Axiom Home Page
Posted By: TroyD From HT Shack a question maybe for Ian or Alan - 12/31/09 12:02 AM
"I am concerned about the possible phase/comb filtering interference with those paired drivers next to each other in the M80 and VP-150 Axioms

Read more: Paradigm Studio/Monitor VS Axiom Audio - Home Theater Systems - Electronics and Forum - HomeTheaterShack http://www.hometheatershack.com/forums/h...l#ixzz0bDhIgQWU
Alan has stated many times comb filtering is a measureable by-product but has little to do with actual listening experiences.

I for one have not had any issues with my VP150, M80s nor the VP100. Yes the Vp series does drop of by a db or 2 off axis as does any other horizontal design speaker.

Where is that Center channel speaker choice article on Audioholics.........
No problems here.
In case they don’t see this thread for awhile I'll quote what Alan said the last time this came up:

Sibilance

 Originally Posted By: alan

SolidState,

I found your quote from Winston Churchill quite apropos. The question is; are you going to begin to accept the truth or are you going to hurry off? The comb filtering you are talking about is in fact a measurement artifact that at worst is not audible and at best is something two ears and a brain quite like. You could start to enlighten yourself by reading "Comb Filtering -- Popular Misconceptions" in our May '09 Axiom AudioFile newsletter:

http://www.axiomaudio.com/archives/may2009.html#feature

If you find comb filtering to be a problem, why are you listening in stereo or multi-channel? You would need to listen to everything in mono to avoid this artifact. To put an even finer point on it; even if you could hear this artifact it would manifest itself in a cancellation of higher frequencies; less high frequency information would not equal more sibilance. Comb filtering measured with a microphone never adds information.

At Axiom we do not produce new models for the sake of having something new. We prefer to continuously improve the models we have, which produces much better results for our customers’ listening experiences. Besides the plethora of improvements we have made to our various models over the past decade we have also introduced the EP500, EP600, EP400, EP800, A1400, Audiobytes, the entire W series, the entire T series, and more. Just another truth for you to either accept or hurry off about.

To sum up: Comb filtering is a measurement artifact of stereo listening. It's always occurring, and our brain and ears ignore the combing effects that are easily measured by a microphone. A brain and two ears are not a microphone. Our research at Axiom and that of many world authorities show that comb filtering is not detrimental to accurate loudspeaker sound reproduction; at worst, it’s irrelevant, at best it actually adds a pleasurable element of spaciousness to stereo and surround sound.

Alan Lofft


The time before:

combing effects of dual center channels

 Originally Posted By: alan

Hi kuro,

While combing effects are easily heard using a pink-noise test signal (and are measureable), they are not significant or audible with music or soundtrack playback.

Moreoever, any speaker or two speakers produce comb-filtering effects. Try it with one speaker and pink noise. As you move your head slightly to one side or the other--only a few inches are necessary-- the arrival times of sounds to each of your ears change as your head changes position and the distance from the speaker driver to each ear changes, resulting in audible comb-filtering effects. You'll hear the high-frequency content alternately increase and decrease because of cancellation and reinforcement.

The notion of time-coherency when put to the test under controlled listening conditions is a lot of high-end blather not based on scientifically controlled listening tests.

It simply doesn't matter with music or soundtrack playback. If we were all ultra-sensitive to combing effects with musical playback from loudspeakers, we'd all be complaining. It would be intolerable.

Regards,


I think the best comment in this whole discussion is from the thread you linked:

 Originally Posted By: Jungle Jack

Either way, you cannot lose if choosing between Paradigm and Axiom. They are both excellent companies which make well engineered speakers.
Cheers,
JJ

Not a problem for me either. It is always interesting how people have opinions and concerns like this, but have never listened to Axioms. These comments normally come from someone who has never been involved in speaker engineering, let alone 30 years like Axiom.

I would say stop being concerned about all these things your reading and make your own opinions from what your brain/ears experience.
Sorry all, I forgot this was the technical forum . I will never post a question like this again.
I am on a few websites trying to gather info so I can make a good selection, given that i plan on spending 5 -6k on a speaker system. Given that the only speakers I can hear are Paradigm and Energy, although I have owned Axiom in the past and am just trying to figure out if there maybe something " better" for that money. But, oh hell no, nothing compares to Axiom in the world and don't try to ask a question or you will get jumped on and pounded if you may think otherwise.

