[GloP]

Hey there,

I've been reading these forums for a while and now it's finally time for me to do something about my bonus room in my house! I recently ordered some Salk HT3 speakers and while Jim Salk is building them I am going to be working on the room.

Let's start with a picture of the room (click for high rez) (Btw, I'm not a native speaker, so I apologize if I made any spelling errors).



I think the dimensions somewhat accurate. The floor is hardwood floor on a what I believe is a wood base (this is on the second floor). I do plan on putting an 8'x10' rug on the left, and probably another 8'x10' on the right. The ceiling is drywall and above it is "under the roof", with isolation put on top. The room is pretty much empty right now and is quite "live". The door is in the lower right.

Eventually, I would like to put a electric 110" roll down screen on the leftmost wall in front of the window with a front projector fixed on the ceiling, the left part of the room being used as the home theater. The HT3s being the main speakers. But for now it'll just be the HT3s as a 2 channel system. I think seating will be a leather couch or Berkline recliners /similar (3) somewhat in the middle/left of the room facing left, obviously. So first of all is this placement seems like the most obvious choice, but there could be other options, so do you think this would be the best choice?

Second, and most importantly, what kind of treatment should I put in the room to make it sound its best? I don't know much at all about treatments so is there any any specific frequency I should be concerned about based on the dimensions? Basically, if it was your room, what treatment would you apply?

Thanks a *lot* for your help! Like I said I've been reading this site for a while and it's a very nice community!

[woodsyi]

I think the way you are planning is the best way.  You will want bass traps on all corners, absorption on early reflection points for 2 channel and diffusion in the back.  Getting your dedicated power in while the room is empty may be good too.   Good luck. 

[Ethan Winer]

Second, and most importantly, what kind of treatment should I put in the room to make it sound its best? I don't know much at all about treatments so is there any any specific frequency I should be concerned about based on the dimensions? Basically, if it was your room, what treatment would you apply?

Room treatment is a deep subject, and a complete answer requires far more than will fit into a single reply here. So here's the short version. All rooms need:

* Broadband (not tuned) bass traps straddling as many corners as you can manage, including the wall-ceiling corners. More bass traps on the rear wall behind helps even further. You simply cannot have too much bass trapping. Real bass trapping, that is - thin foam and thin fiberglass don't work to a low enough frequency.

* Mid/high frequency absorption at the first reflection points on the side walls and ceiling.

* Some additional amount of mid/high absorption and/or diffusion on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. Diffusion on the rear wall behind you is also useful in larger rooms.

There's a lot of additional non-sales technical information on my company's site - articles, videos, test tones and other downloads - linked under my name below.

--Ethan

[youngho]

GloP, a few random thoughts:

Your configuration is probably the best one.

With a 110 inch screen, viewing distance typically should fall between 2-5x the screen size, so you'll probably want to place the prime seating positions between 12 and 15 feet from the screen (assuming 16:9 dimensions and 30-36 degree viewing angle as per SMPTE and THX recommendations). This will put the listeners near the center of the room. The bad news is that this may result in significant peaks and nulls, but careful placement of speakers and subwoofer(s) can help this. Specific frequencies are difficult to predict because they'll depend on placement of the speakers and listeners, as well as details about the room contruction in terms of the walls themselves. For example, based solely on the dimensions, you might predict that listeners in the center might experience relative nulls at around 22 and 66 Hz due to the length modes, 44 Hz due to the width mode. However, the speakers might reduce the effects of the width mode through mode cancellation, and pulling the speakers forward significantly from the front wall will help reduce the activation of the length mode. Drywall construction will reduce the frequency and amplitude of the modes, if I'm not mistaken. The good news about the relative center positioning is that it puts the rear wall 10-12 feet behind the listeners.

The room is only 12-13 feet wide, and Berkline recliners appear to be about 3.5 feet wide, so you may need two rows if you go with these. Because of the width of the room, it will basically necessitate pulling the speakers fairly far forward from the rear wall, although this will be helpful in terms of the length mode. I would consider pulling the speaker at least 3-4 feet forward from the rear wall, 2-3 feet out from the side walls. This will put the speakers in close to a 60 degree arc.

The door in the back corner will make bass trapping in this sidewall-sidewall corner difficult. The window in the front right corner (assuming you're facing left) may limit the width of bass absorption in this sidewall-sidewall corner. You may have to take advantage of sidewall-ceiling corners. I would certainly consider putting up thick curtains in front of that large window in the front wall, thick rug between the speakers and subwoofer, and absorption panels at the first reflection points, as Ethan suggested. Can you talk about what you plan to do in terms of media storage, bookshelves, paintings, also the stuff that you plan to put in the back of the room?

Thanks,

Young-Ho

p.s. phrase in last paragraph should have read "think rug between the speakers and you"

[bpape]

Keep in mind that treating a room for 2 channel vs multi-channel HT is a tradeoff.  There are some common goals and other parts of the acoustic design are completely different.  You have to decide which is more important to you and lean that way in the acoustic design.  You're starting off with some very nice speakers so that's a plus. 

The rug between you and the speakers is a must in either case. 

One other thing - set the seating positions first.  That and the PJ you select will determine what size screen is appropriate.  Don't go into this with a screen size set in stone or we're working backward and forcing speaker and seating position to fit a screen that may or may not be of the appropriate size for the overall best functioning of the room and system.

BRyan

[GloP]

Thanks everyone for your replies, much appreciated. It all makes sense.

