I've got an unfinished portion of our basement which I'm going to frame in for a home theater room. The dimensions of the room will be 230" x 170". Floor is concrete which I'll cover with carpet. Walls will be insulated with Rock Wool for sound. I plan on the following 9.2.2 speaker system

Looking for comments and suggestions on the room, dimensions, speaker placements, ( should height speakers be on the side walls or on the front wall with the TV?) subwoofers, receiver and speaker wire gauge.

I plan to put the AV components in the utility room out of site. Looking at various OLED TV's. 77" or 83"

I plan on putting the HT room door towards the back of the HT.

All comments and suggestions welcome.

 

19'x14' is not a large space so the speakers you're looking at should do fine. I do see that you want 9.2.2, but your list only shows 9 speakers and not the 11 it would take for that configuration. You would have to adjust quantity to hit your goal.

Depending upon your expectations, bass could present some challenges. Concrete is the mortal enemy of low frequencies, its rigid nature dampens low notes. If you want a lot of rumble you'll need several very powerful subwoofers. In the SVS family I'd suggest looking at the PB-16 or the PB-17. The former because it's going to be discounted as it is an outgoing model, the latter because it's a beast (I have one in my living room at this very moment). The 7' opening into the gym isn't going to help matters either, that volume of space will impact how effective the subwoofer(s) will be.

How are you setting up the room, with regards to the seating and where the TV will be placed?

 

Hi Jim:

Thanks for the feedback. The entire home theater room is enclosed by 4 walls in orange. There's a door in the back corner. I plan to cover the floor in carpeting. The TV location is shown. I'll have the center channel and R/L front speakers along this wall as well. The subwoofer(s) along with their placement is a question I'd like to have your comments on. I plan on having six recliners in the room, 3 across and two rows. I would have the back row all the way back hugging the back wall. Side surrounds in line with the front row of chairs. Where would you recommend putting the height speakers.

 

A few thoughts. Are you concerned with sound isolation? Do you have an HVAC plan? Electrical wiring plan? Low voltage wiring plan? Lighting plan? Riser plan? Sound acoustic plan? Under carpet flooring plan? Forget the TV, get an immersive screen & PJ for the best setup. You have a great deal of planning before you nail your first board, or you will be hugely disappointed IMHO.

 

The entire home theater room is enclosed by 4 walls in orange.

Looking at the original diagram seemed to indicate the back corner might be an opening into the gym, having it be a solid wall is a good choice.

I plan to cover the floor in carpeting.

That will help the people in the room, but not the subs I'm afraid. The structure the carpet sits on top of will still be concrete; the material in the carpet will help with overall sound dampening, but the solidity of the concrete will negatively impact low frequency reproduction regardless. The "chest slam" aspect will not really be affected, the rumble and subsonic sensations are where the losses will occur.

The subwoofer(s) along with their placement is a question I'd like to have your comments on. I plan on having six recliners in the room, 3 across and two rows. I would have the back row all the way back hugging the back wall.

The room itself actually decides ideal subwoofer placement; its dimensions, construction, seating locations, etc. all factor in. Certain rules of thumb can be used to make educated guesses, but at the end of the day the only way to really know is to use measurement gear. Some of it is old fashioned trial and error, graphing out several positions and combinations and then making an objective assessment based upon the data. That's beyond what most people can do though.

A common arrangement is to have the left, right and center against a front wall. Those outboard speakers are then flanked by the subwoofers. Depending upon room modes - areas where low frequencies are either amplified or diminished - subs up front might not be the best setup. In that case, along the side walls are a popular choice. Bass waves, unlike midrange and treble, are very long so there are more placement options for subs than speakers. They don't actually have to be pointed directly at the listeners to get the full effect.

One thing I would strongly discourage you from doing is to place any seating up against the back wall. The reinforcement of the bass waves at that location will be so pronounced that the people sitting there will almost certainly consider it obnoxious. Even using the room EQ system your receiver will have - Audyssey, YPAO, MCACC, etc. - will not fully correct that.

