# New Dual Hi Vi D10G 10" Kevlar center speaker build



## Mike Cason

*New Dual Lambda TD12s center speaker build (Upgraded 4-17)*

UPDATE: After listening to my center for a while, I'm not satisified with the Hi Vi 10" drivers. I've just finished a new crossover with a tweeter eq and have a pair of Lambda 12" drivers expected to arrive next Tuesday, April 20th. This will give me dual Lambdas in my mains and my center speaker and the same tweet for good timbre matching.

Woops....I started another build. 

A larger center speaker....

I had most of the materials except a couple of woofers which arrived here today. The initial cabinet is glued and clamped. I'll be using a pair of the Hi Vi D10G 10" Kevlar woofers, my Davis Kevlar midrange driver and my Hi Vi RT2II planer ribbon tweeter. 

The crossover modeled out very well with only 3 capacitors and 3 inductors for this 3 way crossover so DC resistance is down and the response is fairly flat across the -0- line out past 20hz. I had to change a couple of the values of the inductors and capacitors, deviating from Crossover Pro's calculations to get the nice line. I added an additional Sonic Craft Gen II bypass cap in the tweet section. All of the capacitors and inductors are hot glued in place and separated from each other. It has taken 3 days to tweak this crossover to get the numbers I want to see.

It seems like with the newer movie productions, the BluRay material, and even local digital TV, I am seeing more signals being sent to the center speaker. I decided that I needed to upgrade to keep up with the newer programming. 

I think it was Dan Wiggins who posted in one of my threads that the center channel needs to be able to equal the sum of the L & R mains. I'm hoping this design will do that or get close.

I'm using a pair of the HiVi 10" woofers good down to 25hz, crossing them with a 1st order Butterworth at 350 hz, 1st order APC for the bandpass region, and then handing it off to the Hi-Vi tweet with a 3rd order Butterworth upper bandpass corner crossed at 2800 hz. It should be a nice transition with the drivers and crossover.

There has been a lot of discussions about a MTM driver in the horizontal plane causing lobing issues, but Vance Dickason points out that by keeping the woofers crossed low, it would be hard to notice. The other option is some fancy woodwork and point the twin woofers out at 10 to 20 degrees, left & right. I'm not that critical, nor should my guests be.

I'll post more when I can with the progress pictures.


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## BuddahX

Those are some nice looking woofers. Can't wait to see how the center's turn out. Did you build and design your own Crossover? I'm still learning about that.


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## Mike P.

Interesting build! I'm looking forward to your impressions when it's done. What are the cabinet dimensions?


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## Mike Cason

BuddahX said:


> Those are some nice looking woofers. Can't wait to see how the center's turn out. Did you build and design your own Crossover? I'm still learning about that.


Thanks....I like the Hi Vi line of products. I have some M8Ns in stock from previous builds and use their planer ribbon tweeters which have performed very well in my mains and center speaker. They appear to be an upper scale driver company in China with a quality build house and fair pricing. I decided to give these woofers a shot because the numbers are right where I need them. In parallel, I get a 6 db gain so they will work well with the other drivers. 

If they don't sound good enough for me, I'm going to order some Lambda TD10S woofers from AE Speakers if work picks up when I want to change them. I wanted to use the Lambdas to match my mains, but John didn't have any built yet and they are $250 ea vs $105.00 each from Parts Express.

Yes, I do my own crossover work. I did it with pencil and paper for four years with horrible results causing me to rebuild some of my speakers several times and seek out help from others, which I usually don't like to do. I decided to buy a crossover program and it has helped a lot. I don't always go by their calculated values, like this one, so I can change up some of the values of the parts and can get the response I expect out of my drivers.


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## Mike Cason

Mike P. said:


> Interesting build! I'm looking forward to your impressions when it's done. What are the cabinet dimensions?


Hello Mr. Mike...

My inside dimensions are 14.5 x 15.5 x 33".

I'm boxing out a midrange chamber for the Davis midrange to give me a Q of .68 for that driver's enclosure. The tweeter has a sealed back. That will leave me close to 102 liters for the twin drivers giving me a box Q of .82 for the woofers which is a bit high, but my down point is -3 dB is at 40 hz, rolls off nicely, and should be just fine considering I cross over my system at 80hz. If I were to use it as a subwoofer, I would want a larger cabinet of about 180 liters. 

I'm having fun with this one. It is so much easier to work with than the Ultimate 1.1.!

