[JeffB]

I decided to try towing out my baffle with the B200 and I find that I like the sound much better.
The rising response of the B200 was driving me crazy.  When I bought the B200, many people said that the driver sounded nothing like the Visaton posted response graph.
To me though, they sound exactly like that graph.
It is most noticeable listening to television.  Certain background sounds and noises in the upper frequencies were being extremely amplified.  Trying to listen to TV was almost painful cause there was just this annoying high frequency noise.  Listening carefully to my television speakers you can hear that this noise is in the signal, but it is way down in db through the television speakers.  Another example is tape hiss.  On any old recording the tape hiss is extremely audible.  Again if played through the television speakers the tape hiss is way down in db.  Some people talk about speakers being ruthlessly revealing.  Well these speakers do that, but they do it by amplifying the upper frequencies.

Besides the high frequencies being amplified I thought the high frequencies sounded kind of rough and inaccurate.
I also have a car audio co-axial on an open baffle.  The tweeter in this co-axial has much better defined highs than the B200.
Still though the B200 has something going for it in the midrange that is much better than the co-axial.

I have for the longest time been planning on either using a parametric eq or the 1mH inductor 10 ohm resistor circuit that has been talked about.
However, it occurred to me that I could achieve much the same thing by towing them out.

The towing out of the speakers really created a huge improvement in my room.
Not only do the speakers seem to have a much more even response, the roughness that I was hearing in the highs seems to be gone also.
I may have lost some high frequency information doing this, but I don't miss it.  The music just sounds so much more right.

My setup is far from perfect.  I don't even have matching baffles yet.  The left baffle is 48" tall by 17" wide with the driver dead center and 14" from the top.
This was the more problematic of the two drivers.  This is the baffle that I towed out.  The other baffle is more like a three sided box consisting of 48" by 12" boards with the
driver mounted 16" from the floor.  This baffle still points straight ahead.  I suspect that the since the driver is low I am already listening off center to this driver thus reducing some of the high frequency information from this driver.  Also the left speaker is about 1 foot forward of the right speaker.  The speakers are about 7 feet apart.  This arrangement of course place havoc with the imaging.  However, the towing out also improved the imaging, although it still needs work.

Just before trying this experiment I ordered 2 Tang Band W3-871S drivers because they have such a smooth looking response.
I was excited to try these drives, but now I have my doubts that they will compare well to the B200s.

I started this whole thread, because I think that towing the baffles out might prove to be a better solution than the MOX filter.
Of course, after one look at my setup, you could easily decide that it is so far from perfect as to make any conclusion pointless.
I have not yet tried towing in.

[JoshK]

Toe them out and they won't beam at the sweet spot. 

[markC]

The outward toe should definitely reduce the beaming of the b200, which to me, is the root of the problem. However, in my journey so far, I've found that it is much better to add a notch filter to kill the frequency that is most annoying. Of course, results will vary with rooms, equipment, etc.
I've gone so far as to add a baffle step, a notch filter, a zobel and, Gasp! a tweeter with a 3rd order x-over. The sound I'm getting now is the best yet for me with the B200's.
I hope this doesn't discourage your quest. As you stated- There really is something special about the midrange of this driver. It provides a more "in the room" sound than any of my previous boxed speaks; especially with female vocal, which I really enjoy.

[Wind Chaser]

Of course, results will vary with rooms, equipment, etc.

As for the "etc" -  the baffle and how it couples to the room are critical.  Try experimenting with a few different implementations and you should find that is a huge determining factor in terms of how much bass there is relative to HF output.  I positioned mine way off axis (much unlike the way I do with conventional speakers) but mine had phase plugs which opens up the HF dispersion.

[Luigi]

Wind Chaser. You mentioned: [but mine had phase plugs which opens up the HF dispersion.]

Tell me more about this if you wouldn't mind. What precisely does it do to the rising response, if anything, and to the top end in general?

What's involved? I take it you just hack away at the dust cap with a knife and insert the plug of your choice. What phase plugs have you played with? What size?

I'd probably rather mess with the driver physically than fuss around with electrical cures for the rising response.

[mcgsxr]

I would try to get the baffles sorted (ie identical, and wider than 17 inches...) that will improve the balance for sure.

Have you tried crossing them significantly in front of you?  That might remove the beaming highs, but preserve the soundstage some.

I found that amp synergy made an ENORMOUS difference with these drivers.  I have tried 7+ amps, and have finally settled on what I can afford - vintage Magnavox.

Worth experimenting with though, lots of folks have had fun with these drivers, eventually finding some combination that works for them.

[Wind Chaser]

Luigi,

The rising response wasn’t an issue for me.  That’s not to say that they weren’t some what tipped up, but my implementation certainly didn’t sound anything like the Visaton FR plot.

The phase plugs were designed and installed by Planet 10.  There are instructions on the website on how to remove the dust cap and speaking from experience, it’s not that difficult.  My comments on what the phase plugs do are buried in the Gravity Well.  Do a search with my name and “a brief summary” and they should pop up...

