Axiom Home Page Forums General Discussion Home Theater AB Comparison - Axiom M60 & Wharfedale Evo 30

Mike, I appreciate the detail and candor in your review, and always enjoy your participation here. I hope you'll stick around. Thanks again for sharing your thoughts about the Wharfedales; you've certainly piqued my interest.

Love the sig Tom, but couldn't you replace beer with sex and it still be a true statement?

Mike...just out of curiosity, and in case I missed it, were the listening levels matched when you switched speakers? Even just a couple of dB could make a different perception.

Yes, they were. All switching was done on the fly while the volume remained the same. In other words, in the middle of a song the guy assisting me with the AB comparison would push a button at my signal and instantly switch from one speaker to another. At times, I would listen to a short section of material and then have the guy switch the speaker and quickly replay the same section. The poor guy stood and kneeled in the same spot both switching the speakers and manning the CD player for at least two hours with a few short breaks where he left to retrieve a different CD. I had the A80 remote in my hand during the comparison so the only person that could have changed the volume was me.

I think it was a very fair comparison. Nobody in the shop said a word to me during the AB comparison and just did what they could to assist me. After I was done, I offered my candid impressions and asked for theirs.

When I was done, the owner came by and pulled the grille off the M60 and took a gander at the drivers. He said the tweeter was a Vifa and thought the woofers were likely made by Thompson.

That reads like the speakers were not level matched. Simply keeping the volume dial the same does not account for the different speakers having different efficiency ratings. In a sense, it is like speaker level matching your system during HT setup.

If one speaker is slightly more efficient than the other...it will play louder when fed the same volume.

Not trying to invalidate your session, just want to make sure it is known that when comparing speakers, it is important to make sure are putting out the same SPL. The slightest difference can give a speaker an advantage.

This hits on a question I always have during speaker comparisons. Where they each calibrated for their optimal performance? Who says the room doesn't suit one speaker better than another? Is each speaker placed in its optimal location? I am not dismissing the results in this comparison, I just never know how to tell when comparisons are really meaningful.

For example, if you look at Axiom reviews on other websites, criticisms range from too bright to "lack of good highs - pair with a bright receiver". To me, this must be a calibration, room variable, etc. issue, not just speaker performance.

KC_Mike,

While I applaud your efforts to do a controlled comparison, you absolutely must measure the total SPL using pink noise with a Sound Level Meter, and calibrate the volume levels to a fraction of a dB. Moreoever, you must conceal the speakers with a visually opaque but acoustically transparent curtain.

In the 25 years I've done double-blind A/B listening tests, if these testing protocols are not followed, you will always choose the louder speaker (and louder by 0.5 dB even if they subjectively sound the same volume) as the "better." Likewise if you know which speaker is which, it's uncanny how psychological biases will cause you to pick the speaker you "think" you like more. Furthermore, differences in the two speakers locations in a given room will result in different ratings because of placement differences and room effects. I can assure that even seasoned professionals like Dr. Floyd Toole (with whom I served on many listening panels) have documented the biases that result from non-blind listening. In our tests, each speaker was rotated into different listening locations, as each listener sits in different chairs in the room, so that each speaker has been auditioned in several locations by the same listeners, in each of four different chairs. This effectively removes the variables of room placement which, in a simpler test, may cause you to choose one speaker over the other.

Failure to observe these testing protocols reduces the results to anecdotal data.

Regards,

While I am sure the Alan's comment regarding bias can be true and his comment regarding volume difference is also likely to be true in most cases, I wonder just how much it can account for. Just to reiterate, I believe Alan stated there could have been two causal factors present that might have skewed things. One being a difference in volume and the other being a psychological bias where a person picks the speaker they 'think' they like more.

The M60 and Evo 30 have the same efficiency rating according to published literature. The M60 is 89 anechoic and 93 in room response. The Evo 30's are listed at 89 but it doesn't say if that was anechoic or in room response. If it was anechoic, then they are the same. If it was in room response, then the M60's are more efficient and would have been the louder speaker at a given volume.

