A new surround TM - completing the HT

[cjd]

Build a couple, try them surface mounted (no holes in the wall/ceiling larger than some screws probably, so easier to patch up after) and see if they work for you - whether they do or not, share the experience - that will help others.

While I tried to measure a ton of variations and evaluate the crossover across all of them, there is no guarantee here - this is probably more risky as a venture than many other designs out here right now simply because it is intended for use in mounting scenarios far from ideal. Not to say it's a risk, but that I am almost positive I didn't evaluate every possible gotcha and someone is bound to run into that.

[ibilisi]

CJD, are you still considering the TDFC interchangeable with the TBFC? My front 3 are TBFC Dayton 3-ways, considering sticking with the TBFC for timbre. Any thoughts there?

[cjd]

In my experience the TBFC is largely interchangeable with the TDFC - it might need a bit more padding.

[aduljr]

I am definitely going to be building these, perhaps 2 pair. Believe it or not gf has been bugging me for some better surrounds

[jagman]

I'm interested in these, too. Two way on wall/ceiling surround speakers will be nice for a lot of people. Question... for those who want four of them for a 7.1 setup, but are limited to mounting them to the ceiling, ideally, where would you locate them relative to a three person couch? I am really constrained because in my new HT, there is no wall behind or to the left of the couch, but there is one immediately to the right of the couch (as in 6 inches away from the right arm rest). Unforunately I'm pretty much stuck with the couch placement. I would imagine the right surround will pretty much need to be up against the wall and I'll just have to deal with boomy bass from the one speaker (unless you could secretly recommend a change to the crossover ).

[Brian Bunge]

I'm kinda in the same boat as jagman, except I have about 2' to the left of the sofa (assuming I'm sitting on the sofa) with no wall to the right (entry way and stairs to the right). I'm wondering how I would or if I could use one or two pairs of these for surrounds and where I'd place them if I could use them.

[cjd]

these should be pretty well optimized for any dual-boundary setup - in fact, if they were truly ceiling/wall mounted and did NOT have another boundary nearby they might sound a bit more on the thin side. I doubt that's going to be critical for surround - again, the random nulls and off-axis droop is probably going to be no better or worse than anything else the room throws at these - I really should try some more critical listening with them, but I can say for surround duty they rock. We had some movie the other day where the sound-track had something moving in a circle all around (as if it was flying around you) and it was kinda freaky, even as only a 5.1 setup. Even better, it had about the same impact no matter what seat I was in.

[Brian Bunge]

Chris, that's cool! I can't figure out how I'd do 7.1 in this room and I'm probably looking at surrounds mounted in/on the rear wall the left and right of the sofa. I guess I could do in-ceiling for the "sides" and then on the rear wall for the rears, but I don't know if it's even worth it in a room this size.

[aduljr]

I am prob going to do a 7.2 setup. might as well . Now if I can only find a job so I can order these parts.

[jagman]

If the surrounds were ceiling mounted (so high above the couch) but not that far behind or to the side the couch, do you think it best to have the tweeter fire down instead of straight into the room?

[Brian Bunge]

I FINALLY have a job starting in a couple of weeks so I hope to finish my new speakers soon!

[mackintire]

Do you have a cut sheet for this design or a drawing of the cabinet?

[cjd]

Oh. What? you can't extrapolate? I do, somewhere, scribbled on a piece of paper... I'll work one up.

[mackintire]

Danke sehr viel.

[servicetech]

Seems like a lot of us have odd shaped living rooms. Hiding the wire dropping form the ceiling to the wall speaker is an issue for me, I'd like to see a design that worked well mounted in the corner of the wall/ceiling.

[aduljr]

is it me, or are there no dimensions for the box listed in this thread? I can only guess its a box that is ~ 12" x 8". Am I off much?

[cjd]

Not off much, nope. There are no dimensions, and I've been too pre-occupied to find the drawing. I may have to reverse-engineer the box dimensions.

I'm sending myself an e-mail to remind me to do this.

[JonMarsh]

Not off much, nope. There are no dimensions, and I've been too pre-occupied to find the drawing. I may have to reverse-engineer the box dimensions.

I'm sending myself an e-mail to remind me to do this.

Sounds like me... the worst thing is when I get in arguments with myself about priorities and I lose... :W

[jagman]

Would you consider this a 4 Ohm speaker since there is the dip in the impedence curve around 200Hz? Would you consider 4 of these a difficult or reasonable load for a receiver to handle...espcially if the L, C and R were driven by an external, dedicated amp (e.g. XPA-3)?

[cjd]

This uses a 4ohm mid-woofer, so yes - it is a 4ohm speaker. It's not a particularly difficult load to drive as things go.

[jagman]

Thanks! I saw that the mid was 4 Ohms. Initially I thought that if the tweeter was also 4 Ohms, that the amp or receiver could see 8 Ohms as the two could be wired in series. Obviously the impedence plot indicates otherwise. I was working under the assumptiont that it wouldn't be that hard of a load given that the mid is so small... but better to be careful.

[aduljr]

Sounds like me... the worst thing is when I get in arguments with myself about priorities and I lose... :W

lol, I try to keep all my box designs on my pc in case I need to reference it again later.

[JoshK]

great project! I think on-wall projects are lacking in the DIY community. In my case, since my HT system is in the LR, I must appease the wife. Onwalls go a long way in that direction. Will consider these.

[NoDestiny]

So having used these for a while, do you like the design? I'm trying to find something similar to this for my surrounds I'm planning out, just seeing how you liked the direct-sih mid and high off tweet combo.

[jagman]

Edit: changed topic.