 

Hi Jim:
Thanks for the continued advice. I plan to insulate the walls with rock wool. Under the carpet will be some insulation type padding like Duralay, Luxwalk, or Plushwalk. Got you on the sub placement. Are you more in favor of one larger sub or two smaller subs for this size room. Any suggestions on how to improve the subs response on concrete? Is the underlayment and carpet enough or are there any type of damping components available? Understand the issue with the seating arrangement. I'll move those away from the back wall. I'll have a riser platform for the rear seats. Sconces on the side wall on dimmers for lighting. What is your recommendation for height speaker placements? Above the L/R fronts? Ceiling mounted overhead above the first row of seats, or on the wall above the side satelite speakers?
Thanks

 

Be sure to post pics of the build!

 

Under the carpet will be some insulation type padding like Duralay, Luxwalk, or Plushwalk. Any suggestions on how to improve the subs response on concrete? Is the underlayment and carpet enough or are there any type of damping components available?

No matter what type of padding and carpet you lay on top, the concrete will still be underneath. Adding those layers above it will help with reflected sounds from the speakers, but the really low frequencies produced by a sub will still be hampered by the rigid structure. Before getting too concerned though I'd suggest you try it first and see what the results are. Everyone's goal isn't the same, you may not be disappointed with the outcome.

If you do get powerful subs and find out that it's not what you had hoped for then perhaps haptic devices like Butt Kickers might be worth considering. They attach to the seating and send vibrations into the frame, that simulates the rumble sensation a subwoofer would on non-concrete surfaces.


Are you more in favor of one larger sub or two smaller subs for this size room.

The answer most people will give is duals, but that doesn't take into account several key factors; how much flexibility you have with regards to placement options, and if you're able to tune them properly. Because there can be such deep nulls in the output due to room dynamics - ones that can't be corrected with EQ - you need another method to flatten out the response in those frequency ranges. A second sub, placed in a position where its output has peaks in those same ranges, will effectively negate the null (for example, a -5dB null from one sub would be cancelled out if another sub had a +5dB peak in the same range). In essence, you're using the room to fix a problem the room gave you in the first place. But to do that you need the ability to situate the subs where they will compliment each other.

That leads to the tuning part, you need measurement gear and the understanding of how to interpret the readings to position the subwoofers where they can counteract each others null(s). Some AVR's have sophisticated enough room EQ systems to handle multiple subs, but if they aren't already physically placed in locations to compensate for each other then you're back to the original problem; you can't use EQ to pull up a null. And the way to determine if the subs are in the right locations for room EQ to do its thing? Measurement gear. The problem and solution are a loop of sorts.


What is your recommendation for height speaker placements? Above the L/R fronts? Ceiling mounted overhead above the first row of seats, or on the wall above the side satelite speakers?

If you're only using 2 heights I'd position them over the seating area in such a manner that both rows would benefit from them.

 

Thank You!!

 

Carpet padding is entirely inconsequential for subwoofers. Do whatever you like with the carpet padding. To affect bass from a subwoofer, you need bass traps that MUST be 5 to 8 feet long in at least 1 direction, The wavelength of 30 Hz, for example is 10.3 feet, so a bass trap capable of controlling 30 Hz has to have one dimension that is at least 5.15 feet long.

You will literally drive yourself insane trying to setup a subwoofer without having an SPL Meter. You really MUST have one. Be sure you get one capable of accurately measuring 16 Hz--or one that is provided with a correction table that might look something like this:
30 Hz +2 dB, 25 Hz +4 dB, 20 Hz +6 dB, 18 Hz +5 dB, 16 Hz +8 dB. What that table means is if you measure 20 Hz at 70 dB on the meter, you hav to add 6 dB to that measurement to get the accurate measurement of 20 Hz. So your 70 dB measurement is REALLY 76 dB.

