[Jose R.]

I have now completed my third (and most ambitious  ) line array project and thought I would share this with you.
My first line array in 2006 was a two way with Eton 5.5" mid-woofers and Fountek ribbon tweeter - really enjoyed them and this got me hooked on line arrays and open baffle mids.
I then moved to better drivers and made a two-way with Scan 6.5" Illuminators and Raal ribbons in 2009 - an improvement but was not totally happy with the upper mids and felt that the two drivers did not mate well between 1K and 3K.
Earlier this year I began to think of a three-way array and was intrigued by the BG Neo-10 drivers which I managed to get hold of.
Fortunately I am friendly with the owner of a top-class engineering company who agreed to build the baffles and box which I designed.  I decided to go for aluminium due to its rigidity and tonal qualities as I had been dissatisfied with my previous MDF efforts.  He did a superb job on the boxes and he decided to used high-quality aluminium (aircraft-grade). These weighed about 100Kg each without drivers!  Adding the drivers, each weighs about 140Kg...   They are very rigid and do not ring or vibrate - I still need to do some vibration analysis for my own interest.

I have not been able to upload images to this post but pics can be seen in my gallery with notes explaining the pics

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=5111

I am fortunate to have Tact Audio digital amps with very flexible crossovers, delays etc thus setting up the speakers has been relatively easy.  I am using 4th order crossovers at 420 and 2600 and also have stereo JL Audio subs which work up to 60Hz.  I also use a Tact Audio TCS3 with digital room correction - I cannot imagine my system without room correction and in ambitious projects like this it is a must have IMHO.
I am very happy with the results thus far - much better than my previous builds and I am very impressed with the BG planars which cover most of the midrange.  I am runing these open but with a bit of absorption of the rear wave.  The Scan woofers are sealed but I have got removable back plates so that I can run the woofers open (basically a U-Baffle).  Both solutions sound good but the closed woofers sound a bit more focussed.
The 3-way array has been a major step up compared to the 2-way IMHO.
The major improvement has been a marked increase in the clarity, tonality and refinement of the sound.  Imaging and soundstaging are the best I have had (and heard).  The aluminium seems to work much better than my previous MDF efforts and the weight is probably also playing a major role.  In terms of cost, the aluminium is not as crazy as I anticipated and considering the cost of the drivers I have used, it was fairly inexpensive.


Regards

Jose

[studiotech]

Those are fantastic!  I feel a little inadequte with only one Raal and 2 Neo10 per side on my baffles.   
I tried many other cone drivers for my project also, but found the Neo10 the most suitable for matching the Raal too.  Thank goodness they are finally for sale to DIY!  I'd love to move up to a full room correction system in the future, but I will wait for another generation of products to be released before making that jump.  I think in the next several years we will see many more and cheaper choices as the tech becomes more widespread.  With the TACT gear, can you keep all other processing engaged and only turn on/off the room correction function?  If so, what are you impressions of the differences?

Looks like the terminals on your Raal are on the back rather than the top?  Was this an option I did not know about?


Congratulations of a state of the art build.

Greg

[Russell Dawkins]

That's a hefty investment in drivers!! 

I am curious as to how you wired the ten Eton drivers in the first array.

[JohnR]

Impressive work I'd be very interested to read about how you do the vibration analysis.

BTW to insert an image, click on this button:



Then you can select an image already in your gallery here:



Or upload a new one:

[Jose R.]

I'd love to move up to a full room correction system in the future, but I will wait for another generation of products to be released before making that jump.  I think in the next several years we will see many more and cheaper choices as the tech becomes more widespread.  With the TACT gear, can you keep all other processing engaged and only turn on/off the room correction function?  If so, what are you impressions of the differences?

Looks like the terminals on your Raal are on the back rather than the top?  Was this an option I did not know about?


Congratulations of a state of the art build.

Greg

Thanks Greg,

I have been watching your equally impressive build with much interest as we have both used the BG's and Raals.