Do you have the rears ceiling mounted? Have you changed the sides to ceiling mount, too? If you can, please post pics from further away so we can see the location of the surrounds relative to your seating positions. It would be nice to get your advice on optimal positioning and orientation now that you've had them for a while. Thanks!

[cjd]

man, people are still waiting for box dimensions from the slacker designer and you want revised and updated pics and opinions?!

They continue to satisfy. I have not moved the side-mounts to ceiling. The rears are (er... will be) ceiling mounted - I have to move ALL my equipment including the projector to mount these (dust issues, they're all behind me in my HT) and I've just not taken the time to do this yet. I'm running with the rears sitting on the same shelf as the projector, etc.

Inertia sucks sometimes.

[jagman]

Well. Get your arse in gear .

[jagman]

When you mount them to the ceiling... if you have the time/patience... please compare tweeter forward vs tweeter down orientation. Thanks!

[cjd]

Updated the posts with the crossover to include box design.

Or you can find it here.

[NoDestiny]

So do you think they work better in general for a surround VS a standard "bookshelf" speaker or "direct" setup?

[cjd]

It depends so much on the room and general setup. These are still a direct setup, but optimized for less optimal placement requirements. They definitely will not work as well for everyone. Consider that we have nearly the same thing in the Modula MT in a more "standard" design should you find that suits your requirements better

These are absolutely better than more traditional speakers comparing across the 3 seats on the couch that is all we can fit in the space between the walls - it's a very snug setup... Previously panning around the room didn't create any sense of immersion even for the seat right in the middle of the rear surrounds - now, anywhere on the couch is rather eerie if you get an actual sound effect in the movie that pans straight around.

C

[jagman]

Way cool. I've settled on a what to do for the front three channels in my HT. I want to do three RS sealed WWMT towers (the one in Missions Accomplished) for my front three speakers. You did one of the myriad of crossovers for that speaker, right? Do you think that would mate reasonably well with these new surrounds? I should think so but figured best to ask. I like you have a big IB sub so having this combo for HT should be phenomenal.

[cjd]

I only did a center channel crossover option on the WWMT's

That said, I suspect these will blend reasonably well with Curt or Dennis' crossover(s) as well.

[stgdz]

Updated the posts with the crossover to include box design.

Or you can find it here.

I was expecting a napkin or paper towel drawing :W

How is the spousal approval factor with these over bookshelf's?

[jagman]

I like the fact that the box is so symmetric... especially if painted or veneered. It makes tweeter down or forward positioning easy.

[stgdz]

So CJ do these speakers count as mission accomplished now?

[NoDestiny]

Almost have my first one of these built I'm using 1/2" MDF and cut down on the size a bit (5 1/2" instead of 6 3/4"). Well braced of course. Should have one finished by tomorrow with any luck.

[NoDestiny]

After having these for a bit, I gotta say, they blend very seemlessly into the rest of the front speakers on my 7.1! I am really surprised by this. Unless something is discretely on that channel, it just blends so well into the rest of the system, as if the front speakers just simply get "wider". Good work on this design.

[---k---]

After having these for a bit, I gotta say, they blend very seemlessly into the rest of the front speakers on my 7.1! I am really surprised by this. Unless something is discretely on that channel, it just blends so well into the rest of the system, as if the front speakers just simply get "wider". Good work on this design.

No Pictures, No Project!


That is great to hear. It is a very different design. Good to hear that the theory is matching up with our ears. I would love to see some more photos (since CJD is deficient in that area. ).

I'm looking forward to hearing these. Supposedly, CJD is going to bring these over to my place after new years. Time will probably be limited because we'll have other toys to play with. But, hopefully we'll be able to do some listening versus the In-Khan-Neatos.

[NoDestiny]

Image not available

Whats funny is you don't see all that wood glue stain until the flash hits it Oh well, but they are obviously not finished. Need to flush up drivers and figure out how I want to finish them. Also, I think I might experiment with diffuser shrouds that I have planned up in my head (all in due time, though).

These ones I built are 5.5" deep instead of the 6.75" using 1/2" MDF all around except for the woofer baffle, which was 3/4". Netted around the same space inside w/o sticking out as much, though I wish I would have gone 5.75" instead, simply to give the tweet a little more wiggle room (oh well).

I mounted them with screws/washers on the inside of the box, just gotta pull out the woofer to access. One goes through stud, other into an anchor. Once tightened, these things are SOLID on the walls!

Oh yeah, don't mind the cruddy drywall and wall paper job in the background, this house is getting nearly torn down once I move out (one day, when a short sale closes for me, which feels like its NEVER going to!)

[---k---]

That wire gauge looks pretty thin.

[JonMarsh]

That wire gauge looks pretty thin.

It's a distributed resistance damping approach to terminate reflected electrical backwaves from the speaker before they reach the power amplifier. :W

Otherwise, when you turn the overdrive control up to 11, the cones will pop out. :lol: Just ask Marty....

[NoDestiny]

That wire gauge looks pretty thin.

It's a distributed resistance damping approach to terminate reflected electrical backwaves from the speaker before they reach the power amplifier. :W

Otherwise, when you turn the overdrive control up to 11, the cones will pop out. :lol: Just ask Marty....

lol, yeah... its all temporary setup, just threw together whatever was laying around. I don't want to invest anything into the house I'm in. I'll be doing at least 14awg in-wall once I buy my own place!

[cjd]

Spent some time listening to these as "mains" sitting on the floor, tweeter up. A little heavy on the bass response for me. Otherwise was a very interesting experience. Among other things, they were imaging pretty well and throwing a decent soundstage even with me sitting on a couch off to the left of the left speaker...

[stgdz]

cj what is the estimated cost on one of these surrounds.