It was in an article I stumbled opon and given that I am NOt, get that NOT a engineer sound or electroni wise, I wanted to post it to see if infact Alan saw this. ALso, his little reply above was not on the post at that site, so was giving a heads up.... I will never do that again. figured they removed it so no one can see the reply.

To future readers ,no need to reply I understand just to reasearch a little longer and not ask stupid questions. Maybe I will go take some university course on sound engineering and electronics like most of you have here.
Troyd, I think you misunderstood something here. No one jumped on you. Sirquack above was stating about how many other people post in other forums that Axioms do, in fact, have combing problems though they've never heard Axioms before.

(I assume that you're miffed about Sirquack's post, because the only other postings were to post what Alan has said in the past or to note that those individuals have not noticed it to be a problem.

And, though I didn't get into this earlier, SolidState has got an axe to grind..... At this point, I wouldn't put stock in ANY thing he posts on any subject....
Troy, Axiom, PSB, Energy and Paradigm have similar philosophies when they design their speakers, that is to say, they all strive to build speakers that are uncoloured at a reasonable price point. You might also add the British speaker company, Monitor Audio (Silver series) to that list as well, to my ear they are somewhat similar to the afformentioned co's at similar coin.

I auditioned all of these speakers plus a few others, but ended up on Axiom's site asking lots of questions, then ordering up a pair of M80s, VP150 and a pair of QS8s which I'm very happy with especially taking into account the price I paid. By all means, listen to as many speakers as you feel necessary and comfortable with before making a decision esp involving the size of investment you are talking about.

There's no such thing as a stupid question, BTW. I've done my share myself, and thankfully there are in fact, a large number of intelligent people on this forum including some engineers to answer them or give advice, but for the most part, it's just a bunch of guys who enjoy the hobby.
 Originally Posted By: troyd
Sorry all, I forgot this was the technical forum . I will never post a question like this again.
I am on a few websites trying to gather info so I can make a good selection, given that i plan on spending 5 -6k on a speaker system. Given that the only speakers I can hear are Paradigm and Energy, although I have owned Axiom in the past and am just trying to figure out if there maybe something " better" for that money. But, oh hell no, nothing compares to Axiom in the world and don't try to ask a question or you will get jumped on and pounded if you may think otherwise.

It was in an article I stumbled opon and given that I am NOt, get that NOT a engineer sound or electroni wise, I wanted to post it to see if infact Alan saw this. ALso, his little reply above was not on the post at that site, so was giving a heads up.... I will never do that again. figured they removed it so no one can see the reply.

To future readers ,no need to reply I understand just to reasearch a little longer and not ask stupid questions. Maybe I will go take some university course on sound engineering and electronics like most of you have here.


Well, first, you never asked a question. You linked a thread from another site and never asked a question at all. Second, you made this post on a site that just about everyone who posts on, owns the speakers under criticism. It's the official site of the speakers under criticism. So... What do you expect?

All I can say is it costs you nothing more than shipping to try them. If you don't like them (or love them) send them right back. Happy New Year.
 Originally Posted By: troyd
Sorry all, I forgot this was the technical forum . I will never post a question like this again.
I am on a few websites trying to gather info so I can make a good selection, given that i plan on spending 5 -6k on a speaker system. Given that the only speakers I can hear are Paradigm and Energy, although I have owned Axiom in the past and am just trying to figure out if there maybe something " better" for that money. But, oh hell no, nothing compares to Axiom in the world and don't try to ask a question or you will get jumped on and pounded if you may think otherwise.

It was in an article I stumbled opon and given that I am NOt, get that NOT a engineer sound or electroni wise, I wanted to post it to see if infact Alan saw this. ALso, his little reply above was not on the post at that site, so was giving a heads up.... I will never do that again. figured they removed it so no one can see the reply.

To future readers ,no need to reply I understand just to reasearch a little longer and not ask stupid questions. Maybe I will go take some university course on sound engineering and electronics like most of you have here.


Your welcome troyd. I appreciate the kind words for the time I took to look up the answer to your question so you wouldn‘t have to wait for Alan or Ian to see it especially considering the Holiday weekend.

