I've done this a few times, using 3 conductors as a positive and 3 conductors as a neutral, it seems to work well for longer runs, like media room -> garage.
Come to think of it, that resembles the way Audio Quest assembles their wire.
Star-Quad
Edit: 3...I meant 4.
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Eric,
I am going to be using exactly the same Tang bands in line arrays.But I am also using the Apex Jr Tweet at 6k Hz. I am planning to use them in the BFM TLAH design. The 881SI demonstrably works pretty well in a transmission line setup providing pretty good response down to 50hz'ish. But I am using mine with subs crossed at 80Hz or so.
For satellites I was planning to use 2, wired to 4 ohms in about 2L for a 110Hz F3.
Something like that at least. I only bout 55 of them lol.
I am going to be using exactly the same Tang bands in line arrays.But I am also using the Apex Jr Tweet at 6k Hz. I am planning to use them in the BFM TLAH design. The 881SI demonstrably works pretty well in a transmission line setup providing pretty good response down to 50hz'ish. But I am using mine with subs crossed at 80Hz or so.
For satellites I was planning to use 2, wired to 4 ohms in about 2L for a 110Hz F3.
Something like that at least. I only bout 55 of them lol.
Mitch,
Thank you for your feedback. Reviewing the specs for each driver they have their respective strengths and weaknesses. The big ones for the TB 881SI are low cost (factory buyout at PE) and very nice frequency response across most of the audible range. The Vifa is also reasonably priced (though not quite as good as the the TB) but again the spec about it that really caught my eye was its power handling. If 50W per driver is true that's a big deal for me in terms of center and surround speakers as I could use far fewer drivers than I was going to use with the TBs to achieve decent power handling for music and especially movies.
Let's take your plan for satellites as an example. A pair of 881SIs will get you 30W of power handling. In smaller rooms and/or MDUs (multi-dwelling units) that would probably be adequate. But would it work in a larger living room? That's my situation where the center and surround speakers will be located so SPL and power handling will matter.
As I plan on using 25 drivers per side for the L+R main speakers I'm confident either driver will work well. I'm just concerned about the supporting speakers...
Right now I'm leaning toward the Vifa drivers. If nothing else I'll be able to use fewer of them vs. the TBs to accomplish my goal. I think I'll bound my concerns off the PE folks and get their take on it.
Thank you for your feedback. Reviewing the specs for each driver they have their respective strengths and weaknesses. The big ones for the TB 881SI are low cost (factory buyout at PE) and very nice frequency response across most of the audible range. The Vifa is also reasonably priced (though not quite as good as the the TB) but again the spec about it that really caught my eye was its power handling. If 50W per driver is true that's a big deal for me in terms of center and surround speakers as I could use far fewer drivers than I was going to use with the TBs to achieve decent power handling for music and especially movies.
Let's take your plan for satellites as an example. A pair of 881SIs will get you 30W of power handling. In smaller rooms and/or MDUs (multi-dwelling units) that would probably be adequate. But would it work in a larger living room? That's my situation where the center and surround speakers will be located so SPL and power handling will matter.
As I plan on using 25 drivers per side for the L+R main speakers I'm confident either driver will work well. I'm just concerned about the supporting speakers...
Right now I'm leaning toward the Vifa drivers. If nothing else I'll be able to use fewer of them vs. the TBs to accomplish my goal. I think I'll bound my concerns off the PE folks and get their take on it.
Certainly something to consider. I figure my 2 driver satellites will give me 92dB SPL (inc sensitivity from lower impedance). Add on 10w for 10dB more and I'd call that sufficient. But I am also in a fairly small space. Maybe 2m tops between surrounds and listening position. I have also heard that you don't want your surrounds as loud as your mains?
I donno if this is just a plain stupid idea but maybe short dipole line arrays? Say 6 drivers per side. That would give you a heap of power handling. But might limit your vertical dispersion a tad.
I have yet to decide if my surrounds will be dipole or crossfired and aimed at the roof/listening position. Given how small and easy the boxes are I might try all of the above lol.
Those Vifa's though, they do get quite the rap. I just couldn't go with them as they would have near doubled the cost for me and Line arrays with the TB's aren't cheap to begin with.
I donno if this is just a plain stupid idea but maybe short dipole line arrays? Say 6 drivers per side. That would give you a heap of power handling. But might limit your vertical dispersion a tad.
I have yet to decide if my surrounds will be dipole or crossfired and aimed at the roof/listening position. Given how small and easy the boxes are I might try all of the above lol.
