I would think 20’ x 25’ would be about the minimum to be called large.
Rules in audio can always be broken. I have heard an outstanding system in something the size of a walk in closet... and not a big one. I have hear terrible sounding, very expensive big components in a tiny space. I have heard a ridiculously large system in a tiny room that was breathtaking..
If you want scale and volume in a big space you need big speakers. It can be harder to get really big speakers to sound good in a small room. But it is absolutely possible. I think where the utility of the rule comes in is in cost effectiveness and in ease of achieving good sound.
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Most of us approach this from the inexpensive side. So spending $40K on speakers for a tiny room might not be putting money in the right place when $20K speakers would have done the trick... but even then it is a question of what sound do you value... if massive bass is it... then oversized speakers may be the ticket.
Like everything in audio, there is seldom a rule that does not have exceptions.
Rules in audio can always be broken. I have heard an outstanding system in something the size of a walk in closet... and not a big one. I have hear terrible sounding, very expensive big components in a tiny space. I have heard a ridiculously large system in a tiny room that was breathtaking..
If you want scale and volume in a big space you need big speakers. It can be harder to get really big speakers to sound good in a small room. But it is absolutely possible. I think where the utility of the rule comes in is in cost effectiveness and in ease of achieving good sound.
.
Most of us approach this from the inexpensive side. So spending $40K on speakers for a tiny room might not be putting money in the right place when $20K speakers would have done the trick... but even then it is a question of what sound do you value... if massive bass is it... then oversized speakers may be the ticket.
Like everything in audio, there is seldom a rule that does not have exceptions.