Mike


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## fbov

Mike Cason said:


> Woops....I started another build.
> 
> A larger center speaker....
> ...
> There has been a lot of discussions about a MTM driver in the horizontal plane causing lobing issues,


You're not building an MTM, but a WMTW, and so you're crossing plenty low. Lobing is non-issue as long as the driver spacing is much less than the XO wavelength

And here's a link to some very powerful and popular XO design resources:
http://audio.claub.net/software/jbabgy/jbagby.html

Great start!


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## Mike Cason

fbov said:


> You're not building an MTM, but a WMTW, and so you're crossing plenty low. Lobing is non-issue as long as the driver spacing is much less than the XO wavelength
> 
> And here's a link to some very powerful and popular XO design resources:
> http://audio.claub.net/software/jbabgy/jbagby.html
> 
> Great start!


Thanks,

Yes I've seen Jeffs software before and actually have a link to it in my favorites. It looks like he's improved it a bit more now. He has done a great job. His work is well recognized. 

I used the term MTM because it's mostly recognized that way as far as driver alignment like for a monitor, but you are right, being a WMTW is correct. I could say my mains are WWMMT but that would really confuse folks...:coocoo:

I appreciate the links....


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## 1Michael

I have always wanted to do a build with kevlar cones like Focal but they are very expensive and I have no idea how they sound.


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## Mike Cason

buggers said:


> I have always wanted to do a build with kevlar cones like Focal but they are very expensive and I have no idea how they sound.


The Hi Vi woofers are a combination of paper impregnated Kevlar and the Davis driver is Kevlar. During my build in '04, one of the folks working with me on my first xover design said the (Davis) Kevlar was "hard to tame". I don't know if that was an opening excuse to expect poor results from his help or if there was any merit to it. Focal does a nice job with their drivers and now that I've got my xover where it needs to be, I will give a report on the finished product.

If I don't like it, I can change xover parts till I do. Plain and simple....I think as it is, it's going to have a very good presence across the board and will sound terrific.


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## Mike Cason

I'm working on it as time allows. I've got the driver holes cut out with not much room to spare. I had to make sure I've got room to build and install matching speaker grills to my existing system. 

I need to box in an enclosure around the Davis midrange this weekend. Even with a large center speaker box like this, I'm still cramped for room using the 10 inch drivers. They have an OD of 12". I'll have just one inch left under the TV. 

I think my choice of drivers and the layout will yield me a decent center speaker. :heehee:

Here are a couple more build pics to keep the thread going......


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## 1Michael

Are you sealing both the mid and tweet? No double baffle? You might want to put a strong brace behind the enclosure to the rear wall with all those holes on the baffle.


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## Mike Cason

buggers said:


> Are you sealing both the mid and tweet? No double baffle? You might want to put a strong brace behind the enclosure to the rear wall with all those holes on the baffle.


Michael,

The tweeter is a sealed back planer ribbon which doesn't require any additional attention. My build is far from complete. I won't need a double baffel when the enclosure is finished. There will be a separate midrange enclosure, as noted in my earlier posts, and will be continuous from the front to the rear of the cabinet thus providing a very secure bracing system. 

I have plans for some other additional bracing as well to address Mr. Resonance. I'll provide more photos as the build progresses. Please check back later.

Here is my recently completed build:
http://www.hometheatershack.com/for...trom-21-4-2100-gram-18-passive-radiators.html


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## evilskillit

Lookin very good so far, tho those yellow drivers jump right out at you. You'll probably want a grill to keep them from distracting you from the image on screen


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## Mike Cason

evilskillit said:


> Lookin very good so far, tho those yellow drivers jump right out at you. You'll probably want a grill to keep them from distracting you from the image on screen


Thanks and that is a good point. I've thought about that a lot. I think it would be smart to just sell the TV and watch the speakers. I could save some money on the electric bill.:spend:

I have two of the Davis Kevlar speakers behind the grill in my original center speaker under the TV in the photo, and will be covering the new speaker with the same material. You don't hardly notice them at all. The tweeters are barely visible. I have plenty of material in stock along with new gold name plates that are ready to install.


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## 1Michael

Nice build, I like Big speakers:T Unlike you I am very happy, willing, and able to rip off other peoples speaker designs :whistling: And I don't appologize for it neither :neener:
Some day I would like to move into the Xover designing thing, but for now I'll just take my designs from you guys


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## Mike Cason

buggers said:


> Nice build, I like Big speakers:T Unlike you I am very happy, willing, and able to rip off other peoples speaker designs :whistling: And I don't appologize for it neither :neener:
> Some day I would like to move into the Xover designing thing, but for now I'll just take my designs from you guys


Michael,

You don't have to feel that you are stealing ideas here at the Shack. :rolleyesno:

You will find that most of us, if not all members here at the Shack are happy to share our DIY designs with others. That's what this forum is all about. :T Our members contribute a lot of design information with other DIYers and are located all around the world.

