Originally Posted by Oledurt
I am thinking of pulling the trigger on some polk audio RTia series speakers for my home theater. I was thinking the Polk RTi A7's for my main speakers.
I can get the polks for a good price and I have read that people seem to like them a lot. I was telling a friend about this today and he informed me that it is always better to get bookshelf speakers in a home theater and said that floorstanders are for stereo mostly.
I don't understand this. Wouldn't a floorstanding speaker have more bass and isn't that better for movies explosions etc???
Bass has two major dimensions:
(1) Bass extension which is the lowest frequency reproduced with flat response
(2) Bass dynamic range which is how loud the bass plays cleanly.
These dimensions are orthogonal, which is to say that one does not necessarily affect or presume the other.
The way that this relates to your question that I have found that major manufacturers often make their bookshelf speakers and floorstandng speakers with the same bass drivers.
Given a certain bass driver you can put it in a bookshelf enclosure and you have response flat down to a certain frequency. You put the same driver into a far larger floor standing enclosure and it responds to a lower frequency. So far so good. However, all other things being equal the larger enclosure does very little for the bass driver's dynamic range. It turns out that the bass dynamic range of a speaker driver is based on cone area and linear travel. The enclosure size does not affect either one. Furthermore extending a bass driver's response to lower frequencies actually decreases the available clean SPL at the lower frequencies all other things being equal..
If a manufacturer builds the bookshelf speaker with say one driver of a given size, and builds the floor stander with two drivers of the same size, it is probable that the the floor stander will have both more deeply extended response and more dynamic range to go along with that response. If both speaker systems have the same number of the same drivers then the floor stander will be compromising dynamic range for the frequencies in the extended frequency range.
So if you look around you will find a lot of speakers that fit into either category. Beware of the floor standers with the same number of the same sized driver(s) as bookshelves.
Another thing to consider is that it is not unusual for the distortion in a given speaker to start increasing at frequencies significantly higher than the frequency at which it starts rolling off and loosing response. For example, a speaker may start loosing response at 60 Hz, but its distortion may start increasing for frequencies below 100 Hz. This is where proper use of a subwoofer can be very beneficial. But not stressing the speaker by trying to run it down to its limit, you might obtain cleaner sound.
Just FYI I have a Rythmik F15HP sealed servo subwoofer for my bass.
That is an excellent tool for you to exploit in order to obtain better cleaner sound.