So I'm trying to help my sister out with her 5.1 system in a newly renovated living room. Current setup is a Sony BDV-E500W, nothing to write home about but seeing as she is not any kind of an audiophile, she is more or less happy with it.
But the front mains have to go from floorstanding to sitting in her newly built-in bookshelves so I'm repackaging those to fit. See attached, and yes that is just a 3/4" tweeter and a single 2 1/2" midwoofer in those skinny tallboys. But the CC is just a single 1 1/4" x 2 1/2" driver which is kind of ridiculous for the most important speaker in a home theater system so I'm trying to design something better for her.
Design criteria are as follows:
1) the CC and the receiver need to fit above the fireplace and below the tv in a sort of cutout pocket in the wall so it's essentially an in-wall speaker. But here's the killer - audio was not exactly a design priority: max height for the CC is 58mm
, while the width can be as much as 17".
2) the room is getting an L-shaped sectional up against a side wall so there will be both on- and off-axis listening.
3) F3 on the current speaker is about 250Hz.
4) all the current speakers are 4ohm so that would be preferred unless sensitivity is increased as well.
5) preferred shopping is at Solen.
So pretty much the only decent drivers that will fit seem to be the little Aurasound NSW2-326-8a but I'll need at least a couple so the little guys never have to break into a sweat and since I need good off-axis response, I figured that a mildly curved horizontal mini line-array of 6 drivers series/parallel would seem to be the optimal solution.
But I know nothing about line arrays. Anybody able to offer me a little bit of wisdom on this?
But the front mains have to go from floorstanding to sitting in her newly built-in bookshelves so I'm repackaging those to fit. See attached, and yes that is just a 3/4" tweeter and a single 2 1/2" midwoofer in those skinny tallboys. But the CC is just a single 1 1/4" x 2 1/2" driver which is kind of ridiculous for the most important speaker in a home theater system so I'm trying to design something better for her.
Design criteria are as follows:
1) the CC and the receiver need to fit above the fireplace and below the tv in a sort of cutout pocket in the wall so it's essentially an in-wall speaker. But here's the killer - audio was not exactly a design priority: max height for the CC is 58mm
, while the width can be as much as 17".2) the room is getting an L-shaped sectional up against a side wall so there will be both on- and off-axis listening.
3) F3 on the current speaker is about 250Hz.
4) all the current speakers are 4ohm so that would be preferred unless sensitivity is increased as well.
5) preferred shopping is at Solen.
So pretty much the only decent drivers that will fit seem to be the little Aurasound NSW2-326-8a but I'll need at least a couple so the little guys never have to break into a sweat and since I need good off-axis response, I figured that a mildly curved horizontal mini line-array of 6 drivers series/parallel would seem to be the optimal solution.
But I know nothing about line arrays. Anybody able to offer me a little bit of wisdom on this?
Attachments
Hi jReave,
I read a bit about arrays and your solution sounds reasonably enough given the physical restrictions.
Make sure the Auras are as close together as possible and get ready to use eq on them.
Any chance you could find a rectangular speaker that might fit? Then you could make a more typical two way CC, WTW.
I read a bit about arrays and your solution sounds reasonably enough given the physical restrictions.
Make sure the Auras are as close together as possible and get ready to use eq on them.
Any chance you could find a rectangular speaker that might fit? Then you could make a more typical two way CC, WTW.
Sorry to be rude, but it's not a good idea. Line arrays are used to steer sound. A horizontal line array will beam in the horizontal plane, meaning you will only hear sound properly if you sit exactly in front of the speaker. You could mitigate that issue by letting only one driver run fullrange and lowpass the others, but then you'll run into trouble that there are is too much midrange and not enough highs. Furthermore, the Aura NSW2 has a low overall sensitivity of 82 dB (see graph in datasheet), while on contrary, home theatre requires high sound pressure levels. A high sensitivity 2" driver will be a better choice, optionally supported by small woofers in order to reach down to 250 Hz.
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I don't think you're being rude at all
Horizontal beaming, did not think of that. Obviously the coffee hadn't fully kicked in this morrning.
I don't think the OP needs very high levels though. I think a nice little 2" (or even just a tweeter) like you suggest with a couple of oval drivers either side could work out nicely.
Horizontal beaming, did not think of that. Obviously the coffee hadn't fully kicked in this morrning.
I don't think the OP needs very high levels though. I think a nice little 2" (or even just a tweeter) like you suggest with a couple of oval drivers either side could work out nicely.
I guess the horizontal beaming is why the OP proposed an arced (curved) array.
Might even consider using a Bessel array.
See: http://www.diyaudio.com/forums/multi-way/301259-improved-array.html
Might even consider using a Bessel array.
See: http://www.diyaudio.com/forums/multi-way/301259-improved-array.html
In the interest of posting something useful (??), have you seen something like this? Probably more elaborate then what you are after......
Gallery ? Selah Audio
Gallery ? Selah Audio
Thanks guys.
rb132333, that CC you linked to and the other 2 pictured below are exactly what I was thinking of, albeit in a much smaller and less audiophile form.
