Oh you can get that kind of audio quality at home. You can improve upon it, even. It's not cheap. But it doesn't have to be crazy expensive either.
But getting there means actually making audio a priority in your room. For so many people, audio is an afterthought, or it's severely compromised in favor of aesthetics or very low cost. You can't expect IMAX-quality sound from tiny or invisible speakers. You can't get that kind of deep, tactile bass from a $200 sub. It takes what it takes. But if you're willing to make audio a priority, you can definitely equal and surpass what you heard in the theater!
It does start with the room itself. You need to give attention to your room's acoustics and to your seating position within the room. So many people have their couch pushed right back against the wall. That's no good. You wind up with very strong reflections that degrade imaging and clarity and make dialogue difficult to understand. It's also a bad spot in your room for bass. So, ideally, your seat will be about 1/3rd of your room's length (from front to back) from the back wall that is behind your seat, and thus about 2/3rds of the room's length from the front wall. And your primary seating position will ideally be roughly centered width-wise.
The front portion of your room will ideally be somewhat damped with acoustic treatments that absorb reflected sound waves. This makes the sound coming from your front speakers pin-point precise. Directly behind you will be a thick bass trap, to curtail those reflections off of the back wall and help to even out the bass response back there a little bit. Meanwhile, the back portion of your room will remain more "lively" by opting to scatter the sound with diffusion treatments. This will retain the ambience created by your surround speakers, and help to create the enveloping surround effect that seems to "blanket" your seats with surround effects.
The corners and edges of your room can house bass traps, which will reduce standing wave problems and give you "tighter" bass that doesn't linger and reverberate throughout the room well after it was supposed to stop.
What's great is, all of these treatments can look good and come at a reasonable price these days. Between Acoustimac.com and GiKacoustics.com, you can get regular solid color fabric panels, designer fabric panels, suede panels, patterned panels, or even panels with stock or custom artwork printed on them so that they can literally double as posters or artwork. Most people hang some pictures or other decoration on their walls. Why not kill two birds with one stone and have that artwork also be an acoustic panel?
And let's not forget about soundproofing. One of the reasons why the sound in an IMAX theater sounds so clear is because it is LOUD. Louder than THX Reference level, actually. Most people don't listen anywhere near that loud at home. Sometimes it's because their home theater can't play that loud without sounding all distorted, screechy, or on the verge of breaking! But more often, I think, it's because playing movies that loud would draw complaints from neighbors or certainly from other people who live in your house and don't want every room shaking when you watch a movie!
So it's all about creating a good environment for movie watching in your room first. Check out soundproofingcompany.com for the best information and products for soundproofing. You might end up doing some renovations, or even building and entire "room within a room" if you're really serious about getting full THX Reference Volume levels. That's not easy or cheap, but it's also not as expensive as you might think. Today's products make it easier than its ever been to actually soundproof a room. If everything behind the existing walls is already good, a simple layer of Green Glue and a second layer of inexpensive 5/8" drywall right over the existing walls and ceiling can make a dramatic difference and eat up very little floor space and money.
Once the room is good, you turn your attention to speakers and subwoofers. And after that, the processing and amplification to drive them. To get IMAX-type sound, you need highly dynamic speakers that are capable of high output levels without distortion. Easier said than done! And they won't be tiny cubes or skinny sticks that you mount on your wall. They're going to have to be proper speakers that can move the air and get the job done right! Same goes for the subwoofers. First off, that IS plural. More than one subwoofer isn't so much about playing louder (although that's an added bonus side effect
). Rather, multiple subwoofers spread around the room allows you to have even, uniform bass at all of your seats, rather than only being able to EQ a lone subwoofer for good bass at ONE seat, but not at any of the other seats in the room. Having multiple subs creates lots of constructive and destructive interference between all of the bass waves, which leads to a "smoothing" effect so that you don't have any giant humps or dips at any given seat. Just more or a smooth, even, uniform bass response at every seat in the room.
When it comes to amplifier power, you often don't need nearly as much as you might think. Highly dynamic speakers that can play loud without distortion are often highly efficient speakers, too. Many will produce over 90dB of output from just 1 Watt of power if you are 1 meter (about 3 feet) away. Every time you double that distance, the output drops by about 3-4 dB in a room. Out in a wide open field, doubling the distance would drop the output by 6dB. But in a room, even one that is acoustically treated, you still get reflections that reinforce the sound, so a doubling of distance from the speakers only drops you 3-4dB.
THX Reference volume calls for 85dB at the listening position for average loudness content. That's very loud. But that's what you're getting in IMAX or a THX theater. Peaks - big explosions and crescendos and whatnot - get up to 105dB in the speakers, and a crazy loud 115dB in the LFE bass.
Every time you want to get 3dB louder, you need double the number of Watts. If you want to get 10dB louder, you need 10x the number of Watts! So MOST of the time, you only need 1 or 2 Watts. But that can jump to 100 or 200 Watts in the blink of an eye.
So, for example, you might get some efficient speakers that produce 93dB using just 1 Watt from 1 meter away. Now let's say your seat is 4 meters away (about 13 feet). To get there, you doubled the 1 meter distance to 2 meters, and then doubled 2 meters to 4 meters. Each doubling dropped you 3-4 dB. So let's say you're in a well damped, acoustically treated room and dropped 4dB with each doubling. That's 8dB down, so 1 Watt from the amplifier is giving you 85dB of output at this 4 meter distance with these efficient speakers. Voila, you're already at full THX Reference Volume for average loudness content! 1 Watt. Doesn't take much
But then come those 105dB explosions. 10x the Watts gets you 10dB more output. So 10 Watts = 95dB. And 100 Watts = 105dB. We're there!
But what if your speakers weren't as efficient? Maybe they produced 90dB using 1 Watt at 1 meter instead of 93dB. Now you'd need another 3dB of output with these less efficient speakers. 100 Watts gets you 102dB at the same distance with the less efficient speakers. 3dB requires double the number of Watts. So with these 90dB/1 Watt/1 meter speakers, you need 200 Watts to hit those 105dB peaks from 4 meters away.
And now you can see how even less efficient speakers or a farther distance could make the number of Watts needed skyrocket in no time! And most speakers can't handle more than about 400 Watts max. But some can handle a lot more. So it's simply all about getting appropriately efficient speakers and enough amplifier power to handle your particular seating distance.
Them's the basics, anyway. Hopefully that'll be of some help to you
