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Any thoughts on axiom audio speakers? - Page 4

post #91 of 320
Quote:
Originally Posted by cschang View Post
Stereophile splices in port measurements as well. Since the NRC/Soundstage does not, you can see in their measurements of rear ported speakers don't show their actual bass response.

Let's consider a bookshelf spkr rear ported to 40Hz. Wavelength = 1140/40 = 28.5' or 342". The output of the port should be very close to omnipolar at those lower frequencies behind a 7"W x 12"H x 8"D cabinet and an 8"? path length difference between the port and woofer to the mic is of minimal significance. IMHO, the bass response in the NRC measurements would be acceptably accurate.
post #92 of 320
Here is an interesting article from Audioholics that, at least in part, discusses the scale used in frequency response measurements. It seemed relevant to the discussion.


Second, Danny Richie, you discuss the issue of dual tweeters (which makes sense). I see that Axiom isn't the only mfg. to use a dual tweeter design. I am thinking particularly about the Dynaudio Confidence and Evidence series towers. I've heard these a few times and was blown away by them. Is it due to better crossovers/implementation, luck, or ...?
post #93 of 320
Quote:
Originally Posted by Sahak94 View Post
Let's consider a bookshelf spkr rear ported to 40Hz. Wavelength = 1140/40 = 28.5' or 342". The output of the port should be very close to omnipolar at those lower frequencies behind a 7"W x 12"H x 8"D cabinet and an 8"? path length difference between the port and woofer to the mic is of minimal significance. IMHO, the bass response in the NRC measurements would be acceptably accurate.
Understood...but the NRC measurements don't seem to show that. Do you have an example you can point to?

I'm not saying what the NRC does is right or wrong, just that it is something to keep in mind.
post #94 of 320
Quote:
Originally Posted by Eternal Velocity View Post
It's not about how offensive it appears on a graph, but whether it's there or not, plain and simple. There is no need a 50db scale, except to make things look pretty. It serves no purpose in terms of design.
If you clearly see a 1dB high-Q dip and nobody can hear it, yes it's there but why is it important?

I think it's of great value to be able to look at the freq resp graph and know that if it's difficult to see, it's difficult to hear.

The guys on the digital camera forums have this argument all the time. Over there it's known as pixel peeping. e.g, If you can find chromatic aberrations by looking at a cropped section of a pic from your 25 Mpix camera (= to ~50X magnification for example) but it's invisible even at poster size, who cares?

Having said that, there are deviations in the Axiom graphs (NRC or GR) that I believe would be audible and I'm not trying to minimize that.
post #95 of 320
Quote:
Originally Posted by cschang View Post
But who is the audience for the graphs? Designers/engineers or consumers?
Any consumer particularily interested in the graph will not want a pretty smoothed out graph - especially not off axis.

Any consumer satisfied with a smoothed graph is probably not too interested in these things.

Regarding the audibility of 1db - it is very much audible if the dip or peak has a low Q. We miss these low q dips with smoothed graphs. A 1 db low Q dip has more effect on the sound than a 5db high Q peak(though the latter may indicate a resonance). With smoothed graphs we miss the former without straining our vision and may overemphasize the latter.
post #96 of 320
Quote:
Originally Posted by Snowmanick View Post
Here is an interesting article from Audioholics that, at least in part, discusses the scale used in frequency response measurements. It seemed relevant to the discussion.


Second, Danny Richie, you discuss the issue of dual tweeters (which makes sense). I see that Axiom isn't the only mfg. to use a dual tweeter design. I am thinking particularly about the Dynaudio Confidence and Evidence series towers. I've heard these a few times and was blown away by them. Is it due to better crossovers/implementation, luck, or ...?
I adressed this earlier in the thread. one tweeter is rolled off early - think of it as a .5 way to increase output at the bottom of the tweeter passband without running into HF lobing. Power Tapered Line Arrays do this as well
post #97 of 320
Quote:
ok, so now you do take your measurements in some arbitrary room. I'm not saying there's anything wrong with that, especially if it's only above 200Hz but let's not pretend that's equal to a calibrated facility.
My measurement system is one of the latest Clio systems using a highly calibrated mic. It is one of the most accurate systems available. It is not better in any way by any other system. And deviations between the better systems could be less than 100th of a db.

