My New Theater

[Matthew J Poes]

On the expense part: our basement ended up costing about twice what we originally anticipated. The ballooning costs were not labor or from the contractor. About half of the extra costs were from soundproofing issues. I underbought sound caulk, clips, insulation, etc. I spent nearly 10 grand in that alone. Part of that was my fault. I miscommunicated with my supplier and he quoted me to do one wall and the ceiling. I also made changes once I realized that certain areas wouldn’t meet my TL requirements. I added an extra layer of drywall to one wall and boxed in some cavities in a crawl space (which was a ton of detail work).

This stuff gets expensive fast. My best suggestion is to except now that it won’t be perfect. Focus on the most critical things and don’t worry about every little compromise. Or if nothing else, don’t throw money at those last .1% problems. You won’t be happier.

Remember that soundproofing isn’t perfect. STC 60 doesn’t mean 60 db of transmission loss at all frequencies. An STC 60 rated wall does not achieve STC 60 in practice. Try turning only your subwoofer on and playing a movie or music at a level of 40-50 db and that’s roughly what others might hear outside the theater. For some, like my wife, that is still pretty loud.

If you want better we can talk but it’s expensive.

 

[bkeeler10]

Thanks Matt. I had budgeted for double drywall, and was planning on clips for the ceiling. I had not planned on green glue or extra clips for heavy things on the ceiling, or a second door for the back of the equipment cabinet (that was a mid-construction idea), or $2.5k doors, etc. It quickly gets out of hand, and frankly there's a limit to my tolerance to spend (and available funds to spend). And I think I've about reached the limit

 

[Matthew J Poes]

Thanks Matt. I had budgeted for double drywall, and was planning on clips for the ceiling. I had not planned on green glue or extra clips for heavy things on the ceiling, or a second door for the back of the equipment cabinet (that was a mid-construction idea), or $2.5k doors, etc. It quickly gets out of hand, and frankly there's a limit to my tolerance to spend (and available funds to spend). And I think I've about reached the limit

Which is just fine. You’ve made no wasted efforts. One of my local friends helped me come to grips with these limitations and get off the spending spree by reminding me that what we have is a luxury most don’t have and what you have done is still miles ahead of what most are able to do. The transmission loss of your walls is far greater than normal and I’m sure you will be very happy with the room.

There are doors for well under $1000 with STC values in the 40’s. If I can find them I’ll post them for you to look into. I’m fairly certain Mohawk has one.

For door gaskets, Pemko sent me their test data on different configurations. With any door that has an STC value below 50 you really don’t need those fancy sound gaskets. They provide no advantage. The silicone bulb gasket is just as good, as is the Silicone 3 finger. You don’t need to spend more than $50 on gaskets.

 

[Matthew J Poes]

Sorry got my product lines mixed up.

Jeld Wen Tria R series.
http://www.jeld-wen.com/en-us/produ...l-interior-door#/group=All&model=modelM000810

It’s a top notch door, fire rated, and the STC is over 40.

 

[bkeeler10]

Finally got the clips and hat channel finished yesterday. Picture attached. We should be getting sheetrock installation started sometime this week.

 

[Matthew J Poes]

Looks great.

So now that I know that you have EASE, will you be modeling your room. I want to see the ray tracing!

Out of curiosity do you have access to other software from that group?

 

[Sonnie Parker]

Staggered studs on 2x6 plates... blown insulation... dual 5/8" on outside wall and 3/4" plywood with green glue and 5/8" drywall on the inside, with double solid wood doors opening in opposite directions... wife can't hardly hear a thing in our house. This is not really an expensive option, but if you are over/under, that's a different ballgame.

Good to see you making some serious progress.

 

[bkeeler10]

Looks great.

So now that I know that you have EASE, will you be modeling your room. I want to see the ray tracing!

Out of curiosity do you have access to other software from that group?

Room's already built in EASE. I will use it to determine first reflections and evaluate reverb time (not that RT60 is a terribly useful metric in such a small room). Yeah, I'll run ray tracing too and share it.

I use SysTune and EASE regularly, and also have EASERA. I use SysTune to do EQ for audio systems in the field (primarily speech systems so far), and of course we model acoustics and A/V projects in EASE. We are acoustical consultants. I used to work for SoundTube Entertainment (a commercial loudspeaker company and division of MSE Audio), and used EASE there to predict coverage and intelligibility performance for projects our dealers wanted help designing.

 

[bkeeler10]

Staggered studs on 2x6 plates... blown insulation... dual 5/8" on outside wall and 3/4" plywood with green glue and 5/8" drywall on the inside, with double solid wood doors opening in opposite directions... wife can't hardly hear a thing in our house. This is not really an expensive option, but if you are over/under, that's a different ballgame.