Cheers,
Dean
Right. Non technical answer:

I listened to Paradigm Studio 7s. Not so good for the price. I listened to the Studio line including the 20,40 and 60. Damn that sounds good, but I don't have that kind of cash. \:\(

I listened to Axioms M22 M60 and M80 with and without subs. Damn that sounds good AND I can afford it!!

You can burry yourself in the technical details (and HTshack is a technical place more so than here), or you can listen to a bunch of speakers and make your own decision.

By the way, you will find that as you burry yourself in the technical details (being a geek at heart I love that sort of stuff) and start to read stuff by designers, there are many many ways to build a very good speaker.
Tru dat. Also, the Monitor 9's and 11's are much better than the Monitor 7's(you meant Monitor 7s not "Studio" 7s right Fred?) imo. Better range esp on the low end, 7's sounded a bit thin.
Yes, Monitor 7.
I posted the NRC graph for the VP150 when "he who's name shall not be mentioned" kept harping about it. (un)Amazingly, he is now harping about the "lack of NRC testing" of the 150 on other forums, even after seeing my post months ago...my post is amongst the links that Dean provided. Anyway, here it is again for anyone who either missed it or wishes to see it, the graph is available when you click "compare all center channels".

NRC graph of the VP150.
Dean, that was a very thoughtful and comprehensive response. Thank you for compiling the existing Axiom responses on the issue.

Troyd, I don't understand exactly what you were seeking. Grunt provided Axiom staff responses to the issue you raised. Nobody jumped on you. I don't think anybody is eager to engage known malcontents on other forums.
 Quote:
But, oh hell no, nothing compares to Axiom in the world and don't try to ask a question or you will get jumped on and pounded if you may think otherwise.


Sorry if it seemed that way; I don't think that was anyone's intention. It's just that the question does come up on a regular basis, and the context is usually a variant of "I haven't listened to <speaker X> but it's obvious that they will suck because of comb filtering".

Comb filtering is always a factor when you have two or more drivers reproducing the same frequencies, but the general consensus is that the real-world impact in a typical listening room with typical content is quite small.

There are always exceptions, of course -- take any system with a D'Appolito configured center speaker (WTW), put on Nursery Cryme (Genesis), listen to Hackett's guitar on Fountain of Salmacis and walk around the room. You'll hear an obvious "wah wah" change in timbre as you move laterally. Other than that one track, however, I haven't really noticed comb filtering effects at all.

The effect is not restricted to speakers with multiple drivers for the same frequency range, of course -- it is an issue at the crossover points of every speaker. The question is how significant the impact is relative to all of the other factors that contribute to overall response.

EDIT - I took a quick look at the linked thread. I loved the comment one poster made - that "they felt their stacked Advents sounded really good but other people said that was not possible because of their configuration". I thought of hummingbirds.
 Originally Posted By: tomtuttle

Dean, that was a very thoughtful and comprehensive response. Thank you for compiling the existing Axiom responses on the issue.

Troyd, I don't understand exactly what you were seeking. Grunt provided Axiom staff responses to the issue you raised. Nobody jumped on you. I don't think anybody is eager to engage known malcontents on other forums.


Thank you!

I’m guessing Mark is right that he took Randy’s comment out of context thinking it was directed at him, but then he whips out the shotgun and unloads at everybody in the forum and even Alan (“his little reply above”) who was only being quoted.

I’m always amused at multi-paragraph (edited) impassioned posts considering the time it takes to create them. People need to realize they are on the fast track to a heart attack if they let something said in an internet forum get to them that much, then stick with them long enough to generate such a post and probably continue to hold a grudge afterward.

Back in the stone ages (before the internet) I don’t remember ever knowing someone who was like that. I probably avoided them instinctively. It’s interesting how much more variety of human nature the internet exposes you to since you cant get a “read” on someone based on non-verbal queues to know whom to engage and whom to avoid.

Cheers,
Dean

P.S. Also want to reiterate how well I thought the Home Theater Shack members handled the topic (SS not withstanding, but then he‘s also a member here ).

you know what, after re-reading I owe an apology to all.

Yeh, there actually wasn't a question .... well yes there was in the Topic heading. But, that was my lack of communications.

I just stumbled opon that section in another forum. and the reply was not in that thread, so yeh thanks grunt for your reasearch and posting.