If I were into production runs of one of my designs, I would not share as much or any information about my builds in the forums. I would simply show my finished speaker, maybe the drivers used, and the finished speaker's parameters with a response graph. I find that some companies give out too much information, and others don't offer any, other than the speaker's specs. The DIY forums fill that gap, especially here at the Home Theater Shack.

Good luck with your builds...


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## Mike Cason

The cabinet is coming along slowly. I have to wait 24 hours between the gluing & clamping for each step. I've finished the sealed midrange cabinet and got creative with my bracing. I will utilize the space between the holes to secure some left over Sonic Barrier to the top of the midrange box and add some a small amount of polyfil. This will allow both woofers to share the same cabinet space.

I need to keep the crossover as far away from the rear of the R woofer's magnet as possible, so it will be mounted near the back of the cabinet on the midrange box. The woofer will have to be removed to service or change it, so this location should work out well. I'll provide it with some isolation from the cabinet's vibration.


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## lsiberian

You know you can get extreme off-axis response with the faceplate removed on those HiFi tweeters.


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## Mike Cason

lsiberian said:


> You know you can get extreme off-axis response with the faceplate removed on those HiFi tweeters.


Thanks for the tip. I have the tweets mounted high in the mains, but they are far enough away (12'), so we hear them fine. My intention is to point up the center speaker about 12 degrees like I always have so I am on axis with it. I really like your suggestion. I may tinker with it to see how nicely I can mount it in the center speaker first. I may be able to leave it in plane with the mains that way.


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## Mike Cason

More progress today....

I have screwed the crossover down flat on a piece of Sonic Barrier to absorb any cabinet vibration and have used rubber washers under the screws to add a bit more isolation.

I used the Audience Auric #18 gauge interconnect wiring with silver solder for all of my crossover pre-wire connections to the drivers. Please don't post any "snake oil" negative comments about the interconnect wire as it always gets into a heated debate. As an Audience dealer, I personally use the Auric wire on my builds and my finished products sound great! The A3 drivers work extremely well with this very fine wire. The #18 gauge Auric wire will handle 200 watts. I've run my wires to each driver with a gentle twist to reduce induction. My inductors are also 18 gauge.

My careful work with the table saw gave me a very tight fit for my last piece of MDF, the top. It wedged in nicely and I've got it clamped for another 24 hours. All of the inside corners have been glued and siliconed. I have used a glue up and a 1.5" long X 1/4" double brad nailed construction for all my joints. 

The last and most fun part is the final hole filling and leveling, then sanding it getting ready for the laminate work. 

The project is coming along much faster than anticipated.


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## speedie

what software do you use for xo design?
i am using xover pro 
i was wondeing if there is any difference in values from program to program


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## Mike Cason

speedie said:


> what software do you use for xo design?
> i am using xover pro
> i was wondeing if there is any difference in values from program to program


I use Crossover Pro 3. Be sure to regularly check for driver updates that have all of the new drivers' T/S parameters. This program works with Bass Box Pro as well, but I didn't buy it. 

Yes there are some differences between programs. I'm not familiar enough with the high tech ones to use them, so I adjust my xover parts to get my desired cutoff points after my initial modeling.

I've just finished the laminating. Tomorrow I'll do the finish work on the corners, install the dampening material, and drivers. If all goes well, the grill frames will be at least started.

That leaves Saturday to finish the fabric and nameplates. Seven part time days to build and get to this point. Not bad with the cold weather and a couple of other jobs I've had to do.

Rock on.....


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## mdk2008

Man that looks like a serious center! Cant wait to hear some listening impressions! Great work


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## Mike Cason

mdk2008 said:


> Man that looks like a serious center! Cant wait to hear some listening impressions! Great work


Thanks....I like big sound....I don't want to go out to listen to a band or music concert, so I want them to come over and perform for me in my L/R home theater. That is why everything is overdone. Movies are outstanding with my new 21" sub!

I've just sweetened the pot with this new 50 lb. 3 channel XPR-3 Emotiva 300 watt per channel amp @ 4 ohms to drive the mains and the center channel. I'll let the Denon 5308CI(A) handle the surrounds and center backs thus allowing it to run cooler and giving me more presence out of my front speakers. The AVR should last longer running without that heavy load on it and the excess heat. My other center speaker had a 3.2 ohm load which is hard on HT gear if it isn't designed for it.

