Axiom Home Page Forums Thread Like Summary - Why no HP Tweeters or midrange?

I think I already know the answer, but I’d like to hear for sure. Why only HP for woofer sections?

The obvious answer is the bass sections / woofers take the most power / can handle the most power, to create low frequency sounds so a higher capacity for more input /output makes sense. So if I hypothetically choose HP and put a very high powered amplifier in use (say something huge like a one channel ADA 1500) to utilize the HP capabilities of the bigger voice coils and excursion , why do my midranges and tweeters not also “HP” to account for the higher power I’m hypothetically using? Or are they already just naturally capable? Or maybe I just understand the application of HP Woofers?

I think I’ve described that right…let’s see where this goes, maybe I can ask it a different way if needed.

Thanks,
Kodiak.

The HP woofer is more linear at higher SPL over its operating frequency range than the standard woofer. But the standard woofer has a larger operating frequency range right into the upper mid-range. It is why you see an M3 with a standard woofer and no HP option. The reason for this has to do with the higher mass of the coil that drives the HP cone. That higher mass is due to more wire. More wire, more inductance. More inductance, more impedance at higher frequencies. Hence the HP driver is limited to about 250Hz whereas the standard driver goes up to 2200 Hz.

So now you get the picture. An HP mid-woofer would not have the frequency range of the current mid-woofer. That means twin mid-woofers would be needed; one for lower mids and another for higher mids. It's not wrong but it's a higher manufacturing cost to produce two mid-woofer types. There's a sensitivity penalty as well with that design. Axiom opts to use multiple mids, of the same type, to achieve higher SPL. Ditto for the tweeter.

Using multiple drivers within the same frequency range isn't a trivial design exercise because the designer has to understand how they interfere with each other and resolve audible resonant peaks and dips. And the designer has to understand what the root causes of the resonances are - cabinet, driver or cross-over.

It's why an M2 acoustically disappears in more room positions than an M100 does. The M2 is less prone to position error because it exhibits fewer and lower intensity acoustic resonances than the M100. This is the result of fewer drivers leading to better driver integration, smaller and more inert cabinet and a simple cross-over.

The drawback is that the M2 cannot achieve the frequency range, SPL and image size of the M100. But if you use the M2 with a sub, and you're not sitting too far away, the M2 just might be more pleasing to you than the M100. In fact, the M100 might frustrate the hell out of you because it's bass might over-load your room!

The M2 is a killer product. It's a highly versatile, low cost, small footprint, hi-fi speaker. It's perfectly designed for its range. The M3 tries to be too much and as a result, it's compromised in the mids and the bass can be too bloomy in some rooms. But these aspects also make the M3 sound warm.