The Tact room correction can be turned on and off at will as it is controlled by the TCS3 which also does the mains (my arrays) to sub crossover.  The TCS can control 16 channels.  The digital crossovers for each component of the arrays are stored in the 3 Tact  Boz 2200 amps and remain unchanged.  The difference between room correction on and off is literally night and day!  I have been using Tact products for the last 9 years and cannot imagine having a system without it.  Before I started using it, I went through the whole process of speaker positioning, amps, cables, cones etc in a dedicated room I built - room correction was the only thing that made a massive difference.  It still amazes me to see people using "tweaks" to correct sound when, IMHO, the differences are of the order of a few percent difference whereas room correction is orders of magnitude....

The Raal ribbon module was made for me by Aleksandar of Raal Ribbon in 2009 and he put 8 of the 140-15 units on an aluminium frame.  The units were put together by him thus I guess he modified them to have the terminals on the back as it would be easier to wire them. BTW they are 32 Ohm units so that 8 in parallel give me an overall impedance of 4 Ohm.

Regards

Jose

[Jose R.]

That's a hefty investment in drivers!! 

I am curious as to how you wired the ten Eton drivers in the first array.

Hi Russel

Yes, quite an investment over the years    I have however been able to re-use all of the Eton and Fountek drivers for my surround mini-arrays, and the Scans and Raals were used for the current build.
I used power tapering to wire the 10 Etons as per Griffin's paper on line arrays for an overall impedance of about 4 Ohms IIRC.  I will post the pics to my gallery.

Regards

Jose

[Jose R.]

Impressive work I'd be very interested to read about how you do the vibration analysis.

Hi John

Thanks, I tried to insert the pics into the body of the post as you indicate but it seemed to cause the post to hang and that is why I linked to my gallery.
I got the ACH-01 accelerometer from Digikey but have not yet wired it up as suggested in the MH-audio site http://www.mh-audio.nl/tips%5Cach-01.htm
I still have to play around with it and am not sure what program to use to show a waterfall plot - do you have any suggestions?  I also got the Dayton Audio OmniMic Precision Measurement System but this uses the USB microphone and I need a program that will accept the computers mic in which I will connect the ACH-01 to.
I will post the vibration analysis once I get it figured out.

Regards

Jose

[studiotech]

Thanks for the info Jose.  Are you considering using some type of sticky sheets like Dynamat on the walls of the aluminum?

Greg

[Tyson]

Wow, amazing!  I love OB speakers, and I love line arrays, but I've never heard an OB Line Array before.  How would you characterize the sound vs a "regular" OB, and a "Regular" line array?  Or, vs. a conventional box speaker, for that matter....?

Re: pics - you can also upload your pics to photobucket for free, and then just link them in the original post.

[Jose R.]

Thanks for the info Jose.  Are you considering using some type of sticky sheets like Dynamat on the walls of the aluminum?

Greg

Hi Greg

I used bitumen sheets which I guess are similar to Dynamat on the 6mm plates separating the woofer divisions which had a higher pitch than the 12mm plates used for the baffle and sides.  Inside the woofer compartments I used Dynamat type 30mm foam on one side and 25mm Mellatech foam on the other three sides.  I also use the Mellatech foam behind the BG planars to attenuate the back wave - here the Dynamat type was a bit too restrictive.
Still can't seem to attach images from my gallery to the post - get the dreaded spinning wheel which doesn't go away 

Regards

Jose

[Jose R.]

Wow, amazing!  I love OB speakers, and I love line arrays, but I've never heard an OB Line Array before.  How would you characterize the sound vs a "regular" OB, and a "Regular" line array?  Or, vs. a conventional box speaker, for that matter....?

Re: pics - you can also upload your pics to photobucket for free, and then just link them in the original post.

I went straight from conventional speakers to a line array and, from the stuff I read about open baffles, I decided to keep the woofers open - I had always used corner woofers from 60Hz to about 200Hz thus the rapid roll off of the open baffle woofer array could be compensated for.
I have never built a conventional open baffle like the many described on this forum so cannot really comment on how they compare.  I do however feel that line arrays have a certain magic which have hooked me and the open baffle arrangement could be combined.  All three arrays I have made have had open baffles, for the first two only the mid-woofers were open but in the latest one I have the mids open and an option to have the woofers open or sealed.  As the Scan woofers now cover 60Hz to 420Hz, I prefer the sound with them sealed at the moment - better focus to the imaging.  Thsi may change in future - its great to however have options 

My images are in my gallery folder
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=5111

Regards

Jose

[Jose R.]