Good to see you making some serious progress.

Thanks Sonnie. Does your room have its own HVAC system, or are you tied to the rest of the house? How many walls/ceiling/floor are shared with adjacent rooms (as opposed to being exterior walls)? As I recall, you have a nice "buffer zone" hallway just outside your theater which I bet helps a lot on that side.

Due to cost issues, I'm going to start with a single door to the theater and see how that goes. If it becomes a problem, I may add a second door in the future. Fortunately, none of the walls of my theater are shared with bedrooms. I just hope I've done enough to keep theater sound out of the HVAC ductwork (I'm tied into the rest of the house and also have two ducts in the ceiling above the theater).

 

[AudiocRaver]

tHey Brian,

Budget issues can sure hold you back, can't they?

My problem is that every time I am getting ready to spend a few dollars on room construction materials, I think of a piece of gear I want.

 

[Matthew J Poes]

tHey Brian,

Budget issues can sure hold you back, can't they?

My problem is that every time I am getting ready to spend a few dollars on room construction materials, I think of a piece of gear I want.

That's a hard mental block to overcome. I try to remember that the room is among the single most important components. Rooms aren't as as equipment upgrades, but they certainly matter more than most. I know you already know this, I've had the same thoughts myself. What I spent on my room would equal a nice system, let alone nice upgrade. However nothing could equal the performance improvement the room afforded me.

 

[AudiocRaver]

So true. And I WILL do what it takes to get the room sounding right. However, getting it to sound right AND getting it beautiful... That's another matter.

 

[bkeeler10]

So true. And I WILL do what it takes to get the room sounding right. However, getting it to sound right AND getting it beautiful... That's another matter.

As they say, beauty is in the eye of the beholder. And the ear of the beholder, I might add. But I assume you're like most of us in that you are not the only beholder in the house.

Caution: Rant ahead.

When I look at the pretty pictures of most purpose-built, dedicated theaters, I usually notice how much money was "wasted" on creating a "theme" or making it look pretty when the lights are up. That money could have been used to maximize audio and video performance, whether by using better equipment or improving the room acoustically and visually. To each his own I guess, but I don't care much what it looks like when the lights are up. What matters is how it looks and sounds when the lights are down and it's being used for its intended purpose.

If I really had it my way, the front half of my theater would probably be all black velvet. I will be using the absorption and diffusion panels that I need in there, but there's no way I can get away with making the room a black hole. WAF is very low on that idea. I did manage to avoid having a window in there, which almost got nixed.

We were out on Saturday picking flooring for the addition, including carpet for the theater. I think I might get away with some almost-black carpet with light gray flecking in it. That will be close enough. The tough sell will be to get the front 1/3 of the room painted flat black, including the ceiling. But that's probably the best I can hope for.

 

[bkeeler10]

Latest update:

Sheetrock was installed on Monday and Tuesday. Pictures attached. I took the day off on Monday and a couple hours Tuesday morning to be there while it was installed, so I could apply the green glue to the second layer of sheetrock before they hung it. I noticed last night that they failed to cut holes for two of my electrical boxes, which I will need to remedy.

We have a bit of a change of plans on colors. We'll probably be sticking to shades of brown, with walls and ceiling deep, dark chocolate color and carpet dark brown with some flecking. Perhaps a lighter shade for trim. The wife really wants to have some semblance of coordination between the theater and the rest of the house, and sticking to warm, brown-leaning colors makes her happy. Happy wife, happy life, right? While I would prefer shades of gray/black, at least the browns will be very dark and on-screen contrast shouldn't suffer much at all. It's a small compromise IMO.

It's coming along, and I'm getting excited for it to be done. Our house is full of sheetrock dust, and it will be nice when that part is over with.

 

[Travis Ballstadt]

IMHO, deep browns are great colors for a theater room. My entire house is a modern, stark white and grey with bright color splashes in art and furniture. But my theater is deep brown (I think the color was espresso, or maybe coffee bean) with cedar trim, and I love it. It basically turns to black when the lights go out.

 

[bkeeler10]

That's a pretty good-looking room you've got there. Honestly I'm not too concerned about our decision on the colors - I think it will be great.

 

[Matthew J Poes]

I think brown is good too. It's warm and inviting, will look black in a theater with the lights off. Unlike red it isn't likely to have much negative effects on the picture quality.

Mine is navy blue with brown tone wood, charcoal tweed like fabric panels, and chrome wall sconces. I was looking for a modern look. I really like it but it's definitely on the cold side and has no tie in to the rest of our house.

