Axiom Home Page Forums General Discussion Home Theater Crackling speakers

I would also suggest trying the mains to small, you can play with a 60-80hz crossover if your receiver allows for independent settings for each speaker. Let the sub do the job it was intended, to move air with the larger driver. Double bass is not always a good thing.

Double bass is frowned upon in the world of PA systems. Many get a 2-15" with 1 horn cabinet. The lower 15" is considered a "quasi sub". Then they want to add a real sub and it causes problems and muddiness in the low frequencies.

As I stated, I hadn't noticed any S/Q differences with it swithced either way. Wouldn't the Bass Mgmt system (LFE) limit which speakers get which sounds regardless? How do you measure double bass?

What is the shape of a low-pass filter? Surely there has to be some overlap in order to blend the sounds. At what point do you start to send too much information to the sub and the sound becomes muddy anyway? For example, a war scene with explosions in front and behind. In a small configuration, the sub is being sent information from all speakers. In large and if the L/R speaker is rated for the lower frequency, wouldn't all of the explosions be more crisp and have more punch?

Sorry for all of the questions. Just trying to understand what the differences would or should be and why the recommendation is to set everything to small regardless.

Small and Large has nothing to do with the size of the speakers, but how well the speaker can handle the frequencies below the crossover point. THX and others recommend an 80hz crossover, because anything below that becomes non-directional and are frequencies best suited for the sub to produce. A 12" driver can move more air than 2 6" woofers. Yes the m60's and 80's can go below 80hz, that is why there is a gradual slope or hand-off to the sub, it does not just cutoff.

Yes, the bass mgmt controls the direction of the LFE for those speakers set to small, and sends those freq's below the crossover to the sub. If your using LFE+Main your mains are also receiving the full freq spectrum. If that is what you like, that is fine, I'm just going on the industry standard.

Neo, the standard bass management in HT receivers rolls off the sub above the selected crossover frequency at 24 dB/octave and rolls off the speakers below the selected crossover frequency at 12 dB/octave.

If explosions and other very low frequency material sound better on the mains than the sub it means that the sub isn't a good one. They're specifically designed to excel in those frequencies; that's the whole idea behind a sub and bass management.

I was hoping to report that the sub had eliminated the problem entirely, alas that does not appear to be the case.

Let me begin by confirming that I have reached 99.8% audio nirvana with the addition of the 800 and could not be happier in any universe that I can imagine at the moment.

Watched Titanic with my daughter this evening and the sonic veracity of the 7.1 dvd soundtrack absolutely blew my mind, I never would have believed it was possible for sound to be so lifelike and without reservation feel I could die happy having experienced this level of audio reproduction and nothing further.

There were a few electrical pops in the hitting-the-iceberg scene that I mostly noticed because I am attuned to the aforementioned defect I chose to label "crackling speakers" yet they were extremely brief, minimal, and interestingly they did not appear at time of deep LFEs but a bit higher in hz, and it was the dual M80s that expressed the defect.

BTW the 800 manual recommends 40 hz crossover with the M80s, and running no EQ, I couldn't agree more: 80hz and 60 hz sound too unnaturally bright in my room (muy trebly) whereas 40 hz crossover is absolute sonic heaven. I do have wood floors so that may play a role as well, however I am still very happy with the no EQ Axiom philosophy so will persist with that for a while yet. Perhaps if my system were calibrated different a higher crossover would work but the blend at the moment is so sweet, why bother tweaking (except of course for the occasional "pop")?

My one major regret with posting my experiences has been contributing to the nonutilization of the XPA2 since I suspect that the problems I had with the electrical popping issue that may have triggered the protect circuit were largely running the M80s at low hz, and it seems most do not set the crossover much lower than 80 hz and would probably be not have an issue. I would love to hear if others were successful with the XPA2/M80 combo, I would feel less foolish for having pursued that possibility and it is a nice amp.

The whole wind/applause thing I brought up is completely alleviated with the introduction of the 800, as I suspected it was a problem of unanchored HFEs sounding cheesy, accompanied by appropriate LFEs the HFEs are simply superlative.

As when I first purchased the M80s I have reached a watershed moment, although this time I feel it is the promised land, the grass is only greener here, not on the other side. I am so much more impressed with the Axiom system, before I was of the opinion that OK yes this is very good/extremely good, especially for the money and I couldn't think about spending more to increase my reach because how much more would that have to be to incrementally improve the sound in a meaningful sense (while secretly wondering what it would be like if I could afford better) whereas now I am in a state of perfect satisfaction and care not that in some hypothetical world of course things could always be even more superlative.

Better has no meaning once you reach best.

Thank you, Axiom,

Nice write up!

When are you going to spring for a new pre-amp?

FYI, Over on Emotiva's site there are many running the XPA series, including the XPA1 and 2, with M80s and are having no problems.