Sub placement in custom enclosed cabinet

[drd952]

Hi!

I have been set on a rf7 system for a basement theatre for some time now. With the new line coming out, I have decided to a/b and decide from there.

However, the subs have me perplexed. I have a concrete niche in my basement that I want to enclose flush with the other walls.

I was intially thinking of 2 rsw-12s on either side of the RF7s. Then I would build design shelving and the like around the speakers and subs to give it a clean look. The rsw12s and the THX Ultra subs appear perfect for this setup.

The new rt-12ds intrigue me, but I do not know if they will be ideal for this setup. I did not want to corner load the subs.

Any advise is greatly appreciated!

I have attached a rough overhead sketch to hopefully give an idea of what I am talking about.

[ironwoods]

............

I'd just start digging where the x is. []

Will the sub(s) be visable or hidden behind something? (more questions depend on yer answer)

Any hows, I don't think your gonna want anything that may restrict the sound radiated from the cabinet sides in any direction. I have the Heresy in an open room approx. 5' from the rear wall where there is a raised hallway behind them, and am surprised at how well they sound in this area.

I'd recommend to do yer homework on this one, and even stay late on Friday.

[drd952]

This picture gives an idea what I am looking for. Except as of now the L,R would be inside the far subs. The tv would be on a stand with the components underneath. The center would be above the tv on a shelf.

It is basically a large entertainment center that would give the appearance of being built in. I would be basically creating a false wall with openings for everything. Since the opening is actually about 12-13 foot wide, I was going to put a door in on the side for easy access to the wiring.

So the front firing rsw12 and ultra 2 work well in this situation, but the dual passive radiators and triangular shape of the new 12t confuse me. Will they work in this situation or will it completely defeat the purpose of getting them?

[DrWho]

You need to use the file attachment button at the bottom to first upload your pictures to the internet - and then they will automatically be included at the bottom of your post. The insert image button only works for pictures already uploaded.

As far as subs, you would be best off going with the Ultra2's in the configuration that you're planning on. You cannot flush mount the newer RT-12ds - or even the older RSW12 either. The passive radiators need to have room to create sound. Btw, the RT-12d doesn't have to go into a corner.

Aren't all the reference series rear ported too? If so, they cannot be flush mounted either.

Also, there are some considerations to take into account when flush mounting speakers...basically you have to take into account that the speaker cabinet is going to vibrate, which can then be amplified by the cabinet surrounding the speaker and result in a very muddy sound. It isn't too difficult to avoid, but it does take some forethought into the design.

Btw, welcome to the forum.

[drd952]

Thanks for the answers!

So now I have to pretty much change everything! [] I can understand the possibility of cabinet vibrations. But I was going to leave about a half inch around each speaker. The wall will only be four inch thick. Plus, behind the new wall is wide open back two feet all the way to the ceiling. Is that enough room for the rear ports? The only thing that will truly be in a cabinet would be the components

If I go with an 70" SXRD on a stand, can I have the center on a shelf above the tv? Or am I compromising sound this way?

I really want to get this setup perfect, and could use all the advise I can get.

add on: Thanks Dr. Who for setting me straight on the picture issue. I do understand that the rt12 does not need to be in a corner. But how much clearance does it need behind both PRs to be effective?

[Trooper]

The RSW-12's active driver is on the back side and the RT-12s active driver is on the front. Several other Reference subs (RW8, RW10, RW12 and the new RPW10, RW10d & RW12d) have a front port specifically for installing in cabinets, etc.

With not much space around the subs and other components you essentially have two rooms - the main room and the small room behind the false wall. With any of the passive radiator or rear ported speakers you'll have some anomalies created by the fact they're not sharing the same air space. In your situation I think the THX subs are definitely your best bet.

[DrWho]

Thanks for the answers!

So now I have to

pretty much change everything! [] I can understand the possibility of

cabinet vibrations. But I was going to leave about a half inch around

each speaker. The wall will only be four inch thick. Plus, behind the

new wall is wide open back two feet all the way to the ceiling.

Is that enough room for the rear ports? The only thing that will truly

be in a cabinet would be the components

If I go with an 70" SXRD on a stand, can I have the center on a shelf above the tv? Or am I compromising sound this way?

