L&R SEOS Tempest Build - Jeff Bagby Design

I'm a little late getting this started, but it's hard to post when you're making sawdust! I've been intrigued by the SEOS project ever since I started lurking on the DIY boards and had planned on making a purchase after Erich brought the site back online. Once I combed through the available designs, I settled on a pair of Jeff Bagby's Tempests for L/R mains. I'll be running them with a phantom center. I've heard several phantom centers and liked them to various degrees but haven't ever been fully satisfied with one, so it'll be interesting to see if a CD speaker changes that perception. It's irrelevant for now as there's no way I can do a matching set and my current setup even hinders me from really doing a Malcolm type build.

First, big thanks to Erich, for all that he has done and is doing and specifically for his advice and feedback during my decision process. Thanks also to Jeff and to all of you that are contributing to DIYsoundgroup and the SEOS project, whether through designs or otherwise, I think it's absolutely remarkable how things have come together and the community that exists on these boards. Finally, to some of the first SEOS pioneers, Java and Brad and many others whose threads have given me ideas and some confidence. I hope that someday I have the knowledge and experience (or can fake it well enough) to positively contribute.

First, the speaker:
Tempest page at DIYsoundgroup. It uses an Eminence Delta Pro 12A and a DNA-360 compression driver. According to Jeff the specific goal of the Tempest was to design a speaker that gave a nice "midbass kick" which was pretty appealing to me, both because being in an apartment I often can't let loose much with the subs so midbass is all I've got and because that's something I felt was seriously lacking in my current speakers.

On the speaker front I've owned the older models of the Andrew Jones Pioneer speakers. I've also had a set of eD Cinema 12's in my apartment and heard them a couple other places and generally enjoyed them each time. In the last 6 months I've heard Salk HT2-TL's, a pair of LS6's, SHO-10's, Statements, JTR T8's, JTR Noesis, and several others. My hopes for this project was that I could get overall performance somewhere between the eD's/SHO-10's and the JTR stuff, obviously at a cost much closer to the former than the latter.

After I'd finalized on the Tempest design and placed my order I started making the sawdust for the rest of the box. This was the drawing I sketched up and used for dimensions:


Given that this is only my second DIY build after my recent subwoofer build, I decided to make any "overhanging" panels (so in this case, both sides and the front baffle) 1/8" oversized with the intent of flush-trimming at the end. For someone more experienced this is a waste of time, and I'll likely go down to 1/16" oversized on my next build, but I really like this approach as it gives you a bit of a buffer and flush-trimming doesn't take very long.

I also decided I wanted to do rabbet joints around the perimeter of the bottom piece and on the leading edge of each side piece (where the front baffle would drop in). This was mainly experimental and I wanted to see if it made it easier to square the other pieces as I was gluing them together. I felt like it did, it's probably something I'll selectively repeat in the future, but it's definitely not necessary:


I also did a dado groove for the window brace which was more of a pain in the butt than anything, I don't think I'll be doing that again:

Edited by MrSmithers - 1/7/13 at 10:54pm

On Thursday I received my package of goodies from Erich. I've read on these forums multiple times about Erich's packing skills and I was pretty sure people were just being hyperbolic. They were not. Even with some of the "special" things I've seen out of Fedex in the past year, I think these guys would've struggled hurting these parts. In fact, I think an interesting forum competition would be to video yourself dropping one of Erich's packages and then see who can successfully damage something from the lowest height.

Boxes!


I took lots of pictures of the unboxing but suffice to say it was outstanding packing. Here a shot of the woofer:


With the parts in hand, I did what any guy would do, I promptly set the wife to work! I must say, she's getting pretty handy with a jigsaw and can certainly cut way straighter lines than I can:



Meanwhile, I prepped the backs for recessed terminal cutouts. I stole this idea from Brad and at least one other build I've seen recently, I think it looks really clean this way. I cut out a 2 3/4" (this could really be whatever) diameter circle, put roundovers on the outside, and then glued a piece of wood over the hole from the inside:


Then the cutouts on the inner baffle were completed to match Erich's outer baffle, so we went ahead and made a baffle sandwich:


Finally, very late, we had both boxes glued, the second one is clamped here. I only have enough clamps for one box, so I glued one late Thursday night and one very early Friday morning. I was a little worried, due to never trying it, about taking the clamps off after only 4 hours or so, but it didn't seem to cause any problems. On the near box, you can see how the bottom of the near-side is flush, the top is sticking out 1/4". This is what I described earlier about intentionally making the piece too long and flush trimming it later, and I definitely learned that for me, I like the idea in theory, but 1/4" is way way overkill:

Edited by MrSmithers - 1/7/13 at 10:57pm

I was sick on Friday and Saturday so I didn't get anything done on those days. On Sunday I was feeling better so I did the roundovers and started in with the bondo/sanding. I read a lot of hate for Bondo sometimes on the forums, but I absolutely love the stuff. I will admit it's probably the most depressing time of box-building since you're putting in work and not seeing a lot of change/results but it's really nice when you're done. Here's a corner shot showing the roundover and the sanding I still have left to do:


While Bondo was drying I started on the crossover layout. The network was pretty simple but I'd never done a speaker crossover before and wasn't sure how tight I could squeeze it all. Since the woofer hole is over 11 inches, I decided to play it safe and plan for an 8" by 8" board. I definitely think I could've squeezed a bit off each direction, but there really wasn't a need.
I used some of these terminal blocks from parts express, three per board, one for incoming signal, one for out to the woofer, and one for out to the tweeter. I used ring connectors on the binding posts and spade connectors on the terminal blocks but that's not necessary. I first laid everything out on the board how I wanted it and took a picture with my phone. Then I started at one end and began twisting component wires together. Then I would solder, snip off the excess, and glue down any components that was fully accounted for. For the common wire I had a hard time finding bare copper wire around here so I ended up buying a couple feet of solid wire and just stripping it myself, Although I didn't do it here, I think for someone who is hesitant about crossovers, doesn't have any circuit experience, or whatever, that splitting them up into two boards - one for the woofer section and one for the tweeter section might be less intimidating. It's a little more wiring overall but for some it might be worth it. The tweeter is pretty tight but it'll take up to 12 gauge wire (if it's twisted decently well) but that's certainly overkill. Here's a couple shots of the crossovers:



I was pretty worried about that large inductor that's standing up, and was prepared to drill some holes and zip-tie it down, but that thing is solid as a rock. I used velcro to attach the crossover to the box, just because I wanted to be able to easily remove it in the future. I ended up putting it on the side of the box, vertically it was in between the ports and the window bracing (which runs between the woofer and the waveguide).

Thanks fellas.

Last night I got the painting done. The phone's auto exposure makes it look a lot more grey than it is. I'm not Gorilla-level proficient with the Duratex yet, but I definitely felt like I was much better at it just from the sub experience. This time I went for a grittier finish, so I rolled the paint very thin. I still only needed two coats to get a good covering.


Then I got them stuffed and ready for components. We did sections of 1" polyester batting around the bottom section and loose polyfill in the upper section. We cut a pouch around the crossover board.


Tonight I should be able to get the drivers installed and get the speakers home. Hopefully some impression will shortly follow.

Thanks sir! I highly doubt you'll need much help I am really interested in the B&C's though, I almost went that route but the 12's stacked on top of the subs already look absolutely absurd as an apartment front stage, so I figured I'd pass on the 15's for now.

Thanks Brad, your thread was a huge part of convincing me to take the plunge.

Mrkazador, I think a sealed design would look really great. I'm really liking the combo of duratex, the SEOS waveguide, and the woofer. Very black-hole look to the frontstage, even with the lights not completely off.

Drivers are all loaded up and the speakers are home. Listening impressions will have to wait until tomorrow night but I've at least confirmed that they make sound and the correct drivers make the correct range of sound, so I've got that going for me. My TV is about 8.5 feet from my couch, speakers are about 7.5 feet apart, one sitting on top of a SubMersive and one on top of the DoD dual opposed 18" Dayton. The front stage, being in an apartment, looks absolutely absurd. I may build a Malcolm for fun or help some friends with some stuff, but I am quite literally just about out of room in the front of this living room for any more speakers.

First box done:


Couple shots of both boxes:



And the final shot with the Prius ready for loading:


Most people (including me) laugh at the idea of hauling things in the Prius but I think carp was at least a little impressed when I came to his place the other day with the DoD and a CV 5000 amp and still had plenty of room to spare

Thanks sir and appreciate your help in answering my questions! Expect some questions to come your way about the Minion at some point, I don't need them at all but since I'm hopelessly addicted I'm definitely thinking about it.
I really like the Duratex too. This time I used a high density foam roller which was really conducive to my plan of rolling it thin and tacky. It's also nice that the foam roller doesn't hold a massive amount of paint, though I imagine that'd make it harder to get some of the other textures. I'd like to play with staining or veneering someday still. I will probably sell the SubMersive. I love it, the performance for the size is outstanding, it's pretty much bulletproof, and the amp draws almost no standby current, hardly ever gets warm, and doesn't make any fan noise. I'll put it up and if it doesn't sell then I have no problem keeping it around for awhile. However, as you know, this DIY thing starts to get expensive, especially when you have to do the entire tool purchase up front at one time because you don't have anything! I do need to figure out what to do for speaker stands if I sell the SubM, probably just build some I guess.
Yeah, I'm looking forward to eventually having an AT screen and not having to make center channel compromises. I'm really impressed with the Dayton. To my ear they sound very very similar to the SubMersive but I think several of the listeners over at carp's felt like the Dayton had just a little more "weight" to the sound in some instances, which I personally preferred. I had it dialed in pretty well at carp's to where it was tickling the clip lights (running in 2 ohm stereo off one channel of a CV 5000) on very loud scenes or scenes with a lot of single digit content. At my apartment I've only seen it light up the -10 light on the amp one time and I was starting to worry about structural integrity, so unfortunately it's gonna be awhile before the subs can stretch their legs again.