I will have it finished today, except for maybe the grills. I'll be sure to post more pics....:wave:


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## Mike Cason

Drum roll.....:clap:

It's finished and in the home theater now. Usually most DIYers said that their builds sound fantastic, so to be in compliance with everyone else, I'll have to say it is fantastic, and then some!

I listened to regular TV for the vocals and the newscasters' voices, and they sounded like they were in the living room with me. I popped in a Santana DVD with guest Sarah Mclaughlin at the piano and really put this baby to the test in in 5.1, Dolby Digital, and a couple of other surround sound modes the Denon offers and this center speaker passed all the tests. I played a few more tracks and I'm very happy with the improved sound.

Now, as far as any vertical off axis issue on the Hi Vi tweet, there is none. I may just put a single 1" x 2" board under the front of it tomorrow when I finish up the grill, but it really doesn't need it. Sitting in the LazyBoys at 12 feet, I don't notice any off axis problems with any of the drivers. The sound is full and robust, and the high frequencies are very clean and crisp.

Here are a couple of pics, and when the grill cover is finished and I can get my tripod out, I'll take a couple of more pics with the new system finally complete; at least for now.


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## 1Michael

Nice build:T


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## Mike Cason

buggers said:


> Nice build:T


Thanks Michael...:wave:


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## Mike Cason

Ok, Last set of finished pics....The bright yellow Kevlar is nicely hidden now! Thanks for looking! :T


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## speedie

what are your main speakers? diy also and from the pics it appears that there are three towers? 
how does the emotiva amp proform we dont see them here in aussie i looked up there site and it appears that they have a seven channel beast 
i will post some of my speaker builds as they progress
i am planing a seven one system using vifa and peerless products 
cheers speedie


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## Mike Cason

Speedie,

They are all my DIY projects in the fronts and I redesigned my B & O surrounds. You can visit my website at and read all about each of them. I have them listed in my index to the left. I don't have all my builds posted here.

Start a new build thread with your projects under DIY speakers for us. We all like new projects and ideas. I love the Emotiva. It sounds better than my Rotels I've owned over the years, runs very cool, and they have been around for about 12 years now I beleive. I think there is also a 3 year warranty.

Cheers,
Mike



speedie said:


> what are your main speakers? diy also and from the pics it appears that there are three towers?
> how does the emotiva amp proform we dont see them here in aussie i looked up there site and it appears that they have a seven channel beast
> i will post some of my speaker builds as they progress
> i am planing a seven one system using vifa and peerless products
> cheers speedie


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## Paul P

Mike Cason said:


> I love the Emotiva. It sounds better than my Rotels I've owned over the
> years, runs very cool, and they have been around for about 12 years now I beleive. I think there is
> also a 3 year warranty.


It looks like it's a five year warranty. Where are the Emotiva products built ? I've searched their
website and found nothing. The prices are sure interesting, for example a 5 x 185w rms (4 ohms) 
amp for 550 $US.

Paul P


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## 1Michael

So how do those kevlar cones sound?
The first electronics upgrade to my system is going to be the Emotiva XPA5. It seems there are a lot of happy campers with their amps.


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## Mike Cason

buggers said:


> So how do those kevlar cones sound?
> The first electronics upgrade to my system is going to be the Emotiva XPA5. It seems there are a lot of happy campers with their amps.


Hey Michael...

Overall they sound great. I would have preferred to get the Lambda's like I have in my mains in the 10" model, but they are $130 more each. I think if these Hi Vi woofers had the Lambda motors, they would be vastly improved. After I finished and tested them in my shop, I found them to be out of phase. I thought I messed up my crossover wiring or design. I pulled the one out in the crossover compartment and low and behold, the speaker coil was wired backwards in the driver from the factory. I had to switch polarity. I also noticed the same thing in my Davis Kevlar driver. The positive was marked with a red paint and it too was reversed. This has taught me to use my "D" cell battery I've got wired up to check the polarity on all of the drivers in my future builds. For a center speaker, the pair of Hi Vis sounds great. If I were build new mains, I wouldn't use this cheap of a driver.

As far as the Emotiva, my first impressions came from my view of the inside photographs they have on their website. They have done an excellent job with their product line. A 50+lb amp for three channels? There is a lot inside of the cabinet. I had to replace a board inside of one of my Rotels so I could upgrade my eprom chip. I know the tech at Rotel so he sent me the board because their warranty shop in Houston couldn't fix it, so I've been inside of them and have seen their build, by the way, is quite good. They do run hot if you crank 'em up though. I have a cooler mounted on my Emotiva that I really don't need now that I sold the Rotel. The Rotel would shut down on me at high SPL. It could have been my 3.2 ohm load that my old center speaker had. I'm just using it for added cooling set to low speed so it's not noticable. No sense in storing it.