I have owend Axiom M80's v1 though and a VP150 and QS8's. I was for the most part happy with them. I am just trying to figure out "if " this time there maybe a speaker that maybe worth that extra $500. BUt, M80's from $1400 to $2500 shipped is a price point I like. Axiom are my reference speaker. I am undecided wheather to go with a F/O or HG Cherry or the VaSSallo. I like Paradigm's Studio 60/100's but further pricing has placed that at $7500 for the 7 speaker setup. Not, what I am looking to spend. I don't have a wife or significant other, but I can only imagine what would be said or done if I did. I think $5000 is my price point plus andother $200 - $3000 for sub(s) and between Energy RF70 and Axiom is about it. Not liking Monitor Audio too much, maybe it's because my brother almighty had them and sold them and bought these entry level pieces of crap for $1200 and told people they sounded as good as my Axioms at qurater of the cost. Told him to goto the Dr and get that clump of shit affecting his hearing remove then goto a hearing specialist case something must be effecting his hearing. So, no I will not no matter how good they are own something he had or has.

Anyways, I have not heard a M80 v2 the thing I really want to get away from is that the M80 and VP150 was a big difference in timbere match. Or maybe I am not hearing it right. What I hear is if I had 3 M80's acroos the front and do the pink noise test the all sound the same, same volumn, same tone. But, and as expected there is a difference , but maybe it is not that important as I am putting it out to be.
I really loved the Axiom 80's however, I wish I could order them as a say &.5" woofer just for a tad more bottom end in the music video's and or when I listen to music. I bypass my sub then. also maybe one tweeter not two I find it just a tad too harsh/Bright. No I have heard the 60's and no don't want them. can and is it possible without hurting the drivers to just unhook one tweeter, just to see the difference. or at that has anyone tried that ?

I know Axiom has over 30 years of research and involved with the NCR etc, but this is how they hear things and we all like sound a little rdifferent maybe one tweeter would take away from the top end and maybe then the bottom end will come out a little more. Does this make sence. I want a M80 with just a little more bottom, heavier bottom and a little less on the highs. I know that with a bigger woofer that some tightness will not be there and yes I like that part of the system but, maybe a 7.5 and a 6.5 woofers and I will have the bottom. ;\)

maybe I should try a DIY someday. Another thing, I think if not already Axiom should venture into a SUB that runs like four 10 drivers in a V shape array. Four 10's would be tighter and move more air than a 12". can you imagine. Have a dual amp system One amp would power driver 1 and 3, amp 2 would power 2 and 4.


Anyways, long winded but, sorry for the harsh words grunt, sirquack.
Hi troyd, thanks for coming back and setting things straight. I also find a timbre difference between the M80s and VP150 but not everyone does. I’ve come to the conclusion some people are just more sensitive to timbre differences than others. Also, it’s perfectly natural for identical speakers to sound very different in timbre based on location especially playing pink noise. If I play pink noise through my L/C/R M80s the center sounds very different from my L/R mains. This is due to differences in location and how reflections from nearby objects effect the timbre. However, I don’t notice the difference in the M80s with program material only pink noise.

Yes you can disconnect one tweeter and believe some people have tried that however it sounds to me like you would be better served by trying out some more forgiving speaker brands. IMO the biggest strength and weakness of Axioms at the same time is their accuracy. If there are harsh highs on the program material the Axioms will let you hear them. There are other brands that take into account that most recording people listen to are mastered poorly and design their speakers accordingly. Neither Paradigm nor Axiom do this.

What type of music aren’t the M80s giving you good enough bass on. I listen to lots of GOA Trance, EBM, etc… and get awesome bass. Now they don’t give the deep thump of a kettle drum the same way as my EP500 but for 95% or more of my music they go plenty deep enough.

I’m guessing you’ve had your Axioms for some time but I still have to ask this just in case if for no other reason than other people reading this may find themselves in a similar situation. As far as getting a little less top end and a little more bottom end from the M80s have you tried using the tone controls? Also, have you run Audyssey? AFAIK the standard Audyssey curve rolls off the top end since many people listening to poor recordings tend to prefer that. Also speaker positioning can have a huge impact on how they sound especially when in proximity to other objects.
You can also contact Axiom and get resistors to put in before the tweeters that will attenuate the highs a bit.
In music Say for instance listening to Blow at High Dough by the HIP, the bass is very nice the bass drum is suspose to be deep and tight. I get the tightness out of it. umh if I have a DVD in Say Eagles Hell Frezes over Say The Long Run or Life in the FAst Lane the Bass Drum is Tight, Quick, short and bottom end. In these songs alot of accent is put on the ass drum. I love testing speakers to these songs. Now the M80's do this very well However I think after hearing this on a Paradigm Studio 100 the bottem end seems to have that one notch of more balls. Not a $1000 worth though, but ... It is like in these recording Don, or Tyler are using a 22" bass Drum, however on the Axioms it's like they are using a 20" Bass Drum. Now I use and love a 20" kik but, thats the difference between a 20", 22" and or course a 24" goes lower but not as tight , kinda like these kids and those cars you hear a mile away with that loose bass.
Maybe it would be something to experiment with some day.