Quote:
Quote:
I could take a near field woofer response and splice it into the measured response. I can do the same thing also with the port output. John Atkinson of Stereophile and the NRC both do this.
NRC typically doesn't do this. It's a continuous swept sine wave from 20Hz to 20KHz using an old Amber analog analyzer and Peter Shuck's DOS based software. They do have an Audio Precision System One but the Soundstage plots came from the Amber/ Peter's software.
Also, to measure any wavelength accurately then you need to let it propagate for one cycle. A 20Hz wavelength for instance is 56 feet long. And you'd need to have the mic that far away to really catch it with 100% accuracy. Likewise 40Hz is 28 feet long, 80Hz is 16 feet long, etc.

The NRC claims: All small- and medium-sized loudspeakers are measured at a distance of 2 meters (6.5 feet). Where appropriate, larger loudspeakers are measured from a distance of 3 meters (9.75 feet) to allow for proper driver integration.

So if the NRC is measuring 6.5 feet away then they are getting good accuracy down to 170Hz. Below that accuracy will start to drop off.

So it is very likely that they are also splicing in the lower ranges from a near field measurement. And if they are adding in the port contribution of a rear ported speaker then they have to splice that in as well.

Quote:
So there's reason to EQ a subwoofer or take into account a speaker's anechoic response below 200Hz?
EQ to a sub-woofer is needed more often than not. Usually there will be either a dip or a peak somewhere below 100Hz.

Quote:
IMHO, assuming a speaker's freq resp is the same as the T/S calculation up to 200Hz is blind faith.
No, it is easily calculated with a high level of accuracy. Keep in mind that wavelengths in those ranges are quite long. So you won't see a bunch of peaks and dips in the response. You only see a broad band of increase or decrease.

Quote:
Quote:
The NRC also leaves out one of the most telling of all measurements, the cumulative spectral decay.
I think Floyd Toole would disagree with you but then again, I can see how the CSD can be of use to some designers. It obviously was to KEF.
If there is one measurement that can tell you the most about a speakers performance then it is the CSD. It gives you the on axis response without smoothing, and will highlight stored energy issues. And the stored energy issues, break up, or ringing, is the easiest to hear and most offensive by far of any other distortion that a speaker can be measured for.

Quote:
I don't believe the latter statement is correct. John Atkinson of Stereophile highlights this in almost every review. " The traces in the impedance graph are free from the small glitches that would imply the presence of cabinet vibrational resonances."
It would have to be a very serious cabinet resonance for a low level impedance sweep to pick it up. Have a look at JA's measurements and you will see pretty strong cabinet resonances picked up by the accelerometer that do not show up in the impedance sweep at all.

Quote:
Second, Danny Richie, you discuss the issue of dual tweeters (which makes sense). I see that Axiom isn't the only mfg. to use a dual tweeter design. I am thinking particularly about the Dynaudio Confidence and Evidence series towers. I've heard these a few times and was blown away by them. Is it due to better crossovers/implementation, luck, or ...?
Some companies, and I think Dynaudio is one of them, will insert a very small value cap in line with one of the tweeters so that it only adds output above 20kHz. Some add the second tweeter for marketing only and live with the negative effects. Two has to be better than one right?
post #98 of 320
Quote:
Originally Posted by cschang View Post
Understood...but the NRC measurements don't seem to show that. Do you have an example you can point to?

I'm not saying what the NRC does is right or wrong, just that it is something to keep in mind.

What one has to keep in mind when looking at the NRC measurements (or any anechoic measurements < ~100Hz) is that there is no room gain and that's why there appears to be insufficient bass. I'm not sure if that's where you see bass SPL inaccuracies but I thought I'd highlight it anyway.

I took a close look at this Focus bookshelf.

http://www.soundstagenetwork.com/ind...d=77&Itemid=18

Although the relatively short path length difference between the port and driver doesn't result in any cancellation that I can see, the bass from the port in the on-axis and listening window measurements is a bit lower relative to the off-axis measurements because the port is further away from the mic when it's on the back. As the speaker rotates for the off-axis measurements, the port moves closer to the mic.

But your ears are also further away from the port so it's a bit of a gray area in regard to what different people believe is more accurate. Although they're not usually published, NRC can also measure total sound power. The port output is obviously included in those measurements.


Sorry to the OP... off topic for this thread hopefully educational.
post #99 of 320
Quote:
Originally Posted by Sahak94 View Post
Let's consider a bookshelf spkr rear ported to 40Hz. Wavelength = 1140/40 = 28.5' or 342". The output of the port should be very close to omnipolar at those lower frequencies behind a 7"W x 12"H x 8"D cabinet and an 8"? path length difference between the port and woofer to the mic is of minimal significance. IMHO, the bass response in the NRC measurements would be acceptably accurate.
Actually the rear port looses half of its output in the chamber. The rear wave is absorbed into the foam layers of the chamber and never reaches the mic.