The next thing you use the sound pressure level (SPL) meter for is to find the ideal spot to PLACE the subwoofer. The main problem with that is that you would probably be tempted to put the microphone where you sit, and move the subwoofer to different locations followed by recording a series of measurements from 16 Hz to 100 Hz or whatever your top frequency for the subwoofer is. Your best position will have the fewest and smallest variations in your measurements for each frequency. This is brutally annoying to do in a room with "stuff" in it. I will suggest a radical solution that will speed the process dramatically... place the subwoofer where you will sit... right on the sofa or chair--just don't block any radiating surfaces of the subwoofer--and don't block any ports on the subwoofer either. Run a set of measurements where you would LIKE to place the subwoofer. If there are big differences at different frequencies, move to a different convenient location -- if the response is still lumpy, try moving the SPL meter to a different location. The height of the meter for the measurements should be about equal to HALF the height of the subwoofer. So if the subwoofer is 18 inches tall and the radiating woofer is in the middle of the cabinet, you'd want the SPL meter 9 inches from the floor and aimed vertically at the ceiling. If the subwoofer is 18 inches tall, but the woofer is closer to the top of the subwoofer than to the bottom, you might need to put the SPL meter at 10 or 11 inches off the floor. OK, if none of the "easy" locations produce a reasonably non-lumpy response (all readings within a 10 dB window is pretty **** good for a subwoofer).

There is a room dimension interaction with every subwoofer... in fact, there are 3 room dimension interactions with every subwoofer. The height, width, and depth of the room can interact with the sound produced by the subwoofer causing a cancellation that can make it look like some spots in the room have NO BASS at that frequency. This is called a room cancellation. If your height dimension, width dimension, and depth dimension are all the same, you have a TERRIBLE room for bass response. So a room 15 feet x 15 feet with a 15 foot ceiling... terrible room for bass. Even having 2 room dimensions the same can be problematic. The best scenario is if each room dimension is different. It is better yet if each room dimension is not divisible by the same number... so a room that's 12 x 14 x 16 may seem good, the fact that you can divide each dimension by 2 is a bad omen for getting good bass. 9 x 18 x 27 would also be a "bad" room because each dimension is evrnly divisible by 9 or 3. If you have a CHOICE about the room dimensions, having them prime numbers is a good way to go... 11 x 17 x 23 for example. When a room dimension interacts with some frequency, you can end up with a cancellation effect that is profound. You might be measuring 70 to 80 dB everywhere except 1 frequency you measure might appear to have no sound at all because the cancellation effect is so profound. It's just a room dimension causing that problem, so move the subwoofer a bit. I suggest moving the subwoofer 6 to 12 inches... not less than 6 inches while looking for a good subwoofer location. This whole process is so much easier if your test tones can be controlled with a remote control or tablet/phone/laptop. You want to avoid placing the subwoofer anywhere that there is a strong cancellation. There is NO FIX for room cancellations except for moving the subwoofer away from that spot.

The beauty of moving the SPL meter is that you can place it in locations that may have other objects without having to rearrange the room for each measurement. When you eventually find a spot where the SPL meter produces reasonable measurements, put the subwoofer there, and move the SPL meter to your main seat then repeat the measurements just to confirm that you found a good spot at last.

Picking a subwoofer is entirely dependent on the speakers you will use... specifically, the SMALLEST speakers you will use. If you choose speakers that are "done" producing sound at 120 Hz or so, your subwoofer MUST have a driver with low-enough mass to be able to reproduce low distortion sound at 180 Hz... because you don't want the subwoofer to give up at 120 Hz if the speakers also give up at 120 Hz. You have to have at least 1/2 of an octave of frequencies overlap between the subwoofer and other speakers. If you use small speakers that run out of gas at 120 Hz, you will set the crossover at 150 Hz from the subwoofer to the other speakers. An octave is ANY doubling of frequency... 33 Hz to 66 Hz is an octave. 100 Hz to 200 Hz is an octave. 6000 Hz to 12,000 Hz is an octave, 444 Hz to 888 Hz is an octave. The crossover slope for the subwoofer will probably be 12 dB or 18 dB per octave. So if the subwoofer crossover is set to 100 Hz, at 200 Hz, the subwoofer would be "down" in response by 12 dB or 18 dB but it would still be making sound if the SPL level was 80 dB average. BIGGER speakers can use a lower crossover point. If your speakers are -3 dB at 70 Hz, you can set the subwoofer crossover to 100 Hz to get the overlap you need.