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## Mike Cason

Paul P said:


> It looks like it's a five year warranty. Where are the Emotiva products built ? I've searched their
> website and found nothing. The prices are sure interesting, for example a 5 x 185w rms (4 ohms)
> amp for 550 $US.
> 
> Paul P


They may be built in China or Mexico, but here is their company's address. As heavy as they are, and their price tag, I doubt that they are made in China due to the export duty there and the import duty here coupled with the transportation cost. I've bought a couple of pallets of drivers from China and it was expensive to get them here.

Emotiva Audio Corporation 
131 Southeast Parkway Court
Franklin, TN 37064

615-790-6754 | 877-EMO-TECH (877-366-8324)


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## speedie

Mike when you use xover pro do you include the equilisation feature for flattening the graph the part of the program where it asks if you what to include box effects etc
it seems that there are a lot more caps and inductors than other programs designs?
i noticed that your crossover hasnt got too any parts
i would think that some of the latest jeff beck stuff would sound good on your system!
cheers to more beers speedie


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## Mike Cason

speedie said:


> Mike when you use xover pro do you include the equilisation feature for flattening the graph the part of the program where it asks if you what to include box effects etc
> it seems that there are a lot more caps and inductors than other programs designs?
> i noticed that your crossover hasnt got too any parts
> i would think that some of the latest jeff beck stuff would sound good on your system!
> cheers to more beers speedie


Hi Speedie....

No I don't. I include all of the T/S parameters I can load about my drivers and see where they plot out at first. I try to keep the impedance line at 12 ohms. Even though my graph has 3000 hz for my bandpass upper corner entered into what I'm pretending to look for, I really wanted the 2800 hz, so I enter different cap and inductor values until I get the plot line I'm seeking. It's probably not the best way to do it, but it works for me. By getting the drivers with the right sensitivity at first, that makes the crossover work easier. Doubling my woofers, adds about 6 db, I didn't need bandpass boost, and my tweet ended up about 1 or 2 db higher and I'm pleased with the results. I think less components with a well matched set of drivers is better considering DC resistance. A crossoverless loudspeaker is ideal. I used a 3rd order butterworth on the tweet.

Hey....anything sounds great on the system now! Even low organ music. I've got some SACDs of Fredrick Fennels organ material and it's outstanding. Hard rock, Jazz, Blues with very low bass and everything else I throw at it blows you away with the quality. The Houston DIY group has been here and loved it.


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## speedie

I love a man that is passonite about sound
hay i finally got my front and rear
baffles but from the cnc dude just to check that i was happy with the cutting and routing as these where cut out of scrape now i can order the real deal 19 mdf veenered board in tasmanian oak
i must say that my enthusasim has come back to get in and finish this project that i started about one year back i have had the speakers sitting in my cupboard for too long a have hand wound my inductors so it might happen in a hurry now!
i will start a new post as you mentioned and let you know where to look
thanks for your input man
ps my computer had a main hard drive come windows failure and i lost all of my hard work that was done on bass box and xover pro dont you just hate not backing up to that external hard drive:hissyfit:
cheers to more beers speedie:T


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## speedie

mike just read your profile and we have more in common as i am a air con refridge contractor funny hay
also a really keen micro brewer just love that full mash:dumbcrazy:


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## Mike Cason

speedie said:


> mike just read your profile and we have more in common as i am a air con refridge contractor funny hay
> also a really keen micro brewer just love that full mash:dumbcrazy:


I was too for many, many years. Residential and commercial. Low, medium, and high temp refrigeration and ac systems up to 7.5 tons. Quit the brews but enjoy.....

Looking forward to your build posts and get a USB Western Digital back up hardrive and use it once a month. Saves a lot of misery later!

Mike


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## speedie

Mike
I finally got a quote back from the machinist and i must say that after all the input from both parties i am disappointed with there quote of $874.50 aus to supply what i desinged in flat pack ie non assembled
i asked for a budget pre cconception so as not to waste too much time but it was not forth coming
so here i am at the stage of cuting out all my own baffles from scratch then having to veneer them 
such is the life of a diyer!addle:


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## erwinbel

Mike Cason said:


> They may be built in China or Mexico, but here is their company's address. As heavy as they are, and their price tag, I doubt that they are made in China due to the export duty there and the import duty here coupled with the transportation cost. I've bought a couple of pallets of drivers from China and it was expensive to get them here.
> 
> Emotiva Audio Corporation
> 131 Southeast Parkway Court
> Franklin, TN 37064
> 
> 615-790-6754 | 877-EMO-TECH (877-366-8324)


