Axiom Home Page Forums General Discussion Advice from Axiom Owners M80 and VP150 Testing over at Sking Ninja Forum

I'm interested in any feedback on graphs shown about M80's and VP150 ? How important is "off-Axis" response ? Seems to me if I sit in the sweet spot it is not an issue or is it ?
Thanks
pmc

Got a link?

Skiing Ninja M80 VP150 testing

"Skiing Ninja M80 VP150 testing"

Very interesting read. Makes me !

I don't think he likes the speakers....


This guy(gr reasearch) is designing the LS series of speakers for av123.com
they seem to be very nice speakers if you want to pay 6,000 for 2 speakers.
I would say he is tryig to pick axiom apart by the numbers not the sound. Also why would he use the m80ti to do a test rather that the up to date v2??
Has axiom become so big that the (smaller guys) are going to start attacking them?

I‘ve never auditioned the M80’s ti or v.2 version, and as such, cannot claim to like or dislike this loudspeaker.
I have always been cautious of loudspeakers with an overly complicated driver array. Not just Axiom products, but any loudspeaker. Every time you add a driver, complications arise in crossover design and dispersion characteristics. These can be compensated for by proper design, and execution of that design, but it all adds to the cost of manufacturing the loudspeaker.
All loudspeakers are designed with compromises, to what extent is up to the designer, and cost is usually the biggest consideration.

I'm going with "Yes".

It is a blatant attack of Axiom's design principles by a competing company disguised as "science".

Blah blah blah. Danny Richie is credible, Ian's a hack. Look at our pretty graphs.

Completely unscrupulous business practice. Shameless.

Apparently, it is much easier to criticize than to create.

I totally agree with your statements tomtuttle especially the last part. Skiing ninja is nothing more than an opportunist. His business ONLY exists because of the success and hard work of OTHER companies.

I imagine there is also some sour grapes still.

Wow. The number of bad conclusions in that write-up is amazing. Because they don't know why certain design decisions were made -- e.g. minimal bracing, no high-pass filter on the mids -- he basically concludes that Ian is a hack. He doesn't even consider that perhaps other designs were considered and blind tested in the development stage and found to be lacking.

I specifically remember Alan talking about how too much bracing can be detrimental to a speaker's sound. I think he was referring to the Algonquins, but I'm sure the idea carries over in general.

This guy is a complete hack whose suggestions for improvements would likely be detrimental to the overall sound when blind tested against unmodified originals.

To be fair, I'm wary of anything without a high-ass filter.

thanks for the tip.

It strikes me as odd that his numbers vary so much from the third party anechoic measurements done at the NRC.

fredk are you referring to these 3rd party measurements?

http://www.soundstagemagazine.com/measurements/axiom_m80v2/

Clearly, this guy has no agenda. I guess the NRC is lying, right?

Yeah Skiing Ninja has more knowledge and experience than Ian, Welti, Geddes, Toole, and the NRC combined. He is simply a Ninja. I'd like to apply a little Ryute Kempo on his a$$.

My Chito Ryu and Kobu Jitsu sensie once told me something that if you observe it, is almost always the truth. I can't remember exactly how he worded it but:

"Unless you are talking about pro competitors in an entertainment centric field of sporting (read...where image is important to the paycheck,) then you can almost always judge a martial artist's true skill by how little he makes of it. There will, of course, be rare exceptions but their personalities almost always match their mouths and their teacher was delinquent to continue training them to that level"

In other words, since he calls himself a Ninja on a public forum, I'd be willing to bet you could take him. heh heh.

So, what ever happened to the test of the M22's using the "Ninja's" crossover? Did I miss the exciting conclusion, or did it just never happen? I was following the discussion for quite a while, then it just seemed to disappear.

The M22 XO testing with Ian never came about, they wanted to keep them in house, however I did get a set and did some nonscientific testing of my own.

http://axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=229864&fpart=1

That was interesting. Did he test it to help confirm the 2.4 ohm issue that Emotiva has also stated. I personally would trust a word this ol boy writes.

