Axiom Home Page Forums General Discussion Advice from Axiom Owners HP Drivers vs Regular

Would it be fair to say that the standard Axiom drivers sound better than the HP drivers at lower listening levels? We all know the HP's kill it at the higher level. But what happens when the kids go to sleep, who would win that battle?

No audible difference. The HP drivers are more linear than the standard drivers at higher volume levels - particularly at lower frequencies.

copy that, thanks mojo!

That matches my understanding as well - the only thing you give up with HP drivers is cost and ability to use them in a typical 2-way speaker.

Blame it on coil inductance; larger coil diameter and more turns than the standard 6.5" woofer coil. Inductance increases as the square of both.

i'm lost. Axiom isn't putting tweeters on drivers, so why does it matter that they are 2 way only? I'm learning, so please educate me.

Bridgman was pointing out that Axiom's HP driver can't be used in a 2-way speaker like the M3. The HP driver is incapable of handling the mid-range like the standard 6.5" driver can. The reason it is incapable is, as I've described, due to the larger coil diameter and amount of wire. Both increase the inductance. The higher the inductance, the greater the resistance to higher frequencies like mids.

That larger coil diameter and more wire, along with a larger permanent magnet, beefier surround and spider and cast frame, allow the HP driver to reach lower, with less distortion and higher sound pressure.

The HP driver is therefore perfectly suited to 3-way speakers like the M5, M60, M80, M100, LFRs, 160, 180 and QS10. All those have at least one dedicated mid-woofer driver to handle the mid-range. Incidentally, those mid-woofers extend down to the upper mid-bass.

Damn Mojo, that is exactly the explanation I was hoping for. That all makes sense to me now.

Do drivers play a role in imaging? It seems like the audio that wraps around you is on the higher end. To a novice it seems like it's the tweeters job to wrap the sound around you, correct?

It's a good question. The simple answer is, the entire audible frequency range matters.

Above about 2 KHz, the ears use volume (amplitude) differences between the left and right channels to figure out imaging. Below about 700 Hz, they use phase differences. Between 700 Hz and 2 KHz, it's complicated.

It's actually a bit more complicated than that. The amount of reverberant (reflected) signal vs. direct signal determines image depth behind the plane of the speakers. The reflected signal is that which bounces off from the recording venue (or is added by the sound engineer). So when you hear a singer dead center at the front plane of the speakers, that's all direct sound which has been recorded equally in the left and right channels. If you hear drums behind the singer, that's due to reflections that are coherent with the direct sound coming from the singer. Your ears-brain system is built to figure spatial relationships like this out using amplitude and phase differences in the left and right channels.

When I say the entire audible frequency range matters, what I mean is that amplitudes (volumes) must be reproduced at the level which they were recorded for each frequency. This is called the frequency response and some call it the amplitude response. These are the curves that you see on the Axiom product pages. It's also important for this response to not change during quiet passages (microdynamics) and peaks (macrodynamics). If the system loses accuracy during whispers and peaks, there goes the image and soundstage.

You'll run across the words accuracy and linearity. Accuracy measures the degree to which the output from the system reflects the input. By output, I mean level and frequency. Linearity measures the degree to which accuracy is maintained across all frequencies and amplitudes (from very quiet to very loud).

The more accurate and linear a system is, the better the imaging and soundstage. System = the entire audio chain.

The reason why I'm asking is because I wanted to hear the difference between the new divers and the old ones. Using my M50 cabinets I swapped them out. When switching between the two speakers, you can really hear the older drivers fill the room with sound much better than the newer ones. I swapped speaker wires and speaker placement to make sure it wasn't a reflection or difference in cables.