In a real listening room that energy is reflected around in the room, and if backed up to a wall then the coupling effect can increase or magnify its output.
post #100 of 320
Quote:
Originally Posted by cschang View Post
Danny,

Did you work on or measure AV123's Strata Mini? Soundstage has measurements on it. It might be a good one to compare your measurements with theirs.

http://www.soundstagenetwork.com/mea...3_strata_mini/

Sorry, I almost forgot this one.

The little planar tweeters used in those speakers had a very high level of variance. I have measurements that show some of them to be pretty off.

And the NRC got a hold of one that was pretty off.

Other than that, their measurements of that speaker match mine pretty well also.
post #101 of 320
Quote:
Originally Posted by Danny Richie View Post


Some companies, and I think Dynaudio is one of them, will insert a very small value cap in line with one of the tweeters so that it only adds output above 20kHz. Some add the second tweeter for marketing only and live with the negative effects. Two has to be better than one right?
Interesting. Thank you for the info.
post #102 of 320
Danny, I can't say agree with much of anything you've written. If it's opinion, there's nothing wrong with voicing that. But some of this is physics

Quote:
Originally Posted by Danny Richie View Post
Also, to measure any wavelength accurately then you need to let it propagate for one cycle. A 20Hz wavelength for instance is 56 feet long. And you'd need to have the mic that far away to really catch it with 100% accuracy.... So if the NRC is measuring 6.5 feet away then they are getting good accuracy down to 170Hz. Below that accuracy will start to drop off.
You need the mic far away to catch it? I have no idea what you're talking about. Why can't a mic measure peak pressure at any distance from the source?

But wait, before you said "I could take a near field woofer response and splice it into the measured response. I can do the same thing also with the port output. John Atkinson of Stereophile and the NRC both do this."

So at that time it was an acceptable measurement method but now you need to be further away than 57 feet to measure 20Hz accurately???????


I'm done
post #103 of 320
Sahak94,

You can take a near field and get so close enough to the woofer that you have a great differential between its output and the reflection from the nearest boundary.

However, as soon as you back off of it to a meter or something then you really can't measure a long enough time window to catch one full wavelength without a reflection being involved. The wavelength takes longer to fully propagate than the arrival of the reflection. If you gate the reflection then you also gate out part of the time that it takes for the wave to arrive from the source.

That was why John Dunlavy explained to me (when I visited with him at his facility) that his two chambers were 25' square, and with his speakers run up into the air mid way between the floor and ceiling, that the distance to the walls plus the 1' thick foam would let him accurate measure down to 40Hz and that he got a good approximation below that.

Even 1' thick foam wedges won't be 100% effective in the lower frequency ranges. The Auralex Venus bass traps that lined the rear wall of my chamber did not have a NRC rating (Noise Reduction Coefficient) of 100% at 20Hz. Not even close.

There is no getting around the fact that you need microphone distance to measure accurately down low.

From the article that there was a link to from Audioholics:

"A common wedge length is 3 ft, yielding good measurements down to below 100 Hz. An anechoic chambers accurate down to 20Hz would be costly to build requiring at least 14ft wedges to yield adequate low frequency absorption. We know of no such chamber. "

Get it?
post #104 of 320
Quote:
Originally Posted by Danny Richie View Post

The wavelength takes longer to fully propagate than the arrival of the reflection. If you gate the reflection then you also gate out part of the time that it takes for the wave to arrive from the source.

That was why John Dunlavy explained to me (when I visited with him at his facility) that his two chambers were 25' square, and with his speakers run up into the air mid way between the floor and ceiling, that the distance to the walls plus the 1' thick foam would let him accurate measure down to 40Hz and that he got a good approximation below that.

I visited John Dunlavy a couple of times when he was based in Colorado Springs and envied him the chambers. I did some measurements in one of them, to compare with what I doing back home. However, one problem JD couldn't solve was that the small forklift he was using to raise his large speakers away from the floor itself introduced some reflections that interfered with his measurements. There are always such practical problems when you are measuring physically large speakers, not just the theoretical ones.