One mistake I did make that I'll have to go back and correct. I should've painted the foam that you can see through the ports black. It's not a big deal when the lights are off, but it looks kind of silly otherwise with the white visible.

DoD Thread

It started with me asking about vibration and then I added some build pictures so it kinda morphed into a build thread but wasn't laid out as a proper build thread from the start.

The schematic was shipped with the rest of the kit.

I had a chance to do some listening tonight. The first thing I always try listening to is the intro through the chorus of Dire Straits Money For Nothing. As soon as the intro started I started grinning and when the crescendo hits and the solo guitar riff starts I got chills, so I guess that's a good sign. Female voices sound especially amazing, just absolutely on the money. The top end sounds very good to me in my room, I'm fairly sensitive to brightness/harshness and I haven't gotten any of that or any fatigue or whatnot. I'm pretty sure I'm at the limit of my room in that respect as I have no treatments, and although I've thought about it, I don't think it makes sense to fully treat an apartment I'm not going to be at in 6 months.

Obviously the output is/can be silly and seemingly effortless. I think neighbors would complain or I'd physically not be able to take anymore before the speakers complained. The receiver was barely able to attenuate them low enough using Audyssey to still level match at 75dB. I haven't played with turning Audyssey on or off, I only have the basic version and in my experience it's about 50/50 as to whether I like it better or not.

There's some stuff I need to play with. First and foremost, I'm using my subs as speaker stands and the throat of the waveguide is about a foot above my ears. The vertical off axis is good enough that it still sounds fine, but if I squatted with the tweeters at ear levels I liked the sound even more. Flipping the speakers over puts the waveguide about 7 inches or so below my ears, so I'm going with that for now with the added benefit that when I lay down on the couch they're at about the perfect height! I'd like to build stands, but I need to see if there are decent places to put the subs first.

Secondly, I need to play around with positioning. Right now I sit about 8.5 feet from the TV and I have the speakers about 7 feet apart. I started with aiming each at the opposite, outside edge of the couch arm (probably about 35 degrees). I think I'd like to try them a little farther apart and toed in a little more. The soundstage is pretty decently sized as is, I'm not even sure if I could tell blind where I was anywhere along the ~3 feet to either direction from the center of the couch.

I have a dip around 53Hz that I need to figure out. I also have some stuff going on around the sub->speaker crossover that I need to figure out, I imagine I can solve that fairly easily with some delay in the miniDSP, but I want to figure out the sub and stand situation before I put too much time into it. I'd also like to get measurements of the speakers out of the room but that might take a bit.

I did watch some sections of movies, trying to focus on those with panning effects, dynamic effects, and dialogue that I've found "small", "boxy", or just difficult to understand in the past. Dynamics are very good and panning seems very good. In my head I was thinking everytime I started a clip about not having a "real" center and worrying about if that was going to ruin the experience but what I found was, a few minutes into the scene I'd totally forgotten to be worried, everything sounded quite good. I think I'd still prefer to have an AT screen and a matched, equal height front 3 but that's not possible for now. I may build some Malcolm variant and hang it over the TV just to experiment with the difference, but based on tonight I didn't feel like I was missing anything.

Always more to do..the problem is instead of being content this makes me want to build more variants of the SEOS stuff just to compare different woofers, different form factors, and different design decisions and implementations. This DIY thing is definitely a sickness and I believe I've done went and got it.

Conclusion thus far is I'm very pleased. It's hard to say much more because they're so vastly superior to anything I've had in here that it's a pointless comparison. At some point I'll take them over to carp's, he has a bigger and better room and I've heard several different speakers there in the past year, so that'll be more interesting.

I definitely will, just trying to make sure I try a variety of material, toe-in, listening from different positions, etc.

Haha, awesome. I struggled back and forth a long time between the Tempests and Deltalites, I'm looking forward to hearing some of the latter. Maybe you too can convince your wife to jigsaw out your window brace ;p