Here's a little bit more info.
The first diagram below is a quick sketchup of the living room layout. TV in black and the CC in white on the top wall. I'm figuring that sitting on the left side of the couch will result in about a 30 to 35 degrees off-axis angle.
Originally I was thinking about doing something like a 2.5-way speaker in a MMTMM horizontal configuration but I thought that that large off-axis angle to a single tweeter would be too much of a compromise, and without much need for baffle step compensation because the speaker is essentially in-wall, it also presented some other challenges in terms of the FR balance and center to center spacing for the outside drivers and the tweeter when I did up some sims.
The next diagram is the solution I am proposing. All drivers full range spaced as close as I can get them with each driver angled about 6 or 7 degrees from the one beside it. That means that the outside drivers will be firing at about 18 to 21 degrees off-axis so now that side position will only be about 10 to 15 degrees off-axis which seems to me to be much more reasonable. I guess 1 of the things I'm wondering about is if that 6-7 degree angle between drivers is sufficient as it looks to be less than that used in the other curved CC's pictured.
Regarding sensitivity and SPL, I have no doubts that 6 of the Auras will be able to handle everything that my sister needs. Huge THX volumes are not 1 of her priorities. In terms of getting down to 250Hz, again the Auras look like they can handle that easily although distortion below about 1000Hz is a bit of a concern but I've got to figure that 6 of these Auras are going to be much better than the single little driver in the current Sony CC that my sister has been more or less content with for the past 6 years. Really I'm just trying to create something that's going to be an improvement over that at a fairly reasonable price.
rb132333, that CC you linked to and the other 2 pictured below are exactly what I was thinking of, albeit in a much smaller and less audiophile form.
Here's a little bit more info.
The first diagram below is a quick sketchup of the living room layout. TV in black and the CC in white on the top wall. I'm figuring that sitting on the left side of the couch will result in about a 30 to 35 degrees off-axis angle.
Originally I was thinking about doing something like a 2.5-way speaker in a MMTMM horizontal configuration but I thought that that large off-axis angle to a single tweeter would be too much of a compromise, and without much need for baffle step compensation because the speaker is essentially in-wall, it also presented some other challenges in terms of the FR balance and center to center spacing for the outside drivers and the tweeter when I did up some sims.
The next diagram is the solution I am proposing. All drivers full range spaced as close as I can get them with each driver angled about 6 or 7 degrees from the one beside it. That means that the outside drivers will be firing at about 18 to 21 degrees off-axis so now that side position will only be about 10 to 15 degrees off-axis which seems to me to be much more reasonable. I guess 1 of the things I'm wondering about is if that 6-7 degree angle between drivers is sufficient as it looks to be less than that used in the other curved CC's pictured.
Regarding sensitivity and SPL, I have no doubts that 6 of the Auras will be able to handle everything that my sister needs. Huge THX volumes are not 1 of her priorities. In terms of getting down to 250Hz, again the Auras look like they can handle that easily although distortion below about 1000Hz is a bit of a concern but I've got to figure that 6 of these Auras are going to be much better than the single little driver in the current Sony CC that my sister has been more or less content with for the past 6 years. Really I'm just trying to create something that's going to be an improvement over that at a fairly reasonable price.
Attachments
Thanks Mario but the TC6FC02-04 are too large. With only 58mm of height to work with and using only 3mm hardboard for the top and bottom panels, I'm left with only 52mm of space for the drivers. The Auras look to be the best candidates with a frame size of 49 x 49mm.
Not exactly sure what you mean by a horizontal transmission line though? How many drivers would that use and how would that approach satisfy my off-axis requirements?
How about something like this - Parts Express buyout driver - Fountek FE87 3" Full Range Driver - $7.90 each. They have good reviews.
Fountek FE87 3" Full Range Driver 8 Ohm
Fountek FE87 3" Full Range Driver 8 Ohm
Also too large. I was actually debating between the Auras and the Fountek FR58ex until I noticed that even that tiny one was too big.
One thing I've noticed about small little drivers is that there usually isn't a lot of room for the backwave to disperse before it encounters the magnet. That's something quite different about the Auras - there is no back magnet and the rear wave is pretty much free to exit unimpeded which I suspect is 1 factor adding to its high(ish) quality.
No, I think I'm pretty much stuck with the little Auras despite the somewhat high cost for 6 of them for this type of project. It's the viability and execution of the design that I'm unsure of. I may just have to buy them, prototype it and do some measuring and listening to get the real answer to those questions.
One thing I've noticed about small little drivers is that there usually isn't a lot of room for the backwave to disperse before it encounters the magnet. That's something quite different about the Auras - there is no back magnet and the rear wave is pretty much free to exit unimpeded which I suspect is 1 factor adding to its high(ish) quality.
No, I think I'm pretty much stuck with the little Auras despite the somewhat high cost for 6 of them for this type of project. It's the viability and execution of the design that I'm unsure of. I may just have to buy them, prototype it and do some measuring and listening to get the real answer to those questions.
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