woofers. By handing off early to the Neo I get an even power response that is very consistent off axis. If the woofers were to play higher then the off axis response would suffer.
An even off axis response will give you an even in room response.
To illustrate have a look at a full range (or really wide band) driver like the B200. Besides the fact that the top octave is already taking a nose dive, it has a very limited off axis response. Move off axis and the higher ranges really fall away quickly. All of the lower ranges have much better off axis response due to the longer wave lengths. So you will collectively get some gain in the lower ranges from the room, but the higher ranges will give you only what you hear if you are sitting right in front of them. So the power response of the whole room will be even further down in the top end that it already is.
Letting the Neo handle as much as possible as soon as possible is a good idea just from this prospective alone. But wait there's more.
The Neo tweeter has a much lighter weight diaphragm and will play much higher and faster than a woofer. By fast I am referring also to spectral decay. It has much less stored energy and inertia and will be much cleaner. It is also faster in that it will play much higher.
As good and as fast as the small woofer are, they are no match for the Neo tweeters.
BTW, if you want to know how fast a driver is, you just have to look at how high it will play. To cover a high frequency range a driver must move very quickly as the wavelengths are very short. Its ability to move quickly will determine if it can play high or not. If the mass is too heavy and/or it lacks sufficient motor strength to move it then it won't play up high.
If you compare the detail and resolution of the M-130/16 woofer to any good tweeter from 2kHz and up, the tweeter will win every time. With a tweeter like the Neo 3 it wins easily.
Then there is another factor. Everything is a compromise. What I mean by that is that one driver or pair of drivers being feed a wide bandwidth signal has to do a lot all at once. A B200 driver for instance is having to play the lows and the highs at the same time. The problem is that the lower wavelengths force the driver to move in long exertions. Then at the same time it is having to do many smaller ones to play the higher range at the same time. The longer exertions and the amount of power it receives to make it try to play the longer exertions override everything else. It has to make some compromises along the way to try to cover it all.
You see, my A/V-1 sounds great (a two way design) and has REALLY good midrange, but if I make a three way design out of it and delegate 150Hz and down to some other (larger) driver and relieve the M-130 from having to play those lower ranges (like my A/V-4 kit) then the midrange gets even better than it was before. The M-130 no longer has to make a such a large compromise.
The same goes with the highs. The faster I can get the highs handed off to a driver more capable of covering them, the better. And the Neo 3 is so good, so clean, and so fast that from 1,8kHz and up there is not a lot that compares to it. No woofer is going to cover from 1.8kHz to whatever, any better than a Neo 3. Even a design that crosses to the tweeter at 2.5kHz or 3kHz is no comparison because from the 1.8kHz range all the way up to the 2.5 or 3khz range you would be comparing the woofer in one speaker to the Neo 3 in this speaker. There is no comparison.
If the natural roll of and acoustic slopes allowed the Neo 3 to be crossed even lower then I would.
