Magico introduced the Q series subwoofers

[andromedaaudio]

facts please ,simple statements don t convince me , if interested we could open a topic on the subject

A different discussion. Your statement is incorrect...

 

[JackD201]

facts please ,simple statements don t convince me , if interested we could open a topic on the subject

Please do. I would like to share my own experiences on the matter in a more appropriate thread.

 

[Bruce B]

What ever happened to this thread?


"Fast" and "slow" subwoofers: can we put them to bed?

 

[andromedaaudio]

thats a lot of pages , im gonna read into it , I ll be back
we probably dont need to open a new thread then QUOTE=Bruce B;215702]What ever happened to this thread?


"Fast" and "slow" subwoofers: can we put them to bed? [/QUOTE]

 

[PeterA]

your f113's sound great in your system when I heard it in July. nothing to worry about. but there are faster subwoofers which might contribute more. and lets say your main speakers did not go as low as your X-2's. so the sub needed to be a bigger part of the whole. in that case the speed of the subwoofer would be more exposed to it's shortcomings. and in that case as you stepped up to better and better subs you would hear the benefits. and I think this is more what these higher performance subwoofers are intended for. systems with Q1's or Q3's where integration with a pair of f113's or similar does not 'quite' work ideally.

I had a well-known professional set up guy try to integrate two JL F110 subs with my Magico Mini2s and it was less than ideal. I sold the two subs and am happier with the monitor alone. The JLs made the pure tonality, coherence and dynamics of the Mini2 sound congested. We were both surprised, but in the end, I moved on. I think it had to do with speed as Mike suggests. I may someday go to a larger Magico speaker, but I would not try to mate subs with the Q1 in my room.

Does anyone know if the signal comes from the pre to this Qsub, or will it come off an amp like what is possible with some of the REL subs? Also, will this Qsub have user adjustments for cut off points, slopes, level etc? I don't see controls on any of the photos.

 

[DaveyF]

Does anyone know if the signal comes from the pre to this Qsub, or will it come off an amp like what is possible with some of the REL subs? .

Peter, I think you may have hit on something here. I suspect that the ability to take the signal directly from the amp like REL allows, is a MAJOR benefit in getting a seamless blend with a sub and a mini-monitor.

 

[PeterA]

Peter, I think you may have hit on something here. I suspect that the ability to take the signal directly from the amp like REL allows, is a MAJOR benefit in getting a seamless blend with a sub and a mini-monitor.

My limited understanding is that if the signal comes from the amp, it's sonic signature somewhat carries through to the sub. JL Audio does not have this feature. I don't really know the pros and cons. I'm just curious as the Qsub just looks like a black box with no user adjustable controls.

 

[DaveyF]

My limited understanding is that if the signal comes from the amp, it's sonic signature somewhat carries through to the sub. JL Audio does not have this feature..

Peter, that is correct. The mains see the same signal as the sub with the REL connection scheme; not necessarily so with the JL. This is what I believe gives the REL an advantage when dealing with very quick mini-monitor's.

 

[GaryProtein]

The Q subwoofers are bigger and more powerful than that in the Ultimate 3.

Are we to expect an Ultimate 4 soon?

 

[FrantzM]

No, but for equal force higher mass means less acceleration. But most probably it is not directly relevant, as debating sound quality in audio most of the times transcends basic physics interpretations -e.g. simple vectors are not enough to study plasticity and deformations. And you need these properties to relate cone size and mass.

At first view this appears correct after all Physics don't change. In reality the transient reponse of a sub has nothing to do with its mass!! This is a surprise for more than one.


First we have to assume that said driver is operating with its linear range. Modern Day woofers have superb linear motion within their Xmax (Max distance the cone will travel from rest) and we can safely assume that if we keep the travel to 75% of Xmax the motion is for all practical, or even theoretical purposes, linear. Thus the travel of the woofer is a function of its BL (The driver motor strength) and the intensity in its winding. ... To make it short the force is a function of intensity (amperage) in the winding, F - BLi (Motor Strength by Amperage). It still is equal to the ma, mass multiplied by acceleration no doubt and the lower the mass for a constant force the higher the aceleration but and that is the big "but" ... if we admit that the mass is constant, acceleration then becomes a function of the current in the winding. thus accleration (a) = (Bli)/m ... BL is constant , m is also a constant thus the acceleration is a function of current in the windings. The limiting factor becomes mostly the "L" for a given mass ....
Thus a woofer properly driven (IOW lot of stable power) can start a stop on the proverbial dime, regardless of mass ( all that within reasons) you still wouldn't put a 50 lbs cone and expect it to not create problems since you cannot have infinite current in the winding .. so an 15" inch can provide excellent transient response as good as that of a 12 or 15 or even a 10" as exemplified by subs with stellar big drivers such as the woofers of the MM7 or those of the VS Vr 9 and 11 or the Woofers of the Rockport Altair and Arrakis or those of the Wikson X-2 and XLF or those of the Focal or ... One can see the trend .. Of course the myth will be difficult to dispel and we will still talk about "slow" woofers, long after this thread goes forgotten ...

