I think they are the best FR driver in there size and class, that's why I was curious as to Bob Brines top end measurements.
I was the one who recommended this driver on this thread, (and on several others).
I was simply staying on the point of measurements and keeping my subjective review to myself. There are plenty of reviews and testaments of this drivers performance.
I know there are no independent measurements of this driver, and until "somebody" presents some, I will make my claim.
Again, I am not claiming anything about subjective viewpoints.
I would like to have comparisons (measurements and listening) between TB and Alpair (Iknow that Alpair is about half the price of the TB) But I see that Alpair works better in a mall BR box.
Dispersion for CC is crucial, so how compares 8" (alpair) to 8" TB with a wizzer cone? Wizzer cone extends HF a bit but beams more?
Crutial on quality reproduction and horizontal dispersion are the most important for me and my friend.
Am-I sidetracked?
Anyways interesting debate.
Dispersion for CC is crucial, so how compares 8" (alpair) to 8" TB with a wizzer cone? Wizzer cone extends HF a bit but beams more?
Crutial on quality reproduction and horizontal dispersion are the most important for me and my friend.
Am-I sidetracked?
Anyways interesting debate.
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The largest Alpair is a 6.5". The A10.2 is 5.25". The alpairs have a shallow cone to get better dispersion. The TB has a very deep cone (a PITA when i'm EnABLing them) The Alpair also has a 1" domed dustcap that extends its response and improves its dispersion further.
The 5.25" shallow cone alpair will have better dispersion than the TB W8... and not by just a little bit.
dave
A smaller driver virtually always wins for dispersion, for a given cone profile.
Look at a traditional cone driver -- for some portion of the midrange and treble, the driver in breakup is moving within the the solid angle of the cone's shape. So it starts beaming early and thus is exactly what you don't want.
A smaller driver can radiate more like a dome tweeter. The 4" FE103En actually has something shaped exactly like a dome (in place of a whizzer) and the cone profile is very shallow. It starts beaming much higher, thus has comparatively better dispersion.
Bob Brines, did you ever build that special center-channel you designed? (You mentioned it at an LSAF a couple years back.) That would seem to be the perfect solution here.
ETA: Oh I cross-posted with planet10.
Look at a traditional cone driver -- for some portion of the midrange and treble, the driver in breakup is moving within the the solid angle of the cone's shape. So it starts beaming early and thus is exactly what you don't want.
A smaller driver can radiate more like a dome tweeter. The 4" FE103En actually has something shaped exactly like a dome (in place of a whizzer) and the cone profile is very shallow. It starts beaming much higher, thus has comparatively better dispersion.
Bob Brines, did you ever build that special center-channel you designed? (You mentioned it at an LSAF a couple years back.) That would seem to be the perfect solution here.
ETA: Oh I cross-posted with planet10.
Thanks!
This is basically what I want to know! The basics of dispersion, form and size!
Then to get decent dynamic range and efficiency (around 90db) a 6" is better(on dispersion compared to 8"). Cone shape too, the whizzer still extend hf but at the expense of polar response.
A 4" TB (even two) is probably out of the equation besause of efficiency, I don't want double 4" on CC with comb filtering problems!
I'm-I on the right track?
This is basically what I want to know! The basics of dispersion, form and size!
Then to get decent dynamic range and efficiency (around 90db) a 6" is better(on dispersion compared to 8"). Cone shape too, the whizzer still extend hf but at the expense of polar response.
A 4" TB (even two) is probably out of the equation besause of efficiency, I don't want double 4" on CC with comb filtering problems!
I'm-I on the right track?
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I don't want to over-complicate this, but if it were me, and dispersion is the top priority, I'd build a center channel with a baffle comprised of four angled "faces" in a convex shape, using multiple 4" drivers. Each listener ends up on-axis, and the combing would be limited depending on the curve and width.
Bob Brines' solution (mentioned above) was different than this, and very ingenious.
Bob Brines' solution (mentioned above) was different than this, and very ingenious.
Let's suppose you have 4 drivers in a convex shape that it would mean a little upward and downward dispersion? not for me. But an array in arc (horiz. arc) would be good?. It should be prone to lobing/comb filtering?
Anyway it should be the shape of this convex shape? because it adds complexity into the making...
But not undoable for shure
And what is the curve of "this convex shape"?(Listening distance of 6-7 feet, 3-4 feet spread min. at seat)
Ideal would be 90 degrees at source!