Emotiva makes no secret of the fact that everything is indeed made in China. I am in Belgium and recently bought a pair of XPA-1 monoblocks (1000 Watt/4ohm) for my Jamo R909's and added a ERC-1 CD player because it was to cheap not to. I really like that you buy from people instead of from a big company with anonimous shareholders. They make products for other brands too, that's how they started.
The monoblocks stay ultra cool, can't believe it. Emotiva will be getting many more purchases from me, starting with their DAC that is imminent (only 300$ and it has volume control and balanced outputs!). They advertise here if anyone wants to check them out.

BTW, I read your threads on this C and your Maelstrom too. You're a proper nutter!:coocoo:
I will be building my own pair of LLT Maelstrom 18" soon. Your opinion on the LLT principle? M-21 for LLT would be a bad idea? Mike P is helping me a lot, the design is finished (unless we go for the M-21). I can go up to 720 liter gross. We are at 550 liter with the M-18. I want clean, even effortless bass.


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## Mike Cason

erwinbel said:


> Emotiva makes no secret of the fact that everything is indeed made in China. I am in Belgium and recently bought a pair of XPA-1 monoblocks (1000 Watt/4ohm) for my Jamo R909's and added a ERC-1 CD player because it was to cheap not to. I really like that you buy from people instead of from a big company with anonimous shareholders. They make products for other brands too, that's how they started.
> The monoblocks stay ultra cool, can't believe it. Emotiva will be getting many more purchases from me, starting with their DAC that is imminent (only 300$ and it has volume control and balanced outputs!). They advertise here if anyone wants to check them out.
> 
> BTW, I read your threads on this C and your Maelstrom too. You're a proper nutter!:coocoo:
> I will be building my own pair of LLT Maelstrom 18" soon. Your opinion on the LLT principle? M-21 for LLT would be a bad idea? Mike P is helping me a lot, the design is finished (unless we go for the M-21). I can go up to 720 liter gross. We are at 550 liter with the M-18. I want clean, even effortless bass.


The LLT is one type of subwoofer that I've never built, but I've always heard that if done properly it should perform extremely well. These Maelstroms and the motor that drives them are intense, so what ever you build, use thick material for your cabinet and ducting to say goodbye to Mr. Resonance.

Thanks for your input on the Emotiva. I've had it for about 4 months now and am a solid customer for life! It is incredible. I've got the Supercharger 3 channel, 4 ohms, for 300 watts of very clean and detailed power.

Mike


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## Mike Cason

erwinbel said:


> BTW, I read your threads on this C and your Maelstrom too. You're a proper nutter!:coocoo:
> QUOTE]
> 
> I'm not sure of the term "proper nutter", but it probablly does apply to me!
> 
> Well, after a few months of listening to music and watching movies on Netflix, then plugging in some high quality DVDs and BluRay discs, I'm finding my new Hi Vi 10" woofers are not as good as I initially posted. My gear is high end and it really brings out the best, or in this case, the worst in my speakers. My mains have extremely good imaging and coupled with the more audio I'm getting out of the larger center speaker, it did sound better, but falls short of what I like to build. I don't normally use cheap drivers, but the economy is tough so I went with the HI VIs.
> 
> I've got a pair of the Lambda TD12S midwoofers in each of my mains so I think I'm going to step up to a pair of them for the center speaker. The cutout hole of the HI VI is 10" so the mounting screws of the Lambda 10" driver will be too close to the edge of this hole. I won't be able to secure the driver well.
> 
> I'm waiting on a quote back from John J at AE for the pair of TD12s.
> 
> Legacy uses a pair of Aura 12s in their Marquis HD center which sells for $3,200. To have matching pairs of the Lambdas in the mains and center with matching planer ribbon tweets, I should be happy with the upgrade. I've got to run the numbers on my cabinet's volume which should be ok.
> 
> UPDATE: 4-13-10 I've found a pair of 4 ohm TD12S drivers at AE speakers that I've committed to. I hope to have them in next week. They will match the dual 12s in my mains.


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## looneybomber

Mike Cason said:


> I guess if I do end up with a pair of the 12" Lambdas in my center speaker, I really fall into that "proper nutter" category even deeper!
> 
> I'm waiting on a quote back from John J at AE for the pair of TD12s.


