[Zeitgeist]

I've started a new build recently... finally have all the parts, just need to do some more cuts and glue..

It's a 3 way, WCW configuration.. The AE TD12S are custom --- they have a fabric dustcap instead of phase plugs.

Just building a center for now - then going to build L/R.

Drivers: AE TD12S, B&C 8CXT, AE TD12S.
Amplification: Crown Microtech amps (2400/1200s) EDIT: Now, Emotiva XPA-1s, XPR-5 (hopefully), and UPA-7
Crossover: analog JBL M553 (for testing) - EDIT: Now, MiniDSPs w/4 way advanced plugin (3)
Dimensions: 16w x 38h x 14 deep
EQ: Undecided... I have a BFD 1124.... EDIT: MiniDSPs
Preamp: Onkyo PR-SC886 - RCA to MiniDSPs
Cabinet: 3/4" MDF
Connectors: Neutrik Speakon (I've learned to like them more than banana plugs) (2, 1 for woof, 1 for coax)
Type: Sealed
Stuffing: Thinking about 2lb of polyfill - would be about 16oz/cuft. Not sure if this is too much for a sealed speaker.
Driver mounting: Mounting woofers and coax flush with the front baffle..

Still figuring out crossover points... unfortunately the JBL unit doesn't provide much flexibility -- so just going to use as a starting point. Triamping it - in part to the substantially different sensitivities of the woofer and tweeter -- and the flexibility of changing crossover points on the fly. Sensitivities are 93.2 db for woofers, 94 for mid, 103 for tweeter.

In my initial testing - I *LOVE* the 8CXT. I was listening to part of Despicable Me, and you could clearly hear the pluck of the guitar string (during the intro..). I was impressed. It took some time to get the TD12S woofers, but they are SOLID. Between the woofers and the coax - it's almost 60 lbs in drivers!!

Will hopefully get some pictures up tomorrow of progress..

Any questions?

 

[bambino]

I can't wait:sn:. I think the recommendation is 1lb. of fill per cu.ft. so your right in the ballpark weather or not it's all needed will need to be determined. Like i said before i can't wait to see these get off the ground. Do you have any pics of the drivers?

 

[Zeitgeist]

I can't wait:sn:. I think the recommendation is 1lb. of fill per cu.ft. so your right in the ballpark weather or not it's all needed will need to be determined. Like i said before i can't wait to see these get off the ground. Do you have any pics of the drivers?

I've always heard that recommendation for subs - just wasn't sure how it translated to woofers..

I just took some driver pics... somehow I managed to make these drivers look ugly!
AE TD12S:


B&C 8CXT

 

[bambino]

Those look like some serious drivers now i'm really excited to see your build progress!:T

 

[zero the hero]

That is going to be one awesome set of speakers! Have you considered using the MiniDSP for XO use (you'd actually need a pair)?

 

[Zeitgeist]

That is going to be one awesome set of speakers! Have you considered using the MiniDSP for XO use (you'd actually need a pair)?

Thanks!

I've actually thought about them a great deal... They seem to be pretty good and very modular. Any clue if they allow mixing plugins - so that you can use them for XOs and for parametric EQ?

I'm just trying to keep from putting too many devices in the chain.

I think my only minor gripes about the MiniDSP is the $35 or so for shipping from China... and the fact that I wish there was some more elegant rack mount solution. All my other gear is racked - so trying to avoid having "boxes" that sit around..

 

[Zeitgeist]

Actual cabinet w/bracing dry fit. Hard to see - but the two 1" holes are for Neutrik Speakon connectors. I am using two - one for woofer and a second one for the coax. Each of the connectors has 4 conductors.


Still need to cut holes in the bracing that sits behind the woofers


Front baffles - the primed one is the forward most -- cut to recess the woofers. Also has an (approx) .4" deep recess cut for the B&C. That was fun to route! Polyfill sitting next to the baffles... and part of an enclosure -- to chamber the midrange.


Amps, amps, and more amps. On top is crossover and an EQ. EQ is not currently hooked up.

 

[bambino]

Wow! Nice job man. Got a close up of the cutout for the woofer? And what are all the amps for, your starting to remind me of myself, (can't ever have enough) LOL! Your doing some exellent work.:T

 

[Zeitgeist]

I'll get some close ups...

Well for LCR 3 ways that's 9 channels or 5 stereo amps right there. Sounds crazy right? I might bridge a couple so for 9 channels its easy to use 6 amps!!

