AZDoug,
This may be similar to the 1/4in sub flooring Cal used to face the Cornu speakers he built. A perfect match for foam core - which I would still use on the curved parts. I think it may actually be a wood called luauan - similar to mahogany but cheaper. Are you making yours out of this now?
This may be similar to the 1/4in sub flooring Cal used to face the Cornu speakers he built. A perfect match for foam core - which I would still use on the curved parts. I think it may actually be a wood called luauan - similar to mahogany but cheaper. Are you making yours out of this now?
Yes, luauan, yes for new builds once I build it first with just foam board.
I'm thinking it will be easier to do the lamination at once, two foam boards, and two luauan skins, (one on each side of the board), using just PVA glue. For the Naut, the luauan would be used for the visible portion of the curve. Also, could be used for the visible portion of a cornu spiral, as well as it's front face.
I'm thinking it will be easier to do the lamination at once, two foam boards, and two luauan skins, (one on each side of the board), using just PVA glue. For the Naut, the luauan would be used for the visible portion of the curve. Also, could be used for the visible portion of a cornu spiral, as well as it's front face.
How do you plan to curve the luauan wood for spiral that is exposed? Kerfing or soaking in hot water/steam? You might as well use thin stick on veneer for the curve and use foam as the substrate.
Actually I'm using the door skin luan as a veneer. It's pretty flexible. In fact an 8' X 1' piece is curved and sitting in my truck bed. The outside curve is not that small of a radius, so I think I can bend it to that shape. It's only 5mm thick. Hot water or steam could be used to make it more bendy if that is needed.
I remember why I like full range
I was playing with EQ'ing the Nautaloss to achieve a perfectly flat response in-room and it measured well but things just sounded funny on some tracks - especially acoustic pieces in intimate settings mic'd for stereo imaging. I realized that all that EQ'ing was messing with the phase in the 500 Hz to 5 kHz range. I bypassed all the EQ'ing on the Nautaloss II tops (just left the LR XO between the tops and the subs) and the sound quality and imaging dramatically improved. Here is a measurement with no EQ applied and the phase varies smoothly and linearly rather than wrapping through 180 deg with each PEQ applied. There is still one phase wrap at the XO region but it is in a range that is not associated with spatial imaging. I like it better now and it reminds me the importance of having a good speaker to start with so you don't need to apply heavy EQ'ing. The mic was in between the 2 drivers and I think this was at a point that caused the falloff above 10 kHz. Farther away it would not have been an issue. Below 200 Hz is all the room modes going on, I am surprised to get bass down to 30 Hz.
Freq Response & Phase, Distortion, and Impulse Response.
I was playing with EQ'ing the Nautaloss to achieve a perfectly flat response in-room and it measured well but things just sounded funny on some tracks - especially acoustic pieces in intimate settings mic'd for stereo imaging. I realized that all that EQ'ing was messing with the phase in the 500 Hz to 5 kHz range. I bypassed all the EQ'ing on the Nautaloss II tops (just left the LR XO between the tops and the subs) and the sound quality and imaging dramatically improved. Here is a measurement with no EQ applied and the phase varies smoothly and linearly rather than wrapping through 180 deg with each PEQ applied. There is still one phase wrap at the XO region but it is in a range that is not associated with spatial imaging. I like it better now and it reminds me the importance of having a good speaker to start with so you don't need to apply heavy EQ'ing. The mic was in between the 2 drivers and I think this was at a point that caused the falloff above 10 kHz. Farther away it would not have been an issue. Below 200 Hz is all the room modes going on, I am surprised to get bass down to 30 Hz.
Freq Response & Phase, Distortion, and Impulse Response.
Attachments
When using dual drivers one must be low passed below the spacing distance between the two. This prevents severe phasing issues that causes wild polar interaction and lobing on and off axis.
Spacing is about 4 in or 0.1 m. This is about the same spacing used by the IDS 25 speakers and their clones, and all run full range. The lobing is not an issue at listening distances of 4 ft or more away. I just had mic close for near field. Or are you saying this is not the case with just two drivers?
But he didn't and still likes them...
Clearly he must be wrong then?