I really want to get this setup perfect, and could use all the advise I can get.

add

on: Thanks Dr. Who for setting me straight on the picture issue. I do

understand that the rt12 does not need to be in a corner. But how much

clearance does it need behind both PRs to be effective?

Well you actually have quite a few options here so don't give up hope yet...

As far as the ports go, as long as the airflow isn't restricted and the

propogation path length difference to get around to the front driver is

less than 1/4 wavelength then you will be fine. In other words, if you

can see the sound wrapping around the entertainment center in under 7

feet then it won't be a huge issue.

A better option would be to rebuild the speakers and convert them to a front - ported design....though that is a lot of work.

As far as the space around the speakers....you will want to create a

front bezzle, which is like a picture frame that surrounds the speaker,

but just doesn't touch it so as to block as much of the gap between the

speaker and the entertainment center. Behind the bezzle you will want

about 4" all around the cabinet and you will want to line it with

acoustical foam (so that the foam is just not touching). And since

you've got floorstanders you should have the speakers sitting on the

floor too.

Another option you might consider would be to go with the RB-75's for

mains as they are front ported...in which case you will need to build a

stand inside the entertainment center so that the speaker is mounted to

the floor and not physically connected to the EC in any way. Or even

better, you could go with the Ultra2 lineup...I know it costs more

money, but perhaps you can build your system in pieces (which is more

fun if you ask me). I'm usually not a fan of "bookshelf" speakers, but

there are extra benefits from the baffle gain that actually make them a

better performer in some cases...

Also, don't forget to account for proper toe-in of the speakers...you

want to make sure the drivers are in front of any surfaces so as to

minimize early reflections.

A completely different thing you might consider is to go with a front

projection system and either mount the speakers beind the screen, or

make the black part a speaker grill for your speakers. When going this

route you won't have to worry about the space behind the scrim and can

use pretty much whatever speaker you want. Don't like the look of a big

screen in the room? Put it on a motor and have your normal TV behind

it...

I know, I know...$$$$$$$ - just throwing ideas out there []

Btw, what part of chicago are you located? I'm up in the aurora/naperville area

[Petrol]

....Aren't all the reference series rear ported too? If so, they cannot be flush mounted either...

No, the RW-8, RW-10 & RW-12s have their ports on the front

[DrWho]

....Aren't all the reference

series rear ported too? If so, they cannot be flush mounted either...

No, the RW-8, RW-10 & RW-12s have their ports on the

front

I was refering to the floorstanders, like the RF-7's.

[drd952]

Thanks guys!

Couple of things though.

"As far as the ports go, as long as the airflow isn't restricted and the propogation path length difference to get around to the front driver is less than 1/4 wavelength then you will be fine. In other words, if you can see the sound wrapping around the entertainment center in under 7 feet then it won't be a huge issue."

I apologize Doc, but I still do not understand this.

This is a quandry because I really wanted to go with reference because of the line's ability to excel with movies and music. I was going to go front projection initially but WAF factor plus kids will be watching SD on this screen as well. Much easier to work a tv than a projector. I was going to rough in all the wiring for a future projector if/when upgraditis hits later on and my kids are older.

I am starting to wonder if the clean look of the flush wall is not worth the headache. If I do decide to upgrade in 3-5 years, I am stuck with the dimensions, or a bigger project than I might want.

If all walls are drywalled as is, should I have any problems with speakers? I was kicking around having theater type curtains that would close off the space when not in use, and could be draw halfway during viewing to accentuate the screen. Acquiring curtains that do not affect sound shouldn't be a problem right?

Dr. I live in Oak Lawn, two blocks from the Chicago city limits!

Sorry it took so long to respond, I was out of town!

[Petrol]

....Aren't all the reference series rear ported too? If so, they cannot be flush mounted either...

No, the RW-8, RW-10 & RW-12s have their ports on the front

I was refering to the floorstanders, like the RF-7's.

sorry, my bad Dr...

btw, I'm just wondering... why all the bother with insuring that the mains are flush with the front wall?

unless your dead set on Hiding them, seems to me that you would want them to be about the same distance from your listening position as the center is... just spread them out about 8'-9' apart and draw an arc through them.

either that or you could just go with RB-7s as they are front ported and quite capable to handle your room size to me

[DrWho]

btw, I'm just wondering... why all the bother with insuring that the mains are flush with the front wall?

unless

your dead set on miding them, seems to me that you would want them to

be about the same distance from your listening position as the center

is... just spread them out about 8'-9' apart and draw an arc through

them.