John Atkinson
Editor, Stereophile
post #105 of 320
Quote:
Originally Posted by Sahak94 View Post

What one has to keep in mind when looking at the NRC measurements (or any anechoic measurements < ~100Hz) is that there is no room gain and that's why there appears to be insufficient bass. I'm not sure if that's where you see bass SPL inaccuracies but I thought I'd highlight it anyway.

I took a close look at this Focus bookshelf.

http://www.soundstagenetwork.com/ind...d=77&Itemid=18

Although the relatively short path length difference between the port and driver doesn't result in any cancellation that I can see, the bass from the port in the on-axis and listening window measurements is a bit lower relative to the off-axis measurements because the port is further away from the mic when it's on the back. As the speaker rotates for the off-axis measurements, the port moves closer to the mic.

But your ears are also further away from the port so it's a bit of a gray area in regard to what different people believe is more accurate. Although they're not usually published, NRC can also measure total sound power. The port output is obviously included in those measurements.


Sorry to the OP... off topic for this thread hopefully educational.

I think we are saying the same thing.

If Stereophile measured the same speaker, the FR at the under 100hz would be very different.
post #106 of 320
Quote:
Originally Posted by stereoeditor View Post

I visited John Dunlavy a couple of times when he was based in Colorado Springs and envied him the chambers. I did some measurements in one of them, to compare with what I doing back home. However, one problem JD couldn't solve was that the small forklift he was using to raise his large speakers away from the floor itself introduced some reflections that interfered with his measurements. There are always such practical problems when you are measuring physically large speakers, not just the theoretical ones.

John Atkinson
Editor, Stereophile

Yeah, I remember that (forklift).

He mesured two of my speakers back then and they measured just like they did back in my chamber.

He was one of the kindest guys I have met in this industry to date. He practically spent the whole day with me and would share anything he knew.

By the way, thanks for the nice mention in the Axpona show covered for my Carnegie Acoustics client. It was good seeing you again.
post #107 of 320
I was reading a very interesting article by Gene DellaSala regarding graphs. I just found it interesting. here is the link. http://www.audioholics.com/education...o-measurements

I found it interesting to learn that it is the exact same speaker, same graph with the only difference being presentation. Would have fooled me. Graph's attached at bottom of post.

Also while I am on here, I have a question that my wife asked me last night, she asked me why Axiom owners audition their speakers in home for complete strangers? I replied to her, I have no idea. I do recall about a year ago on a different forum when I was contemplating the move from Paradigm Monitor to the Studio line, an Axiom owner had chimed in and said the Axiom are of a similar sound to the Studio's. I later got a pm from the same person asking if I was interested in Axiom speakers and that maybe he could help in getting me an audition. I did not respond. A few days later I got another pm asking me if I had any further thoughts about the Axiom audition. I did not request an audition and did not reply again. I thought it was a little strange.

So I guess my question is, why do Axiom owners audition their own speakers for strangers?
Could it be out of the goodness of their heart?
Could it be that they believe in the product that strongly?
Could it be something I am unaware of?
Any ideas? Just something that made the wife go..hmmmm.
LL
LL
post #108 of 320
Oops....I killed the thread
post #109 of 320
Quote:
Originally Posted by John1400 View Post

Oops....I killed the thread

No you didn't. I have no idea why Axiom owners allow strangers into their home to audition speakers. Maybe they're compensated somehow by Axiom? Maybe they enjoy being unpaid representatives and extensions of Axiom's marketing and advertising arm? Dunno.
post #110 of 320
Quote:
Originally Posted by Chu Gai View Post

No you didn't. I have no idea why Axiom owners allow strangers into their home to audition speakers. Maybe they're compensated somehow by Axiom? Maybe they enjoy being unpaid representatives and extensions of Axiom's marketing and advertising arm? Dunno.

Aw c'mon - it's not unique to Axiom, Axiom just makes an effort to facilitate it.

I think for any ID speaker company you could go to their owner's thread here and see many "Does anybody living in xxx have these so I can come and audition?"

For the record, I considered Axioms and went to somebody's house herein Calgary to listen.
post #111 of 320
Gee, nobody has offered the reason why I have auditioned my speakers for folks. It's nothing complicated. I'm just trying to be helpful to a fellow enthusiast.

Someone living near me shows an interest in the speakers I own. They often ask if they can come listen to mine. Sometimes I ask them if they'd like to hear mine. Do I care if they like them? I suppose I hope they do, just cuz I own them.

Do I care if they buy any? Not in the least. My goal is for them to end up with a system that gives them as much pleasure as mine gives me. I really don't care if that's with my speakers or not.