I had the Axioms hooked up in my home for two weeks before I did the AB comparison and I went into the comparison with the gut feeling the M60's would fair better because I perceived they were better based on my memory of the Evo's; which I hadn't heard for months until this past weekend. Alan can in no way ascertain for himself whether I had a bias for one or the other going into the AB comparison; so I thought his mentioning it somewhat implied a bias did exist.

Even though their efficiency ratings are the same, let's assume there was still a small difference in SPL and for the sake of exploration let's say the Evo 30 was .5 to 1db louder than the M60. Can that difference account for detail missing in one speaker yet present in the other? Can a minor SPL difference account for one speakers lack of bass attack as opposed to the other? Can SPL difference account for my finding the M60 to be more localized (sound coming from the box instead of dissapearing into the room)as opposed to the Evo; which dissapeared into the room? When I heard the detail of a guitar pick strumming the strings on the Evo 30 that I couldn't hear on the M60 on a particular track, could that be due to SPL difference? Also, even though I was bias towards the M60's, let's assume the oppostie was the case for the sake of exploration. Could a bias manufacture and introduce things into the source material that didn't exist to begin with? Could a person imagine detail that really wasn't there only because they had a bias? Imagine any of you doing an AB test in mono and hearing detail in one speaker that wasn't present in the other and then somebody suggesting to you that the difference(s) you heard could be due to your bias and/or uneven SPL.

In my original post, I made reference to a jazz song that had a lot of snare syncapation which the M60's muddled together while the Evo's clearly intonated each tap of the snare. Would anybody suggest that had I turned up the volume on the M60 (assuming it wasn't as loud as the Evo)during the same track, that the muddling of those snare taps would have suddenly dissapeared and become distinctly separate?

I am perfectly willing to go back to the dealer and borrow one of their SPL meters and see if both speakers are true to their claimed efficiency (there shouldn't be a singificant difference if any at all since both claim to be exactly the same). If I found a discrepency, I would be willing to do the AB comparison all over again; but I suppose at this point it wouldn't matter because anybody could claim, since I professed my preference for the Evo's after Saturday, I will have a psychological bias that will cause me to pick the Evo's regardless.

I respect Mr. Loft and am aware of his industry experience. I also don't disagree with his comments regarding the louder speaker bieng perceived as better or that people can have a bias. However, my bias was towards Axiom going into the comparison. Secondly, these two speakers have the same efficiency rating providing Wharfedale's rating was done in an anechoic chamber. If Wharfedale's rating was in room response, than the M60 would have been the more efficient speaker which means it also would have been the louder of the two at a given volume. Only two scenarios are possible regarding efficiency based on the specifications; either they were exactly the same or the M60's were more efficient. Other than that, as I eluded to in the previous paragraphs, I am very skeptical that a small (or any for that matter) SPL difference can manufacture something that already isn't there...whether it be detail, attack, etc. Conversely, I remain skeptical that a small SPL difference can cause those same characteristics to dissapear.

That is like hearing detail on speaker 'X' that isn't there on speaker 'Y' but thinking by turning up the volume on speaker 'Y' the detail will be revealed. Conversely, by turning down the volume will the extra detail revealed by speaker 'X' no longer be present?

In summation, I wasn't biased towards the Evo's and the efficiency ratings of these speakers dictate that they were either the same or the M60's may have been the louder of the two. For those reasons, and the others I eluded to in the previuos paragraphs, I stand behind my findings.

So, (he says in a valiant attempt to defuse the situation), we all agree that we'd likely pick the speakers that sound best to us, regardless of how we got there and, as a result, feel good about the money we spent feeding this relentless and absolutely subjective hobby?

No response is really needed.

KC- i was scared that alan's post might put you on the defensive. i went back and read what you had wrote on the first review, and i agree that a slight difference in volume would not account for all the variying factors that you perceived when you heard the two speakers. plus, i see what you are saying when you went into it expecting the axioms to be better.

i dont think alan was knocking your conclusions.. rather, with his technical background, i think he is more interested in the clinical/measurable aspect of the whole session.

i can dig what you were saying, and i am glad you were able to find the speaker that was pleasing to your ear. i think you have made a solid decision, and i dont think any of us are trying, nor would we attempt to change your mind.

i hope you still hang around and have conversation with us.!!

bigjohn