The 2.4 Ohms isn't an issue when the XO is set at 40hz and up in a receiver any way. Only those running a 2 channel system would need to worry about it and even then a proper amp should still be able to handle it, like all the ones Axiom recommends. I know many speakers have drops this low, as I have mentioned many times, the M22 drops into the 2 ohm range and no body has a problem driving them.

I'm running my M80s in 2 channel on my 2809 with absolutely NO problems.

Exactly!!

What if you run the M80's with the 4 ohm load of the VP150

Ok, I'll hook up all my Axioms to ONE channel....NOT!!

Still no problems with my Denon's (yes I have done it)

jakewash, you just blew the ninjas mind!

Ok...

The only thing of interest to me here is his claim that the M80's do drop to 2.4 ohms from 10-20hz. I mean, this goes right back to the problems that some have had with Emotiva amps. All along, it's been said here that M80's don't have any impedance drops of that magnitude and that Emotiva was full of you-know-what. But if this guy apparently has confirmed that it does have a pretty serious dip, then doesn't that deserve a little explanation and/or rebuttal from Axiom?

For those that had shutdown problems, were you running your M80's full range? If you had them crossed at anything above 20hz, that should have eliminated the dip, right?

I fully realize that this Ninja character may be full of it too. Perhaps he has an axe to grind with Axiom over the 'issues' with his crossover. But still, this is a bit disconcerting to me.

I'd really like to hear Axiom's opinion on that data.

I agree Peter, I've never seen a graph from a reputable 3rd party showing anything below 4ohms across the frequency response.

What stands out to me (no, I'm not reading the article; I like my blood pressure low) is that he tested with M80tis. There have been significant crossover changes in the transition to v2s. A little birdie told me that it resulted in a much improved sound.

I have not either, and as was stated, if you are using a sub it will not matter anyway since you will be setting you AVR XO to send those lower frequencies to the sub.

BTW - For the people who did have Emotvia amps trip... Were you using a sub and setting the pre-amp XO above 20 Hz?

I would like to know this as well... My xpa5 has never tripped even in direct stereo mode with the m80's. I don't understand why the xpa5 can handle the load when the more powerful xpa2 can't.

I never heard of a skiing ninja before I read this post. What kind of nerd is a skiing ninja anyway????

I have nothing much to add here... Just hoping I can be quoted out of context on the ninja's website.

Oh, and BTW.... Don't ever believe a review done by the manufacturer or a competitor. Both have reasons to spin the 'facts'.

Skiing Ninja's frequency response graphs for the M80, even the on-axis plots, seem to be quite different from others I have seen.

I couldnt care less what the measurements were or who's a hack..

I just thought it was amusing that someone would want to do something like fabricate a new baffle or cover over tweeter holes or make tweeter pods...

... Maybe its just me but if my speakers needed that much modification to be good i would...... oh, i dont know... But better ones?

Well, I finally got around to reading the linked page. He's not just attacking Axiom, but us weepy board members who are too emotional to have valid counterarguments. Nice. I don't really know what he thinks he's accomplishing.

Steve, with my MPS-1 I tried various modes, direct, stereo (80hz crossover), and movies (all speakers small/80hz crossover), and still had shut downs. The shutdowns occurred normally during explosions in movies, or when the music was turned up a bit, but not to insane levels.

>>The only thing of interest to me here is his claim that the M80's do drop to 2.4 ohms from 10-20hz.

Doesn't the impedence drop to zero (ie just the DC resistance of the voice coils) if you take the frequency low enough ?

Impedance = Resistance + Reactance. The reactance would be zero, but the resistance would still be there.

Well, that to me blows all of their propaganda out of the water. If you crossed over at 80Hz, the M80 did not even see those supposed low impedance's between 10-20 Hz.

Listen, in the end people should buy what they are happy with. It's just fascinating to me that the Emotiva amps seem to be the only "high end" amps that have trouble with this speaker, yet my lowly 120W receiver never has a problem with it. I mean, when Micah came over we listened to the "Finding Nemo" fishbowl scene at 105db, and we listened to about 5 minutes straight of it. This was after we had already listened to music at this level for almost an hour. The Denon never had a problem. I just think something smells very fishy here.

