AE TD15X + B&C DE500 + QSC Waveguide questions & build thread

So I've got a pair of TD15X's, a pair of B&C DE500's, and a pair of QSC waveguides on the way all set to arrive next week. I'm not dead set on the XO but am thinking somewhere between 900hz and 1.2kHz. I'm using a DCX2496 for crossover so can tweak that quite a bit. I'm trying to design the enclosure now. I'm thinking of going ported even though my IB sub is good up to 120hz. I've tried to eye up how big of an enclosure I can put up with and I think 20" wide x 18" deep x 48" high looks pretty reasonable. I could stretch any of the dimensions a bit but don't want to stretch them all too much. That gives me about 225l (or 8cuft) to work with. Where I'm having trouble is juggling enclosure size, port air velocity, and port resonances. I found an old thread where John recommends 140l tuned to 27hz with a 3"x16" slot port 26" long. I modeled this up but found that that puts the first port resonance really low - well within the passband the TD15X will be playing in (in fact the 2nd, 3rd, and 4th resonances are probably in the passband with that setup too). I have some 4" PVC pipe in the garage so was looking at using that tuned to around 30-35hz. If I only use one port the 1st port resonance is just out of my passband but then the air velocity gets too high. If i move to dual 4" ports the air velocity is under control but then the port resonance is right back in my passband again! If I make the box bigger the port gets shorter and therefore resonance goes up but I can't go much bigger than this. Also if I just tune higher I end up with a big bump in the FR at tuning.

Any thoughts? Am I better off just sealing it? I just hate to waste the extra low end (and reduced THD on the low end) that ported would add for this build. The more I think about it the more I think I should just seal it up...

I should add I'll be powering with a 100W/ch Onkyo receiver for now but will likely be upgrading to a pair of pro amps when $ becomes available (so I've been modeling sending it 400W or so to see the "worst" case for chuffing).


Here's the T/S params:
TD15X- 8ohm
Fs 23.2 Hz
Qms 3.82
Qes 0.31
Qts 0.28
Vas 467 Liters
Cms 0.45 mm/N
Mms 105 grams
Sd 855 cm2
Rms 4.0 Kg/S
Bl 16.7 T/m
Re 5.6 ohms
Z 8 ohms
Le 0.3 mH
Pe (max) 500 Watts
Pe (transient) 1000 Watts
"no" 1.82 %
1WSpl 94.8 dB
Linear Xmax 14 mm (peak)
Mech Xsus 20 mm (peak)

Another question (I'm in way over my head here but have been dreaming of a setup like this and decided to go for it...) what kind of considerations should I be making regarding the baffle layout? I have a 1 1/4" roundover bit but have no idea what would be ideal or even how to figure it out... Any help here would also be greatly appreciated. It's freezing rain here today so I may get some garage time in, hopefully someone out there can help me decide on something so I can get building

I may just build it 20x18x48 sealed and figure out the port later...

Thanks Noah. I think I'm just going to go back to 140L tuned to 30hz with one 4" port. I'm reading through Findbuddha's thread now as it looks like he's already asked (and received answers to) nearly all of the questions I have

I've not really set on an XO frequency yet. It will be active so I'll be able to play with it a bit. I'm going to start with 1.2k but will be playing with XO's down to 900hz.

Regarding the enclosure size it seems the smallest I can make the baffle is about 20"x32". With the +/-10 degree vertical window that would put things a bit low for floor-standing but would make putting them on a stand kinda' silly as the stand would be ~16"... I think I'm going to compromise and go with a 20"x40" baffle, 14" deep. With the double baffle that should give me close to the 5cuft I'm going for once the displacement of the driver, waveguide, and port is subtracted.

I've searched and searched but cannot seem to locate the dimensions of the QSC waveguide. Does anyone have them handy so I can draw up the baffle layout? Hoping (unrealistically) to get started in these today.

Thanks Nate! Say, when I was looking through threads of similar builds I saw you're doing something similar as well. I went looking for your thread but didn't find one. Do you not have a build thread yet or is it on a different forum maybe?


Thanks for the input, do you have a build thread somewhere I could follow/read through? I have seen the measurements and will try treating the FR with notch filters to see how I prefer the sound.

