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Re: M80's - center and amplifier selection
EastCoast #412617 06/10/15 01:38 AM
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Dr SQ:

Some great questions; however, I have no idea of how Axiom's drivers operate in their different models. One of their gurus would have to answer that if they choose.

As I've said before, I kinda admire the simple driver complement in the M50s & in the M22s/M2s as well. After owning fat speakers from the 70s & 80s that featured all kinds of drivers plastered randomly over the front baffle, I've come to feel that simpler is often the best, IMO anyway...

TAM

Re: M80's - center and amplifier selection
exlabdriver #412635 06/10/15 02:49 PM
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Originally Posted By exlabdriver
As I've said before, I kinda admire the simple driver complement in the M50s & in the M22s/M2s as well. After owning fat speakers from the 70s & 80s that featured all kinds of drivers plastered randomly over the front baffle, I've come to feel that simpler is often the best, IMO anyway...
TAM


TAM --

A reasonable point of view. Your rosewoods are a thing of beauty too.

Just a few weeks now until my m80s (regular V4s) and EP500s arrive. My use will be primarily theater, secondarily music (although just music at first, until the room is finished). The intention is to use the subs to round out the bottom end for both use cases, as in your setup. I know that some prefer to use a full range speaker only for music, and this is a trend that Axiom has supported actively and explicitly with their m100 and lfr1100 models. Matt has the big boys, and finds that approach more pleasing. I respect his opinion. Troy seems to favor the full range approach as well, but is finding that the regular m80s, while coming very close, are not quite full range at reference levels. That's not too surprising either, as Axiom has said the same as the reason of entry for the m100 and lfr1100 models, quoting the following from here (with some skips).

Quote:
We started with what was then our flagship the M80, which has been around since the mid 90s. That’s not a speaker we ever looked at as having any sort of limitation. It has good frequency response, good extension, sounds great, can play loud . . . there really weren’t any major identifiable issues. But in most applications, our customers were using M80s in the context of a home theater system with a subwoofer.

When you take a subwoofer out of the equation, now extension and linear extension, particularly at very low frequencies, becomes something that you are looking for. You need to have good dynamic capability at those low frequencies to really give you the sense that you’ve got full bottom-end, full frequency range, and you’re not losing anything – especially at high levels.

There were two major things we needed to address. The first one was the newly redesigned woofer, which is available in high-powered versions for the M60 and M80 as well. It’s a woofer with a larger voice coil. It’s got a larger roll surround, which means there is more linear excursion capability, and it can handle far more amplifier power than the existing M80 can. Now that’s not to say the M80 is any slouch! But if you’re going to be running high levels right down to 30Hz or 25Hz, you need that power handling capability.

The other thing that we’ve got to remember is that if you’re only going to have two loudspeakers carrying the full range, if you’ve got really high dynamics, you’re not splitting that output level between five or seven speakers and a subwoofer anymore – you have to get that out of two speakers. So in large spaces you have to run more power through the speakers to get that satisfying dynamic level up. In the tweeter to deal with power handling, we’ve gone to a die-cast faceplate assembly. The old one was plastic. That’s actually significantly increased the power handling capability of the tweeter due to the cooling: we’re actually using the faceplate as a heat [sink].

We’ve started to trickle down the developments into the other models, but the M100 is really an ultimate statement of a true full-range speaker that is perfectly suited to two-channel reproduction.


So what's my point of view? I'm not entirely sure, but I'll give it a shot. I haven't had the luxury of auditioning multiple setups at the factory, which would be ideal. But, I don't personally a priori subscribe to the "purist" notion of cutting the sub out for music. And, having a pair of top end subs coming, I couldn't see the point of disabling them for music. So, the logical question seems to be "do I really even need the m80s?". As noted above, it does seem that the woofer cones have a rather small window in which to play dominantly, say 80-160 Hz, one octave, if using subs with a standard crossover. Maybe that's just a very specific and important, albeit narrow, window, and they do it very well. Maybe they actually are contributing in parallel along with the 5.25" drivers considerably up the register into the upper midbass & midrange and improve power handling in that way (as referenced in the prior question).

