Axiom Home Page Forums General Discussion Technical Questions NRC Graphs

It seems I managed to delete the entire post on this subject inadvertently this morning. Below I have reposted the graphs of the M60, M80, EP500, and EP600.

There were some questions as to why a flat anechoic response was better than a flat room response. I was answering kcarlile on his comment that 'speakers would have to be measured anechoically to be able to work properly in the majority of rooms'.

My response was that you are on the right track here. It is important to be careful not to get your goals backwards. The measurements must be done in anechoic environment in order to bring the performance accurately to your room. It is a red herring to think that a flat in room response is the ultimate goal. The ultimate goal is to accurately place the performers in your room; not turn your room into an anechoic chamber.

M60 Graph:



M80 Graph:



EP500 Graph:





EP600 Graph:

Ian
Is there any possibility you can leave this post at the top of "Tech Questions" page like the "Auditioning in your area" thread is on the Question and Comments forum?
If you could, it sure would be helpful when I recommend or audition my M60s.

That same little spurt on the M80s is shown on the graph at soundstage.com too, except it looks way worse there.

Why do the M80s have that odd recession & peak around 100-200 hz while the M60s don't? they use the same midrange & bass drivers, and have a similar case.

Graph for M80s on soundstage, August 2001.



Graph for m80s on enjoythemusic.com, November 2002

Ian, thanks for confirming my hunch. Can you also repost the M50 graph?

Below is the NRC Graph for the M50.

In reference to the little dip and rise at 150 Hz in the M80 compared to the M60; it is just the microphone positioning being up right under the tweeter and only 2 meters back in the anechoic chamber giving it an increased angle of attack on the very tall M80s.

In reference to the M80 graph from SoundStage: that was done back in 2001 and there have been modifications since then.

I saw some numbers in your description of the M60s like

Freq Resp +/-3dB (Hz) 37-22K

Do those numbers come from the graph in this thread? If so, how do I read such a graph to get these numbers?

The chamber is accurate to 85 Hz and then there is a correction applied below that. For heightened accuracy of measurements below 85 Hz we measure out on our pole in mid air. The pole puts the product and microphone up about 20 feet in the air. The sub graphs above are from the pole. You can see in the NRC graph above of the M60 the bass rolls off quickly below 37 Hz and this trend lines up with the pole measurements of the bass response of an M60, hence the 37 Hz spec.

>>For heightened accuracy of measurements below 85 Hz we measure out on our pole in mid air.

... and this is why all new Canadian speakers come out in the fall. The US manufacturers have a 12 month growing cycle, we can only test speakers in the summer.

Just kidding, of course, but I bet we all just had a vision of Ian up on a pole in a parka, with the wind and snow howling past, hooking up wires to the binding posts

Yes; and if all wives are like mine, I can also picture Amie out there with him telling him to secure that parka, to be carefull on the ladder, reminding him that red is positive, watch out for the microphone, and don't forget to shovel the walk before coming inside!

Sorry Amie; it's just that darn WAF-LOL
(actually she likes the way my system sounds-It's EveryThing Else!!!)
Rich

In reply to:

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(actually she likes the way my system sounds-It's EveryThing Else!!!)

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Newlywed? If not, I should think you'd realize that it's our system, no?