Updated NOUSAINE subwoofer data list

[TVodhanel]

>>>Hey Tom,

Would you be able to guess at how a Nousained PB2 Plus would do in the 25-63hz average based on the original 20-39CS you guys sent to him?<<<

Nah, There is just way too many people making every best case assumption for what their products MIGHT do if Nousaine-d as it is. It is always..."this formula, or that theory, or I have this much Vd..."....blah,blah,blah....so I *know* my subwoofer would do this or do that.

I can tell you how the PB-2+ does compared to the 20-39cs in MY tests...but I won't pretend that should be held as a parallel to what someone else might measure(using a different measuring environment, different mics, different software, different PC, different input signal ect).

We have had one unit Nousained...the old(circa 2000) 20-39($479 passive and $599 powered). 91dB/20hz,105.8dB/25hz and 109.5dBs from 25-63hz....WITH in room extension to 25hz in TN's huge 7500 room.(where is the Nousaine measured FR curve on this unit?) That was with a little 12" driver that would be lucky to measure 14mm of xmax on a dumax machine(that is the machine some folks think is an absolute indicator of a subwoofer's future performance btw). Those seem like respectable numbers from a 3 year old unit @ $599.. And believe me, we wouldn't be turning down a chance to be in a big subwoofer showdown in SoundVision and have another model Nousaine-d someday!

Heck, the rsw15 outguns it across the board in TN data and is about the same size and price?...I just don't see the big revolution in performance...

Tom V.

SVS

[TheEAR]

formica,

Yes when applied to midranges and tweeters the XBL 2,XBL 3 and XBL 69 is a marketing hoopla.

Again the sublime quote...

"Many more to come all using Adire Audio XBL^2 enabled motors for bass, midrange & tweeter where it significantly cuts down on motor based distortion."

Yeah many more hype and BS from another start up with not much to their credit,what's after XBL 69 in supertweeter that have cone/dome travel of inder 0.01mm. Sure to reduce DISTORTION,sure. Like all audiophiles are stupid.

I sure know I will not buy anything else besides maybe a sub from these guys.

Why not flare the ports...on midrange chambers,so the massive airflow ...flows better. LOL

I am going to torment the person who wrote this for a long time.

Faboulous one do you have more quotes from them?

So I may LOL so loud the windows will need to be XBL 69 enabled not to break.

[Colin]

Adding Tom Vodhanels numbers for his old SVS 20-39 model to Frankies and Brians lists (16 subs) dramatically changes my equations. It puts the tall SVS tubes right back on top for the greatest bang (20Hz output) for the least buck (retail price). It shows that the lowest cost per 20Hz shake is the basic 20-39 SVS subwoofer tube, with the lowly KSW-15 now coming in second. At the still admirable 25Hz level, the SVS tubes still reign in value, with the mediocre (87 SPL) PSB Subsonic 5i is the second best value. Of course, this analysis says nothing about attack, decay, frequency response curve, impedance and sensitivity. All of which make very big differences in the matching of subs to mains. All it says is that big ole tubes, like big ole horns, give a lot of boom for the buck.

[DanWiggins]

Hi all, perhaps I can explain a bit about how XBL^2, and linear BL in general - benefits mids and tweeters...

In drivers, per Dr. Wolfgang Klippel, there are 3 sources of THD:

BL nonlinearity - motor strength changes as the driver moves

Cms nonlinearity - suspension stiffness changes as the driver moves

Le nonlinearity - driver inductance changes as the driver moves

These three sources are what generate THD when a driver moves. BL accounts for ~65% of the THD in a driver, Cms for ~25%, and Le for the last 10%. The big source of THD in a driver is from a nonlinear BL curve.

Cms nonlinearity was solved in the 30s, with the introduction of the progressive and regressive spiders; they maintain a relatively constant Cms value over a wide range of motion. Likewise, Le nonlinearity was solved in the early 60s by Ejvind Skaaning, and the heavy use of copper in motors. BL nonlinearities, however, have been the difficult part for designers to tackle, and as the primary source of driver THD, has been the most important one to crack.