[JANDG]

I have solved this rising responce for me with simple XO's..& what awaited is a wonderfull midarnge that is basically amazing. I use a .22mH coil on the B200 the a G2 ribbon parrelled off that w/ a single 2uf cap in series w/ + of g2 ribbon. I highpass my 100k tube amp w/ a .01uf cap @ amp input for 150hz HP..Bass is handled by vifa M26wr-09-08's & BASH plates set @ 150Hz.. the rising responce is gone..even with toe in.. which I use.. The ribbons take to the 2uf/10k hz cap because of the HP on the amp, also the 4250hz roll of the B200 just seems a perect match, I also use no padding resistors anywhere...only the slight resistance of the 22mH coil.. I can push the B200 & g2 ribbon to very high spl's with a 300B PP amp or any of my flean tubers & doesn't break up to my ears. When I stumbled on this after much experiments.. I was floored & still am, have not touched xo set up since I found this combo...easy & cheap to implement.I figure this works because of the rising responce of the b200 & results to me are seemless & no hole.I just thought to bring this up as I agree to rise..but can be sensibly conquered cheaply & easily, as you did.

[Luigi]

Hi Wind Chaser


Many thanks for that. I quickly found your ref in the Gravity…Star thread, which is now the size of a novella.

The oddest thing really. I went and measured up my current open baffles which have the Fostex FE206E drivers (with the 15/16ths socket mod) and they are almost to the inch identical to yours!

I guess this shouldn't surprise that much, as most significant others won't allow dinosauric speakers in their living rooms, let alone ones that have to breathe out in the middle of the room.

One of the things I found intriguing is the mention made by some others that an 18-inch baffle width is the best for imaging. I have always found that the less width there is on the front baffle the better for imaging. I note yours are 9.5 inches wide, just enough to sneak the b200s on the front without overhang. Mine are about 10 inches wide which allows about an inch of clearance either side for the Fostex.

So Im going to now get my cabinet maker pal to create some more rigid baffles using his CNC miller and cast off bits of ash or oak, depending on what is available. Plus mitre joints to avoid the rattle of piano hinges.

And I might well touch base with Doug from Planet 10 once we get the new baffles sorted.

Again, thanks for the input.

Cheers

Luigi

[Russell Dawkins]

FWIW I'm in favor of toeing in rather than out, so the axes cross in front of the listening area - tends to give a wider sweet spot and the nulls off to the sides are aimed at the wall between and behind the speakers, diminishing a major reflection and further improving imaging and the side walls, doing the same.

[Wind Chaser]

FWIW I'm in favor of toeing in rather than out, so the axes cross in front of the listening area - tends to give a wider sweet spot and the nulls off to the sides are aimed at the wall between and behind the speakers, diminishing a major reflection and further improving imaging and the side walls, doing the same.

Ordinarily that is how I prefer to position my speakers too.  However because the phase plugs open up the HF dispersion, having them towed out off axis did not diminish the size of the sweet spot or compromise the imaging.  Mine were tilted in only 10 degrees or so and I had excellent localization with a bigger sound stage plus a fat sweet spot.

Luigi,

Those 10" baffles with wings were my first baffle.  As you progress through that thread you'll see I improvised on a design by Nigel Smith which didn't produces as much bass, but paid off in other areas.  I'd elaborate more but I'm in desperate need of sleep.   If you slog through the Gravity Well you'll get a better understanding I what I found and concluded.  Bottom line is OB's are cheap and easy to make, so experiment with different designs and see what works best for you.

[opnly bafld]

One of the things I found intriguing is the mention made by some others that an 18-inch baffle width is the best for imaging. I have always found that the less width there is on the front baffle the better for imaging.

Cheers

Luigi

All of the 18" baffle users that I know of have flat baffles, no wings.
On some other forums I have seen people suggesting much wider baffles, but many find imaging suffers.

Experiment, it is easy and fun.
Lin

[JohninCR]

Wings around a main driver are tricky to get right, and definitely take some experimentation.  What I've found to work best is folding the baffle right at the driver cutout using angled wings that are also tapered (smaller at the top) and one 1/2" to 1" shorter in depth than the other giving you a left and right speaker.  Then the wings guide the wave as it expands rearward instead of acting as reflectors to cause early reflections and unnecessary disturbance of the rear wave.  Also, making them as deep as Luigi is talking will likely "close in" the sound pretty drastically compared to a flat baffle.  Those kind of depths can be dealt with for a bass augmenter driver(s), but not the main driver.

[JeffB]

I have new news.
mcgsxr suggested wider baffles.
I don't really have room for wider baffles on a permanent basis, but on a temporary basis I can do it.
So I changed the left baffle from 17" to 33".  I haven't got around to the right baffle yet.
Wow, what a change.  The bass became so much stronger.  I have a sealed subwoofer with two 10" drivers that I have been
using with the B200's.  I was assuming more or less that the subwoofer was properly filling in the area where the B200's were rolling off.
I had a low pass on the subwoofer at 160Hz.  I have a high pass filter on the B200 at about 65Hz.  The wider baffle really brought that left speaker to life.  More output and lower frequency.  I dropped the lowpass to 140Hz.
The whole lower frequency sound and integration with the subwoofer became immensely better.
It is clear that the where the subwoofer and B200 overlap the B200 has the far better bass. 
Thus, the lower I can get the B200 to go the better.
Don't pay too much attention to the cross-over numbers.  I am simply looking at the dial on the eq.  The readings I get with an SPL meter versus the eq setting don't seem to make much sense to me.  I have been forced to assume they are wrong and just listen by ear.
I am jealous of you people with room for wider baffles.