There is 1 RADICAL shortcut to subwoofer placement that works 100% of the time and is AUTOMATICALLY the best place in the room to place the subwoofer. Put the subwoofer directly behind your main seat, almost touching the seat... get it as close as possible to your main seat. This means your direct sound from the subwoofer will overwhelm any room effects and you will hear the most linear bass you can POSSIBLY achieve in any room. This works best with subwoofer crossovers of 100 Hz or lower. So using speakers that are -3 dB at 70 Hz or lower is ideal for the near-field placement of the subwoofer. You will always hear the direct sound from the subwoofer before it has an opportunity to interact with the room. Obviously, you have to be CAREFUL setting the level of the subwoofer when it is that close so it doesn't become overpowering. That's another place the SPL meter helps you. You can measure, say 300 Hz, and 50 Hz and adjust the subwoofer level so 300 Hz and 50 Hz have the same reading on the SPL meter. A lot of people reject this location for the subwoofer without even taking a shot at using it because they think it MUST be WRONG. But they are all incorrect. If you can manage nearfield subwoofer placement, you will automatically get the best bass you can get in your room because you are so close to the subwoofer, the room is kind of removed from the equation.

Small speakers require a sub on the small side... 10-inch driver or 2 8 inch drivers would be the best choice. You also have to decide whether you want a sealed-box subwoofer or a ported subwoofer. Sealed-box subwoofers sound best with music, but it is **** difficult to find any sealed-box subwoofer that can produce bass much below 22 Hz... and it will begin rolling-off bass response at 30 Hz. Even if the sealed box is kind of large, it might still only reach 20 Hz at 5 or 6 dB below 30 Hz dB level. I solved this by getting a subwoofer with 2 ports and 2 plugs for those ports. I remove 1 plug for movies and TV shows, and I put that plug back in for music. 2 plugged ports turns the subwoofer into a sealed box subwoofer. If your budget-limited for the subwoofer, I heartily recommend Hsu Research VTF-3 in whatever the current configuration is. Mine has a 15-inch driver in a larger than average cabinet... and it is FLAT in my room from 10 Hz to 110 Hz. You cannot hear 10 Hz at all, but when I play a 10 Hz test tone, it feels like somebody turned-on a large fan and the SPL meter still response to the 10 Hz wind as though it is an audible frequency. Needless to say, 16 Hz is reproduced at the same level as 80 Hz (1 port plugged, 1 port open)... it is an astonishing accomplishment to get that kind of bass response from a sub-$1000 subwoofer. You only need 1 subwoofer if your subwoofer is THAT good. The only reason you'd ever need 2 subwoofers is to cancel a room mode (bass suckout at some specific frequency) you cannot avoid for some reason. One Hsu Research subwoofer has been plenty for the last 3 rooms I've had (19.5 x 23.5 x 10.5 and 20x24x 8.5 and 13 x 28 x 8.5 all in feet). It will play louder than I need and I found a great location in each of those rooms where there has been little or no bass suckout problems.

To experience 10 Hz bass in your theater room... in the movie called Edge of Tomorrow (Tom Cruise, Emily Blunt), at the beginning of the movie while the opening credits are still running... when the Village Roadshow (one of the backers of the movie) appears, a bass frequency sweep begins at about 40 Hz. That frequency sweep goes lower and lower and lower until it finally ends at 10 Hz. If you feel wind in your room at the end of that sweep, you'll know your subwoofer is reproducing 10 Hz.

 

Carpet padding is entirely inconsequential for subwoofers. Do whatever you like with the carpet padding. To affect bass from a subwoofer, you need bass traps that MUST be 5 to 8 feet long in at least 1 direction, The wavelength of 30 Hz, for example is 10.3 feet, so a bass trap capable of controlling 30 Hz has to have one dimension that is at least 5.15 feet long.

You will literally drive yourself insane trying to setup a subwoofer without having an SPL Meter. You really MUST have one. Be sure you get one capable of accurately measuring 16 Hz--or one that is provided with a correction table that might look something like this:
30 Hz +2 dB, 25 Hz +4 dB, 20 Hz +6 dB, 18 Hz +5 dB, 16 Hz +8 dB. What that table means is if you measure 20 Hz at 70 dB on the meter, you hav to add 6 dB to that measurement to get the accurate measurement of 20 Hz. So your 70 dB measurement is REALLY 76 dB.