Then, yet again mind you wasn't the difference between the M80's v1 and V2 have a different crossover point. Also, they changed the drivers a little bit too I think. Maybe if I actually heard a M80 v2 I will get what I am after.
 Originally Posted By: kcarlile
You can also contact Axiom and get resistors to put in before the tweeters that will attenuate the highs a bit.


Has anyone here ever tried them and written a review of how they compare to using the tone controls? Just curious.
 Originally Posted By: troyd

In these songs alot of accent is put on the ass drum. I love testing speakers to these songs. Now the M80's do this very well However I think after hearing this on a Paradigm Studio 100 the bottem end seems to have that one notch of more balls. Not a $1000 worth though, but ...

I’d love to see that first type of drum you mentioned played ;\)

Did you hear the Axioms and Paradigms in the same room and some would say with the same equipment? If you heard them in different rooms then it’s like comparing apples and oranges because of the room acoustics involved. Also if they weren’t hooked up to the same equipment did you ensure all the settings were the same including any EQ being used? A dealer often tweaks setting to get a particular “sound” just the way they tweak settings on displays to get a particular “look.”

Are you within driving distance of Axiom, Troy? arranging an audition at the plant or through someone who owns the V2 M80 would answer many of your questions.

Which Monitor Audio's did your brother have, if I may ask?
 Originally Posted By: kcarlile
You can also contact Axiom and get resistors to put in before the tweeters that will attenuate the highs a bit.


This could be the ticket for taming the highs. The sole reason for dual tweeters is for handling more power, that's it. It's not to increase over do the highs. The Axiom experts have written this several times.

Maybe I've missed it but what sub are you using?
haha, yeh I missed the "B" ...... As for testing not in the same room, Axioms were in my house, Paradigm instore. I took my Denon 3803 with me when I went though.
Same settings and other equipment. Never side by side though.
I usually don't change the controls leave them at 0, I did add a little bass, but not much maybe to one. Not really into EQ'ing because every movie recording is different, I'd be screwing with that every time. The only thing I run a eq on is band PA and my drums. But, that's consistant.

No, not even close I am in Nova Scotia so about 1800 miles away. Monitor Bronze, from what I can remember. Athena, that's it that's what he has now, pieces of crap.

well, I am going to have to sit back and listen to them first, I may try the resistors if, they haven't changed. I plan on getting a Emotiva XPA-3 for the fronts and two UPA-2
for the rears. However, I am also thinking XPA-5 for my two rears, Centre and two backs and a XPA-2 for the front L/R. Wish Denon would come out with a Pre/Pro and I'd be in Heaven
 Originally Posted By: troyd
Wish Denon would come out with a Pre/Pro and I'd be in Heaven


They do have one but you have to sell your soul for one!
And you otta know Mel ;\)

michaeld has the resistors on his M80s, IIRC, he liked them much better this way.

Troy as you have mentioned the Studio 100's are a better all around speaker than the M80's, IMO, but not $1000 or more worth. This is where you have to compromise, unless you are willing to spend BIG bucks to get better than the M80s, you have to buy the M80s.

I did notice the M80s sound even better and that much closer to the Studio 100s with Axiom's amp running them, so maybe look to those after market amps once you have the M80s again. \:\)
Unfortunately I lost my mind the same time I sold my soul
 Quote:
Troy as you have mentioned the Studio 100's are a better all around speaker than the M80's, IMO, but not $1000 or more worth. This is where you have to compromise, unless you are willing to spend BIG bucks to get better than the M80s, you have to buy the M80s.