Oh, right. I'm currently running my IB up to 120hz (it's an "outie" so it works fine) but I'll be crossing at more like 80 or 60 with these, depending on how it sounds once I've got them up and running. In 5cuft tuned to 30hz it's flat down to 80hz, -1dB @ 50hz, and -3dB @ 40hz. Sealed in 5cuft it's flat to 200hz, -1dB @ 100hz, and -3dB @ 60hz. It probably won't be much of a difference in the passband but excursion is matched with more output on the ported down to 50hz so why not try the ported version.

Thanks for the link. Funny, I was just reading your thread yesterday, came up when I was searching for similar builds I'll have to keep my eye on it and see where you end up.



Yeah, that's what I'm thinking too. Since it will just be the front two (I'll be trying a phantom center for now) I'll be using the DCX to manage the XO to the sub as well which should make integration a snap.

Looks like it's elevenhorns.com:

http://www.elevenhorns.com/welcome.htm


Googled for elevenhorn and "jeffrey jackson" and got only 2 results, this thread and a page refering to the elevenhorns.com website. Those horns are beautiful but beauty comes at a price! Those have to be a pain to make though.

I've got the DE500's, waveguides, and one of the TD15X's (UPS says they have the other one somewhere but think they put it on the wrong truck!). The plans are all drawn up, wood is in the garage, caps for tweeter protection are ordered, foam for the waveguide is ordered(whether it's necessary or beneficial is questionable but I ordered it anyway). Also I just picked up a Marathon MA-2000 off eBay to power the TD15X's.

I plan to get serious in the garage this weekend and it sounds like the wife has some get togethers going on and is planning on bringing the kids so it looks like there's a real possibility I'll be posting build pictures soon! I'm super excited about this build!

Yeah, I really wanted the 'M' but found the 'X's used from chasw98 for a great price (which is really the only reason I ended up going ahead with this project).

I've now got everything in hand except the caps for protection of the compression drivers. I cut the foam yesterday, it went OK but they look a little rough from the front, I'm going to see what I can do to clean that up (trying to cut off small amounts doesn't work very well so cleaning it up is going to be a pain!). Tip (duh!) start your cuts from the side of the foam that will be visible, the final through cut can get a bit "ugly".

It's currently -17 here and looks like it won't be much warmer this weekend (how's the weather up there Michael!?). I'm still going to attempt to get the wood cut and holes routed this weekend though! If I don't do it now I don't know when I'll be able to get another block of time so I'll be cutting and routing all bundled up. If I can get all the cutting done this weekend I can do the gluing in the house. Hopefully I'll have some pictures to post tomorrow or Sunday

Well, I braved the cold. I got all of the panels cut, TD15X holes routed (internal baffle and flush hole for outer baffle), port holes routed (I decided to do the port on the back as I'm going to experiment with plugging it and don't want the plugged port showing if that's how I end up running them), terminal cup hole routed, and the flush portion for the horns routed. Doing the horn counter sinking part was the most difficult. I can do circles just fine but trying to do a rectangle threw me all off. I did OK running the flat portion of my router's base along a piece of wood clamped down as a guide. One spot has a slight "wiggle" but I don't think it will be noticeable.

I've still got a bit to do, cutting the port, cutting the through hole for the waveguide (in the inner and outer baffles), do a small roundover on the outer baffle for the woofer cutout. Then I can glue the sides and back together, glue the port into place, use a flush trim bit to cut the through hole for the port, roundover the port hole, cut braces (I have some scraps the perfect width already but also picked up some 2x4's to do the most important spots), glue the braces in, glue the baffles on, roundover all edges of the box, install drivers... Man, I was thinking I was about done but when you write it all out it sounds like a lot!!

I do have a couple pictures of large pieces of MDF cut into smaller pieces of MDF but it's not much to look at yet...

Everybody likes pictures so here's a couple I took Saturday

Thanks, hopefully I'll have some pictures of construction soon... I actually surprised myself with how close I was able to get the waveguide to the woofer, I was VERY nervous about doing the flush hole for the waveguide but now that it all turned out good I'm stoked! I'm still trying to figure out what to do with the bottom half of the front baffle. It just looks so lopsided with everything squished up on the top portion and ~23" of nothing between the bottom of the woofer and the floor. I'm going to poke around Home Depot and see if something jumps out at me. I'm thinking of maybe tacking a 'V' shape of some kind on them so it looks less "funny" and direct attention to the beautiful woofers

Also I need to figure out what to use for feet, what did you end up using? Yours looked really good.

I don't think you need to worry too much about the spacing on yours, yes it's not ideal but like you said you don't hear any problems so who cares