I appreciate this honest feedback. I am very much a newbie when it comes to sound and because I am a mobile DJ doing small pop-up classes/parties powered makes more sense at the moment. In the future, I would prefer to have a Passive system and a proper amp and i will try to cross that bridge of knowledge when I get there, but for now, I am mostly curious if it's that big of a deal if I don't match the tops (brand wise) with the sub and how that will play out.
I will say there is nothing wrong with powered, it is my personal preference even for larger systems. I just wanted to state that passive was a viable option, and to hammer home to make sure you never purchase a passive system without the manufacturer specced amp/processor.
Something I forgot to ask, is what type of dB (volume level) are you shooting for? The levels you are trying to achieve should help to guide your choice of speakers. Two caveats here:
1) dB specs for speakers, especially on the cheaper end of the market can be BS (that spec might have been achieved by blowing up the drivers for example)
2) Loud does not equate sound quality, however speakers which are more capable should give you more head room.
I am going to go through some quick and dirty basics here, if you already understand these things great, but they are worth going over. I am sure someone will chime in that explain better and more in depth.
If you are in search of dynamic music, this is where volume matters. You want a loudspeaker system to be linear, ie what you put into it is what you get out of it. At some point every speaker is no longer linear, because you have reached its capacity.
So this means:
1) Good source material (high quality samples, files etc: rather than low quality MP3)
2) Not clipping or adding additional compression (limiters)
3) Have enough "rig for gig"
If you are pushing a system too hard it will start to limit; either because the processing is limiting to protect the drivers or because the driver is working as hard as it capable of.
Clipping (those pesky red lights) should be avoided as:
1) It is not going to make your system louder (a good system is clean)
2) You will be adding distortion, which on the output stage (rather than input) will not sound pleasant and will make the spectral balance harsher.
3) Clipping adds in higher frequencies. Think of this in terms of subs, if you are clipping a sub amp you are now sending lots of high frequency to a large driver, which may destroy the driver.
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When you are driving a system into limiting things will sound less exciting because it is unable to handle the impact of the loud transients. When this occurs audio engineers and DJ's often respond by "turning things up," to try to bring back the excitement. This does make it a little louder, but it makes the system limit and compress further (you will miss your transients even more now). You often end up with a very loud mix that is not exciting. Keep in mind your ears play a role in this and if expose them too much volume they will begin to dampen things; again this may lead you to turn your system up. This is a cycle to be aware of; know what your system is capable, and take care of your ears; your audience will appreciate it.
Think of your system like a car, if a car is capable of going 120mph does not mean it is intended to be driven at that speed all day every day.
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As to subs and tops and mixing and matching there is no exact answer:
In short keeping to the same brand and sometimes speaker series will get you closer to the top and sub working together well, however there are ways you can do this yourself.
There are two main factors for a sub and top working well together (note the second one you can probably ignore):
1. Crossover: This is the frequency where your top box is no longer working and your sub takes over. In addition to making sure the frequencies crossover, the phase of the signal at the crossover point needs line up. If you achieve this it will be a natural transition from top to sub.
2. Time alignment: this is having the arrival time of the top and sub be at the same time; note this matters more for larger venues, and you can only choose one spot for this to be perfect. Additionally this is getting into measurement, which is above your current scope.
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When it comes to crossovers you have two:
1) Processing: This is the crossover frequency your DSP or powered speaker is set to, for example "65hz."
2)Acoustical: This is where your subwoofer acoustically takes over from your top.
For example if you have your subs +18dB over your tops (which is a valid decision for House music) and your processor has a crossover at 65hz, your system might now have an actual crossover point of 110-120hz.
So before you can make a good crossover decision you need to know how much your subs are doing.
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Keep in mind your top boxes probably don't need to go low as you think (most powered boxes have a DSP option for running with a sub)
1) They can get in the way of your subs
2) Your subs will be better at producing lower frequency's and having your speakers ignore the lower stuff will mean more headroom for the frequencies they can do).
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In general adding more top boxes for the same area will not make things louder; it will make things sound worse and cause comb filtering (making the sound very uneven for your audience).
In general subs (same make, model, processing) are additive; this has to do with wavelength of the frequencies they reproducing. Depending how bass heavy your music you may use 2 subs to 1 top or 10 subs to 1 top etc. If you have more than one sub a quick and free way to get more volume is to put your subs together, this causes the sound to couple.