I have added more pictures to my gallery which show the stuff I have been trying to explain

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=5111

Regards

Jose

[Ric Schultz]

Very cool!!!!!  I will be doing something similar by the end of the year.  But first I am making a speaker with just 2 BG10s and one BG3 in between.....using 2 GR Research servo 12s for the bottom.  Using highly modified Behringer xover.  All open baffle.  I have most of the parts here and should have it up for demo in about one month.  I will be A/Bing with some seriously expensive speakers.  This is going to be fun!

Later will have a bigger system using a separate baffle for mids and highs utilizing 6 BG 10s and 18 BG3s with possibly a Raal in the middle of the array for a super tweet (and maybe an option for what you are doing--all RAAL tweets).  There would be 4 12 inch servo woofs per channel in the biggy.  Two highly modified Behringer xovers.

Triamping using the modified Behringers gives what he said.....way better sound.  You can equalize the speaker for super flat response at your listening postion.  However, its the bass eq that makes the most difference.  No bass nodes and dips and super clean sound all the way up the scale.  A must for super serious listening.

Someday we will have high-end receivers with built in triamping, xovers and room eq.....then this kind of sound will be available for way less.

Both these speakers are going to be commercial products but I will share every tiny thing I do with everyone so it could be copied by DIYers (including details of the modified xover).  The smaller speaker will be something like $7500 and the larger one would be at least $16,000.  This is all wholesale direct.

The only thing I can suggest for you is to felt around all the mids and tweets (more focused, less bright and purer sound) and to remove any binding posts and speaker wire terminations (spades, bananas, whatever).  A seriously big jump in transparency comes from getting rid of the binding posts and spades.

You have a seriously world class speaker, my friend.  Enjoy it for years!

Oops, forgot to mention that you could brace all the magnets of all the woofs together using two long aluminum bars (epoxy one on each side of the vent hole on each of the woofs).  I bet this would be mind blowing!  I am going to brace the magnets on the 17lb. GR Research servo woofs. 

[Tyson]

Ric - rather than a multiple modded Behringers, you might want to check out the latest 2x8 board from miniDSP - They said they would be putting it in a box pretty soon.  It's built for consumer voltages, unlike the DCX which is built for pro voltages.  Also, less need for mods since it's built better in the first place than the DCX.  It has all the same functionality of the DCX and it can be used as a 4 way crossover from a single box.  Plus it's got a built in option for an analog volume control, and the ability to add a digital input board for 2 digital inputs along with the standard 2 analog inputs.  Theoretically you could use this as a single plug & play preamp for 2 digital sources and one analog source.  How cool is that? 

All I know - once they case it up in a box standard, my DCX is going up for sale.

http://www.minidsp.com/onlinestore/detail/7-minidsp-kits/flypage/73-minidsp-2x8-kit?sef=hcfp

Sorry about the thread jack, Jose...

[Jose R.]

Very cool!!!!! 
Someday we will have high-end receivers with built in triamping, xovers and room eq.....then this kind of sound will be available for way less.

The only thing I can suggest for you is to felt around all the mids and tweets (more focused, less bright and purer sound) and to remove any binding posts and speaker wire terminations (spades, bananas, whatever).  A seriously big jump in transparency comes from getting rid of the binding posts and spades.

You have a seriously world class speaker, my friend.  Enjoy it for years!