I will never understand why folks try to make something nefarious out of a simple act of kindness.
post #112 of 320
I would like to start out by saying I really don't like being a part of discussions that involve endless innuendoes about someone's integrity backed up by acoustical measurements. It is something that I and the rest of the Axiom staff in general try to stay clear of. We find it much more effective to stick to our research and our product development and continuously strive to deliver to our customers a better audio experience. And though it may not seem like it from some of the contents contained in this thread we actually have thousands of very happy customers. The vast majority of people who purchase our products are extremely happy with them; even ecstatic over how we have managed to deliver to them their greatest audio experience ever. Unfortunately from time to time our stay clear approach leads some to draw a conclusion that we are somehow in agreement with the innuendo pusher. So for some clarity I will put forth some observations.

In the world of loudspeaker measurements you can easily show a set of measurements that look great and a set that look bad, and they can be all of the same product. To the audio engineer it is the family of measurements that mean something, and the family is large. Some of the measurements will look good and others not so good: this does not matter as it is the relationship between them and the significance of their audibility that does matter. You will be making trade-offs from one measurement to another; there is no free ride. When you change one thing you are probably changing many things. Understanding these interrelationships is the key to a great loudspeaker design.

One thing I have learned over the years in this business is that you should not take any measurements for granted by their appearance alone, and you should not take them in isolation. We are all drawn to a flatter is better approach to measurements but in the world of audio engineering this is not always a reliable assumption. Some measurements cannot be flat without distorting others that should be flat and some you don't even want to be flat. Another alluring thing about acoustical measurements is the ease at which you can point to one measurement or another and then draw conclusions about the effect on the listener experience.

This becomes even more compelling when the measurement in question has a bit of a nasty look to it. This is why controlled double blind testing is such an important tool for scientifically judging the listener experience. There is no way you can look at two measurements and not have it bias your listening tests if you know which one is which. I certainly cannot do it and I think anyone who claims they can is playing a fool's game. Besides, whatever test you can do sighted you can do blind and whatever test you can do yourself you can subject to a panel of people individually without any intermingling during the test. The only reasons to not do it properly are either to try to save time and money or to save your ego. The ego one is a big deal if you have spent your time making claims about what people can and cannot hear based on this measurement or that, as a lot of your claims will go down in flames when exposed to the controlled double blind test.

Earlier Brent posted links to some of our research thus far into comb filtering and its effect on the listening experience as demonstrated in double blind listening tests. Comb filtering is an interesting phenomenon as it is in fact being introduced any time you simply move from a mono speaker to stereo speakers. This is a fact that Danny Ritchie dismisses entirely with the term hilarious. I am not sure of the technical meaning of hilarious when it comes to acoustical measurements, which makes it a bit tough to answer to, but the fact remains that it does exist in large doses by moving from mono to stereo, but we prefer stereo over mono. At Axiom we regarded this phenomenon of stereo listening as curious and worthy of further investigation.

The first thing we wanted to know is if this preference for stereo was a result of the large separation between the loudspeakers and the resulting increase in imaging and spaciousness created by said separation was somehow trumping the comb filtering. Comb filtering is an ugly looking measurement and, like most, our first thought was it must be detrimental to the listening experience.

We next tried placing the stereo pair immediately either side of the mono loudspeaker. This gave us about 15 between the simultaneously playing components. Again the pair of loudspeakers won over the single loudspeaker in the double-blind listen test. The margin of the scores came much closer together but the scores remained in favour of the pair playing together. The same holds true in double blind tests between our M60 and M80 models. The major difference between these models is the dual mid/bass drivers and dual tweeters in the M80. The M80 wins even though comb filtering is introduced by its design. In all cases the amplitude was level-matched for the testing. So when it comes to comb filtering I would caution against any looks bad therefore sounds bad conclusions being hastily drawn.

Comb filtering is an area of great debate especially in the commercial end of the market where multiple speakers and/or line arrays must be used to achieve the required SPL. There is no shortage of opinions surrounding this phenomenon and no shortage of comb filtering either. If you are concerned about comb filtering occurring in each of your speakers, though ok with it in your stereo pair, I would suggest purchasing speaker models that do not use multiple drivers playing the same frequencies (lower frequency drivers excepted) and use a 2-way bookshelf for a centre channel. This will at least limit the comb filtering to one axis in the vertical domain centred around the x-over point. Psychoacoustics being what it is, if you are concerned about it, and can see those multiple drivers, you will never be able to get past that concern during your listening; no matter if it is a real issue or not.

