As long as it can provide satisfaction for your high quality digital entertainment, then, yes, you can call it as home theater.
However, a relative definition of term still has some common similarities or standards.
It is the same as you define other object such as car, computer, speaker, etc.
So, what makes yours as home theater? Basically,it really should consist in 3 parts combined together:
- Huge Display Screen.
It should literally 'huge' for the size.
The purpose of this big display screen is to provide you various kind of visual output with high definition quality.
And this So, this doesn't has to be a TV.
You can even use computer monitor if it is suitable and capable to satisfy the main purpose.
- Video Source.
Commonly it is DVD/CD Player, portable MP3 player, i Pod, gaming system and it's kind.
For a wider terms, this including satellite TV or TV cable service.
Well, DVD/CD player, based on most people preference, is a must have device, since it is widely used to watch favorite movies and other digital entertainments.
- Surround Sound This what makes you feel just like in theater.
Watching your favorite movie just like you are part of that movie.
You can see the surround sound specification by its number.
You might often see terms like 5.
Well, the first number indicate the number of speakers or main audio channels, while 1 or 0 tells you if the system has sub woofer or supports effects channel.
1 means "Yes it has", and 0 means the other way.
For example: 5.
1 have 5 main channels and 1 (low frequency effects) bass channel.
By the way, 5.
1 is a main build for surround sound.
It is widely used for movie theaters and some entry level systems such as Onkyo HT-S 3300.
So, if you want a satisfying minimum requirement of surround sound, you can go with 5.
If you miss any of these 3 things, I'm afraid to say that you just own an ordinary TV set.