In traditional overhung or underhung drivers, BL starts to change as soon as you start to move. This is why measured BL curves show consistent parabolic shapes - the B field integrated over the voice coil length is different for every position of the voice coil. As such, the driver begins distortion at extremely small motion, and continues to increase THD has driver excursion increases.

Linearizing the BL - making the BL flat over excursion - eliminates the THD associated with the driver when operating in its linear range. The wider and flatter you can make the BL curve, the lower the overall THD of the motor.

XBL^2 is applicable to mids and tweeters for a couple of reasons:

1. Lower distortion. As soon as the BL changes, THD increases. Keeping BL constant over range of motion - even if it's just a few mm - will help lower THD. Since most mids are overhung, they have a completely parabolic BL curve, and will exhibit increasing THD with just a few mm of excursion.

2. Longer stroke. This allows a smaller diameter driver to be used to generate the same SPL. SPL is about displacement of air. Displace X amount of air, receive Y dB of SPL. Giving a designer the option of moving to a 4" mid, rather than a 5.25" mid, is a serious advantage. Off-axis response is enhanced with the smaller diameter driver, and the usual tradeoff with SPl limitation is gone.

3. Wider bandwidth. Strange it sounds, to claim more stroke AND wider bandwidth. However, the primary limiter of bandwidth on the upper end is not mass, nor compliance, or BL. It's inductance. The easiest way to reduce inductance is to not create it in the first place. Since inductance goes as the square of the number of turns, shortening the voice coil by 30% can halve your inductance, and double your bandwidth. XBL^2 uses very short voice coils to achieve very long strokes; for example, we have a 4" prototype driver with a 6mm long voice coil that has 5.8mm of one way linear stroke. Typically you'd need a voice coil around 14mm to achieve that kind of stroke. We cut the length of the VC way down, meaning much lower inductance.

4. Lower mass. Moving mass, along with BL, sets your efficiency. The lower the mass, the more efficiency you gain. And with a shorter voice coil, you cut the moving mass considerably. The Fs also increases, however. But for many designs a high Fs isn't an issue; efficiency is more important. Additionally, it's always trivial to add mass to a driver - removing it is often much more difficult. Give a driver designer a lower starting baseline of moving mass and they'll love you.

5. Higher BL. XBL^2 motors keep more of the voice coil in the peak B of the field, meaning more BL over the stroke. Motor strength is a "single point" function; motor efficiency is the integral of the area under the BL curve. The more area under the curve, the more potential for work with a given input, meaning the higher the efficiency. Making the curve wider and flatter, and keeping the B value high, means more efficiency in the design, especially over motion.

6. Less compression. The number 1 source of compression in a driver is NOT thermal; it is BL. As the BL drops, the driver loses efficiency. This is INDEPENDENT of the power delivered - it is purely an excursion based function. Power compression can take seconds to build up in woofers, and even tens or hundreds of milliseconds (dozens of cycles) in mids. BL compression, however, happens instantaneously on the first cycle and every cycle. Keeping the BL up over the entire stroke eliminates this source of compression.

7. Higher BL, take 2. Because the voice coil is so short, you can run a narrower gap. For a given angular deflection, the amount of axial displacement of the end of the former is dictated by the length of the former. Using a short voice coil, you can decrease the axial displacement for a given angle of deflection. This means you can run a narrower/tighter gap, and still have the same resistance to scraping/rocking. Narrowing the gap will increase the B field, meaning more BL.

There are several other advantages to using XBL^2 in woofers, midranges, and tweeters, but these are the primary ones that our licensees are benefiting from. Typically the lower THD, longer throw, lower inductance, and lower mass are the most appreciated reasons, with the others being a strong 'second tier' set.

Thanks,

Dan Wiggins

Adire Audio

[TheEAR]

Mr Wiggins,

Good,I am glad you posted detailed info like this.Like I said,I agree 100% with XBL when used in any woofer,its a clear gain.

As woofers have to displace good amounts of air,and the longer the linear cone travel the better(to some extent).The Tumult is a prime example,very long linear throw and even when aproaching excursion limits its much more at home then most woofers at half max excursion.

But...

In midrange use,XBL may help.The gain may be audible at very high SPL.