I think it is worth noting that Danny is not without a conflict of interest in his voluminous recommendations he is putting forth on these forums. According to his website he is the distributor of expensive x-over component parts and thus has quite an interest in promoting them as making a big sound improvement. This does not jive with the evidence however. In the case of inductors it is certainly possible, using cheesy little cores, to measure saturation within the power band the speakers themselves can handle. But Axiom does not use such cores, our cores will not saturate anywhere near the power band before which you will end up with drive units all over the floor. This theory of air core good, any core material bad does not hold. It is a simple double blind listen test to conduct. All you need to do is use two coils with exactly the same mH and DCR values, one air core and one laminated core; then switch between them into the same speaker. We have done this test many times over the years with people who swear they can hear the difference; but they never can. As a side note to this it is much more difficult to do this test with capacitors because getting the two to have the same DF is pretty much impossible and the DF affects the amplitude response. However it can be done and the results will be the same as with the coils. This said though I doubt the capacitors are Danny's issue on the M80 crossover as they are already all film caps. All of this creates a bit of a quandary for us at Axiom because we know that there is a camp out there that believes these x-over part upgrades make a difference and we would obviously like to be able to give them what they want. The problem is we could not honestly put this out there as an improvement; we would be left with having to charge more but not actually deliver more. This is one of the main reasons why I was really hoping the Skiing Ninja x-overs would at least match the performance of the production x-overs. Skiing Ninja could then be the ones selling the upgrade to their followers and we would still have the speaker sale. Unfortunately the upgraded Skiing Ninja x-overs lost the double blind listen test to the production ones. It was a few months after these results came out that the smear campaign against us at Skiing Ninja appeared on their website: coincidence?

One of the reasons their x-over lost the double blind listen test is because of Danny's obsession with the waterfall graph. He ended up taking the x-over point down to where the threshold of compression and distortion was now manifesting itself in the dynamics.

These waterfall graphs need to be kept in perspective. First, all the high Q stuff is going to be visually unappealing but not necessarily where you need to focus. The low Q stuff in relation to the amplitude response is where to keep your eye out. As a side note to this; for Danny to say he can get perfect measurements in his room is also not quite accurate. They can be a reasonable facsimile but certainly not perfect. Why would anyone spend the huge amount of money required for a true certified anechoic chamber if they could get the same results in a room? We wouldn't; but we do own a true certified anechoic chamber and we own it for a reason. I also saw where Danny was trying to say he had an anechoic chamber in the past and was able to compare his current in-room measurements to that chamber. But from both his description and the photo on his web site that was not a real anechoic chamber. Thus truly accurate measurements never existed for him to make said comparison.

While we are on this topic of using really expensive parts on x-overs: there has been some talk around Axiom lately of perhaps offering expense component versions of our x-overs in our Customize Yours section. We would not promote them as adding to the sound experience but we would have them available for those who want them. We are not of the mindset that we need to change the way people think. Everyone has their opinions of things and that is great. We would certainly be interested in being accommodating to these varied opinions whenever possible without causing a conflict with our core values.

In closing I would like to touch on this Axiom loudspeakers are all bright comment that a few individuals have mentioned in this post; one of them numerous times. We cannot control or even begin to surmise on every person's individual experience and/or motives when listening to and commenting on our products. We would love it to be 100% positive but it will not be. There will always be some small percentage where it just doesn't work out for any number of reasons. That is why we have a 30 day return policy. Instead we monitor for any sort of repetition of improvement suggestions. We then check them against our lab results and in double blind listening tests against competitor product. Last September we had a 30 year anniversary get-together party here at Axiom. It was really fun by the way. We had factory tours, engineering seminars, and wrapped it up with a live band playing dockside. One thing we did do was have a blind listening test running for the entire day and anyone could sign up for a time to participate. It was between an Axiom and a B&W. We had 26 people participate. I just went through all the comments and found that there were seven comments that contained words like bright, harsh, and sibilant. Six of these comments were a criticism of the B&W and one was of the Axiom. This is consistent with the results we get in other competitor double blind listening tests we do. Axiom products are not overly bright by any comparison we can find and certainly not by the amplitude response measurements. That said they are not purposely laid back either. We go after neutrality and that will mean if it was a harsh recording, it will come out that way.