Thanks Rick - coming from you this is high praise indeed and much appreciated.  I have followed your builds over a long time with much admiration and have learnt a lot from what you have done with line arrays etc - I am certain that you will come up with some seriously good speakers as usual

Your suggestion on the felt is spot on - I have made theaded holes on the baffle to allow me to fit a 3mm aluminium cover plate which will be backed by some thin neoprene foam to allow it to compress over the rivets on the BG planars.  The cut-outs on the cover plate will only show the active parts of the drivers which should at least look cool  .  I will need to measure and listen to see whether the plate does any damage even though it is thin.  Aleksandar felt that this additional "wave guide" would not be a good idea but I will still give it a try.
I then plan to play around with felt over the whole baffle to hear what it does. 
The great thing about my latest build is that it has given me a lot of options to play around with - perhaps too many....  Still it is fun.
I totally agree with you that DSP is essential and that in years to come we will wonder why it took so long to implement
The speaker wires are all soldered directly to the wiring except for the woofer cables as I wanted to be able to remoce and replace the back cover easily while trying out different options.  There are no binding posts on the speakers.
I am amazed at the effect of the aluminium - the sound is clear, detailed, no muddiness and just so much cleaner than I have had before.  The costs are also not crazy if one is looking at really high-end speakers and I can understand why more speaker manufacturers are using it.  It helps to however have a friendly engineering shop....

Thanks and regards

Jose

[Jose R.]

Ric - rather than a multiple modded Behringers, you might want to check out the latest 2x8 board from miniDSP
Sorry about the thread jack, Jose...

No problem at all.  I have looked at various DSP units over time and none of them, IMHO, can do what the Tact stuff does.  My music is entirely digital as are my amps and most other gear has analogue inputs and or outputs which does not suit my purposes.  The Tact Boz 2200 amps for example can only take a digital signal.  I can input analogue signals to the TCS3 of course but from the TCS3 on all remains in the digital domain.
For interest, I use a Slimdevices Transporter and modded M2Tech HiFace for digital inputs and an Oppo 83 for SACD, Blu-Ray etc via HDMI into the Tact TCS3

Regards

[Jose R.]

Very cool!!!!!  I will be doing something similar by the end of the year. 

Hi Rick

Further to my reply and knowing you use of the Scan drivers, I must admit to being a bit disappointed with the 6.5" units on my previous arrays and wondered if the Etons were perhaps not better.  I though I had a decent MDF baffle which was well braced.....
Hearing the Scan Illuminators on the Aluminium baffle has been a revelation and I am now highly impressed with them - fast, detailed and low distortion.  They blend perfectly with the BG planars and I can now understand why they are so highly rated.  I am way impressed 

Regards

Jose

[Tyson]

No problem at all.  I have looked at various DSP units over time and none of them, IMHO, can do what the Tact stuff does.  My music is entirely digital as are my amps and most other gear has analogue inputs and or outputs which does not suit my purposes.  The Tact Boz 2200 amps for example can only take a digital signal.  I can input analogue signals to the TCS3 of course but from the TCS3 on all remains in the digital domain.
For interest, I use a Slimdevices Transporter and modded M2Tech HiFace for digital inputs and an Oppo 83 for SACD, Blu-Ray etc via HDMI into the Tact TCS3

Regards

True, but the miniDSP 2x8 is only $300, and I'm betting the TacT stuff is a bit more

But, back on topic - are you using a passive crossover for the mids/highs? 

[Ric Schultz]

Tyson,
No way a minidsp can compete with an EVS modded DCX.  I replace the whole ADC input stage, the whole DAC output stage, change the whole gain structure, change the XLRs to RCAs, upgrade the ADCs to the latest AKM part and also upgrade the DAC chips to the latest AKM 24 bit DACs....everything direct wired, I do not use the ribbon cables. Optional better regs for the input and output stages, direct wire the digital in using either XLR or RCA, etc. Also, the DCX operates at the better sounding 96K instead of 48K.   Pretty seriously tweak.

Maybe the minidsp could be modded to compete....this I will have to look into.  But stock....no way Jose!



Jose,
I think you have me mixed up with Rick Craig.....he has built many a line source speaker.

[Jose R.]

True, but the miniDSP 2x8 is only $300, and I'm betting the TacT stuff is a bit more

But, back on topic - are you using a passive crossover for the mids/highs?

No, all crossovers are digital - three 2200 amps control the three-way arrays, sub has its own amp but the sub to Mains crossover is digital and done in the TCS.

Yes the Tact stuff is quite a bit more .....