I'm talking about doing both....mount the center in the front wall, and

then build false walls in the corners to create the arc. It'd look

something like this:

_____

_/____\

/______\

|______|

|______|

lol, what a crude drawing []

The angled corner walls would only need to be about 3-4 feet in width

to accomdate most any speaker on the market (though smaller can be

arranged too) and they would be perpendicular to the direction of the

listening position. There are various ways of going about the

project...building scrims and what not. I've actually just started up

my own custom audio company and this is one of the tricks we

employ....full fledged HT's that look like normal living rooms until

you flip "the switch" [] (so screens, acoustical treatments,

curtains, etc etc that fold up into the wall until you want to watch a

movie).

[drd952]

I have attached the drawing correctly, I think. The room is 14' deep by 30' wide

To get a better handle on my options, I could use some info on the Ultra system.

Basically, is the room size acceptable for the system? Will it be too powerful and a waste of money?

I am of the understanding that 4 monopoles are optimal for surround duties as they give direction. Yet the dipoles give a more wide dispersion of sound.

In my situation which looks good for sides and back surrounds? I am guessing that I have three options:

1. all monos

2. all dipoles

3. monos on sides dipoles in back.

Plus I will most definitely need to mount the center above the screen. Is it a better idea to have all LCR higher to maintain the same level, or have the LR at a more optimal height?

One more question, would I be better off with the 525s or the 650s for my mains?

Money is not an issue.

Sorry for the long post, but I would love to have better info before going to the store and talking to someone who wants to sell me.

[TheSoundBroker]

The Ultra 2 system will work well in your room and works far better when build in than any other product in the line. As the room layout sits, I'd set it up as a 5.1 system with twin subs, and twin monopoles on the back wall mounted centered between the first and second and third and fourth seats (though you don't give a distance and I'd need to calculate up the coverage to make sure you have adequate rear coverage with monopoles). Your side surrounds certainly are a problem. The ones on the right appear to be so far away from the seats that you will have coverage issues. Between the openings on both sides and the distance, you may end up with some really wierd effects (such as surround info coming from the front off the right side). If you are going to go 7.1, then monopoles all around are the way to go. 525's for surround, 650's for mains (though if money isn't an object and you can live with the size...650's all around is a great way to go). Another possibility is to go with a pro cinema surround that has a 90 degree spread...though they make the Ultra 2 surrounds look like beautiful artwork and they are BIG.

Now...putting home theater designer cap on...

Since money isn't an object [], there is a way to make this FAR better. Instead of spending all your time messing around with building a cabinet in an odd niche, you are a few simple construction steps away from making this an absolutely awesome home cinema. Here is what I would do.

Extend the rear "bathroom wall" all the way to the left and right to make one symmetrical enclosed room at 14 x 30. Put a doorway into that wall to access the bathroom and points beyond. Build in a 2' deep screen wall on the new front (current right side surround wall). What this gives you is a 28' x 14' ( visually enclosed) theater room. A 7.1 system would make perfect sense in that space and you now have room for a much larger screen, plus two or even three rows of seats on risers. I'd build a nice equipment and media storage cabinet into the niche space, maybe with a computer center. Now, you've taken it from a nice home theater in the basement, to a full blown home cinema with some very simple construction. I know a lot of guys here would KILL for a space like that!

[TheSoundBroker]

I did up a quick sketch to give you an idea of what this would look like.

As you can see...construction wouldn't be that difficult or involved and the results speak for themselves.

[drd952]

Thanks for the reply Soundbroker!

My horrible drawing has skewed things a bit. The distance from the left side surround to the middle seat is 14'. The distance from the right side surround to the middle seat is 16'.

So it isn't as lopsided as my drawing appears. Yet the two open spaces are there, especially the one on the right. The one on the left is a six foot wide hallway.

The distance from the rear surrounds and the seating area will be about 4-5 feet. So the distance to LCR is about 10 feet.