The next thing you use the sound pressure level (SPL) meter for is to find the ideal spot to PLACE the subwoofer. The main problem with that is that you would probably be tempted to put the microphone where you sit, and move the subwoofer to different locations followed by recording a series of measurements from 16 Hz to 100 Hz or whatever your top frequency for the subwoofer is. Your best position will have the fewest and smallest variations in your measurements for each frequency. This is brutally annoying to do in a room with "stuff" in it. I will suggest a radical solution that will speed the process dramatically... place the subwoofer where you will sit... right on the sofa or chair--just don't block any radiating surfaces of the subwoofer--and don't block any ports on the subwoofer either. Run a set of measurements where you would LIKE to place the subwoofer. If there are big differences at different frequencies, move to a different convenient location -- if the response is still lumpy, try moving the SPL meter to a different location. The height of the meter for the measurements should be about equal to HALF the height of the subwoofer. So if the subwoofer is 18 inches tall and the radiating woofer is in the middle of the cabinet, you'd want the SPL meter 9 inches from the floor and aimed vertically at the ceiling. If the subwoofer is 18 inches tall, but the woofer is closer to the top of the subwoofer than to the bottom, you might need to put the SPL meter at 10 or 11 inches off the floor. OK, if none of the "easy" locations produce a reasonably non-lumpy response (all readings within a 10 dB window is pretty **** good for a subwoofer).

There is a room dimension interaction with every subwoofer... in fact, there are 3 room dimension interactions with every subwoofer. The height, width, and depth of the room can interact with the sound produced by the subwoofer causing a cancellation that can make it look like some spots in the room have NO BASS at that frequency. This is called a room cancellation. If your height dimension, width dimension, and depth dimension are all the same, you have a TERRIBLE room for bass response. So a room 15 feet x 15 feet with a 15 foot ceiling... terrible room for bass. Even having 2 room dimensions the same can be problematic. The best scenario is if each room dimension is different. It is better yet if each room dimension is not divisible by the same number... so a room that's 12 x 14 x 16 may seem good, the fact that you can divide each dimension by 2 is a bad omen for getting good bass. 9 x 18 x 27 would also be a "bad" room because each dimension is evrnly divisible by 9 or 3. If you have a CHOICE about the room dimensions, having them prime numbers is a good way to go... 11 x 17 x 23 for example.

Thanks: Room Dimensions are 19' x 14' x 9', so it looks like I'm good with the room interaction. I plan to have two SVS Ultra towers which have dual 8" woofers and a SVS PB-2000 in the room. Don't have much leeway on where to put the towers, they'll be on either side of the OLED screen, but I can move the Sub just about anywhere. The room's not built yet so I was planning to have multiple subwoofer cable boxes throughout the room to be able to hopefully get the sub in the best location. Thanks for the idea for an SPL meter. Do you have any recommendations? I was also planning on putting bass traps in all 4 corners of the room. Floor to ceiling. Right choice?

 

I have an old analog Radio Shack SPL meter that was $30 or so... had it measured against a reference microphone to get a correction table made. Since I've had the same meter since the 1970s, I'm not a good source for "new" SPL meters that work well. You can sort of roll your own SPL meter if you get a $50 Behringer reference microphone (USB) and connect that to laptop running Room EQ Wizard software with Windows (free) and you get all the benefits of the kind of overwhelming stuff REW can do with measurement data. I do not know if there are Mac or Linux versions of REW. I find it difficult to believe somebody put so much into free software. And it has been free for 20 years or more already. If you are interested at all in getting into measuring your room, you can't beat REW for the sheer volume of information it can provide if you know what it all means. REW has an SPL graph you can display if you want to use it for measurements. You can also save multiple sets of measurements and REW will display ALL of them at the same time, each set of measurements in a different color so you can see the measurements with the biggest problems incredibly easily. It's great software.

 

Sorry for the long delay, but I've finally got the ok to start building a dedicated home theater in the unfinished portion of my basement. The framing was completed today. 23' x 14' x 9'. I plan on having a 7.2.4 sound system. SVS Ultra Towers, Ultra Center Channel and Prime Elevation Height Speakers. SVS PB 2000 subs. Rear Surrounds are Def Tech Studio Monitors 65. Side Surrounds are Def Tech Bipolar SR9040's Receiver is Onkyo RZ50. Plan to buy amps to drive the front towers and center channel. Looking at putting an 83" OLED or 100" micro LED for the display. I'll continue to post as the build continues. Hope to get questions answered within the thread. Thanks for you support. Pictures below