I'd say there is an ideal listening height that is best when these speakers are used. That's where both speakers in the same cabinet from the woofers to the ear have an equal path length.
Same goes for a lot of speakers though, sitting down and standing up will mess up the distance from the woofers to the ear in a lot of them. Even when disregarding the difference in off axis response you also get in that case.
A crossover part on one woofer will change the phase at that crossover point though, unless you use a fancy type of phase linear crossover.
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Even on axis spacial inconsistencies will occur. The point is that this would be no different acoustically than placing two tweeters crossed at 3380Hz being spaced 4" above one another. Unless your shooting for some acoustical special effect it is simply not done.
X,
Slap a passive inline filter on your sub amp and use the 2x4 to handle both of the TC9's. Setup the same as you have done, but this time walk around the room, move side to side. Now switch to the suggested cross point on either driver, your choice, but both the same and do the same listening test. The off axis response will be improved and a broader listening position realised.
Slap a passive inline filter on your sub amp and use the 2x4 to handle both of the TC9's. Setup the same as you have done, but this time walk around the room, move side to side. Now switch to the suggested cross point on either driver, your choice, but both the same and do the same listening test. The off axis response will be improved and a broader listening position realised.
One example hardly sways my opinion of the design, the designer, or the company's marketing dept. behind it. 🙂
I am bi amping and XO is performed with miniDSP 2x4, with TC9's driven in parallel (high pass at 150 Hz and going full range above that, sub driven by the low pass of the XO below that). Are you saying split the parallel driven TC9's with a XO?
The sims show no lobing in the horizontal plane with two drivers vs one at listening distances. The vertical polar is different but that is function of sitting or standing, which we know will be different and accept to be the case.
The sims show no lobing in the horizontal plane with two drivers vs one at listening distances. The vertical polar is different but that is function of sitting or standing, which we know will be different and accept to be the case.
There you go again... simply not done... By you it isn't, others are more willing to find out for themselves. 😛
I'm saying use another crossover for the sub, or heck for that matter this test does not require it at all. Hook up each TC9 to each 2x4 output.
A passive low pass would also work, but will take considerable time and effort to match up with the active portion. For now we can just do a little test with the mini alone.
A passive low pass would also work, but will take considerable time and effort to match up with the active portion. For now we can just do a little test with the mini alone.
Why not do a different test.
Measure both nautaloss I and II on and off axis at say 0 15 30 deg horizontally.
In the case of nautaloss II with mic height between both vifa's.
You'd need some kind of rotation table like an office chair or something.
The vertical off axis will change compared to the single driver, that's a given. But I am not that sure about the horizontal response. From all I have read about it (and that's a lot, more than a lot actually) the off axis will mimic the response of a single driver. At least it will with the large arrays. Might be a fun test and way easier than splitting up the Nautaloss II to rewire.
I'd do it myself if my setup was ready:
compared to
Well, apart from the part of putting my speaker up on an office chair 😉.
Measure both nautaloss I and II on and off axis at say 0 15 30 deg horizontally.
In the case of nautaloss II with mic height between both vifa's.
You'd need some kind of rotation table like an office chair or something.
The vertical off axis will change compared to the single driver, that's a given. But I am not that sure about the horizontal response. From all I have read about it (and that's a lot, more than a lot actually) the off axis will mimic the response of a single driver. At least it will with the large arrays. Might be a fun test and way easier than splitting up the Nautaloss II to rewire.
I'd do it myself if my setup was ready:
compared to
Well, apart from the part of putting my speaker up on an office chair 😉.
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You are partly correct. Summation only occurs below 3380Hz.
Called a "Lazy Susan", a turntable, commonly used in kitchen cupboards. Simple enough to make
eYup and situation is different with line arrays 😉
BTW Wesayso, I'm really liking your arrays. How long did it take to cut up and how many board feet of material did this take?
BTW Wesayso, I'm really liking your arrays. How long did it take to cut up and how many board feet of material did this take?
I agree single driver Nautaloss I vs II is test to do. The turntable can be used if outdoors with no walls. Otherwise mic has to be moved around room. Like I said, the AkAbak sim already shows that the horizontal polar will be the same.