I think that is about right. Past a certain point its a game of diminishing returns. I have seen descriptions of the Paradigm Sigs vs the Studio 100s and they are described as a smoother more refined sound, particularly on the highs. Thats a lot of cash for audio nirvana though.

I am curious why you turn your sub off for music? On a lot of tracks, there is not enough bass to notice the difference between using a sub and not, but for stuff like pipe organ and deep synth the sub adds noticably.

For the size and price, the M80 does deliver an impressive amount of bass though.
I've heard that the M80v2s are actually much improved over some iterations of the tis, but since the v2 was a process over several years, it's hard to say how much improvement you'd really see. Axiom is constantly tweaking the speakers, so a v2 bought 2 years ago probably isn't quite the same as a v2 bought today.
onn - Your setup is the craziest axiom setup I've ever scene! Words can't describe it, I hope it sounds as good as it looks! Next time I buy a component and my wife gives me the stink eye I'm showing her your setup \:\)
 Originally Posted By: roar

Next time I buy a component and my wife gives me the stink eye I'm showing her your setup

Reading this forum with dyslexia can be fun. I was sure you said “Next time I buy a ‘competent’ wife . . .” and not what you really wrote.
 Originally Posted By: roar
Next time I buy a component and my wife gives me the stink eye I'm showing her your setup \:\)


Just don' tell her I'm single and probably for a reason or two \:D otherwise you won't get anywhere showing it to her.
Or do you mean you'll show her my setup to show how bad it can REALLY get? \:D
Mel
Troyd,

I will start this answer to your “question” with a conclusion; you need not concern yourself with the measurement phenomenon known as comb filtering. Since we produce multi-driver systems here at Axiom we have put much research into understanding the impact of comb filtering on the real world listening environment. There are huge benefits to using multiple drivers, especially in the area of being able to produce large dynamic range without distortion, so it is not something that should be casually thrown out of your design options. Certainly, on the surface, if you were to only look at the measurements taken by the microphone of comb filtering, without any further research, you would probably decide it is something that must be avoided. But this would be an over simplistic and very counter productive way to actually design a great sounding loudspeaker. It would be akin to simply taking a bunch of measurements and then go about drawing theoretical conclusions based on those measurements without feeling the need to do any real world testing of your theories. This will result in some great marketing propaganda and some great discussion material in which to back up your theories; but it would not result in a great sounding loudspeaker. The proper approach is to go through the somewhat painstaking process of understanding each measurement and its effect on the final listening experience, paying careful attention to the thresholds of audibility and the interrelationship with other measurements that may hold a greater significance to the end listening performance.

So let’s take a look at comb filtering in this light. First off comb filtering can be measured any time two drive units are playing the same frequency and the microphone is not located exactly equidistant between them. For example, if we take a standard stereo pair of speakers located say 8 feet apart, any movement of the microphone off centre, even as small as ½ inch, will show the affects of comb filtering. For more detail on this you can check out our newsletter article on comb filtering http://www.axiomaudio.com/archives/may2009.html#feature . In order to avoid comb filtering occurring in our listening environment not only would we have to restrict ourselves to loudspeakers that only used one driver per frequency allocation, which would have huge detrimental affects on the ability to achieve great dynamic range, but we would have to restrict ourselves to only having one speaker in the room, in other words return to listening in mono through one speaker. Given the obvious enormous downside to doing this perhaps first we should review the real world results of comb filtering in our listening environment before rushing off and getting rid of all our speakers save one.

One of the more revealing tests we performed in our lab was to set up a double blind listening test where we had three identical speakers, in this case we used the M2, and compared only playing the single speaker in the middle against playing the two on the outside simultaneously. We conducted this test in two separate sessions; one with the three speakers placed side by side, which gave us about a 15” separation between the drivers playing simultaneously, and one with the two outer speakers placed one meter to each side of the centre speaker. The amplitude response was preset so the two speakers had the same output as the single speaker and only a mono source was used. Not to wander off into a completely different subject, but it is worth at least noting that these sorts of tests must be done double blind. Any attempt to do them sighted or with the participants knowing what is on test will result in the participants who understand the effects of comb filtering on the measurements becoming biased in their judgment. This holds true for virtually all tests in audio and we have proved this over and over.

