HT Project: New in-walls + surrounds

[cjd]

Nope. :P

Not yet anyhow. I need to though.

C

[---k---]

Big holes in wall cut. Boxes trial-fit. This is going to work! I think...

C

Yeah, but more importantly, how is my center coming?

:rofl:

[cjd]

Your center is doing a brilliant job of holding things up right now. :P

It's not anywhere yet. My wife made me buy a new dining room set! I mean, geeze. That takes time you know? And we had to get parts from 3 different stores!

Friday is movie night, but I'm hoping to find a little time tonight and tomorrow night to finalize the boxes, put some lining on the walls. Need a little more time with the router too which won't happen till Saturday afternoon at the earliest. Got folks staying overnight Sunday>Monday and the HT doubles as our guest room, so...

sigh.

Life takes time. And speaker projects are nowhere NEAR the top of that priority list.

I have to figure out what projector to go with too. Must be 1080p and support 24p, anamorphic stretch, and the 11.5' throw distance to a 41" tall screen (84" diagonal for 16:9?). Dust is a concern (cats'll do that). 7.5' ceilings make offset important. And budget. Right now there are only two options: Optoma HD80, and Panasonic AE2000U. The latter has dust issues and seems to go really dull quite quickly. The former just means I have to squeeze it up against the ceiling, but that's possible. Just a little more of a headache. But not unreasonable.

C

[---k---]

Your center is doing a brilliant job of holding things up right now. :P
C

:rofl: Now that deserves a picture! Next you're going to tell me that it makes a great stool when hanging the screen!

I hear you about the dinnning room set. Back at New Years, my wife purchased one of these: http://www.ikea.com/us/en/catalog/products/50045529
Oh my gosh, you know how many pieces that thing comes in! It took me, no joke, 6 hours to assemble and her helping for about 2 hours. Ughhhh...

I think you get twice as many project done around the house as me, so...

Your theater is going to rock when you're finished.

[Hdale85]

Does the new Epson with the rated 50,000:1 CR have constant height? Also could always have a video processor handle the CH of course adds a bit to the cost but also opens up a lot of options for projectors. The new Epson is like 2600 and has a 200 dollar MFG Mail in rebate. I believe this is what the price was could be wrong But I know its close to 2500.

[cjd]

Does the new Epson with the rated 50,000:1 CR

It doesn't actually have that kind of CR...

have constant height?

Nope.

Also could always have a video processor handle the CH of course adds a bit to the cost but also opens up a lot of options for projectors.

It doubles the cost in this projector price category. If I could use my HTPC that would be one thing (I actually do that now) but blu-ray support on the HTPC is horrendous (so is HD-DVD if I cared about that at this point). Software problems with the players. I would also have to upgrade my current PC hardware, and XP support is far fuzzier anyhow, Linux support doesn't even exist, and Vista is not an option.

Also, it's $2600 after that rebate.

Ryan: I think your speaker is just holding up a few tools at the moment. Maybe not even that. At one point it had a shelf of DVD's I had to move...

I'll try to get some pics taken and actually uploaded into the thread soon.

C

[Hdale85]

I knew it wasn't really going to be 50K:1. I haven't had any issues playing HD-DVD's on my HTPC it plays all of them just fine ever since I got an HDCP video card. But I understand all your points I've heard there are issues with BD+ on the HTPC platform... But I have not experienced this. I ordered a BD drive that will be here tomorrow. It was really cheap if it doesn't work out to well I'll just get a standalone player or a PS3.

[cjd]

If my current HTPC were up to snuff, it would be a much more obvious choice. But it's an old 3200 Sempron with an ATI9800 video card. So nowhere near capable of HD playback. I count about $800 to bring a new HD capable system online. I think that's what I ran it out to be. I have an unused copy of XP32bit but still am not sure if it will work. If I do that, I'd really want to try to use the PC as pre-pro.

[Hdale85]

Yeah thats kind of what I want to do. I just ordered parts to upgrade my gaming rig and now I have enough parts left over to build a sept HTPC while it used to be all just one rig. Not sure what I'll do though and part of my problem with using the HTPC as a pre/pro is that not to many great sound cards out there.

[cjd]

Baffles covered in felt, foam in boxes, baffles screwed down (though I have to remount one - looks like I messed it up, isn't lined up right) and mid/tweets mounted in all 3. Wall is painted black. Should be able to mount into the wall shortly, assuming i fix the mussed baffle. Getting there!

C

[cjd]

Pics of progress!
First up: the frame, velvet wrapped. And of course, the new speakers in th wall and awaiting measurements'n stuff.



Next up, got the new SeymoreAV acoustically transparent stuff installed. A bit of a pain - the angle suggested to prevent moire means it stretches slightly oddly and getting all the wrinkles out proved... un-fun. My fingers still hurt!



This is vinyl. It smells HORRIBLE. Gave me a headache working with it, and this morning my lungs hurt a bit (I'm hoping it was the vinyl not me getting sick!) I wish I'd known now bad it was earlier, but oh well. Watched a movie on it, and it looks good. Definitely some lumen loss through it (I could see the bit of the projection inside the IB manifold where the screen is over that - kinda funny - not quite as bright as on the screen, but brighter than I would have thought) but not problematically so. Beyond that I dunno, we just enjoyed the movie. Looked good.

C

[---k---]

Looks very cool. I think you forgot the 1" roundover on the screen frame, corner braces. :P I know there isn't much you can do about the frame being that close to the edge of the speaker, but is that going to give you any issues? Felt?

Reminds me of Art S. theater. Mark Seaton has a great photo with his big speakers behind the screen. The theater is dark, but there is some lighting on behind the screen showing the monsterous speakers behind the screen. It is very impressive.

