Thank, DaveC...i was thinking about this overnight and realized there is an obvious non-techie question in here from me:
In the same way we have all seen the presentation by standalone mini-bookshelves be transformed by adding a massive, high quality sub, what happens if we add proportionately massive sub towers to truly full-range speakers (so you are talking truly massive if your speakers are big Wilsons for example)?
(I am aware of the flaws in these mini-monitor/sub systems...but I suspect some of those go away when the main speakers are actually full range.)
So if we added, for sake of argument, 2 towers of 6-10 x 18" cones per tower (to keep life simple, assume expertly designed and extremely well set up)...do we think that those full range speakers take just as great a leap forward as those mini-monitors?
I remember reading that Dan D'Agostino had a 'wall of Krell MRS Master Reference Subs' with his Wilson X1s many years ago. (Each Master Ref Sub is 2 x 15" cones, weighs 450lbs...and a wall of them was apparently something like 6 of them).
Thank, DaveC...i was thinking about this overnight and realized there is an obvious non-techie question in here from me:
In the same way we have all seen the presentation by standalone mini-bookshelves be transformed by adding a massive, high quality sub, what happens if we add proportionately massive sub towers to truly full-range speakers (so you are talking truly massive if your speakers are big Wilsons for example)?
(I am aware of the flaws in these mini-monitor/sub systems...but I suspect some of those go away when the main speakers are actually full range.)
So if we added, for sake of argument, 2 towers of 6-10 x 18" cones per tower (to keep life simple, assume expertly designed and extremely well set up)...do we think that those full range speakers take just as great a leap forward as those mini-monitors?
I remember reading that Dan D'Agostino had a 'wall of Krell MRS Master Reference Subs' with his Wilson X1s many years ago. (Each Master Ref Sub is 2 x 15" cones, weighs 450lbs...and a wall of them was apparently something like 6 of them).
The catch and difficulty with any speaker designed with more limited bass extension is that unless it is expected to be used with a subwoofer, they almost always have some elevation of the bass range they do cover to enhance the harmonics of the range they are missing and not sound overly bright, or light on the bass. If you think of some of the old Linn micro/mini-monitors and compact ProAc speakers they subjectively sounded rather balanced on their own despite the obvious limitation in low frequency extension. That subjective balance is largely formed by a relative balance of the upper and lower range energy. In overly simplified terms, if you drop off an octave of bass energy with a speaker that extends to 60Hz vs 30Hz, you have to subjectively make up for it some with elevated response at and above 60Hz. It is an imprecise adjustment which works better on some material than others.
The problem comes in when you have a speaker voiced to sound full with limited extension and you then extend the bottom to 15-20Hz vs 60-80Hz of the speaker itself. It can sound very good, but it often becomes a tenuous balance of just enough vs too much. This is where a more full range speaker will have a balance that may be more complimentary to adding deep reaching subwoofers. Of course if you work some form of electronic correction into the mix like a Trinnov, Lyngdorf, Dirac enabled component, or similar into the mix, this mostly becomes a non-issue, while adding the ability to usually add a high pass for the speakers and delay to match the bulk energy arrival and phase of the speakers with the subwoofers.
I think of the effects in terms of car motors and the adage, 'there is no substitute for displacement' when it comes to bottom octave response. My previous Rockport Cygnus had usable response to 20hz, supplied by 2 x 10" woofers for a total radiating area of 157 in2 per channel. When I add 3 x 12" Rel subwoofers per channel my useable low frequency radiating area increases by 339 in2. Is it meaningful? Most definitely.
Isn't this an interesting observation, as it very much mirrors my experience. I used to consider 'displacement' as merely the driver surface area multiplied by maximum displacement, but like DaveC, I found that more driver surface area worked much better than, for example, 1/2 the area at twice the excursion. I often thought it might have to do with the smaller excursions being more in the linear region of the driver, or perhaps how much easier larger drivers couple with the room.In speakers it's more surface area, as adding more bass via excursion is not as good as more surface area. It is hard to put my finger on exactly why it's so much better. I have my own horn speakers with 15" woofers and also a pair of 3-way towers with 2x7" woofers per side and the 15s are simply in another league. I have measured less distortion and lower extension in the 15s, but there's more to it...