Andromeda.. Cone breakup is mostly a function of the cone material and geometry. that is when the motion of the cone becomes non-pistonic. Break-ups have also the bad tendencies to be non-harmonically related to the signal in order they sound their own regardless of the signal . It is not become the driver is "slow" that it breaks-up nad one can have 1 inchers that reproduce higher frequencies extremely well. Youdo have to contend with directivity as you use larger cones and that is the one of the reason (and perhaps marketing ) why you don't see big drivers reproducing midrange. In reality some 18 inches go happily to 2~3 KHz without any breakups ... Facts, not opinions.

 

[FrantzM]

Hi

GOt this form my files in OneNote. Explain much better than I could with measurements:

HERE

http://www.diy-audio.narod.ru/litr/WooferSpeed.pdf

Hope that'll help bury the notion ...

 

[microstrip]

At first view this appears correct after all Physics don't change. In reality the transient reponse of a sub has nothing to do with its mass!! This is a surprise for more than one.
(...)
Facts, not opinions.

We can not say that the transient response of a sub has nothing to do with its mass from the quoted article - IMHO the single case measurements shown do not prove anything.

I would say it has all to do with its mass, as the mass of the diaphragm will influence the design of the whole speaker motor. Most of the time engineering is managing technical compromises and audio is one good example of it.

As you say, there is no theoretical limitation on the transient response of a woofer due to mass. However there are engineering limitations on the maximum force that can be applied in practice to a given design - the inductance being one of them. But unhappily the inductance is not a free parameter - and I could think that larger mass can force to have an higher inductance.

Most audio myths come from experience and are statistically built from anecdotal evidences. Although it is always easy to get a few exceptions, they show the general situation and should not be assumed as scientific rules. Most of the time they show the perceived benefice versus cost ratio, not the achievable absolute performance.

Although I agree with you about how dangerous audio myths can be, it is not surely because of the very naive article you refer.

 

[stereo]

The Q subwoofers are bigger and more powerful than that in the Ultimate 3.

Are we to expect an Ultimate 4 soon?

you are always free to complement your Ultimate 3 with a Qsub-18, set up at a very low cross over frequency. If set up below 30Hz, integration will not be a problem, but my building's floor would probably have collapsed already ;-)

 

[andromedaaudio]

Please show me a response of a 18 incher with workable response at 2-3 khz .
the point i wanted to make is that in general conesize/weight relates to freq , the smaller the cone the higher it can go without break up , there are some 4 inchers that extend quite a lot off course .
take a look at the accuton site and go through all the units , the smaller and lighter the higher the break up .


http://www.accuton.de/drivers/detail.php?driver=22&matID=1&appID=1

regarding subs ,a stable current delivering amp helps a lot off course ,boulder comes to mind ,that is why tough load speakers will benefit tremendously from a amp like that .
But since a loudspeaker is a electric acoustical system even high currents/strong magnetic fields still have to fight the big pull of gravity and air resistance

At first view this appears correct after all Physics don't change. In reality the transient reponse of a sub has nothing to do with its mass!! This is a surprise for more than one.


First we have to assume that said driver is operating with its linear range. Modern Day woofers have superb linear motion within their Xmax (Max distance the cone will travel from rest) and we can safely assume that if we keep the travel to 75% of Xmax the motion is for all practical, or even theoretical purposes, linear. Thus the travel of the woofer is a function of its BL (The driver motor strength) and the intensity in its winding. ... To make it short the force is a function of intensity (amperage) in the winding, F - BLi (Motor Strength by Amperage). It still is equal to the ma, mass multiplied by acceleration no doubt and the lower the mass for a constant force the higher the aceleration but and that is the big "but" ... if we admit that the mass is constant, acceleration then becomes a function of the current in the winding. thus accleration (a) = (Bli)/m ... BL is constant , m is also a constant thus the acceleration is a function of current in the windings. The limiting factor becomes mostly the "L" for a given mass ....
Thus a woofer properly driven (IOW lot of stable power) can start a stop on the proverbial dime, regardless of mass ( all that within reasons) you still wouldn't put a 50 lbs cone and expect it to not create problems since you cannot have infinite current in the winding .. so an 15" inch can provide excellent transient response as good as that of a 12 or 15 or even a 10" as exemplified by subs with stellar big drivers such as the woofers of the MM7 or those of the VS Vr 9 and 11 or the Woofers of the Rockport Altair and Arrakis or those of the Wikson X-2 and XLF or those of the Focal or ... One can see the trend .. Of course the myth will be difficult to dispel and we will still talk about "slow" woofers, long after this thread goes forgotten ...