I'm sure it's their overactive protect circuit. It's only in the amps people have reported problems with, and the ones that don't have it, M80 owners seem quite satisfied with.

I couldn't swear to it Peter since it's been a while but my recollection is that with the XPA2 and M80s with an 80 hz crossover setting the protect circuit did not trip, the results are probably in the thread I started on that topic but the point is probably moot, because I did not test the crossover issue extensively since at that time I was waiting for an 800 to be built and was not that intrigued by the possibility of discarding the LFEs entirely, and the prevailing opinion at that time was that the supposed dip below 4 ohms question was not a real issue, e.g., Alan stated that the 80s were a nominal 4 ohm design with no dip below 4 ohms across the audible range, I suppose it did not occur to me at that time that the audible range is typically defined as 20 Hz - 20KHz and that the problem might be in the range of 10-20 Hz.

“The real alarming part though is that the mids have no high pass filter at all. They are only crossed over to the tweeter and allowed to play as low as the lower end roll off allows. Not only does this mean that they will easily reach exertion limits with low frequency information but that they also contribute to making the impedance in the lower range even lower.”

Can anyone verify this? It can’t be accurate!

I'm sure the design information could be accurate. However, his analysis could be completely wrong.

Axiom didn't stay in business this long (lacking the marketing power of Bose) or get this dedicated a following by not knowing how to design a speaker.

I really didn't pay attention to the M80 graphs since I don't own any. I did look at the VP150 graphs and was concerned.

I have previuosly stated on this board that the VP150 had not lived up to my expectations. Of course that is in comparison to my M22s and QS8s; both of which I am completely happy with. On another thread I recently mentioned that I have the VP150 on a shelf below my LCD TV and had recently turned it over so that it angled up toward ear level. That has made a positive difference and movie dialog is now generally better and satisfactory.

Still the graphs did concern me. If the graphs were accurate then no placement of the VP150 would give satisfactory performance off axis in the normal home environment. There are too many satisfied VP150 owners for that to be likely.

I am a retired engineer (BSEE, MSEE) but mostly computer background and don't own expensive audio test equipment. Still my old Pioneer VSX-45 does have MCACC so I decided to make use of it. It's an older generation MCACC and takes equalization measurements at 63Hz, 125Hz, 250Hz, 4kHz, and 11.3 kHz. Since I have crossover set at 80Hz the 63Hz does not apply.

I made equalization measurements at 5 different room seating locations from dead center front up to 45 degrees off axis. What I found was no more than 4 db difference across each set of frequency measurements. Correcting for trim level the 125Hz ranged from -5.0 to -4.0, the 250Hz from -5.0 to -4.0, the 4kHz from -2.5 to +1.5, and 11kHz from -1.5 to +1.5.

My results were very different from the ninja graphs which show ranges of over 15 db difference off axis. My results can be explained by room variations even if the VP150 were a point source and had perfect 360 degree dispersion. I don't know how to explain the ninja graphs; but something seems very wrong.

In the text with the ninja graphs was the statement " What the listener will really hear can vary greatly even from one ear to the next." Again there are too many satisfied VP150 owners for there to be any truth in that statement. Bottom line is I have to totally discount the ninja information about the VP150; and believe my experience and my ears.

Did he do the graphs in an anechoic chamber, or did he just use a room in his office or something?

I was curious about that, too.

In the M80 section of the ninja report it says:

"All measurements were made by Danny Richie at GR Research. Danny has been contracted as an outside party for measurements before and has an established reputation in the community for high quality work that is beyond reproach."

Of course my concern is how speakers perform in my home and the VP150 performs well. It would perform even better if I could place it in the center of my TV screen, but then I would miss an important part of the picture.

I really don't care how the ninja graphs were arrived at. I have done enough to allay my concerns about the VP150 in my home.

Bill

If someone is looking for a specific "result", the tests can be made to accomodate the result.