Too bad your enclosure wasn't bigger. I have a pair of TD15h's I'm gonna have to sell...but then you'd have to upgrade your L/R's and your subs..:T


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## Mike Cason

looneybomber said:


> Too bad your enclosure wasn't bigger. I have a pair of TD15h's I'm gonna have to sell...but then you'd have to upgrade your L/R's and your subs..:T


Thanks for the offer. I did check with AE's website and there isn't any way I could squeeze them in, . :hissyfit:

As far as my mains and sub, I'm running paralleld 12s so I'm good there and I don't think my subwoofer build could ever be better. It is the very best I have ever heard. I would put money down that it will beat Wilson's XS sub. I'm using Kevins Maelstrom 21" and the TS1200 Face Audio amp bridged to mono: http://www.hometheatershack.com/for...trom-21-4-2100-gram-18-passive-radiators.html It is in my avatar.


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## Mike Cason

*Re: New Dual Lambda TD12s Center speaker build*

I managed to get a pair of new 4 ohm 12" Lambdas from AE Speakers. They normally only sell this driver in an 8 ohm configuration which makes a good crossover hard to build because they are so efficient and I would have to parallel them resulting in a 6 dB gain. This would make padding the other drivers hard to do in an efficient way in my crossover. I did have to EQ my tweeter to keep a flat -0- line, but that's it.

I'm about as perfect as can be on my -0- line and the f3 is about 58 hz, which is ok becaue I cut off everything at 80 hz to the sub. I've got 100 liters left with driver displacement after building my internal midrange box and the bracing figured in.

Someone will probably point out that my inductors shouldn't be all lying flat, but there is plenty of room between them because of the extra large board I used, so I don't expect any inductance problems. If I were to use a smaller board, then I would have stood one or more up to eliminate any problems.

I just finished the crossovers tonight and the drivers should arrive next Tuesday. I've got about 1/2 day to enlarge the mounting holes and rebuild it. I'm anxious to see the finished weight which I'm guessing will be about 130 lbs. That's a beefy center speaker. I hated to order the cheap drivers in the first place, but money is tight. I'll never make that mistake again.

I'll keep the build posts coming in.

















Mike P. How come most of the pics are now being displayed as attachments? Is there just too much bandwidth usage now? Hope you are doing well.


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## Mike Cason

*Re: New Dual Lambda TD12s center speaker build*

Well I got the drivers installed and the new crossover wired in.

As I said before, I'll never buy another cheap driver again. Hey this is DIY and why do it twice? You'll end up paying more in the long run because you won't be happy with inferior products.

Here is the finished pictures and yes, it does weigh in at 130 lbs. I've still got to do some woodworking on the grills to allow them to fit over the sides of the new Lambdas.

What a remarkable difference in _*quality*_ music and vocal reproduction; as well as movies. Now my mains and center speaker have the same mid-woofer drivers and tweeters for a better timbre match.


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## speedie

hay mick how a goin 
looks like you have been playin around with your project to get what you want
is the box the same one that had the original drivers in it and if so how close where the t/s specs of the new drivers in relation to existing box volumes
from your comments it would appear that hivi drivers dont suit your needs but on the other hand the tweeter and mid are still in use?
been thinkin along the lines of ordering some emotiva gear for my humble set up your comments swayed my thinkin
have been off line for some time now as we had bad things happen with both the isp lines and modem failure 
all the best to ya speedie


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## lsiberian

*Re: New Dual Lambda TD12s center speaker build*



Mike Cason said:


> Well I got the drivers installed and the new crossover wired in.
> 
> As I said before, I'll never buy another cheap driver again. Hey this is DIY and why do it twice? You'll end up paying more in the long run because you won't be happy with inferior products.
> 
> Here is the finished pictures and yes, it does weigh in at 130 lbs. I've still got to do some woodworking on the grills to allow them to fit over the sides of the new Lambdas.
> 
> What a remarkable difference in _*quality*_ music and vocal reproduction; as well as movies. Now my mains and center speaker have the same mid-woofer drivers and tweeters for a better timbre match.


Why did you leave the faceplate on the RTI tweeter?:help:


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## Mike Cason

speedie said:


> hay mick how a goin
> looks like you have been playin around with your project to get what you want
> is the box the same one that had the original drivers in it and if so how close where the t/s specs of the new drivers in relation to existing box volumes
> from your comments it would appear that hivi drivers dont suit your needs but on the other hand the tweeter and mid are still in use?
> been thinkin along the lines of ordering some emotiva gear for my humble set up your comments swayed my thinkin
> have been off line for some time now as we had bad things happen with both the isp lines and modem failure
> all the best to ya speedie


Yes it is the same box I had before. With driver displacement I'm at 100 liters. My box tuning's f3 is right at 57 hz. The Lambdas will go lower though. I crossover at 80 hz anyway for my 21" sub to take over that duty. I've got a nasty impedance hump at 30 hz which I won't notice because it is the fs of the driver and it is so far away from my xover point of 500 hz. The Davis Kevlar midrange is a fantastic mid and the HI VI RT2II tweet matches my mains, so all I had to do was redesign and build a new crossover. It did take some work to make the 12s fit though! I have to do some modification on my grill frame to make it fit, but I do my own upholstery work too so it shouldn't be a big deal. I don't have to make a new one.