Mark Seaton, Duke LeJeune and Others, here is a direct question:
- If we look at how transformational adding a Velodyne DD18+ is to a smaller speaker...
- This means that this transformation is created by adding a sub that has 4.4x more cone surface area than the main speaker
DIRECT QUESTION: IS IT LOGICAL THEN TO TAKE THIS RATIO AND APPLY IT TO FULL-RANGE SPEAKERS AND "KEEP GOING"?
Yes, speakers are also often rolled off up top to match the bottom end so when you extend the bass the the tonal balance is off.
Yup, I think it's "there's no replacement for displacement".
In speakers it's more surface area, as adding more bass via excursion is not as good as more surface area. It is hard to put my finger on exactly why it's so much better. I have my own horn speakers with 15" woofers and also a pair of 3-way towers with 2x7" woofers per side and the 15s are simply in another league. I have measured less distortion and lower extension in the 15s, but there's more to it...
Thank you! All else being equal, are SPLs logarithmic to cone size or linear? Just curious is my cone surface area approach (clearly assuming linear progression) is missing a logarithmic increase in scale.I don't use cone area ratios as a primary metric for system design. I DO take thermal and mechanical compression as well as SPL targets into account, to make sure one part of the system doesn't prematurely become the limiting factor. So cone area does get factored in, but not specifically as a target ratio.
That being said, what I do isn't normal... I'm inclined to use fairly large midwoofer cones, for the sake of radiation pattern control. So I tend to end up with lower cone area ratios than what you described.
When pairing more "conventional" main speakers with subs I'd probably still pay more attention to uncompressed SPL capabilities than to cone area ratios. And adding subs to main speakers which are already full-range raises issues that would probably have to be resolved on a case-by-case basis.
I think thats only 'not normal' in hifi pretty typical in pro/theater/touring applications....
That being said, what I do isn't normal... I'm inclined to use fairly large midwoofer cones, for the sake of radiation pattern control. So I tend to end up with lower cone area ratios than what you described.
...
All else being equal, are SPLs logarithmic to cone size or linear?
That being said, i wonder how the Velodyne DD18+ SPLs at sub 48hz compares with the SF Guarneri...ie, what is THAT ratio?
...and therefore once again, whether that ratio can be applied to the big Wilson's capability and the level of SPLs one would seek for matching subs to produce to get that same level of uplift in scale/performance/presentation.
For a doubling of cone area we theoretically gain 3 dB in SPL, but in the real world of course all else is never equal. Cone mass increases, which changes the frequency response curve and lowers efficiency (but extends the low end deeper, assuming box size is appropriately increased). The larger woofer might have a more powerful motor which would bring the efficiency back up, possibly accompanied by an increase in voice coil diameter which would increase the power handing, which would also tend to increase the max SPL capability, assuming amplifier power is scaled up. And so forth.
Making guesses based on the published specs, I estimate that a single DD18+ will go ballpark 6 to 8 dB louder than a pair of Guarneri Tradition speakers.
Extrapolating from the Guarneri Tradition to the Wilson Alexandria XLF, I guesstimate that it would take about 6 DD18+'s to "match up" in roughly the same way with a pair of the big Wilsons.
"On paper" that looks to me like overkill... NOT that "overkill" is necessarily a bad thing when it comes to subwoofers... or high-end audio in general...
Thank you! All else being equal, are SPLs logarithmic to cone size or linear? Just curious is my cone surface area approach (clearly assuming linear progression) is missing a logarithmic increase in scale.
That being said, i wonder how the Velodyne DD18+ SPLs at sub 48hz compares with the SF Guarneri...ie, what is THAT ratio?...and therefore once again, whether that ratio can be applied to the big Wilson's capability and the level of SPLs one would seek for matching subs to produce to get that same level of uplift in scale/performance/presentation.
Any experience with this device, Anti-Mode 8033 Automatic Subwoofer Equalizer?
While surface area is a useful figure to understand, ultimately we care about headroom, distortions, and efficiency to the degree it limits output.
I think thats only 'not normal' in hifi pretty typical in pro/theater/touring applications.
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