I love your suggestion, it is very similiar to my original plan. However the wife was not keen with devoting that much space to a theater at this time. We have three boys under the age of 5 and need more space from them to play. I actually thought of doing exactly what you wrote up only having it go down the right side. Those dimensions are 12' wide by 35' deep. Alas at this time, I have to make due with an eye on the distant future. I figure I will be using this new setup for about eight years then I will redo it. I have read many great things about this system, plus the flush installation option keeps speakers protected from little people.

So with the center, should I mount it below or above the screen? I know that is an age old question, but maybe this system does have a preference. Also, with the correct dimensions, am I still better off with 5.1 with the monos in back, or will the mono's work as sides with the dipoles better as rears in this situation?

Thanks again!

[DrWho]

Go with dipoles on the rear channels (and monopoles for the sides if you end up going that route).

If I were in your situation, I would consider mounting the side

surrounds from the cieling and bring them in closer to the listening

position - tilted down of course. I would also mount your rear

surrounds at the same height and also tilted down. If you can't bring

them in, then you'll most likely be better off sticking with 5.1 for

now...and if you already plan on changing things in the future, then it

will be easier to transition to 7.1 later on.

Whereabouts in Chicago are you located? I know of a great high quality

cabinet builder in the Wheaton area that could build a great customized

cabinet for that inset in the wall. He's the guy we use for all our

custom install jobs. And since you're planning on changing things in the

future, it should be possible to build it now to also work as an

equipment rack for your future setup (the 17" width of the speakers

will make this a very good looking option too).

Btw, I vote highly for the 650's over the 525's.

[TheSoundBroker]

I agree with Dr. Who as to the placement and composition if you are set on that design. Because you are so close...do dipoles in back and monopoles on the sides if you think you need them (I'd probably go with a 5.1 system). Oh...and the center should be above the Television. However...here is another thing to noodle around in your brain...

Why not have both? Put in a movable partition wall that when open, gives you that nice big space on the right side...and when closed gives you a full theater. This is pretty easy to do and would give you the ultimate in family flexible space. You'd have a 12 x 35 space for the boys to play in when open..close the wall and you have a 14' x 30' theater. Do the screen wall with a hard side enclosure on the abutting side. With that design, everybody wins. You get the nice big theater you want with ideal speaker placements. Your wife gets a big space the boys can run around in and go crazy when not watching. The boys get a big playroom AND a big theater (which they will LOVE having by the way). Here is a company I found with a quick search on Google that makes a trackless partion wall that not only looks like a regular wall (even has doors) but they also do acoustic walls with up to STC-50. It is a totally DIY thing and their prices look very reasonable. They can even do a wall with a full blown Dry Erase system...imagine a play wall where the kids can write on the whole thing...heck, I want one!

[drd952]

Are you guys trying to get me divorced?

As of now, the boss is telling me that she wants the right corner for a sitting area for people while they watch the kids play.

However, you guys have really perked my interest. The ceiling mount for all surround speakers could be accomplished. but man, those speakers are not exactly dainty. Isn't it going to look alittle industrial down there?

What about the removable walls covering both openings, will that help the sound field? Or is it the distance of the side surrounds that is the main issue? Like I said, I can do the ceiling mounts, but it seems that part of the system's charm is the clean look it has when mounted on walls.

What about the new in-wall dipole mounted in the ceiling for the side surround, with one side facing the sweet spot? Would that be a viable option? I am not a fan of inceiling speakers, but if it sounds good, I am open. I do not think it would have enough of an angle toward the viewers, but I am certainly not an expert!

I love the idea of the nook being converted into a rack system later on. I think I will run cable to the far right wall for future conversion for speakers and screen. Plus I will rough in the approximate place for a projector.

Soundbroker, if the center should go above the screen, should the L,R also be at the same height?

Doc, I live on the southwest side in Oak Lawn. I work in Downers Grove off of Finley and Butterfield. I am most certainly interested in the cabinet guy. I am going to make a trip to the local THX Ultra dealer in Palos Hills this weekend and see what they offer. I do have another custom cabinet guy in New Lenox called Riverton Cabinets, they are online. They did all the cabinetry in my home when it was built four years ago. apparently they do a lot of high end entertainment center type work, so I thought I would see what they can do as well.

Thanks guys!

[DrWho]

Are you guys trying to get me divorced?

lol!

You've got a PM.