My budget for building speakers is always based on the quality of the listening room first.
If there is another person involved, such as your girlfriend, her expectations need to be well understood.
You wrote about building a "pair of speakers" but an A/V system requires five speakers and one subwoofer. If possible, the five speakers should be identical. At the least, all three front speakers should be identical and oriented the same way (no hoizontal center speakers and vertical left and right speakers) for optimum fidelity.
The typical woofer-tweeter-woofer center speaker
sitting on top of a TV set in a horizontal orientation is a compromised (for better appearance) design placed in a less than optimum position. (The center speaker provides up to 2/3 of the sound energy in a typical film mix (excluding the subwoofer), so its design should not be compromised to make it 'look better' on top of the TV set).
Magnetic shielding will be a concern too.
To ensure your project is a success, I suggest thinking about three important subjects first:
(1) Room size and dimensions:
(For example, why waste your energy building five high quality speakers for a "low quality" small near-square room -- this type of room would also have a strong negative effect on subwoofer bass frequencies)
(2) Room acoustics:
Will you be able to treat the room so you get the less reverberant/dryer acoustics needed for A/V?
(Two channel stereo works best in a more reverberant than average room -- A/V does not).
Directional speakers (controlled dispersion) are also a plus for A/V, while wide dispersion speakers are best for two-channel stereo.
(3) What does the girlfriend REALLY want?
Women often are not as direct as men in their
conversations:
For example, is she thinking of five very small speakers and a small subwoofer hidden in a corner
or behind the couch?
- Is the appearance of the speakers more important than the sound quality?
- How flexible is the "budget"?
One question whose answer would clarify your post:
(a)When you wrote "two midranges", did you actually mean two "midrange-woofers" as in an Woofer-Tweeter-Woofer two-way design? That's what I assumed.
One comment on running woofers "flat out" (no crossover):
This is the most common arrangement in loudspeakers today (crossover = one capacitor and maybe one resistor) but almost all are cheap
speakers and don't sound very good.
-- There are a few exceptions:
I really enjoy my own EPOS ES-11 satellite speakers with no crossover at all on the small woofer. I recently enjoyed an audition of the $500/pair Triangle Titus speakers with a similar no-crossover woofer. The woofers in these speakers were especially designed to be used without crossovers. Without crossovers, MOST woofers available to DIY speaker builders would provide too much mid-range SPL relative to bass frequencies (no baffle-step compensation) and a rough frequency response at the high end of the woofer's frequency range.
I'm also not in favor of wiring woofers in series
because back-EMF from one driver will modulate the voice coil of the other driver. I don't know if this is audible -- maybe it's just an old wife's tale -- let others comment on whether this makes an audible difference.