Magico Q7: "most impressive product in 23 years of TAS reviews"

[A.Wayne]

@charles , you nailed the difference and I'm still waiting for those technical papers detailing the undisputed superiority of sealed enclosure...

@Clee, never heard the S5 so cannot comment or give my opinion vs the the wilson's ...


Regards ,

[rlacoste]

Originally Posted by A.Wayne

Hello rlacoste,

I disagree with the group delay statement when using a rear firing port, there is no real proximity effect and as such a sealed speakers is no more linear phase than a vented , If only discussing Front firing ports , agree ...

Regards,

You are rewriting the book on loudspeaker design…
Sealed box has 2nd order high pass behavior while vented box (front or rear) has, at best, 3rd, but usually 4th order high pass behavior.
The group delay is a measure of the slope of the phase response at any given frequency. In any passive loudspeaker which is a minimum phase device, there is a unique relationship between amplitude and phase which allows for determination of phase from amplitude. Therefore phase response can be calculated from frequency response.

A group delay of a 3rd or 4th order system ( i.e. vented) is always larger then a 2nd order system ( i.e. sealed).

Read Dickason's "Loudspeaker Cookbook 7th edition" for a reference :
Page 31 –sealed box group delay simulation - max GD 7.5ms
Page 64 –vented box group delay simulation - max GD 40 ms (no less than 24)

[Charles]

Originally Posted by A.Wayne

@charles , you nailed the difference and I'm still waiting for those technical papers detailing the undisputed superiority of sealed enclosure...

@Clee, never heard the S5 so cannot comment or give my opinion vs the the wilson's ...


Regards ,

Wayne, I can tell you have thought about this issue deeply. Ditto for rlacoste. When I purchased my Krell MRS I was assured that it would match the Wilson XS sub. I can tell you this is not the case. I have several cuts that the MRS simply would not play without obvious breakup. Its build quality is of the Magico level. Its bass was asolutely superb as I'm sure the Q7's is too. The solution would have been for the MRS to have a clip limiter to give the woofers maximum available excursion without audible distortsion. I don't know why Krell didn't do this. Mr. D'A may have been too proud to put a limiter on his MRS. It stayed in production for a long time. I know the Magico folks are very smart so time will tell if the problem has been solved.

[A.Wayne]

Originally Posted by rlacoste

You are rewriting the book on loudspeaker design…
Sealed box has 2nd order high pass behavior while vented box (front or rear) has, at best, 3rd, but usually 4th order high pass behavior.
The group delay is a measure of the slope of the phase response at any given frequency. In any passive loudspeaker which is a minimum phase device, there is a unique relationship between amplitude and phase which allows for determination of phase from amplitude. Therefore phase response can be calculated from frequency response.

A group delay of a 3rd or 4th order system ( i.e. vented) is always larger then a 2nd order system ( i.e. sealed).

Read Dickason's "Loudspeaker Cookbook 7th edition" for a reference :
Page 31 –sealed box group delay simulation - max GD 7.5ms
Page 64 –vented box group delay simulation - max GD 40 ms (no less than 24)

Is that your reference book .....


You do realize you are mixing up what i have said, research linear phase and then look into the understanding and the relationship of port location on a BR, next look up the importance of what you propose factoring listening distance and port location , its not to mean it does not exist , its of little to zero importance to the differences you purpose ...

Its like this

Horn speaker fan boys ....... Sensitivity is everything
Panel speaker fanboys ........ Mass and no box is everything
BR fanboys ......... Vents produce real bass
Seal box fan boys ...... group delay is everything

Sounds familiar ....

You can harp and spin the science anyway you want , in the end there is no one key to this lock, if there was there would only be one type of speaker selling , there is no best speaker in the world regardless of who writes it or how many times it has been spoken or how the marketing department spin the science ...

Charles experience mimics mine ....

Sometimes its as simply as ,

A man should look for what is, and not for what he thinks should be.
-Albert Einstein

Regards ....

[rlacoste]

Originally Posted by A.Wayne

Is that your reference book .....

Regards ....

Is that it? A sneer at Dickason work, a smiley and a dismissal of the audibility of higher GD?? Any real merits, other than your “opinion”? You know, like references, more worthy perhaps, to point to us commoners (with names, page numbers, links etc...)
I am disappointed Wayne, I was hoping you can do a bit better than that…

[A.Wayne]

Originally Posted by rlacoste

Is that it? A sneer at Dickason work, a smiley and a dismissal of the audibility of higher GD?? Any real merits, other than your “opinion”? You know, like references, more worthy perhaps, to point to us commoners (with names, page numbers, links etc...)
I am disappointed Wayne, I was hoping you can do a bit better than that…

Au contraire , it's you who has dismissed what i have said...

Ohhh, i can do a lot better , where do you want to go with this, I'm also aware what we are discussing is not covered in Dickason's book, yet you are hanging on to your GD axiom .

Interesting topic by Dickason , the part about VB optimized drivers usually having less mass, I'm sure you are aware of what mass does to the signal, yet you are willing to trade one advantage for another and still call it the best, sadly you are holding on to one part of a very complex puzzle , so i guess you believe everyone else doing VB must have not read Dickason's book........


