Not necessarily!
Hi,
I've seen a 5.1 package, an EPOS avs 5.1 home cinema system. The front & rear speakers are identical. the salesman said that the same size format makes the system a better match than different sized front & rear (same power requirements, same sonic levels (?) etc).
Welcome to the Forum,
The power requirments and sonic levels rationale sounds like chaff to me. However,
voice matching speaker is generally advisable and there are several levels at which this can be done:
Using
PSB Image T-45 tower speakers as an example, this can be done by using the same model (
T-45); if not, then from the same series (
Image); if not, then from same the brand (
PSB), or just having the same size/type woofer (
5.25"/metalized polypropylene), etc. Each option involves different cost, WAF, and room real estate.

yet?
IMHO, exact matching the rears to the fronts is more for multi-channel music (i.e. SACD or DVD-A) than movies. In fact, for movies you may
NOT want to exact match to have rear speakers more capable of providing a diffuse sound to enhance surround effects.
The speakers are smaller 2 way bass refex HxWxD (235x130x187cm) (9.25x5.12x7.36inches).
I think the salesman is being disengenuous, because the benefit of exact matched speakers is achivied by upgrading (read more $$) the rear speakers to match an
excellent pair of front speakers.
--
Not by limiting the entire system to small satellites just so that they match.
I listened to the system in the store and the sound (esp with movies) was quite impressive.
Compared to what?
Just saying, I would listen to several other speakers before pulling the trigger. Furthermore, the subwoofer described in the EPOS system, does not appear to be very robust. Online I saw the EPOS set you referenced for about $1800 US--with that much cash, there are many options!
Last thought. Defining your: budget, use (movies/music/both), room size, and your system goal (a starter system--to be replaced later, or your dream system for the long run) will help you narrow the field.
Cheers,
XEagleDriver