 

[bkeeler10]

Okay it's been a couple of weeks, but I'm sorry to say there hasn't been much progress. The sheetrock part is completely done, and we have trim mostly installed. Paint should be coming soon.

Anyway, it's about time to start building my subwoofer boxes. Recall that I had intended to buy two of Rythmik's F25 kits (two 15" drivers per kit) and build four boxes for them. Well, they recently came out with an 18" line and I'm thinking to go down that route. I can buy two F28 kits (each with two 18" drivers). However, I'm thinking about doing just two boxes instead of four.

There is a great deal of placement flexibility with four subs, and some great advantages in a sealed rectangular room, according to the research done at Harman. Specifically, a sub in each of the four corners of the room is supposed to yield a fairly flat frequency response that is fairly consistent across a large listening area. This arrangement also takes advantage of corner loading to yield a great deal of output.

However, the research also suggested that placing two subs at the midpoints of the short walls of the room is nearly as good in frequency response and (IIRC) also is good for lots of output.

The issue is that the F28 kit installed in two boxes is not as flexible because one box will have the amp and the other box will have to have a run of speaker wire to the first box with the amp in it. That means that phase can't be controlled for individual boxes - the two that share an amp will get the same signal at the same time. Rythmik is also saying that there could be problems with running two boxes with one aml, which I suspect is related to the servo control.

Anyway, what do you all think about four individual boxes with an 18" woofer in each versus two boxes that each have 2 18" woofers?

 

[Matthew J Poes]

Okay it's been a couple of weeks, but I'm sorry to say there hasn't been much progress. The sheetrock part is completely done, and we have trim mostly installed. Paint should be coming soon.

Anyway, it's about time to start building my subwoofer boxes. Recall that I had intended to buy two of Rythmik's F25 kits (two 15" drivers per kit) and build four boxes for them. Well, they recently came out with an 18" line and I'm thinking to go down that route. I can buy two F28 kits (each with two 18" drivers). However, I'm thinking about doing just two boxes instead of four.

There is a great deal of placement flexibility with four subs, and some great advantages in a sealed rectangular room, according to the research done at Harman. Specifically, a sub in each of the four corners of the room is supposed to yield a fairly flat frequency response that is fairly consistent across a large listening area. This arrangement also takes advantage of corner loading to yield a great deal of output.

However, the research also suggested that placing two subs at the midpoints of the short walls of the room is nearly as good in frequency response and (IIRC) also is good for lots of output.

The issue is that the F28 kit installed in two boxes is not as flexible because one box will have the amp and the other box will have to have a run of speaker wire to the first box with the amp in it. That means that phase can't be controlled for individual boxes - the two that share an amp will get the same signal at the same time. Rythmik is also saying that there could be problems with running two boxes with one aml, which I suspect is related to the servo control.

Anyway, what do you all think about four individual boxes with an 18" woofer in each versus two boxes that each have 2 18" woofers?

I think those are outstanding subs. They have the lowest distortion of any subwoofer I've ever seen measured by Database. They have far less distortion than even the 18" Velodyne with servo. If ever a subwoofer could be nominated as an audiophile sub, it is that sub. Personally, I would go with 4 single 18's instead of 2 double 18's if it were up to me.

I also would suggest that you play around with placement and be willing to try other locations. I don't actually find Harman's locations to be the best. Dr. Geddes came to similar conclusions and believes that Harman decided on those locations because they work well enough and are an easy recommendation. Not because they always work best or are optimal.

 

[bkeeler10]

Yeah, I have to admit I'm having real heartburn about going with only two boxes. Thing is, four separate 18" kits would cost a lot more - I would probably have to move to the 15" to get four boxes done right. I'll be checking pricing on it though.

Over on the Rythmik thread of the forum that shall not be named, everyone that has any iteration of the 18" subs simply loves them. Gotta find a way to get them in to my theater if I can. I keep thinking, though, that four 18" subs in a 2300 cu ft room is much more than I will use 95% of the time. Even four 15" is a lot of sub for that size room. The only thing that keeps me going back to it is the headroom at subsonic frequencies. Sure 30 Hz is easy to have plenty of headroom at, but an octave below that is a different matter entirely.

 

[Matthew J Poes]

Yeah, I have to admit I'm having real heartburn about going with only two boxes. Thing is, four separate 18" kits would cost a lot more - I would probably have to move to the 15" to get four boxes done right. I'll be checking pricing on it though.