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Yess I understand to match L-R but his paradigm have different (substitute) woofers that I have no idea of what models. So i'm moore concerned(above all) of a good dispersion CC than any other diggin of what would match L-R sound but more concerned to at least recover a good CC. I konw I'm in the reverse way around!
Ok I think I'll go for the alpair 10.2...I guess
Many thanks to all your contributions
Imagine it this way. You have four people sitting in front of the TV, sitting in a U-shaped pattern. The center channel baffle is similarly U-shaped (i.e., curved in the horizontal dimension). Each person is on-axis with one and only one driver.
As for comb-filtering, since the baffle is curved, the drivers won't comb-filter -- there will be a single deep (i.e., not audible) notch in the response, the frequency of which is dependent on the angle of each baffle section, as well as driver-to-driver spacing.
Does that make sense? This is just one way to accomplish the goal of good dispersion. Perhaps it is overkill!
As for comb-filtering, since the baffle is curved, the drivers won't comb-filter -- there will be a single deep (i.e., not audible) notch in the response, the frequency of which is dependent on the angle of each baffle section, as well as driver-to-driver spacing.
Does that make sense? This is just one way to accomplish the goal of good dispersion. Perhaps it is overkill!
yes, same speaker for the center as the front speakers sounds best.
and being a two way the dispersion is much better then on any full ranger! (wheezer cone, flat cone/membrane ...)
my center is a wtw pseudo d'appolito standing upright under my flat screen, tilted a few degrees to aim the tweeter
Since measurements got a bit of ink here, I thought this might be interesting.
This is a prototype speaker that I am working on. It uses the Alpair 10.2. The box is nominally 15L tuned to 35Hz. It is bottom vented and currently standing on four 1/4" bolts.
The gray plot is a 1/2m raw, ungated, unsmoothed FR. The black vertical line is where I chose to splice the driver/port nearfield to the farfield. The low end to the black trace is as stated the combined nearfield and the top end is a gated 1/2m farfield. The gate was 5ms. The red plot is the published MA A10.2 on-axis plot (I used SPLTrace @ 200 points). Other info: My measurements were taken in a 20'x20'x9' garage. Concrete floor, three sides and ceiling drywall, and the fourth side a steel door covered with 1" of acoustic fiberglass. The speaker was in the middle of the room with the driver 4.5' above the floor
Let the comments begin.
Bob
This is a prototype speaker that I am working on. It uses the Alpair 10.2. The box is nominally 15L tuned to 35Hz. It is bottom vented and currently standing on four 1/4" bolts.
An externally hosted image should be here but it was not working when we last tested it.
The gray plot is a 1/2m raw, ungated, unsmoothed FR. The black vertical line is where I chose to splice the driver/port nearfield to the farfield. The low end to the black trace is as stated the combined nearfield and the top end is a gated 1/2m farfield. The gate was 5ms. The red plot is the published MA A10.2 on-axis plot (I used SPLTrace @ 200 points). Other info: My measurements were taken in a 20'x20'x9' garage. Concrete floor, three sides and ceiling drywall, and the fourth side a steel door covered with 1" of acoustic fiberglass. The speaker was in the middle of the room with the driver 4.5' above the floor
An externally hosted image should be here but it was not working when we last tested it.
Let the comments begin.
Bob
I like it.
Blow the measurements though for a minute Bob -15 litres tuned to 35Hz? That must have a fairly serious vent.
(not a criticism I hasten to add).
Back OT WRT the measures, glad you managed to get SPLtrace going. I've never been able to get it to work properly for some reason. No doubt I'm doing something wrong. Either way, looks to be quite a nicely balanced result, since the elevated top end will come into line off-axis as your other measures show.
Blow the measurements though for a minute Bob -15 litres tuned to 35Hz? That must have a fairly serious vent.
(not a criticism I hasten to add).Back OT WRT the measures, glad you managed to get SPLtrace going. I've never been able to get it to work properly for some reason. No doubt I'm doing something wrong. Either way, looks to be quite a nicely balanced result, since the elevated top end will come into line off-axis as your other measures show.
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Nice work Bob. Yeah, I thought it'd be something like that. I looked into a box along similar lines a while back (couple of litres larger IIRC & with & rear-firing vent), but since I have a 6in duct length cutoff point, I didn't pursue it. Just a personal thing re the duct length; I really should get out of that habit.
That rise is build into the driver -- see the red trace. It should lead to some boxiness, bit I don't hear it. When I get an afternoon, I'll hook it up to a minDSP and play with it. If it definitely sounds better with the rise removed, a low Q notch filter may be in order.
Bob
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