So how are those speakers mounted? Do they slide in and out of the wall, or are they permanently attached?

Also, how did you build the curved frame?

[Hdale85]

99% sure that the frame is not curved just an illusion.

Stretching screen isn't all that fun even with blackout cloth I used for the last one I had.

Edit: If it does curve its not much....hmm

[cjd]

Curved frame it is. To work with the anamorphic lens I use - it's a 2.35:1 format screen.

2x6 stock frame with a "cap" of pine that I found with the right shape. It's actually back-cut slightly. I'll try to remember to snap a pic.

I'll grab a snap of the back wall too. They're screwed in to studs, but they do slide in and out. The baffle has a 3/4" overhang.

I'll probably be doing some more felt work around the bracers and stuff, yes.

C

[cjd]

Some interesting notes.

Measuring with the screen in place introduces some interesting challenges, both getting data and for the end result - building an appropriate crossover.

Comb filtering is abolutely present above about 2600Hz, looking to max out at +3/-7dB or so, and completely smoothing once gating is brought below the point where there's lots of reflection induced anamolies in the response.
Total loss on the tweeter is estimated at about 3dB - it looks like I am not going to be needing any padding at all on the tweeter.
Reflections are a pain! I need to get some heavy felt and cover the frame with it I think. Some of this will not go away no matter what I do. In-wall behind a screen placed this close is just going to bring with it these problems - no way around it.

Crossover cost seems to be about $68 each. I'm not going to post this as it's such a case-specific design and it is abundantly clear that I'll be solving very install-specific anomalies in the crossover.

Fun though. Can't wait to test it out once finished!

C

[Bent]

any focus abnormalities with a curved screen?
(or is the focus better, due to the screen being more consistantly the same distance from the lens?).

[cjd]

Depends if I use the lens or not. With the lens, its more even. Without the lens, it's slightly soft at the edges - well within the tolerance of my eyeglass prescription's ability to adequately focus.

A bigger deal to me was the pincushion issues. Which aren't ideal either way - as it is, it's a little off without the lens again.

On a different note, I have discovered it's fun to sit in the IB manifold and crank up the tunes... does that mean I need to seek counseling?

C

[cjd]

Progress. Crossovers assembled and installed.

Not at all surprising, there's a little sibilant harshness making me suspect a peak around 3-5kHz (as it happens, I'm cheating - I know there's a peak here but my ears also hear it). I've done no wall or frame treatment as yet though, and a little experiment when I was measuring suggests that this will help quite a bit. I've also got an Onkyo that does some room EQ functions built in and I may be entirely lazy and let it do its magic. I do have a notch filter that would solve this issue, but it drops impedance below 3ohm so I'm hesitant. And it's not at all problematic sound-wise unless it's cranked up.

Now to get rid of all the "junk" in the room on which the speakers used to sit. And, of course, I have yet to do surround channels.

C

[---k---]

No pictures, no progress.

Very cool. Looking forward to Sunday and hearing them.

You going to have some wires hanging out of the wall so we can do some comparison between my center and yours? I should have the crossover assembled. I would be interested in seeing if I have a preference between the tweeters, etc.

[cjd]

no wires out the wall, no.

No wires in your speaker, for that matter...

Pics? Maybe once I finish cleaning up.

C

[---k---]

Sorry about making more work for you over at AVS.

Stupid question time. Did you do measurement for each speaker in the final location? So a measurement for the left, a second for the center, and a third at the right? I was just wondering about your comment about the measurements getting funky reflection, likely due to the frame. Looking at the photo for the center, I wouldn't expect much funky frame reflection, but I would expect it in the right and left.

And, I've assumed that you're doing the same crossover for all three speakers.

[cjd]

Same crossover, yeah. Side reflections, just not much to do passively to tame that sensibly. The reflection is likely the screen, not the frame. At least, the peak in response is just about exactly the wavelength of the distance from tweeter to screen... Even this, though I could notch passively, I want to avoid fixing because it just throws impedance too low. So the goal was a system with a nominal response in the target window to being flat, and let the room EQ that so many receivers now ship with work to tweak out anomalies introduced by the difficulties of placement in real life.

C

[---k---]

So how about an update?

How did the mains end up? You still having to use EQ in the receiver?

What do you have planned for the surrounds? That's my real question, as I got some in-walls planned for later this summer.

[cjd]

Sound is still not right. There's that kinda honky sound going on. And still EQ which helps. Since it's no mess to just deal with the problems for now, I'm focusing on other stuff around the house and yard that I need to do right now.

Surrounds I have planned TM's with the RS180 - tweeter vertical, mid-woofer at a downward facing 45 degree angle, or so. Partially in-wall.

We'll see if/how well that works. Got the wood, just need a nice weekend and the table saw fired up to get some boxes done!

C

[---k---]

That sounds like an interesting surround. I guess you're going for the indirect sound field.

[cjd]

It won't be that indirect, though I do want it to be somewhere between completely diffuse and obviously direct - as you know, the seating area is VERY close with a wall directly adjacent to the left and right sides of the couch. The challenge is to get it so that the SPL differences in the different seating positions are minimised - particularly with the side surround channels.

It'll either work, or it won't. But I sure hope it works.

[---k---]

Yes, you're area is challenging. Though, I'm thinking a more traditional approach will work best for my room, I'm very curious to see how you deal with it, and how this unique approach turns out.

So, are you going for full 7.1 then, not just 5.1? If 7.1, I really want to see where you hide those side speakers!

[cjd]

Yup. 7.1 to go with a new projector and a PS3. No more HTPC. It's just 5.1 at the moment.

[Bigdaddy]

Any updates? I'm dying to know how the in-walls are progressing. I will have a very similar AT setup.

Phil