If I do not respond to further measurement-by-measurement analysis from Danny Ritchie, complete with his hyperbole conclusions as to exactly how each one will affect the listening experience (not backed up with any scientific listening tests), please don't take that as some sort of agreement with him; it is not. I simply have no desire to battle it out with such people because I have no respect for them.

Hopefully this post does not cause TheDudeAbides to have to don his flame suit.

Cheers,

Ian
post #113 of 320
Quote:
Originally Posted by Chu Gai View Post

No you didn't. I have no idea why Axiom owners allow strangers into their home to audition speakers. Maybe they're compensated somehow by Axiom? Maybe they enjoy being unpaid representatives and extensions of Axiom's marketing and advertising arm? Dunno.

Or maybe they just like the product and want to share the experience? I auditioned Salk speaker in two different locations. And had an offer to listen to Ascends in a similar way. Nothing usual for ID speakers...you should know that!
post #114 of 320
Quote:
Originally Posted by kma100 View Post

Or maybe they just like the product and want to share the experience? I auditioned Salk speaker in two different locations. And had an offer to listen to Ascends in a similar way. Nothing usual for ID speakers...you should know that!

That's true but it doesn't change the fact they also become unpaid salesmen and extensions of the company's marketing and advertising. They have in effect been branded. Doesn't matter what your motives are it's just that there are also unintended and/or unrealized consequences.
post #115 of 320
Quote:
Originally Posted by IanAxiom View Post

This is why controlled double blind testing is such an important tool for scientifically judging the listener experience. There is no way you can look at two measurements and not have it bias your listening tests if you know which one is which. I certainly cannot do it and I think anyone who claims they can is playing a fool's game. Besides, whatever test you can do sighted you can do blind and whatever test you can do yourself you can subject to a panel of people individually without any intermingling during the test.

Axiom is located in a pretty small town to my knowledge. Given that, even in a double blind scenario, your employees are already familiar and biased towards the "Axiom sound", who are the listeners in these comparisions? Does the listening room accurately represent real life living rooms in terms of size and spectral balance, or is it heavily "treated" for a low RTA?
post #116 of 320
the reason we let people audition our speakers is so that they (the customers) can somewhat hear what they sound like in a home setting. instead of a bestbuy setting or whatever.

what you have to do is sign up to be available for auditions. I've had one person audition thus far. Im in the Costa Mesa area and he was curious about axiom. He called axiom and they gave him my email. he emailed me , to see if I would let him audition my speakers for he was interested in the same set I have. I said sure. He brought over a six pack and we listened to music and watch parts of movies he had and wanted to listen to, in addition, we had a great time discussing this great interest of ours.

Now. there is a paper I can download that i can fill out concerning the audition and if the person buys axiom speakers i could potentially get what is called axiom dollars, and save them for future purchases.

the reason this is done is because some buyers aren't willing to take a 30day trial. so in order to help those folks out if there is a good person willing to let someone come down and listen to their speakers, it takes away any risk and they get to see the speakers in action.

now some idiots might say that this is crazy or weird. I find it no stranger than like a craigslist. only difference is Im doing this people a service. I get to do something nice for someone, help someone make a wise choice. I didn't have somewhere i could go to listen to these speakers before I bought them I would have liked that. save me some anguish while they where being shipped. If they buy they buy if they don't they don't I didn't try and convince him to like or dislike I was just having fun TURNING IT UP!

anyways i've been really happy with my selection, and i have compared them with B&Ws, Energy, and Polk and 100% glad I went this route. the person that came has a brother with paradigms. He left Floored and really impressed with my setup. Blown away and wow he said more than once. ( I didn't fill out the paperwork by the way, I just thought it was fun )

I'm sorry you and our wife feel it strange to meat people that are interested in the same hobby as you. It's not just about bragging or talking **** on forums about your gear or others. to me it's about an enjoyment i get from wall shaking DTS HD master soundtracks and others and being able to share it with someone who gets thrills from it as well. and i dont' know i just feel that the best thing you can do in a day is something for someone else. and alot of axiomites seem that way.

here's my gallery for reference http://www.blu-ray.com/community/gal...member=Vanorge
post #117 of 320
Didn't know we shared the same wife!
post #118 of 320
I too normally don't respond to this sort of thing and only came here because I was mentioned (specifically) and was tipped off to the thread.

I have to respond to this one though as Ian has mentioned me several times and has stated many things that are simply not true at all.

And by the way, there is no "T" in Danny Richie.