The results of that test were a clear winner for the widely separated pair and a slight nod for the closely positioned pair; the single speaker lost in both tests. The moral of the story here is to be careful when interpreting your measurement results and falling into the trap of thinking a microphone is giving you the exact results that will be perceived by two ears and a brain. In the case of comb filtering such a simplistic approach to loudspeaker design would cause the designer to throw out all the benefits of multi-driver systems to gain nothing. Forget about having to choose between taking a small degradation in one area in order to achieve a much larger benefit in another, which would also be a valid design decision; in the case of avoiding comb filtering you have to give up a very large benefit to gain absolutely nothing. I think one of the most eloquent comments ever made regarding the dangers of taking microphone measurements for granted was by Dr. Floyd Toole in one of his papers written back when we were doing our research at the NRC; “A measurement microphone performs a simple transduction of the pressure summation at the diaphragm location, without regard for the direction or timing of the incident sounds. Two ears and a brain, however, are rather more elaborate in their processing”.
Amen
Thank you very much Ian for the considerate and very informative respose. I always think it quite odd that combing effects are brought up today, when most home theater setups consist of 5 or more speakers positioned all around the listener, all of which reproduce the full spectrum of frequencies, more or less. As you stated, the only way to truly rid yourself of the combing effect is to have a single speaker with a single driver for that frequency. Nobody would want to listen to that.
Ideed, line array speakers have become common with the emergence of the home theatre. Thank's for the very informative post Ian.
Thanks for the great information Ian.
Mel
I like a post that explains the details behind the conclusion. Without that, most people just think you might be making it up.
Comb filtering has no effect?
Really?
Prove it.
Ok then, here's what we did...

Nice experiment Ian.
I want to be a test listener in one of these some day, once Axiom takes their show on the road across all Canadian cities for some countrywide marketing and polling demonstration.
Thank you, Ian.
What about hairbrush filtering? ;\)
 Originally Posted By: onn
 Originally Posted By: roar
Next time I buy a component and my wife gives me the stink eye I'm showing her your setup \:\)


Just don' tell her I'm single and probably for a reason or two \:D otherwise you won't get anywhere showing it to her.
Or do you mean you'll show her my setup to show how bad it can REALLY get? \:D
Mel


I meant I would show her your system and tell her that's what I REALLY want and I'm saving us money by making the choices I do!

It took me 3 years to buy 3 M22's, I couldn't imagine how long it would take to get "sign-off" for your setup.

(I'm only half joking, I have a wonderful wife \:\) )
Did you really buy that beast ??? I love my Home Theatre, but unless I win the lottery not that much.
Mabye if I listened to pipe organ music. But no I think the sub over exaggerates a little much. I feel it is more smooth and natural without. Specially when you have good speakers, about the lowest note played in a band, the Axioms or if you wish Paradigms can produce it well. Plus as I said I love drums and listening to a kik drum the way it is spose to sound is awesome. The sub , would be over kill on it unless of course it is a sub like Paradigms SUB 2 with 6 10" drivers in a array like the QS8s.
Holy crap onn

Is that real wood ? that's not veneer or vinyl is it? Them are the pictures Axiom should have on there website, of that qaulity of all thier real wood.

Yup, that's it I am getting my real wood Cherry Bordeux or Nutmeg

thems awesome
Thanks Ian

And it explains enough that it doesn't matter if it is Axiom, Paradigm, or Martin Logans I am not going to nitice it. Nor did I with the last pair of Axioms
Troy, re using a sub....as well as giving music more low end extension, the sub can also take over some of the lower frequencies that your mains would otherwise be playing so the sub will let the mains concentrate on the mid/upper bass. You can always tinker with the sub settings if you feel the bass is not to your liking(ie too much).
When I first started buying my Axioms, I remember a lot more people listening to 2-channel music as strictly 2 channels, no sub. I was kind of afraid of what people were saying about the subwoofer making the sound too bass-heavy, but I can't say I've run into that in my own setup. Simply calibrating the sub to the same SPL seems to make music sound fine to me.
I used to listen to music with the sub. Then I read posts here and there on 2 ch music and bypassing the sub. Yes, I can use the sub but I find myself always fiddling with it. Changing it to music, then turning up the volumn for movies etc.
Then I realized, then music I listen to well I don't know of any instruments that go below the 30hz. and then M30's they go down that low so, then I thought I can't be missing anything. The sub is gonna produce sounds from 80ish hz to well down to what 30hz. if I read the graph right M80 will produce that at a good volume level.

yeh, I will have to experiment again, just have to figure out if I want two EP-500 or one EP 800 horizontally in the center
 Quote:
Then I realized, then music I listen to well I don't know of any instruments that go below the 30hz.