Those Vifa's though, they do get quite the rap. I just couldn't go with them as they would have near doubled the cost for me and Line arrays with the TB's aren't cheap to begin with.
110 Apex Jr tweets arrived today. Happy times. TB Fullrangers should be in early next week.
Just trying to think how I could rear mount these tweets. Bit of hot glue round the back of them once they are screwed on? Making a tinnie tiny gasket for each one might make my brain explode.
Just trying to think how I could rear mount these tweets. Bit of hot glue round the back of them once they are screwed on? Making a tinnie tiny gasket for each one might make my brain explode.
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I wired them with "pig tails"
Soldered about 75mm (3 inch) leads to each tweeter--assembly line fashion. Once complete, then grab some food and do something different for the brain to wake back up.
I did the pig tails so I could just simply twist the wires together and get different impedances to try out. I revised the lines months later and it made it much easier to re-wire.
I don't envy you!
Soldered about 75mm (3 inch) leads to each tweeter--assembly line fashion. Once complete, then grab some food and do something different for the brain to wake back up.
I did the pig tails so I could just simply twist the wires together and get different impedances to try out. I revised the lines months later and it made it much easier to re-wire. I don't envy you!
A labour of love I guess
I know the feeling,
After wiring 96 tweeters with 192 wires--then the harness has to go in. I then reconfigured the tweeters again 6 months later--I'm glad I won't be doing that again.
Make sure you get all the tweeters lined up correctly--I screwed up a few so had to put "flags" on all the negative wires so I could get them all correctly wired.
Brain fade is a serious problem with tweeter arrays--but once you are done--they do have a unique look to them. The doubting your sanity part will also come into play...
Thankfully it looks like I have a CNC lined up to do my baffles!
On another note, I heard that the apex jr tweets perform a bit flatter wired in reverse. Seen some graphs which indicate it as well. I'd have to assume there is some truth there?
Also I am wiring em for maximum output straight off the bat. Always better to make some cuts in highs than boost.
On another note, I heard that the apex jr tweets perform a bit flatter wired in reverse. Seen some graphs which indicate it as well. I'd have to assume there is some truth there?
Also I am wiring em for maximum output straight off the bat. Always better to make some cuts in highs than boost.
When wired as a 2-way with 12dB/Oct filters--you would reverse the polarity on the tweeter. Mine are 3-ways with 12dB/Oct filters so the midranges are reverse polarity.
I tried crossing 48 of them at around 4.5KHz more or less--did not work. Went with 6 KHz with the 3 ways and a bessel filter to give it a little bump at the XO point. My twenty 3-inch mids started to drop off around 5.5KHz so it helped even that point.
Initially, I figured 48 of them could withstand 4.5 KHz without distortion and they could--it just didn't have the output or smooth frequency response to work properly. I used an 18dB/Oct 3rd order crossover reverse-polarity and it sort of meshed with the 5" woofer lines--because the woofers were dropping off fast in the midrange.
Using twenty 3" full-ranges with rising response (they gain +12dB from 400 to 8KHz!) that did the trick as I crossed them over with a 12dB/Oct 2nd order filter at 6 KHz. From 100 to around 14K I get +/- 3dB passively so I'm happy with it. A proper subwoofer will bring up the bottom end and I can always throw a bump of EQ at 16KHz to bring it up. No worries about power handling or distortion when running 48 tweeters--EQ to taste.
Learned a gold mine of information when building arrays--the most valuable is to not use smooth frequency response drivers--use "TV speakers" that have a 3dB per octave rising response to counter the natural 3dB/Oct falling response due to phasing issues. If I'm ever crazy enough to build another pair, it would be the rising response Vifa 3.5" full range "TV speakers" and use DSP to EQ them. They would be two-pieces, each one would run 12 Vifas for 24 drivers standing 2.3 meters (7.7 feet) tall. Each array would be crossed over to a subwoofer at 80Hz.
My brother is interested in arrays for their even volume for the first 3 meters, very large sweet spot and most importantly (to him)--they look cool and can be very slim for the WAF calculation. Already have the design done with the Vifas and included a super tweeter with volume adjustment to taste (XO at 14KHz 1st order)
Real men built tweeter arrays--once! Good luck, take your time, make sure all of them are lined up, sealed, wired properly and check about 3 times to counter the natural brain fade of building them.
I got a wild idea the other night for a tweeter line for these line arrays. I'm almost ready to build my Roger Russel inspired line but was thinking what if the high frequency disapoints? I wouldn't want to have to buy a lot of ribbons to solve that problem, let alone wire them all up.