However in tweeter use where piston travel is minute the gains are more on paper then real audible gains.

Again I would like to be proven wrong.

Dan Wiggins and TV join us,people we have good company here at the Klipsch sub board.

Mr Wiggins,in a not too distant future I will most probably order a dual Tumult Acoustic Visions Everest.Here XBL "enabled" Tumults are for real.

And talking about subwoofers,I would love to get the SVS B4-Plus and the Everest and compare them side by side.As I do with my Sunfire,Aerial,Revel,Klipsch and Velodyne.

AH the joys of limitless subwoofing.

Now if we can invite Bob Carver to discuss subs,would be great.

[formica]

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On 10/8/2003 5:13:30 PM DanWiggins wrote:

In drivers, per Dr. Wolfgang Klippel, there are 3 sources of THD:

BL nonlinearity - motor strength changes as the driver moves

Cms nonlinearity - suspension stiffness changes as the driver moves

Le nonlinearity - driver inductance changes as the driver moves

These three sources are what generate THD when a driver moves. BL accounts for ~65% of the THD in a driver, Cms for ~25%, and Le for the last 10%. The big source of THD in a driver is from a nonlinear BL curve.

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

Note that I haven't read Dr. Klippel's white papers, but one would think that the relative importance of BL, Cms, and Le would vary depending on which property is governing the system?...

or... in other words... BL would be more significant (affect distortion more) in a system which is subjected to large magnetic forces while Cms would be more significant in a rigid system subjected to small forces?

I'm also unaware of the principals behind XBL, so don't be shy to step in here...

but if it performs as advertised, I'm not denying the possibility of reducing distortion by improving BL linearity in a small driver... but rather it's overall significance (versus improving Cms linearity for example).

Rob

[Jolly Roger]

"It shows that the lowest cost per 20Hz shake is the basic 20-39 SVS subwoofer tube, with the lowly KSW-15 now coming in second"

Where do you figure the Adire Dharman @599 into this?

[DanWiggins]

TheEar wrote:

As woofers have to displace good amounts of air,and the longer the linear cone travel the better(to some extent).The Tumult is a prime example,very long linear throw and even when aproaching excursion limits its much more at home then most woofers at half max excursion.

But...

In midrange use,XBL may help.The gain may be audible at very high SPL.

However in tweeter use where piston travel is minute the gains are more on paper then real audible gains.

XBL^2 isn't about long stroke - it is about low distortion. You can gain longer stroke if desired, but it really arose from an R&D effort into driver distortion. Flat BL - REGARDLESS OF EXCURSION LEVELS - will lower THD. This is a prime benefit for any driver.

As far as tweeters go, consider the dispersion aspect. Which has better off-axis dispersion - a 0.5" dome or a 1" dome? The 0.5" dome will have a 3 dB @ 45 degrees off axis frequency of 27 kHz; the 1" dome is rolling off at 13 kHz. For wide dispersion, a smaller dome is desirable. HOWEVER, that often means reduced SPL - you have 1/4 the Sd for generation of SPL.

BUT, with a longer throw motor, you can gain that SPL back. SPL is displacement - Sd times throw. Reduce the Sd to gain dispersion, increase throw to gain back SPL. A 0.5" dome tweeter with 2mm of clean stroke will generate as much - or more - SPL as most 1" diameter domes. But with enhanced off axis response. Meaning the reflections, and the total power response will be much smoother overall.

Extension is also a benefit. Say you want to stick with the same size dome - you're happy with your current Sd. And you are happy with the current SPL potential - the excursion is fine. With an XBL^2 motor you can typically cut the voice coil length by a factor of 2 or more, for the same stroke (that also implies cutting the Mms significantly, too). That quarters the inductance, meaning the natural roll-off of the driver has been raised. If your dome is clean to 30-40 kHz before breakup modes, now you can have extension out there. Is that important? Some would argue no, some would argue yes. But what IS important is now you can actually reach that point. Whether you want to or not is the designer's choice, but at least they now have that choice.

