unamplified orchestras or bands?

Starting from 18th Century, brass instruments began to intrude a classical chamber orchestras. L.V.Beethoven was probably the pioneer in coupling strings and brass.
We all know that tuba will sound much louder than viola and trumpet will be much lowder than violin.
We also want to hear both parts of instruments in the orchestra.
I assume that today in 21st Century the microphones to string instruments are closer than to brass instruments incide the concert hall.
Brass instruments are designed to sound loud enough on the open street while violin you have to listen inside the room with good accoustics.
How would such orchestra sound unamplified or unequalized?
How was it done back on the 18th Century?
Probably brass musicians had to realy control the breath not to sound realy loud?
The simple answer to your question, at least with orchestras and certainly in the 18th and 19th centuries, in addition to what J k mentions is that the conductor of the orchestra is there, in part, to make sure of the proper balance of the instruments. I'm a bit puzzled by your mentioning microphones--no major orchestra I know of (and certainly none that I have heard in concert, except perhaps at Broadway shows) uses mikes for sound reinforcement in concerts in their concert halls except in unusual circumstances (for example, the Rodrigo Guitar Concerto or the Glass violin concerto, where the soloist may use a mike, due to the lack of loudness of the guitar or to catch the small details of the violin part, to be heard over the orchestra). If you're referring to mikes for recording purposes, that's a whole 'nother thread on recording engineers and their preferences.
Hi Marakanetz,

I suppose, as mentioned above, some engineers probably mic an orchestra that way, but many of the best classical recordings are very very simple...one to three mics...that's it. The band practices (with the conductor) to make sure that all of their individual volume levels are appropriate for various movements. That's all part of playing in an orchestra. If the hall, orchestra, and conductor are decent, the sound should be balanced without any technical tricks.
Haydn and Mozart used brass before Beethoven did, both as ensemble players and as solo instruments.

Yes, tuba and trumpet CAN sound louder than viola and violin, but not necessarily. A fine trumpeter can play with as much delicacy and control as any violinist.

When an oschestra is amplified (usually in commercial music settings) or recorded in a studio and a lot of spot miking is used, the exact opposite of what you suggest is true. The brass is miked up close and the strings much farther away. Otherwise the strings' timbre would not be natural sounding at all, with way too much high frequency content.

Brass instruments were indeed designed to sound loud outdoors. The hunting horn and precursor to the French horn being the best example.

As far as how an unamplified (live) orchestra might sound, you owe it to yourself to find out. You obviously have a great interest in music and there is nothing like the sound of real, unamplified intruments to fine tune one's ears.