Ian, your post was hilarious as well. And by hilarious (non-technical term) I mean extremely funny. The reason being is that you completely don't understand a bunch of things. I guess it is only funny if you get the joke. Sadly though, you don't get it. And I mean you don't get it to the point that it is really sad and that's no joke.

So I am going to respond to what was said because some of it was false. Plus, I will help you (Ian) with some educating material that if taken properly could be of great value to you in the future. I am not responding to give you a slap in the face or something so understand that is not my intention. So I apologize if it appears that way in the response. I will always be honest in all completeness and I am direct to the point. Tactfulness though is not one of my strong suits so don't misinterpret any lack of tactfulness with an intent to demean. I am just being honest.

So bare with me and I will respond to each of these points.
post #119 of 320
Before I hash through this post, these comments struck me as more than interesting.

Quote:


And though it may not seem like it from some of the contents contained in this thread we actually have thousands of very happy customers.

So does Bose. So please don't confuse good engineering with good marketing.

Quote:


Some measurements cannot be flat without distorting others that should be flat and some you don't even want to be flat.

Just out of curiosity, what measurements would I not want to be flat? Please, where would be a good place for peaks and dips?

Quote:


Another alluring thing about acoustical measurements is the ease at which you can point to one measurement or another and then draw conclusions about the effect on the listener experience.

You mean like when there is a 15db hole in the response? One might conclude that the particular frequency range where the dip is might not be as loud.
post #120 of 320
On comb filtering again:

Quote:


Comb filtering is an interesting phenomenon as it is in fact being introduced any time you simply move from a mono speaker to stereo speakers. This is a fact that Danny Ritchie dismisses entirely with the term hilarious.

I found your confusion of its application to be very funny (hilarious).

When a speaker has a comb filtering issue, you can't dismiss it as if it is like unto the effects of listening to a stereo pair of speakers. That is not the same thing. For one, much of what is mixed to the left speaker or right speaker in music is not exactly the same. If the signals were the same then it would just be a dual mono feed. It's not. It's different. This is what puts instruments in their own separate space in the sound stage. And, it is why we have layering in the sound stage.

Plus, even if the two speakers do get the same signal, and if you are sitting in the sweat spot, then there is still no comb filtering effect because they are arriving in phase and the image is then placed in center stage.

Your side wall, and often more so, ceiling and floor reflections, can and will cause comb filtering effects also. This can also be exactly the same if listening to a single speaker playing in mono. So room effects have little to nothing to do with using a single or a stereo pair of speakers.

The only way that you get real comb filtering effects from two speakers is if the seating distance is different from one speaker compared to the other. Then at the wavelength of the differential there will be some cancellation. However, there could also be a coupling effect of some of that same energy from room related reflections. It's all of those things added together, on axis response, off axis horizontal, off axis vertical, room reflections, etc, that make up the total power response that we hear.

So for the power response to be accurate the listener must give some careful attention to their room to minimize reflections that have adverse effects. As a loudspeaker designer, I can't control that. That part is on their end. However, as a loudspeaker designer I can control the on and off axis responses of the speakers that I design. And that is the information that the customer is interested in seeing, because that is the part that they have no control over.

Now here is comb filtering at its worst. Ian, please take careful note here. This will help you.

I have never posted this information before or discussed it because there was no value in doing so. At least there was no value in it for me. But this is your speaker and it will allow you to confirm what I am telling you. This is an on axis response of your VP150 center channel. So even by your own argument that there will be comb filtering effects from a stereo pair anyway, does not apply.



Note that the elevated top end is what give many listener that "bright" impression and the listening fatigue. But that is not why I am posting this. I am trying to help you understand something. I had to really make sure I was dead center on the speaker when taking this measurement to avoid the comb filtering effects. So I was an equal distance from each tweeter.

Here is what happened when I moved the microphone over 1". See Green line:



And this was from 1 meter away. And yes, that was a movement of 1 inch.

Now that is comb filtering! Your tweeters that are on each end of the box are now out of phase at just over 8kHz. With this speaker, you can't even get the same sound at each ear.

Now most people are off axis more than 1" when watching a movie. So here is what happens with the off axis response. The Red line is the on axis response again. Then there is 10 degrees off axis (Orange), 20 degrees off axis (Yellow), 30 degrees off axis (Green) and 40 degrees off axis (Blue).



Now that is a pretty rough off axis response.

Can you see the problem now?

Quote:


Comb filtering is an ugly looking measurement and, like most, our first thought was it must be detrimental to the listening experience.

Ian, it is VERY detrimental to the listening experience. It makes holes in the response.
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