I'm very curious, but at some level I don't really care. I've wanted a pair of m80s for over a decade, and darn it, that's what I'm getting. I guess I'm a "more is more" guy at heart, even if the more seasoned and wise approach is occasionally (usually?) perhaps "less is more". In fact, if cost wasn't an overriding consideration I'd definitely want the HP upgrade on the front three (with VP180) just to make sure I wasn't "missing something", even though the explicit justification for that driver is as a proxy for the subwoofer. Its a psychological flaw on my part, which seems to be not so uncommon among "enthusiasts". Come to think, maybe that's a decent definition of enthusiasm. wink

Rambling aside, really looking forward to my speakers. Shouldn't be too long now. cool

Re: M80's - center and amplifier selection
EastCoast #412636 06/10/15 06:47 PM
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I'm convinced that my 2 Channel Tube Driven M2s + EP400s are outstanding for my music system requirements - they are just stunning & pleasing to my ears.

My M22s + EP800s + VP160 are a match made in heaven for my medium size HT room - overkill actually, especially in the low end.

With the bookshelves, I don't feel that I'm 'wasting' the lower end of big floorstanders because excellent subs do their job so well without stress nor distortion...

TAM

Re: M80's - center and amplifier selection
DrStrangeQuark #412660 06/11/15 02:42 AM
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Yes, those quoted comments certainly have some validity, but personally when I listen to music I would never "take a subwoofer out of the equation" or "have two loudspeakers carrying the full range". The most pleasurable and cost effective music listening for me continues to be with bookshelves plus sub and in surround mode.


-----------------------------------

Enjoy the music, not the equipment.


Re: M80's - center and amplifier selection
EastCoast #412675 06/11/15 01:26 PM
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Originally Posted By EastCoast
Hi, all - I've been stalking this site for a while now, and I'm thinking about switching out my Boston Acoustics setup for Axiom.

I'm thinking about the M80's - thought about the M100's, but I don't think I have the space to let them breathe (ie. placement from the walls) due to the room not being dedicated. Also, I have a sub, so the extra bass ability of the 100's is kind of useless to me.

So, on the assumption of the M80's, wondering about the VP150 with them - adequate or not? My center channel HAS to fit in a defined space in a cabinet, and the VP160 and VP180 are both too big. But if I go M80's and VP150, am I going to be extremely disappointed with the VP150?

And, how power-hungry/loving are the M80's? I currently run my LCR off an Emotiva XPA-3 (330WPC @ 4ohm), although I have been considering going in for 3 x XPA-1L monoblocks (500WPC @ 4ohm).

Room is just under 3,000 cubic ft (21.5 x 18.5 x 7.5)

So what advice do you have for me?


I really, really need to proof read abit, before clicking Submit.
Eastcoast. I have a ANTHEM MCA50 ... it's a 5 channel AMP of which currently, I use the Left/Right and centre channels only. Actually, for now I only have those three speakers.
It is 365w per speaker. I played around the last few days and if I did this right I have it set for reference level 80db at -15bd on my volume control with pink noise.
Now, when in two channel with my M80v3 at 97db ( on my SPL Meter ....I used my iPhone for this ) playing MJ The Way You Make Me Feel and Jam...... I find that's the limit before it breaks up. I get that Ptfff sound and the drivers are really at the end. At 95db it is ok, the bass goes Thumpppp
Granted it is the This is It DVD ....maybe it's the recording as this was taken during rehearsal. But, then again so wasn't Eagles Heartache Tonight .... Yet, though another concert recording. However, it is it is still a point.
I don't and won't have the room for the M100's. Andrew said, I wouldn't like his recommendation, but said I am probably looking for the M100 to get exactly what I want. I have no doubt and would love to. But, I am thinking specially after looking at the drive differences I most likely would get what I want with the M80HP. I have asked in a post for those M100 users how far are there M100's placed from the back wall, but still waiting for a reply. I have read from 2ft to 3ft. What.... 3ft ????? that puts the speaker almost 5ft out into the room.
Really music that I listen to, Rock, some Jazz, maybe ( I hate to say it) new country , like Luke Bryant, that girl Taylor Swift and that guy in the song Highway to Hell, Shania. So, there really isn't that much low end bass that is sub woofer needed. Lowest note on a bass guitar is what 31hz Low B, A Note on a piano 27hz. A Kik drum typically 30 - 35hz. Yes I imagine using African Mahogany and a specific size and studio enhancements you can get lower. But, I think the M80HP will be sufficient for the volume level I like music and if I am reading the grafts right.
Also, I must add I have no room treatments other than the couch and drapes, but once the room is done it will be properly treated.


