5x5 meters is about a 16' x 16' room. My daughter's bedrooms are bigger than that. That's a really small room for a bar. If you have 10 people in there it's packed. Are you sure about that size?

Next issue..... with all the questions you are asking, it sounds like you're not very "up to speed" on audio gear, specing it out, or connecting it properly. So as some have suggested, go to a professional audio company. Get one or two to come to the location of the bar and give you a quote and get educated on what they are selling and recommending.

If the room truly is that small, and I know everything in Japan is smaller, including bars, the system you will need is not going to be a very big or powerful one. I've played in bands in some pretty small places, but even our practice room was bigger than that room you are describing.

An attempt at helping:
In most cases, when you daisy chain speakers on a 70v line, it's not really a hi-fi system. Background music and voice announcements like you hear in retail stores fit this category. For a sound system in a club or bar, you need it louder so you will use an amp (or amps) and connect one or two speakers (at most) to a channel on the amp, and match that to the amp's output ratings. Add amps and speakers for more coverage and more volume. Most amps will support 2 channels and depending on the amp ratings, and the speaker impedance, you could possibly connect 4 speakers like you want, to one amp with 2 channels. Impedance and wattage rating for the speaker and the amp must be matched.

Another option is to have a line level signal that feeds a number of self powered speakers. With this option, all you need is the mono output at line level fed to the powered speakers. All mixers have a way to give you a mono output. There's generally a mono out on the back of the mixer somewhere. Software based mixers can do that internally. Also, you may actually want to use a stereo out if the room is as small as you say it is.

Again, my recommendation is to go have a professional talk with you about what you're planning to do. Get them to the site and discuss the options. Take notes, and ask questions. And yes, in a small space, a nice home style stereo system with the power to push 4 speakers might be the perfect solution...and cheaper too. Adding a sub if you need it is not a big deal.


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