I should just buy stock in an amp company... I would have bought integrated Digmoda amps but that's some serious money there too.

 

[bambino]

Let me know when you buy that stock i'll join you.:bigsmile: I guess when i think about it you need all those amps, wait a minute.... does that mean i need all 17 channels of amplification i have? What are we to do with all that power.
Oh, i know build more speakers:devil::T.

 

[Zeitgeist]

Let me know when you buy that stock i'll join you.:bigsmile: I guess when i think about it you need all those amps, wait a minute.... does that mean i need all 17 channels of amplification i have? What are we to do with all that power.
Oh, i know build more speakers:devil::T.

I've thought about building surrounds with the B&C drivers... but then I'm looking at another 8 channels of amplification.

So I should just stock up on Emotiva multichannel amps then... :flex:

 

[bambino]

I've thought about building surrounds with the B&C drivers... but then I'm looking at another 8 channels of amplification.

So I should just stock up on Emotiva multichannel amps then... :flex:

Better get the Emotivas before they go up in price again or wait and hopefully they will go on sale again soon.:spend:

 

[Zeitgeist]

Agreed!

 

[Zeitgeist]

Test fitting the speakers before gluing the front baffles together..


Closeup of B&C recessed cutout.


To do:
Paint
Glue bracing in
Drill holes for hurricaine nuts... and install
Glue cabinet
Cut 45 degree 1.25" bevel on front baffle
Put polyfill in
Install speakon connectors in rear
Install and wire drivers

 

[bambino]

Exellent job on the octagon cutout!:sn: Did you use a template or was that done freehand?

 

[Zeitgeist]

Freehand I stuck the B&C in the hole... and then traced around the flange w/a sharpie... and then cut within the sharpie.

The lines are actually straight.. for some reason in the pic there was a reflection or something weird. The B&C fits like a glove on the cutout..

When it's all black, should be pretty good.

 

[bambino]

Well executed, for freehand work the lines look perfect and like you said any imperfections will disapear once it's painted.:T

 

[vinculum]

I'm just going to blurt it out here...

Wow, a Seaton Sound Catalyst clone! Drivers, dimensions, ect.

Looks great so far! I wish we would see more DIY coaxial projects. What do you project your final cost per channel will be?

For surrounds you could stick to just the coax in a ported box and get down to 80hz, if that sparks your interest.

 

[Zeitgeist]

I'm just going to blurt it out here...

Wow, a Seaton Sound Catalyst clone! Drivers, dimensions, ect.

Looks great so far! I wish we would see more DIY coaxial projects. What do you project your final cost per channel will be?

For surrounds you could stick to just the coax in a ported box and get down to 80hz, if that sparks your interest.

I have no idea what you're talking about... :whistling:
Don't they say that imitation is the sincerest form of flattery?? onder:
But.. I don't have a rear chamfer on mine... I just beveled the front of the baffle over the weekend..

I think weight probably came out to 110-120 lbs. All the MDF and then the driver weight (probably 60 lbs for drivers).

Lets see.. cost...

$45 - Wood:
Well, each speaker is about 1.5 sheets of MDF (plus or minus) -- so that's 45 for wood.

$840 - Drivers:
B&C - about $240 shipped (I think it was free shipping)
AE drivers - about $600 shipped

$5 - Connectors:
Maybe $5 for the Neutrik Speakon connectors

So, lets say that's maybe... $1000 for drivers, wood, wire, etc. Maybe even including cost for DuraTex (that I have yet to buy)

Then there is:
Cost for amps (3 channels of amplification per speaker...)
Cost for crossover ($200-250 for DCX or $400 for DBX Driverack PA+) --- need 2 of them for 3 channels
Speaker Wire (I think it was $70 or so for 500 feet, I can't believe I used 450 feet (50 feet per channel) just for 3 speakers)

Not sure how to quantify the cost for amps and crossovers yet - since I'm using what I have on hand..

IF I were to go the Digmoda route - I think I'd hit the $1500 price point pretty quickly. Integrated amp modules aren't cheap.

Needless to say - when I started pricing everything out - in terms of crossovers and amps - I was surprised - it really adds up!

Why yes - that does Spark my interest! The B&C coaxes are really amazing drivers.

 

[vinculum]

I'm sure Mark would be flattered. Who wouldn't? He's probably even following along to see what crossover parameters you select. I'll be curious myself to see what methods you use to arrive at the crossover frequencies and slopes. Keep up the good work!