I will only have one row of seats or a couch. As far as screen size goes, this is because I have a 110" fixed screen from my previous home that I'll probably be selling when I go with an electric screen on the left side of the room and it seemed like a good fit size wise for the room, but no real constraint there even though it'd be nice if I didn't have to go much smaller (I don't mind being at the closest range of the recommended values if I have to ).

Can you talk about what you plan to do in terms of media storage, bookshelves, paintings, also the stuff that you plan to put in the back of the room?

Acutally I don't have many plans at this time for the rest of the room, I figured I'd start with the primary function of the room, music then secondary movies, and go from there. I might put a small bar on the right hand side of the room or a foosball table or something similar. As far as media storage/bookshelves and paintings, I do intend to put stuff on the walls but I'm pretty flexible if that makes any sense. Are you saying that if I put bookshelves in the back for example, it would a good idea to help handle diffusion for example?

Thanks again everyone!

[youngho]

GloP, I have to add the disclaimer that I know only the little that I've read in books, articles, and online. I lack the formal learning and practical experience that others here have to offer. But I do have a few more thoughts:

To start, the Salk speakers sure are pretty! If I were you, I might consider starting with real-world stuff to help establish the acoustic of the space. Floyd Toole writes, "If the listening room is also a normal living space, it may not be necessary to use any special acoustical devices at all. With a little thought, bookcases, display cases, paintings, fireplaces, etc. can all do the job without making the room look at all “technical”" in a white paper on loudspeakers and rooms (http://www.harman.com/wp/pdf/LoudspeakersandRoomsPt2.pdf). Siegfried Linkwitz writes, "Rather than special products for acoustic treatment of a room I prefer the normal stuff of life - books, curtains, pictures, rugs, wall hangings, shelves, cabinets, chairs, sofas, etc. - to establish the acoustics of my living spaces" on his website (http://www.linkwitzlab.com/rooms.htm). These are pretty smart guys, but since I figure you'll add this stuff eventually, anyway, you may as well think about what you'll have and where you plan to put it. Some of this stuff may help provide some degree of absorption and/or diffusion.

Linkwitz argues for symmetry with respect to the room-loudspeaker-listener setup, which could become a tiny bit of an issue if you sit more than 12' from the front wall. Perhaps a closed cabinet or bookshelf might go to the right of the listening position if so, which might help make this part of the room more symmetric for the listener(s).

Looking again at your room, you're a little limited by the width of the room. Linkwitz argues for pulling the speakers at least 3' from the nearest room boundaries, but if you do this, then the speakers will less than 6' apart, which is rather narrow. Furthermore, you might have to place the screen height a little higher to avoid having the speakers cast a shadow, but then depending on how far you're sitting, this may result in a slightly uncomfortable angle in terms of tilting your neck back. If you put the speakers 2' from the side wall, then you'll definitely want to absorb the first reflection points on the sidewalls, so you might go ahead and pick up two panels for this purpose.

After setting up "the normal stuff of life" and treating the first reflection points on the sidewalls, you might spend some time optimizing the speaker and listener positions. After that, before buying too much else stuff, you might consider taking a little time and/or spending a little money to get some basic measurements (http://www.realtraps.com/nti_minirator.exe or http://www.nti-audio.com/Home/Products/Minstruments/Acoustilyzer/tabid/60/Default.aspx or http://www.trueaudio.com/ or http://www.etfacoustic.com/) to more clearly define what your problems are so that you can properly address them? I think that this would be money and time well-spent.

Young-Ho

[Big Red Machine]

You can fit 4 Berkline 088's on a 10 foot wide platform (That is what I did in my HT).  In the back of your room where it is wider this would work nicely.  You could easily do 7, even 8 seats with your depth of room.  My room is 15 wide rear and 13.5 wide front and 24 feet deep with the door in the same spot.  Check out my photos for an idea of how everything fits (V3's up front).

[Big Red Machine]

I have one at home that has dimensions on it.  This one I had at work.  Rotate it 180 degress and it looks like your room.  The blue shapes are the head figures.  The red up front is the curtain.  The squares in the back are the coffered ceiling sections.  You can see the platform and 2 rows of seats with room to walk along the back where the DVD storage is.

More photos here from last year's HT GTG:  http://alhull.com/hemi2007sanctum/index.htm

[Speedskater]

When reading technical white papers keep in mind that Siegfried Linkwitz writes about two channel music systems and much of the Harman / Floyd Toole literature is about multi-channel home theater rooms. Two channel music systems place different demands on the room than multi-channel systems. The number of expected listeners in the room will also change the room requirements.

[Big Red Machine]

All true Kevin.  And I personally do not like the "overdamped" HT's that most of my HT peers have built.  But for the surround experience they do sound pretty darn good.  On the other hand, my room is a dedicated HT but does sound very good in 2 channel mode.  I went old school with dead front and live rear.  I do not spend time in there listening to stereo or SACD but it is pretty nice.  I bass trapped fairly heavily as well.  My point(not sure I have one)?  Lots of folks only have enough room for a multi-purpose room and it does work for both if you don't overdo the HT stuff.

[youngho]

Linkwitz and Toole often approach room acoustics and loudspeaker setup from different viewpoints, but they do agree about "the stuff of life" helping in terms of room acoustics. Also, despite its title, virtually everything in the white paper by Toole which I linked is relevant to two-channel systems.