Andromeda.. Cone breakup is mostly a function of the cone material and geometry. that is when the motion of the cone becomes non-pistonic. Break-ups have also the bad tendencies to be non-harmonically related to the signal in order they sound their own regardless of the signal . It is not become the driver is "slow" that it breaks-up nad one can have 1 inchers that reproduce higher frequencies extremely well. Youdo have to contend with directivity as you use larger cones and that is the one of the reason (and perhaps marketing ) why you don't see big drivers reproducing midrange. In reality some 18 inches go happily to 2~3 KHz without any breakups ... Facts, not opinions.

 

[IanG-UK]

back to the Magico sub, I would like to see/know how the 136 dB at <1% was tested..

I guess the listener was happy to agree with 1% distortion since he entered the pain threshold 10dB earlier.

 

[FrantzM]

Well high SPLcan cause pain whether it is at 1% oe 20% distortion.. In fact the higher the distortion at low frequencies the lower the threashold for pain ...

Andromeda

I will backtrack a little . Indeed most 18 icnh don't do well in the 3 KHz but 2 KHz is not a problem for several.. I will point you toward BC drivers

B&C 18 inch Woofer won't go much below 35 Hz ...

Later to address your points..

 

[Mark Seaton]

Another mistake that people make, IME, is that IF one is using a mini monitor and a sub in a small room, the wave length of the bass wave is going to be a MAJOR limiter to the response that the room can support. That is simple physics -- by increasing the size of the driver does NOT change that. BTW, this is true in larger rooms as well....something that i think we may need to keep in mind more than we do.

The "speed" mythology and misunderstanding will take a bigger club to beat out of the audiophile vernacular, but let's quickly nip this misconception... Sound does not require any amount of space/distance to be perceived or reproduced. If this were the case, headphones would sound like super tweeters with the rest of the speaker disconnected. There are certainly acoustic differences in small and large spaces, but there is no particular low frequency limitation due to room size.

 

[NorthStar]

Regarding speed:

1. Isn't it related to phase/delay, and 2. size of the driver?

_______________

Why according to some subwoofer's experts; in a stereo system it is preferable to have multiple smaller drivers (woofers, like 8 or 10 inchers) to better integrate those subs with the rest of the system? ...And a 12 incher(s) would be the very max.

For home theater, ok, 18" or more is just fine. ...For the LFE channel (.1).

 

[Mark Seaton]

regarding subs being slow `in general ` .
in my opinion its got to do with membraneweight /total weight being displaced.
in general subs need a large stiff cone /long throw motor this all adds up as weight .
the more weight the slower the performance /more start stop time needed,but bass from large membrane basspeakers sounds also great so its a compromise in the end
displacing large amounts of air takes time and energy

While there are many things related to *subjective* perceptions of bass quality and what is often described as "speed", moving mass of a driver has no more direct relationship than box volume does.

Parameters of course have to be in proper balance for the intended application, just as frequency ranges of a loudspeaker need to maintain proper balance. Once you look at a subwoofer/woofer in terms of tracking the low passed (limited high frequency) signal required to blend with the next drivers higher in frequency, you find that the only effect of added mass is reduced efficiency all else being equal, which it rarely is.

For the most part, in sound reproduction problems come from quantities, parameters and behaviors which change. Constants like moving mass and cone area are straight forward to balance out in a system for optimal behavior. In the case of subwoofers, many (most?) do not even exhibit the theoretical frequency response of an ideal woofer in a sealed box. Real parameters like inductance skew things significantly and are complex variables that change with frequency, excursion and current. Now add suspension and motor strength variables which again change with excursion and current, and you have a multi-dimensional problem we are trying to tame and minimize variations in.

IMO, most sonic qualities relate to actual frequency response both within and well beyond the operating bandwidth and how that response changes and modulates in real use. If you look carefully at some of the more commonly preferred solutions, you usually find strong correlation with limiting such variations within specific situations or within output and extension limits. Next factor in some common trends in room acoustics and setup to cover many of the remaining generalizations.

 

[Mark Seaton]

Regarding speed:

1. Isn't it related to phase/delay, and 2. size of the driver?

1) Only so far as it relates to the speaker or driver it has to blend with. It's relative, not absolute.

2) Only when a design is compromised to meet a physical size restriction or the motor (magnet/coil/spider) is not appropriately matched to the cone size and box volume.

Why according to some subwoofer's experts; in a stereo system it is preferable to have multiple smaller drivers (woofers, like 8 or 10 inchers) to better integrate those subs with the rest of the system? ...And a 12 incher(s) would be the very max.

For home theater, ok, 18" or more is just fine. ...For the LFE channel (.1).

I went through this with a designer claiming the superiority of columns of 6.5" drivers... Of course I then broke out the total cone area, motor and box volume as if it were 1-2 larger woofers as a single entity... Sure enough that stack of 6.5" drivers matched up perfectly with high efficiency 15" drivers (borderline pro-hifi) which make for a good deal of efficiency, headroom, linearity and a nicely shaped frequency response.