There's a lot of benefit to an XBL^2 motor, other than just stroke. If you look at the dynamic THD from a driver (some of the iEC and AES test standards spell out how to measure dynamic, "musically based" THD), you'll find that, in terms of dynamic THD, a driver with XBL^2 and an Xmag of 12mm has the same dynamic THD as a standard overhung driver with an Xmag of 16mm. You gain significant reductions in distortion over the majority of the operating range, such that you can decrease the actual "linear" limits of throw, and still show dynamic THD reduction.

I know it has been popular to look at "max SPL @ F @ 10% THD" as the guideline for performance of a driver. However, IMHO that is as valid as looking at cars at their torque and HP peaks only. To me, and many others, the actual shape of the torque curve is critical. I'd rather have a torque curve that was flat from 1000 RPM to 5250 RPM, and at 300 lb-ft over that window, than a torque curve that started at 100 lb-ft at 1000 RPM and peaked at 350 lb-ft at 5250 RPM. On paper, which engine is more powerful? On the strip, it will be a completely different result...

XBL^2 is about reducing the distortion of the driver at all points. In typical overhung and underhung designs, THD steadily increases from 1mm of excursion and beyond. With an XBL^2 motor, the THD typically stays flat - VERY low, until you're 85-90% of the way to linear excursion. That is the big advantage.

formica wrote:

Note that I haven't read Dr. Klippel's white papers, but one would think that the relative importance of BL, Cms, and Le would vary depending on which property is governing the system?...

or... in other words... BL would be more significant (affect distortion more) in a system which is subjected to large magnetic forces while Cms would be more significant in a rigid system subjected to small forces?

I'm also unaware of the principals behind XBL, so don't be shy to step in here...

but if it performs as advertised, I'm not denying the possibility of reducing distortion by improving BL linearity in a small driver... but rather it's overall significance (versus improving Cms linearity for example).

You are correct about the relative importance of the system; however, for 99.5% of all cases, the box compliance dominates, not the driver's compliance, at least in the bass range. Thus the big influence on the system from the driver is the motor itself, BL. Above that, the compliance becomes much less of an issue. BL and Le start to dominate. Le dominates once you're up near the roll-off of the driver. So for the majority of the range - basically below the roll-off corner on the high end - BL tends to dominate.

XBL^2 is described at http://www.adireaudio.com/tech_papers/xbl2_motors.htm - specifically the PDF download file http://www.adireaudio.com/Files/XBL2DetailsPaper.pdf describes how we use one implementation. It's really the concept of one or more voice coils transversing two or more magnetic gaps that have the direction of flux the same.

Dan Wiggins

Adire Audio

[fabulousfrankie]

One more Klipsch sub makes it to the Nousaine list, the RW10. The review was of the Cinema 10 package which is made of two pairs of RSX-5's, a RCX-4, and a RW-10. The main reveiwer had only positive things to say and seemed to be impressed by the new Reference satellites(which rock btw), but he thought the RW10 lacked impact. Like every speaker review in S&V mag it's sent to be Nousained even if he's not the reviewer, here's Nousaine's comments as well as it's measured performance:

The bass limits for the RW-10 were measrued with it set to maximum bandwidth and placed in the optimal corner of a 7500-cubic-foot room. In a smaller room users can expect 2 to 3Hz deeper extension and up to 3dB higher sound-pressure level(SPL). The subwoofer had good extension and excellent dynamic uniformity but only moderate output capability. True acoustic turnover frequencies were 10 to 20Hz lower than the markings on the crossover-control knob, and the overall level fell by 6dB from top to bottom as the control was rotated through it's full range.

FREQUENCY RESPONSE:

39-95hz +/- 2.2dB

BASS LIMITS:

(lowest frequency and maximum SPL with limit of 10% distortion at 2 meters and in a large room)

89dB at 25Hz

94dB average SPL from 25-62Hz

102dB maximum SPL at 32Hz

Bandwidth Uniformity 96%

[TheEAR]

Dan Wiggins,

Very interesting read,thank you very much for such a detailed post.

Looking forward to the Pinnacle Everest sub sometime next year.

[fabulousfrankie]

I put all the data on the list in a much more orgainzed format. I hope you find it easier to read...it took a long time so you better appreciate it. Instead of going back to the original post here's a link to see what it looks like. If you want to compare the looks to the old list I moved it to here.