It does really depend on what you listen to.

I wonder if the bass you feel you are missing is because of the room. That is one of the disadvantages of mains that reach really low. You do not have much flexibility in placement to make up for nulls and standing waves. It might just be that your mains are positione in such a way that there is a noticable null in the upper bass, affecting the way the kick drum sounds. There is no way to know for sure unless you do some measurements.

Personally I do not fiddle with my sub. I did my room measurements, equalized to flatten the response and set my levels to match the mains and now leave it alone. I ran the sub hot for movies when I first got it, but now that I am used to more ballanced bass, I much prefer it.
Ian, thanks for describing that interesting single vs multiple speaker test and emphasizing how important it is that any test of audio equipment needs to be double-blind to be taken seriously.
Troy, my music/movie ratio is about 99 to 1 and I always use my EP500 for all music, even compositions that don't contain very low bass. If the sub level is properly calibrated it just gives the impression that the speakers(not the sub)are putting out the lower bass and playing the higher frequencies a bit more cleanly.
 Originally Posted By: troyd
Did you really buy that beast ???


It's worse than that. I got the Denon POA amp to go along with it! If your going to lose it you might as well go all the way. The finish on the speakers is HG Rosewood.
Mel
Troy, with the M80s, I use my PB13 Ultra for music in 2.1. Yes the M80s work incredibly well on their own, especially when given gobs of power from the A1400 \:\) , but for those of us with out one, allowing the sub to do the work below 60 or even 40 hz frees up the M80s and your receiver's amp section to do the best they can with the higher less demanding frequencies. Once the sub is calibrated properly you won't be able to tell that is playing.
Thanks for the information Ian!
OK, I've just got to stir the pot a bit here. I know no one is present who fits this, but for those who think that Axiom mis-designed the M80s and the VP150, to what purpose? Do they think that Ian et al. just drew some stuff on paper and went, "Hey, that looks neat-o! Let's build speakers that look like that!" without testing anything?
Well, they DO look neat-o.....
OK,
and I know this question has been asked before, so I will go do some long ago searching. But, now I got to asked cause if not your gonna wonder , " well, what's the damn question ? lol

I know why I need that sub in movies, but why do I need it in music. I listen to Eagles, Elton J, Fleetwood, Tragically Hip.

I can see that if the M80's roll off at 30hz and the sub will start to take over ( so to speak ) around 80hz and keep to volumn level going to say 25hz when it starts to roll itself off. OK, I guess I answered the question in the question and calibrated right, would be awesome. But, then if I have a good sub like that why the 80's whynot get a speaker like the 60's where that much bass in a front is not needed that much specially if the LFE is set to 80hz.
The 80s offer a little better/smoother IMO, midrange, they do have a slightly different sound than the M60s, yes it is only really noticeable with A/B comparisons but it is still there. The 80s also offer better upper/mid bass than the M60s which is where the sub, when crossed over properly, won't be playing.
 Originally Posted By: troyd

I can see that if the M80's roll off at 30hz and the sub will start to take over ( so to speak ) around 80hz and keep to volumn level going to say 25hz when it starts to roll itself off. OK, I guess I answered the question in the question and calibrated right, would be awesome. But, then if I have a good sub like that why the 80's whynot get a speaker like the 60's where that much bass in a front is not needed that much specially if the LFE is set to 80hz.

If your receiver allows separate crossovers for each channel there’s no reason you have to set the crossover at 80Hz. I have the crossover on my L/C/R M80s set to 40Hz though I seldom find the need to use the sub for music.
I have my M80s crossed at 60Hz, my VP150 at 90Hz, and my QS8s at 100Hz. Sounds wonderful, but one of them may change soon...
 Originally Posted By: kcarlile
You can also contact Axiom and get resistors to put in before the tweeters that will attenuate the highs a bit.

I came across a post I cannot remember where right now, that Alan replied on. He mentioned they used to send out resistors for the older Ver. 1 M80's. However, since they changesd the driver and crossover settings in the mid/tweeter frequencies for V2 they found it toned down the highs and helped in the mids.
© Axiom Message Boards