After reading about a paraline project on here I thought maybe that's the solution for a tweeter line requiring a lot less actual drivers and still get a very good dispersion patern.
Look at this thread: http://www.diyaudio.com/forums/multi-way/217298-square-pegs-11.html
That thread is filled with loading midranges into these paraline horns but for a line array you would keep it simple with just one tweeter in each paraline and build an array of those. Haven't done the math yet but it would be a cool way to build your own poor man's Scaena line array with about a 6 KHz single cap crossover...
It would put an end to the comb filtering discussion.
Hopefully the paraline would work well with a dome tweeter, the 6K crossover point would make selecting an affordable tweeter easyer. Plus you get some horn effect to match the line array's sensitivity right?
With the paraline built with a 5mm internal dimension it would theoreticly have good output to 22,666hz.
After reading about a paraline project on here I thought maybe that's the solution for a tweeter line requiring a lot less actual drivers and still get a very good dispersion patern.
Look at this thread: http://www.diyaudio.com/forums/multi-way/217298-square-pegs-11.html
That thread is filled with loading midranges into these paraline horns but for a line array you would keep it simple with just one tweeter in each paraline and build an array of those. Haven't done the math yet but it would be a cool way to build your own poor man's Scaena line array with about a 6 KHz single cap crossover...
An externally hosted image should be here but it was not working when we last tested it.
It would put an end to the comb filtering discussion
.Hopefully the paraline would work well with a dome tweeter, the 6K crossover point would make selecting an affordable tweeter easyer. Plus you get some horn effect to match the line array's sensitivity right?
With the paraline built with a 5mm internal dimension it would theoreticly have good output to 22,666hz.
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Another pioneer NSF Array
I have had these drivers around for a long time (6 years) in the box. I can not afford to buy a better amp for my Avebury system, so I could not help myself but to make some sawdust and build some cabinets for these. I have always been curious about arrays. These cabinets are nothing special at all, really a slapped together mess, the main goal was to get an idea of what an array sounds like.
The first photo shows the driver spacing of some panels I had cut well before I had done any research (like reading Jim's white paper). The goal of these panels was to space the 15 drivers/cabinet to create a floor to ceiling cabinet. Needless to say, that was a waste of time, definate sound phasing issues...
Having the drivers right next to each other (second photo) certainly produced a clearer sound, which justified a stereo listen (photo 3).
Already I was noticing a larger sound feild eventhough the bandwidth was really lacking. However, this proved enough to go for the full 15 line build. (photo 4)
I have had these drivers around for a long time (6 years) in the box. I can not afford to buy a better amp for my Avebury system, so I could not help myself but to make some sawdust and build some cabinets for these. I have always been curious about arrays. These cabinets are nothing special at all, really a slapped together mess, the main goal was to get an idea of what an array sounds like.
The first photo shows the driver spacing of some panels I had cut well before I had done any research (like reading Jim's white paper). The goal of these panels was to space the 15 drivers/cabinet to create a floor to ceiling cabinet. Needless to say, that was a waste of time, definate sound phasing issues...
Having the drivers right next to each other (second photo) certainly produced a clearer sound, which justified a stereo listen (photo 3).
Already I was noticing a larger sound feild eventhough the bandwidth was really lacking. However, this proved enough to go for the full 15 line build. (photo 4)
Attachments
Listening Impressions
The 15 driver arrays had a much better mid-bass presence, and as expected, a high roll-off. I also found the mid-treble quite shouty and the low bass lacking all together. None the less, I really liked the big sound scape.
Using test tones and chomatic scale, I used the EQ in Foobar to remove the shout at around 2kHz, (-4dB) the extra bass at around 125kHz (-3dB), add some treble gradually up to 10kHz (+6dB) and low bass at around 77kHz (+4dB) and 55kHz (+8dB). This turned out surprisingly well. Almost as good as my Avebury System. The Avebury wins hands down on low bass, and a more refined treble. (I built this with the Alpair12 enabled). But when it comes to enjoying music, these "stupid cheap arrays" sound really good, better then they perhaps deserve to when compared to baltic birch all out Avebury build! Do not get me the wrong, the Aveburys put out a big sound scape also, however the main diference is, and it is an important one:
When I hear the Avebury (point source) the music is "over there" like you are sitting in the back row at a concert.