I'm not done putting in everything I want to but it has everything the old list has.

[formica]

Sweet... now that's a data list!!

Do you have more info on those DIY subs that were tested? just curious...

[fabulousfrankie]

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On 12/5/2003 1:27:55 AM formica wrote:

Sweet... now that's a data list!!

Do you have more info on those DIY subs that were tested? just curious...

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

No I don't have much on them...the only thing I think I know about is TV's 30" ICBM. I know it's was 30" sonotube using 4 12" woofers with a single 12" port. I think it was using Hsu ASW1201 drivers but I'm not too sure on that. I believe this is one pic of it, I saw this pic somewhere else and bookmarked the page cause it looked cool.

[fabulousfrankie]

I just wanted to bring to everyone's attention here that TN tested the Paradigm Seismic 12. There seemed to be quite a bit of interested when TheEAR said he was going to review it so I though you guys would be interested in how it compares to other subs. It's got a 12" downfiring woofer and two 10" passive radiators packed in roughly a 14" cube. It places itself within the top 10 on the list.

Here are it's number's using TN's normal method:

Figures are for a corner loaded subwoofer, 2 meter mic distance, 10% distortion limit, and the SPLs have been averaged from the maximum output at 1/3 spacing at 25/31/40/50/62hz.

Paradigm Seismic 12 108dB / 20hz~87dB

Max output w/10% distortion - 113dB~62Hz

Frequency Response - 25-117Hz +/-3.5dB

You can reference the list to see how it compares to other subs.

I've begun to add TN's measured FR for the subs to the list. Even though it can be completely different in another room, it's a good piece of data to see what kind of extension can be expected(I don't have it for all subs but I'm still not done updating it). I've also added a link to the old style list at the very top because if you want to reference the data in a post you can just copy and paste it much easier from the old style list.

[TheEAR]

The Sunfire Signature beats these numbers and yet it does not even figure on the TN list! And where is the Aerial SW12,Revel B15,SVS Ultra,PB2-Plus and B4-Plus/K2

Where are these subs,they would re-arrange and grab the top positions with ease.

[fabulousfrankie]

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On 1/10/2004 11:48:44 PM TheEAR wrote:

The Sunfire Signature beats these numbers and yet it does not even figure on the TN list! And where is the Aerial SW12,Revel B15,SVS Ultra,PB2-Plus and B4-Plus/K2

Where are these subs,they would re-arrange and grab the top positions with ease.

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

I know the only SVS TN has tested is the original 20-39CS so that's why that's the only one on the list. AFAIK, he hasn't tested any of the other subs you mentioned. I'm pretty sure all of those subs would grab the top spots.

I was talking to John Janowitz and he's suppossed to be getting two new Stryke subs Nousained soon. One will be his Mini Thunder which is a 1.5 cu ft enclosure with a 12" SAE1204 and dual 12" PR's powered by a 350W amp. The other will be the Thunder 12 which is a 3 cu ft enclosure with an AV12 and dual 15" PR's powered by a 500W amp. He's also coming out with a updated Power 15(which currently tops the list) which will have a newer version of the HE15 woofer with 30+mm of excursion and lower distortion which will be Nousained later.

[CO1]

Nice to see Tom has done some testing on the latest version of the PW-2200 which has since moved up the list from the original version. Great cheap slam, especially for Canadians.

[fabulousfrankie]

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On 1/21/2004 8:19:32 AM CO1 wrote:

Nice to see Tom has done some testing on the latest version of the PW-2200 which has since moved up the list from the original version. Great cheap slam, especially for Canadians.

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Actually it's not the latest version of the PW2200. I was in the process of updating the list with all the FR data I could find and I found a more recent review than what was on the list(from some time in 2001). The 25-62Hz ave went up a less than 1dB but the 20Hz figure dropped a full 7dB...maybe Paradigm tuned it higher?

[fabulousfrankie]

One other thing I forgot to mention, if you look to the right of a few subs you'll see a little number...just put your mouse pointer over and a little popup box will come with some relevant info on the sub.

[fabulousfrankie]

It's been a while, but the list is up to date.