Over on the Rythmik thread of the forum that shall not be named, everyone that has any iteration of the 18" subs simply loves them. Gotta find a way to get them in to my theater if I can. I keep thinking, though, that four 18" subs in a 2300 cu ft room is much more than I will use 95% of the time. Even four 15" is a lot of sub for that size room. The only thing that keeps me going back to it is the headroom at subsonic frequencies. Sure 30 Hz is easy to have plenty of headroom at, but an octave below that is a different matter entirely.

Well of course another option is to go with two for now and add more later.

A lot of folks take a stance that you absolutely must have identical subwoofers. That isn't necessarily true though. Dr. Geddes actually designed his approach around dissimilar subwoofers. His idea was based on his own speaker designs, so there are some caveats needed to translate to other people. All of his speakers used big pro drivers capable of in excess of 120db's at 80+ hz. Many of the big models could even do that as low as 40-50hz (such as the Abbey and Suma). He then used two subwoofers with a 12" driver which typically didn't extend much deeper than the mains, maybe down to 30-35hz in room, but again, could do well over what was needed for loud. In that iteration, the 12" could do maybe more like 115db's at 35hz, rather than 120. He then would add a single larger sub in a larger enclosure. In his ultimate design (in my opinion) he used a large 6th order bandpass approach that could exceed 115db's down to 20hz in room. I have followed a similar approach, but found that larger drivers such as 18's are nice for this uber sub. The number of modes that need to be excited for the smoothing of the bass is largely above 50hz. There is typically only 2-3 additional modes below that point, so multiple subs don't help much. In fact, by 30hz multiple subs don't impact smoothness much at all, EQ and placement ends up being the best solution.

All that to say, You could go with the two 18's for now and add a third or fourth of a different type later. As long as its peak output is at or beyond the loudest level that you listen to above 50hz, it won't be a problem. It will still provide significant LF smoothing. Some people call these midbass modules.

The Rythmik subs are great. Their past efforts were good, but their distortion wasn't that much lower (if any lower) than the most linear DIY subs on the market. An 18" ultimax also has very low distortion and high output at a low cost. The benefit of the servo sub wasn't so compelling at the time since simpler methods could achieve similar results. Then...they came out with this 18" driver and things changed. The new more powerful amps combined with the new driver and servo technology has led to similar overall output to the ultimax but with even lower distortion. Add in the ability to modify the system Q and you get a really nice sounding and flexible subwoofer. It's truly impressive. You won't be disappointed.

 

[bkeeler10]

The one thing I will say is that the spousal will to spend more money on the theater after it is "done" will be very low. Some of the more transient things like processors and projectors won't last forever, due to lower long-term reliability and changing technology and such. However, good high quality speakers, subs and amplifiers are timeless in a way, and IMO are worth investing in for the long haul. Spending a little bit more now to avoid the upgraditis bug in the future is the way to go.

Which is to say, I intend to get the bass system and speaker system that I can be happy with for at least 10 years, and maybe up to 20 years. In the case of the subs, I may never change them. So I gotta do it right the first time. I may just have to bite the bullet and get those four F18. And here we go again . . .

 

[Matthew J Poes]

The one thing I will say is that the spousal will to spend more money on the theater after it is "done" will be very low. Some of the more transient things like processors and projectors won't last forever, due to lower long-term reliability and changing technology and such. However, good high quality speakers, subs and amplifiers are timeless in a way, and IMO are worth investing in for the long haul. Spending a little bit more now to avoid the upgraditis bug in the future is the way to go.

Which is to say, I intend to get the bass system and speaker system that I can be happy with for at least 10 years, and maybe up to 20 years. In the case of the subs, I may never change them. So I gotta do it right the first time. I may just have to bite the bullet and get those four F18. And here we go again . . .

Yeah the money I spent during the build was so much easier than today. I asked my wife about a receiver upgrade for an amount that was relatively small compared to other expenditures and her jaw hit the floor with some kind of mumbling about how I better hope the couch is comfy.

 

[bkeeler10]

I got to thinking about the subs again, and perhaps the way to go is to use three 18" boxes. It's hard to imagine how that would not be enough output in my fairly small, sealed room. In fact, there's a bit more radiating area in the three 18" woofers than there would be in four 15" woofers.

I haven't read Geddes' research very extensively, but my recollection is that his method relied on three subs. Well, perhaps I'll start with three and do some positioning and measuring, and buy a fourth right away if things aren't working out.

 

[Sonnie Parker]

You know I've been all over the map with subs... including eight 18's at one time... with close to 8,000 watts of power.

My room is a lot more at 3900cuft... and my two 18's are totally sufficient for my room, and they are far from the best out there. It's much harder to equalize and integrate 3 subs vs. 2 subs, unless you can get two of them placed symmetrically in the room and run them in parallel.