Anthem MRX520
M5HPv4
VP160HPv4
QS10v4

Re: M80's - center and amplifier selection
DrStrangeQuark #412982 06/22/15 04:06 PM
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Hi DrStrangeQuark,

I will see if I can answer some of your questions and add some insight into the design behind the M80 and M100. I will start by digressing a bit to establish the design goal.

It has been refreshing as of late to see Dr. Toole’s video of his speech in Montreal making the rounds:

Dr Floyd Toole Video

It contains much content on the topic we call the “family of curves” (Floyd calls this the “Spinorama”) and its importance to sound quality. To put it simply; it is the family of curves that predicts how well a speaker will perform in subjective listening. The more interesting question is why the topic is so rarely discussed compared the volumes put into topics that have little to no impact on sound quality. I can only surmise as to the reason for this but here are two likely candidates:

1. There is nothing visual on the product itself to point to that demonstrates a differentiator affecting the family of curves; making the topic somewhat boring when compared to say a cone material or even a crossover part.

2. Most manufacturers and reviewers do not have the equipment to measure the family of curves. This is especially true with all the curves required to create the sound power curve.

The relevance of the above is to show a key design goal in all of our speakers. This graph

M80 Graph

shows the Listening Window and Sound Power curves for the M80. When deciding on the crossover points, crossover slopes, and driver design there are two main things to consider:

1. To not have audible distortion up to the maximum SPL of the speaker system where compression occurs.

2. To achieve the desired Listening Window and Sound Power response curves.

Given these dual goals we are not in any way attached to a particular slope or frequency point for our crossovers; there is no benefit in holding onto a goal such as “only using 24 dB per octave filters”. The only purpose the selected slope serves is the end measured benefit to the family of amplitude response curves as measured in the finished speaker design (design goal 1 above excepted). In the case of the M80 there are four woofers and two tweeters per speaker. We often call the two 5.25” drivers mid-ranges, in fact our spec sheet shows them as such, but in reality they are woofers and should really be referred to as “smaller woofers” as opposed to midranges (perhaps I will change our spec title). When used in the M22 they are, of course, called woofers. The reason this is important is because of how we treat the lower crossover point of these 5.25” woofers. They are mounted in small sealed chambers of their own that cause a natural slow roll-off starting at 170 Hz. For reasons that benefit the family of curves substantially we do not put any electrical high-pass filter on these woofers. The 6.5” woofers use a combination of the woofer design itself and their low-pass crossover to create a slow almost shelf like roll-off at the 160 Hz crossover point.


Ian Colquhoun
President & Chief Engineer
Re: M80's - center and amplifier selection
EastCoast #412984 06/22/15 09:05 PM
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Hi Ian!

Thanks so much for the generous response. Very interesting, and it does answer the questions (at least qualitatively) about which I was curious (and also corrects a couple of misconceptions / incorrect assumptions). The close correspondence between your design priorities and the decades of acoustic research by the NRC is quite clear. I'm enjoying learning at least a little bit about the practicalities of the subject, from several sources. By no means is that sort of insight essential for enjoying the final product artistically (which is a faithful in-home representation of music and film soundtracks), but I think that it can add a new layer of appreciation to the hobby when the conjunction of basic research (especially with regards to the way humans perceive sound), tremendous engineering effort, and underlying scientific principle is acknowledged.

I take it from your description of the slow, shelf-like rolloff of the 6.5" woofers (part electrical & part mechanical), that they are indeed working in tandem with the smaller 5.25" woofers, and appreciably so, for another octave or two above onset of the crossover frequency (and likewise below, where the smaller woofer is rolling off mechanically). Very naively, it seems like this gives them "more to do", which strikes me (again, very naively) as a good thing, with potential benefits for global power handling. Are you able to quantify the effective combined filter slopes that apply in these two cases? If it is more detail than you generally care to get into, or too much of an invitation for "back seat engineering", then I understand.

Cheers - DSQ

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