As far as the Hi Vi woofers I used, they are ok for a small project like a sitting room, but to use them in the first place with all of the work and quality drivers I currently employ, it was a bad judgement call on my part, especially with my setup and amplification. It's not much of a driver. Times are tough, so that causes us to make some bad choices at times. I'm happy as a kid in a candy store now! :T

Take care Speedie!


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## Mike Cason

*Re: New Dual Lambda TD12s center speaker build*



lsiberian said:


> Why did you leave the faceplate on the RTI tweeter?:help:


I almost did it! I really like the idea of the wide vertical axis so I did some ear tests of my mains and the center in regards to the location of the tweets. (RT2II Tweets)

I'm sitting back at about 12 to 13 feet from the system and by standing up behind the chair and raising myself up and down, I couldn't tell the difference from the mains. Sitting down, I'm closer to the center speakers tweeter. Most people don't watch movies or listen to music in the standing position anyway.

In the sitting position, I'm almost on dead center between the tweeters. I thought I would need to place a 1 x 2" board under the center speaker, but it isn't necessary. I hear the nice crisp highs very well. The Lambdas have a fantastic vertical and horizontal off axis presentation at 500 hz. If I were to raise the bar to 1500 to 2000 that they are capable of producing, then the off axis could create a problem for me.

The last and probably most important reason for not removing the faceplate is the overall appearance of the tweeters with the faceplates removed. I have a plate full of projects and really don't have the time to work on re-inventing the mousetrap, mind you, a nice looking mousetrap. 

During auditions, DIYers and enthusiasts like to see the drivers so I remove all of the grills before holding them.

I cherish your suggestion and it has become a part of my good memory and I might apply it further down the road. Especially if I lose one of the tweets and have to purchase another one. Then I can experiment with the bad one.

Again, thank you very much for your input. These forums are so wonderful.

Best regards,
Mike


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## Mike Cason

*Re: New Dual Lambda TD12s center speaker build*

I felt I need to make a last post to this center speaker build after listening to my system for the past 3 hours. I listened to Eric Clapton's 2007 Crossroad album. I listened to it at 100 dB all the way through, distortion free, and I am so happy! 

I am completely astonished and overwhelmed at the final results. 

The power, the clarity and detail in my speakers, and having such a large and capable speaker array is somthing to cherish, behold, and be so thankful for. My system which is finally completed after several years of building, changing out drivers and gear, testing new equipment; and the disappointments along with the highs I've endured during all of my builds is finally over. 

I've just experienced an all time high and satisfaction after listening to this album with my new center speaker installed along and my recent 21" subwoofer build. This a personal goal that I set for myself years back; a system I could be happy with.

I wanted great, but couldn't afford to buy the marked up fancy enclosures at the high end audio stores which I don't think sound as good as mine do, and I have achieved a great satisfaction with my DIY speakerbuilding. I encourage everyone to don't give up if a build fails. Like Diana Krall sings, "Just do it again!" :sn:

After the addition of the very nice center speaker, I've noticed a complete "concert like" soundstage that I never knew that I could get out of a home theater. I bitstreamed my OPPO BD83 through my Denon 5308CI(A) and the performance was in 1080p with 7 channel DTS surround.

One suggestion for each of you during your home theater build, is to have a very capable center speaker because today's material and decoding sends so much information to that speaker now. I used to be a "stereo only" guy when it came to music concerts, but that has changed. Movies are equally as good. 

Today is the first day since I've finished it that I could sit for 3 hours cranked up and really enjoy that front row, center chair reference point I refer to sometimes in my posts. At 100 dB, it was breath taking. I wanted to go on up to 120 dB to push the limits of my subwoofer, but that would have been both stupid and could cause hearing damage, not to say that 100 db won't. 

I want to give a special thanks to everyone here in the forum that has been onboard and helped me with my builds, and a special one goes out to Mike P. for all of his patience and help with his wonderful WinIsd modeling. Sonnie has also been a tremendous help. All of the other posters suggestions and critics have paid off in a big way as well!

Thank you all.....Mike :T


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