Axiom Home Page Forums General Discussion Home Theater XPA 2 Now! A Keeper?

Sorry about that... it's late and clearly I need to go to bed... I was thinking of David (Terzaghi) and his continued hints that if he buys more speakers before buying a ring there will be serious hell to pay.

Definitely time for bed!

Jason

Too much time in the room of death coupled with lot's of speakers and a cool named amplifier, and all the other fun toys. Get some rest.

I thought maybe my wife had me posting something in my sleep just so she could say she had witnesses!

When I was having problems with my RPA-1, Emotiva told me that they have run tests with M80s and they can dip to 2 ohms.

If this is the case I would like to see an updated impedance graph from Axiom. The one I posted shows they dip nowhere near the 2 ohm mark.

That is interesting. When I was having issues a year or so ago, Emotiva had never heard of Axiom. There was also a guy with 4ohm Rocket bookshelfs shutting down his mps1.

Here is my long post, near the end you'll find MadScientist, that is Lonnis from Emotiva adding in to the conversation.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=162446&fpart=1

Hi SatKartr,

When I said ". . .that a number of amps, not just emotiva, have not paired well with the m80s" and you replied "so it is also an Axiom issue to understand just what type of amp works well with the m80s", I want to clarify my comments.

It is only under extreme conditions, such as the SPL levels that you are trying to reach, SatKartr, as well as some other Axiom M80 owners (sometimes multiple M80s) that some separate power amplifiers, Emotiva included, shut down or overheat. For the vast majority of users, the Emotiva, Parasound and Outlaw amplifiers will drive the M80s without problems.

It all comes down to a matter of current flow through the output devices at extremely high sound pressure levels, and the ability of the amplifier's heat sinks and/or fans to dissipate the heat generated by lower impedances. The M80 is "nominallly" a 4-ohm speaker and does not dip below 4 ohms anywhere over the audio spectrum.

In terms of heat dissipation and high SPL levels, prior to the development of Axiom's A1400-8, there was a memorable party at Ian Colquhoun's home. At the time he was running five Denon monoblocs at 350 watts per channel into the M80s, dual VP150s and five QS8s, plus two subs, an EP600 and an EP500. At one point in the party, the level controls advanced farther and three of the five Denons shut down. I was using earplugs all evening and even with the ear plugs I retreated into the woods outside Ian's house! The SPLs were deafening. That evening was the genesis for developing the A1400-8, as Ian had grown tired of the Denons shutting down at extremely high listening levels.

I'd also point out that there is no substitute for expensive output devices that can handle very high current flow into lower impedances without overheating. That's what we use in the Axiom A1400-8 and that's also why the amplifier is relatively expensive. In order to reach a particular price point, other manufacturers may choose devices that are much less costly and will be fine in most playback situations for most listeners--but not all.

Regards,

Alan

Thanks Alan for the clarification, sorry if I misconstrued your comments.

That party does sound very memorable! Ian must be quite over the top.

I'm not sure the amp is overheating though. I picked up an spl meter and am measuring 90-100 dbls in HT (doesn't happen with music at this spl) when the protection fault kicks in, which can happen within a minute or so of initiating a movie (e.g., the intro to Hulk).

Thank you everyone, I appreciate your help and efforts to increase my knowledgeability, at this point it clearly seems to be an Emotiva issue so I will pursue it via their tech support, and of course will let you all know if there are any solutions found.

Hmm. Is 90-100db for short periods of time considered extreme?

I'd say not, my Rotel can do that for long periods of time and only get warm to the touch.