thank you for the resource recommendation. The tweeter I use is most similar to the BestonRT003C @ this website, with a few tiny differences. Mine have no mounting flange (I glued mine into place), no phasing plug, and thus is not loaded to go as low as 4KHz. The ones I have will only go as low as 7KHz with an 18db/oct xover. The magnet is also larger on the Beston RT003C compared to mine.
Minus the flange on this unit, my tweeters are about 1.75 inches (44mm) x 3/4+ inches thick (20mm, I was able to measure one with a micrometer).
There are 2 great ways to use tweeters like the Beston RT003C by making a stalk, or hanging them from a ceiling or a metal bracket frame. The "holder" of this tweeter is a small cube about 3 inches square on a side. The circuit design would be to put 3 in series and then parallel those 2 sets of three. The passive crossover could easily be made on a circuit card outside the tweeter "box" itself. Every surface of the tweeter box not directly in front of the diaphragm areas needs to be covered with sorbathane or at least neoprene foam. Getting a scoring tool with a number of ridges allows you to make V-shaped grooves all over the sorbathane/neoprene. This will drastically reduce the secondary reflections of high frequencies off the (previously) hard flat surfaces like the flange.
Once the box is built and the tweeters mounted into it, you need to align the box so one of the tweeters faces the listener, pointed at about a 30 degree angle slightly off axis away from the box (up-down direction), and 90 degrees turned so that one of the corners points up and down. A wooden stalk can be made from a 1x2 piece of wood covered with scored sorbathane/neoprene. I find it best to mount the tweeter slightly further away from this super tweeter compared to the other components in the users speaker box. This stalk will be mounted to one of the bottom corners.
A second choice is a sturdy metal L-bracket or two covered with scored sorbathane/neoprene. Screwed to the back of your existing cabinet, this(these) bracket(s) allows the tweeter to be hung with fishing twine so that when gravity allows the tweeter to hang, in the same orientation as above. The fishing twine won't re-radiate edge-transmitted sound, and they won't reflect sound either.
I would need to find my papers on crossovers, but it you have a 2-way loudspeaker with a 1 inch tweeter, I'd recommend a crossover frequency down 3db at about 12KHz to the new tweeter array. The imaging doesn't suffer because only one of the tweeters contributes to the direct sound. But the sound power of the system will increase dramatically. The Beston RT003C is actually a very small tweeter. I believe the specs are a bit optimistic. But you would only need a resistor pad (T) in front of the crossover, to balance this super tweeter with the rest of the loudspeaker components in the original box.
The component speakers at Parts-Express seem very expensive if you are building your own loudspeaker systems from scratch. The easiest way to make a major system is to do without a single hollow box except for the speaker producing the lowest frequencies. A very good loudspeaker can be made from normal components if each component loudspeaker only handles 2-2.5 octaves each. The large heavy bass unit should sit right on the floor and act as a base for the entire system. The rest of the component loudspeakers can be arranged in the smallest possible boxes, hanging off of a solid steel bar of a reasonable height. By having a crossbar holding each component loudspeaker in place, you can even positionally phase align each component.
Sadly with skin effects, reflections, resonances, internal standing waves and re-radiation, boxes make a huge amount of spurious noise. Once you make a box that is inert (like making it out of 3 inch thick - 75mm, concrete) it is usually too heavy to be movable. In point of fact, in most cases the box interferes with the sound from the components, almost as much as it helps the bass to have that one component in a box.
If you choose (up to 7KHz) component loudspeakers that produce frequencies that are not higher up than the frequency whose length is equivalent to 4x the actual cone diameter (not counting the surround or frame). So for example, a 14 inch speaker with a cone exactly 12 inches in diameter, could be producing a 360 degree radiation pattern that would fill all the space from the floor into the room, up to about 300 Hz. This rule becomes more difficult to implement as you go up in frequency, which is why I use arrays for the ultra-high frequencies to retain the 270-360 degree radiation pattern. 16 inch or even 13 inch cones on 18 inch and 15 inch loudspeakers are also useful, although their "full loading" frequency is lower.
6 component loudspeakers, with 2 inch domes can overcome the "best" -3db crossover point of one 2 inch dome component, by coupling. With 6 x 2 inch domes mounted in a box similar to the one mentioned above, the xover frequency could rise to -3db at 6KHz. Although not absolutely optimum, the crossover point on the 6x ribbon tweeters listed above could be lowered to 6KHz as long as pure tones in that frequency range are not played at full power. The tweeters that would cross over @ 6KHz, could have a sensitivity of 92/93 db with 2.83 volts applied, and a real power handling of about 30w RMS. The dome upper mids also mentioned above would also be range of 1500-6KHz, and their sensitivity could matched to the tweeters.