When I hear this slapped together Array, the music is "right here" and I REALLY like that! I want to get up and dance (although I have to watch when I stand, as my ear goes just above the array, where you hear a significant SPL decrease. So what you read about in line array theory is true. The sweet spot is larger. And yes, they go "swish" with certain sounds in trance music too. But when you are sitting or even dancing, this is really no big deal at all. My Avebury system sounds diferent all over the place, so in that way, the array wiht its comb filtering is more even thru out my room! Do not get me wrong, if you want as big of a band width as possible from a six inch driver, build the Avebury. But I tell you what, I am kind of thinking I would like to persue this line array idea some more. I would like to try a better driver, something with a more refined high and something I can push thefelt lows on more. I still want to stick with full-range, as I am sold on that concept, although I would not be completely heart broken if I need subs at 40Hz and below!
I have a feeling also that I can get better bass from this current build if I build the cabinets better, as in unscrew them and actually glueing them! Yes, you read that right, this was all 100% a no loss, cheap skate, half ^$$@) build! But it has proved its worth, not nesicary a baltic birch build, but awell built recycled wood well build, atleast something I can share photos with. And I can tell you this, after cutting all those holes and doing all that wiring, no point messing around, get good wood, and use good wire (I used cat 5) - (thankfully, that part is glued and done proberly!)
At this point, I am debating whether to sell my Avebury system to pursue a better line array build.
My system is PC based using Foobar for music and media player for DVD (no EQ on the movies thou -) I am using a M-Audio fast-trac Pro outboard DAC and the speakers are being driven buy 40 watt Peter Daniel Chip Amp kits - another advantage of the Arrays - higher sensitivity!I am listening to the arrays nearfeild in a 10 X 14 foot room.
All and all, this has been quite fun!
Allen
The 15 driver arrays had a much better mid-bass presence, and as expected, a high roll-off. I also found the mid-treble quite shouty and the low bass lacking all together. None the less, I really liked the big sound scape.
Using test tones and chomatic scale, I used the EQ in Foobar to remove the shout at around 2kHz, (-4dB) the extra bass at around 125kHz (-3dB), add some treble gradually up to 10kHz (+6dB) and low bass at around 77kHz (+4dB) and 55kHz (+8dB). This turned out surprisingly well. Almost as good as my Avebury System. The Avebury wins hands down on low bass, and a more refined treble. (I built this with the Alpair12 enabled). But when it comes to enjoying music, these "stupid cheap arrays" sound really good, better then they perhaps deserve to when compared to baltic birch all out Avebury build! Do not get me the wrong, the Aveburys put out a big sound scape also, however the main diference is, and it is an important one:
When I hear the Avebury (point source) the music is "over there" like you are sitting in the back row at a concert.
When I hear this slapped together Array, the music is "right here" and I REALLY like that! I want to get up and dance (although I have to watch when I stand, as my ear goes just above the array, where you hear a significant SPL decrease. So what you read about in line array theory is true. The sweet spot is larger. And yes, they go "swish" with certain sounds in trance music too. But when you are sitting or even dancing, this is really no big deal at all. My Avebury system sounds diferent all over the place, so in that way, the array wiht its comb filtering is more even thru out my room! Do not get me wrong, if you want as big of a band width as possible from a six inch driver, build the Avebury. But I tell you what, I am kind of thinking I would like to persue this line array idea some more. I would like to try a better driver, something with a more refined high and something I can push thefelt lows on more. I still want to stick with full-range, as I am sold on that concept, although I would not be completely heart broken if I need subs at 40Hz and below!
I have a feeling also that I can get better bass from this current build if I build the cabinets better, as in unscrew them and actually glueing them! Yes, you read that right, this was all 100% a no loss, cheap skate, half ^$$@) build! But it has proved its worth, not nesicary a baltic birch build, but awell built recycled wood well build, atleast something I can share photos with. And I can tell you this, after cutting all those holes and doing all that wiring, no point messing around, get good wood, and use good wire (I used cat 5) - (thankfully, that part is glued and done proberly!)
At this point, I am debating whether to sell my Avebury system to pursue a better line array build.
My system is PC based using Foobar for music and media player for DVD (no EQ on the movies thou -
) I am using a M-Audio fast-trac Pro outboard DAC and the speakers are being driven buy 40 watt Peter Daniel Chip Amp kits - another advantage of the Arrays - higher sensitivity!I am listening to the arrays nearfeild in a 10 X 14 foot room.All and all, this has been quite fun!
Allen
Attachments
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Hmmmmm.... Maybe I posted my system in the wrong thread....
Chech this out!
http://www.diyaudio.com/forums/multi-way/23208-system-pictures-description-221.html#post3207732
James.
Chech this out!
http://www.diyaudio.com/forums/multi-way/23208-system-pictures-description-221.html#post3207732
James.