IMO GD advantages you are claiming amounts to nothing in the overall picture, when venting the cabinet towards the rear wall really helps to eliminate most of the nastiness associated with VB.

Your GD assertions,

Group delay being a measure of the time delay of a waveform amplitude through a speaker , amplifier or cd player is no different as it relates to speakers, As to VB vs Sealed , the GD function of both are very similar until Port resonance and coupling..

Unfortunately sealed enclosures also radiate low frequency, not only from the front, but from the rear and sides too. This signal bouncing off the front wall
( speaker rear) and adding to the ambient character and boundary reinforcement of the speaker is delayed to the original signal, same as firing the ports to the rear, this does not technically eliminate GD as present in a VB, but what it does is add this character to the already delayed reverberant field of the original signal in the room, the delay is not at all obvious from the listening position, if front firing i will agree, this is an issue and no likey .....

Any advantages you think you had has been reduced to naught....


Since all frequency components of a signal are delayed when passed through a device such as a loudspeaker and propagating through a medium, such as air, this signal delay will be different for the various frequencies unless the device has the property of being linear phase.

Linear phase should not be confused with minimum phase, is the Q7 linear phase ? time constant ...?

So unless this is so , tells me that any signal consisting of multiple frequency components will suffer distortion because these components are not delayed by the same amount of time at the output of the device.

Less take a look at the Q5 step response as tested by stereophile, it's far from being linear phase, each and every speaker has it's advantages and disadvantages , it's the sum of it's strengths that adds up to good audio , the Magico measures well, take nothing away from that , aside, I do not see nor hear this technical advantages to sealed over VB as presented by you, I see each presenting a different set of strength and weakness's .

Regards...

PS: looks like i cant post pics , so a link will have to do ....

Magico Q5 loudspeaker Measurements | Stereophile.com

DB Keele

http://www.xlrtechs.com/dbkeele.com/papers.htm

[CLEE]

[QUOTE=A.Wayne;477977
@Clee, never heard the S5 so cannot comment or give my opinion vs the the wilson's ...


Regards ,[/QUOTE]

I have both speakers in my room for a couple of months. Previously I thought ported design make more sense but the Magico caused me to rethink . The Sasha actually has more bass output subjectively but it is not as well defined and I can still detect a slight discontinuity with the mid-range. It is possible that my room suit the S5 better. If you have opportunity, it may be of interest to listen to both side by side.

[Charles]

I think that we all owe Ivan a debt of thanks for providing a forum for discussions such as this. Right now I have reservations regarding the ability of sealed boxes to really do the low frequencies unless they are servo powered with multiple woofers. Before purchasing my Maxx's my concern when I spoke to Wilson was whether they would breakup on the bass spectaculars. I have many of them. I can report that Maxx3's are virtually immune to woofer breakup and they have otherwise excellent bass.

Will the Q5 play the Telarc 1812 SACD cannons at a loud level? My Krell MRS would handle the 1812 very well but I have more than several cuts it simply wouldn't play and you worry about the woofers. I want a rugged speaker. With sealed box the lower the resonance frequency the more vunerable the woofers become to breakup because of the massive amount of air they must attempt to move. This means massive excursion of the woofer cones. The Magico's may be very rugged. I've just never heard anyone comment on this aspect of their design.

[A.Wayne]

Originally Posted by CLEE

I have both speakers in my room for a couple of months. Previously I thought ported design make more sense but the Magico caused me to rethink . The Sasha actually has more bass output subjectively but it is not as well defined and I can still detect a slight discontinuity with the mid-range. It is possible that my room suit the S5 better. If you have opportunity, it may be of interest to listen to both side by side.

Interesting ,

I had a problem with the midrange also , but was/still willing to concede it could have been a setup issue , as it was the first time hearing them and i had no previous reference ..

Regards ...

[Charles]

A.Wayne, This is a fascinating thread and no one has posted on it for awhile. I have not heard from any Magico folks regarding the ability of the Q7 to manage a crushing bass transient such as exists on cut 10 "Festive Psalm" of Reference Recordings "Psalms" so I must assume the Q7 may not handle it well?? Or that no one cares. This is no knock at all against the O7. It would just be interesting to know if Magico has solved this age old issue with sealed boxes and 20 Hz bass. Also, now Magico is releasing the Qsub 18 subwoofer so for folks that can afford it, the problem is solved anyway.

I wonder what your opinion is of the Qsub18 from a theoretical design standpoint? BTW, I am going with an XLF. I have made the measurements and the XLF will fit in my room. I do want to say to you that I have heard a lot of bass in my time. Although I believe the sealed box design may be theoritically better, I love Wilson bass. I can't imagine better bass and the ruggedness of the Wilson bass systems are undeniable. So it's the XLF for me not the Q7. Also there's the incompatibility of Magico and McIntosh. There's also the knowledge of what my Maxx3's sound like in my room. The "Wilson" sound signature is good in my room.

When one is considering purchasing a statement system many factors go into the ultimate choice. If I were a Magico afficionado I would be very excited about the Qsubs. I am sure the electronics and drivers will be commensurate to the Q7. It is an extremely exciting development IMO.