I would add an extremely durable 6 Box of mid-bases/midranges would utilize a very inexpensive 5 inch speaker with a 4 inch, polypropylene cone (or carbon fiber as I mentioned in a previous post) which as an individual component would have a high frequency cutoff of 900-1KHz, would not be useful to 1500Hz @-3db on the top, and they mate well with the 14/12 woofer at 300 Hz.
The SIX BOX as I call them have many advantages like, huge power handling, coupling drivers for 360 degree radiation (although one driver must point at the listener so there can be phase alignment). This way you only need 3 xover points, 300Hz, 1500 Hz, and 6KHz, but unlike some companies like JBL, you would have a system that fully couples to the air in your room and produces a dispersion pattern similar to reality. Reciprocal opposing forces when the component loudspeakers "play" are all balanced and thus there is no micro-movement of components that badly affects phase alignment.
There is no perfect loudspeaker system. There are good loudspeakers and bad loudspeakers, but few try to achieve the sound of reality. I use 15 inch loudspeakers that are in my "floor stand" (2x) and they are tuned to resonate at 20Hz in my room (24x18x9 feet). I'm thinking of cutting a port in a door that goes to a garage/living-area or huge dimensions (33x33x18ft) to reduce the pressure on my woofers, so this is why I need a 5 way when a 4 way would work really well.
I use 3 converted 160w@4/8/16 ohm tube guitar amplifiers, with gentle parametric equalization for the midrange domes because the human voice range of 400-2KHz is the most critical frequnecy range there is for "reality". I just overpower the bottom with 3200w of interchangeable low end power (I live on a ranch with 400 amp incoming service to satisfy my needs). Normally ranches need electric wood chippers and such like and with barns etc. so the provisions for power require a 1 gauge incoming twisted pair from the street transformer, and a service box nearly 4 feet high. I bought it, I didn't make it, but it suited my interests.)
The midbass is the region I consider more important than the low bass. So in this range of frequencies I use a Phase Linear 400, one of the best sounding of the monster amps. In another similar system I use a Yamaha Class A/AB 150w/ch amp which is smoother but less powerful on the crescendos of full orchestras. But now-a-days amp power for the lowest low end is cheap. But once you approach the vocal range, use good quality amps. You'll hear it once reality becomes really transparent. REMEMBER that each component loudspeaker group will need a passive crossovers to protect the component loudspeakers. This makes amp needs
For the tweeter array I suggest a very high quality full 25w/ch Class A amplifier. High frequencies actually consume more power per given loudness level than extreme low frequencies. The compactness of the 20KHz signal requires more power to reproduce at the same SPL level. Luckily there are very few times when the highs require such power, unless you are enamored by the London Verdi's Requiem of a Thousand. If so then you'll need the power figures I recommend. A 25w/ch full Class A amp requires about 1000w total power to operate properly.
The way I have suggested designing your "reality" loudspeaker system" you will have about 2900w/channel power consumption at MAX. MAX continuous power is really not important at this level. Peak power becomes more important as the system will really be operating at about 8-10w/ch (MAX) for the loudest music normal people play. The system peak power would be about 5000w/ch for short duration signals. I can recommend cheap watts per channel for the extreme lows, but the other amps would be determined by what you can find. Remember that tube amps store about 300-500 volts on their plates for peak power (you do the math). But tube amps don't have great current output for the bass, or high power output for the extreme highs. Here watts per dollar amps work well for the lows, and super clean Class A amps work well for the extreme highs. Your total 17:1 ratio of loud continuous power to peak power gives you a rough 50:1 max power to peak power ratio. This is pretty transparent.
I use other combinations for other systems but this is the best to make a reference system. If you find a pair of amps or receivers with high power or current that you like, then it is possible to configure systems that utilize these kinds of power components. If you MUST have a speaker "box", then I can recommend boxes with all non-parallel interiors. But the box really does "get in the way" of the best sound, component loudspeakers can produce. I guess that sums up my philosophy of sound based on listening test results from 12,000 listening tests on regular music listeners. The smallest radiating enclosure possible produces the best sound. At the extreme low end, in order to match the radiating patterns of the other components, enormous power compensates for the required enormous rooms to reproduce extreme low frequencies like 20Hz.
The recommended system above is a reference system. It will give you an insight into vinyl discs you have never experienced before. Fewer component loudspeakers can be made into systems that reproduce sound well, but usually with changes in radiation pattern that affect the way we perceive sound in enclosed rooms. Remember the voice test. If you know someone who sings and plays something, you can test your system for "reality" by making a recording with reference mics surrounding your musical helper and then when you play the recording back, it should sound like the "musical friend" is right "There". Then you'll know you made the system correctly.