Sloped baffle

>>>In both the Green Mtn Audio speaker specs, now, we are talking flat impedance & phase response. :-) Nothing like that in the Magico S5.

Interesting. Any independent measurements you can point us at to verify your claims? The ones we see in SP are not that impressive. In fact, they are quit awful (and are not even time coherent as claimed). Even the so polite JA had to say that: “..the listening axes on which the speaker is (almost) time-coherent and offers the most neutral response don't coincide”. Which is just one typical issue this concept have. Not to mention that distortion level with first order XO will be significantly high: “…occasionally thought I caught a hint of lower-midrange congestion”. All and all, a concept that does not really work, due to all the other problems it creates.

Hi guys, I'm back to the real world... first, Al, thank you for your gracious words...
If Green Mountain audio meet specks, what Bombaywalla posted are truly amazing, it takes a lot of crossover work to bring phasing in line to plus or minus 3 degrees. I've never seen a graph of a speaker with specks that tight. 6db pads done correctly will keep you within 15 degrees or so. I'm not a pro and have nothing to lose by showing my stuff. I'm using HiVi D6.8 woofers (same as Totem Forest) and a low to mid Scan Speak Tweeter in an MTM. I've never used photo bucket, so hopefully this works, but I just uploaded my graphs & crossovers to photo bucket... Hopefully, you can view this, if not, I'll try to figure it out and post again.

http://s28.photobucket.com/user/timlub01/media/XO_HiVi_D68_ScanSpeakD2608_MTMrev4_zps302ac070.gif.html

it is true that the measurements by reviewers are few for Green Mtn Audio speakers. I don't know why?
I believe that Green Mtn Audio speakers are different from conventional high-order x-over speakers that are prevalent in the market. If one is used to measuring the conventional high-order x-over speakers that are prevalent in the market that same technique is unlikely to work for Green Mtn Audio speakers because of the requirements of the distance & listening axis required to ensure that the drivers integrate. I believe that JA was not knowledgeable about this when he did the meausurements for the Diamante speakers. I also understand from the manuf that JA was advised by the manuf many times how to setup the speaker to measure it correctly but JA completely ignored the manuf's recommendations & did his own thing. The result is poor measurements & also measurements done incorrectly.

Yes, the slopes of 1st order x-over are shallow compared to 2nd or 3rd or 4th order x-over so signal will bleed thru at high levels. While 4th order x-over speakers can be driven to 120dB SPL, 1st order x-over speakers can be driven to something like 105dB SPL. If this is a no-deal for you, so be it. But 105dB SPL for in-room/in-house listening is plenty loud by any stretch of the imagination. Yes, it's not outdoor rock concert SPL.

Have you owned any Green Mtn Audio speakers by which you claim " All and all, a concept that does not really work, due to all the other problems it create."?? Or, are you one of those people who reads reviews & makes decisions based on the printed word? Or, are you a speaker manuf with an axe to grind?
Because I speak from personal experience & from the experience of my friends & relatives who own & have owned Green Mtn Audio speakers. Everyone that I know of has had & is having an excellent experience with these speakers. Yeah they have limitations (which speaker does not?) but their limitations are of ommission rather than of commission.

I do not intend to convert you to 1st-order speakers - never intended to for the get-go - please buy what you like & enjoy it. But I would not make such sweeping remarks without personal experiences.

Anyway, this thread is about "sloped baffle speakers", "time & phase coherence". There are very few speakers that meet the time & phase coherence criteria & I believe that Green Mtn Audio is one such brand hence it gets brought up time & again in such discussions as an available commercial product. I'd prefer that this thread not take a downward spiral focusing on Green Mtn Audio speakers or Green Mtn Audio bashing. Let's keep the discussion on "sloped baffle speakers", "time & phase coherence". Thanks.

I would have to see the detailed measurements to accept the, IMO, unlikely results claimed by this manufacturer.

Excellent comments gents. I'm hoping Al (Almarg) and Ralph (Atmasphere) get around to reading Roy's articles and sharing their comments.

Although it has been said many times, designers of audio gear take into account many features and do their best to balance, maybe better said ... optimize, what comes out of the metaphorical oven. I'm sure phase coherence is just one of many important factors. That's why I'm hoping Al and Ralph weigh in here to help us better understand the relative significance of phase coherence as compared to other factors.

Bombaywalla, I agree that one shouldn't base expensive purchase decisions solely on reviewer comments. But there's a problem; one that has been touched on by many A'goners including me over the years. There are very few hi-end B&M stores around anymore. And to the extent such stores are around, setting up meaningful and fair auditions is very difficult. Oh ... and as far as Green Mountain is concerned, no dealers near me.

Not sure what else to say. Another potentially huge sleeper problem that is finally getting the press it deserves.