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my views on the results:

1) the 5400 is a very impressive driver. in the passive box it's performance is not
supprising, however the sealed box is most impressive.
2) except for the 5400, all of the diy 15 sealed have unusual high THD between
50-100hz. a bit strange considering the level of those drivers.
3) the sdx-15 is disappointing below 25hz and impressive above 25hz.
4) the JL fathom's THD graphs don't look much at first glance, however it's
performance considering the driver size is very good. also in the cea2010
it gave gr8 numbers.
5) the svs ultra is one amazing subwoofer for the money. even it's sealed mode
gave good results. the 10hz mode is pretty useless except for maybe very
small rooms.
6) the yamaha subwoofer shows just how much marketing "bla bla" is involved
in this industry...
7) :hail: to Ilkka.
 

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I think that the LMS results confirm that it is the real deal. Its performance in the 100L sealed is really impressive and the 200L PR system is more of the same. I don't know of any other drivers that will perform like that in those box sizes. The fate of Audiopulse/TC seems to be in doubt so maybe that has hampered interest. That and the $2000 retail price.

F113 i thought did really well for the size of the box and backed up it's hype that it has had going lately.

The SVS PB13 Ultra definately backed up it's rep as well and was the surprise of the group IMOP. Everyone assumed it would do well, but it seemed to do even better than could be hoped. Impressive.

The sealed SDX 15's did ok, but I was a little underwhelmed, especially after the performance of some of the other units. To me it seemed like the performance below 20hz was poor.
 

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Elite Shackster
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Discussion Starter #43
The sealed SDX 15's did ok, but I was a little underwhelmed, especially after the performance of some of the other units. To me it seemed like the performance below 20hz was poor.
Do you mean the distortion? Yeah, it's a bit higher than for example with the TC-2000, but IMO distortion below 20 Hz isn't the most important thing in a subwoofer. If everything else is OK, then you might be check that also the VLF is clean as possible. Also the SDX15's distortion is mostly 2nd order harmonic so it's extremely hard to hear.
 

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Elite Shackster
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Discussion Starter #44
2) except for the 5400, all of the diy 15 sealed have unusual high THD between
50-100hz. a bit strange considering the level of those drivers.
It's the inductance doing its evil work there. Most of these high excursion drivers have very high real world inductance (and its variation with current and excursion). But luckily the THD contains mostly low order harmonics so it isn't that easy to pick up.

4) the JL fathom's THD graphs don't look much at first glance, however it's
performance considering the driver size is very good. also in the cea2010
it gave gr8 numbers.
Driver size but also the size of the enclosure. It's MUCH smaller than for example the PB13-Ultra.
5) the svs ultra is one amazing subwoofer for the money. even it's sealed mode
gave good results. the 10hz mode is pretty useless except for maybe very
small rooms.
I would choose the 10 Hz mode over sealed. Though I wouldn't use anything else than the 20 Hz or 15 Hz with it. Those others are just wasting its performance.
6) the yamaha subwoofer shows just how much marketing "bla bla" is involved
in this industry...
The Yamaha didn't quite cut it but IMO it's not THAT bad. It gives high SPL in mid bass range which means it's a pretty good "party subwoofer".
 

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Ahh, I don't like high inductance...

The 10hz on the ultra does look better than the sealed option, and both do waste
It's performance.

Yahama went a bit far stating the 1500 does 16HZ, and does it "well"...
 

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Do you mean the distortion? Yeah, it's a bit higher than for example with the TC-2000, but IMO distortion below 20 Hz isn't the most important thing in a subwoofer. If everything else is OK, then you might be check that also the VLF is clean as possible. Also the SDX15's distortion is mostly 2nd order harmonic so it's extremely hard to hear.
I agree about the amount of distortion at 16 and 20hz not being that bad in the real world, but it is still higher than the TC2K. Mostly though it was the output. The dual SDX's in 140L had 2 Ce4000's running to it right? The LMS was in a smaller enclosure with 1 amp and it put up significantly better 20 and 16hz #'s while being cleaner too. Maybe that's not a fair comparison but still...
 

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Elite Shackster
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Discussion Starter #47
I agree about the amount of distortion at 16 and 20hz not being that bad in the real world, but it is still higher than the TC2K. Mostly though it was the output. The dual SDX's in 140L had 2 Ce4000's running to it right? The LMS was in a smaller enclosure with 1 amp and it put up significantly better 20 and 16hz #'s while being cleaner too. Maybe that's not a fair comparison but still...
Well the LMS-5400 is by far the cleanest and the best driver I have ever measured, so naturally any other "normal" driver will look bad compared to it. :)
 

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I am a bit surprised that the latest round of results hasn't caused more discussion? Are the results so clear that no one cares to comment anything or are they too difficult to understand? There was a lot of discussion prior to the measurements about the LMS woofer etc, but now no one says anything about the results they got. :dontknow:

Do I have to start giving random points to the subwoofers in order to get some more traffic here? :sarcastic:
LOL, No . . . . we don't need no steenking random point assignments for the speakers!
Ilkka, I think what happened last year was all of us DIYers were interested in the "ultimate" driver. Everything was pointing to the LMS-5400 18" but we didn't have anyone with the right credentials to do the building and testing. The process that you proposed took more than half a year to bear fruit. Then you kinda let the cat out of the bag when you tested the drivers in "free air" after you had finally received your unit that had shipped over seas. We were all blown away as soon as we saw your results. The LMS-5400 performance was easy to recognize as the top driver. The only final proof needed was to measure it in-box.
You constructed TWO boxes and had the CE 4000 to drive them with. There was going to be NO question at the end of this adventure as to which driver was "the best" and for us sumo-scientific guys we thought we were finally going to have THAT driver and box that would rattle the frequency response all the way down to 10Hz and reference levels with little or no distortion.
Your test procedures and display of results leave little else for us to imagine. The graphs and pictures show and answer almost all of our questions. You ARE good at that you know!!!
The LMS-5400 IS THE BEST sub driver to date . . . . . . however to our amazement it is no longer realistically available to the DIY world. We sit in utter amazement and silence. Our dreams have been answered and yet we sit with head in hands wondering how this could have happened. Yes there are a few people lucky enough to have the LMS driver but way fewer than needed for it to become an ICON.
Don't be dismayed at the lack of discussion, we're still trying to wrestle with our realities. We'll get back at it . . . . . but we will have to replace a discussion about the worlds best driver with . . . . . what . . . . .I dunno.
Phil
 

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I agree with Phil--DIY took a big hit in the gut when TC went bonkers-retail on us...

I know I'm in a bit of a quandry as to what to do; hence the near silence (except when confirming the the 13 Ultra is really an excellent offering).

I love the SVS, and feel it is really the ideal mix of aesthetics, performance and value, but couldn't help thinking that DIY with the LMS unit would finally put the nail in my upgraditis coffin...
 

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I think you're taking this a bit too seriously man :dontknow:
Nah . . . . . I'm OK . . . .
What's happened in the months since I assembled my LMS-5400 18" based system is that I realized how smooth and distortion free the upper range of the frequency response is. I've decided that a 120HZ X-over point is reasonable and am now searching for a way to design a two way speaker to go along with the LMS. The problem is to match the spl output and power handling capability of both the LMS and the new two way unit .I could use the two way as mains and/or surrounds.
Anybody here have any real world experience with a 6.5 inch driver that is rated at 150 watts and can do 110 db?
 

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Ilkka's measurements

Ilkka has performed additional measurements labeled under "Miscellaneous Measurements" on several subwoofers and has again supplied food for thought.
The performance enhancements produced by "response shaping electronic controls" contained within the subwoofer units provides additional adjustments usable in differing room sizes and treatments.
The graphs also show that electronic shaping of the response curve is very doable and very accurate. If anyone has lingering doubts about the ability of receivers, amps, BFDs, Room EQs, and parametric equalizers to add performance enhancements to a sound system, they should now rest easy.
 

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Elite Shackster
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Discussion Starter #53
Re: Ilkka's measurements

Ilkka has performed additional measurements labeled under "Miscellaneous Measurements" on several subwoofers and has again supplied food for thought.
The performance enhancements produced by "response shaping electronic controls" contained within the subwoofer units provides additional adjustments usable in differing room sizes and treatments.
The graphs also show that electronic shaping of the response curve is very doable and very accurate. If anyone has lingering doubts about the ability of receivers, amps, BFDs, Room EQs, and parametric equalizers to add performance enhancements to a sound system, they should now rest easy.
Phil,

I moved your post/thread here. Please do no start new threads because I want to keep the main page as clean as possible so that each subwoofer will be easier to find. Thanks! :)
 
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Interesting stuff, have you ever tested a Wilson Watch Dog 2 sub? or the Revel 30?

John
 

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I've come across something interesting in Illka's tests. I was running through the DIY subs that were tested and simulating them with WinISD to see how closely the predicted max output matched up with what was the actual real world results that were measured. Most of them are quite close, which was actually a bit of a surprise.

All of the subs had the most deviation from the theoretical down at the lowest freq's 12.5 & 16hz. The 2TC subs... TC2000 and LMS5400 were extremely close to what WinISD predicts. The TC2000 was short a maximum of 2.1db at 12.5hz from predicted in the 270L vented design. The LMS was off a maximum 0.9db from the predicted max output at 16hz in the 100L sealed:eek:! Seems like what you simulate is pretty close to what you will get with TC's subs.

The SDX subs on the other hand were way short of the predicted max output in both the dual driver 140L and single driver 100L sealed. They are both really close down to 25hz, and the 100L sub is only -2db off at 20hz. The 100L is 4db short of the predicted output at 16hz and 5.9db short at 12.5hz. The 140L dual driver sub is even further off from the predicted output...it is -6.5db at 20hz, -5.8db at 16hz, and -9.4db at 12.5hz:scratch: from what is predicted. I wouldn't think anything of this if the 2 TC drivers weren't so close to what is predicted.

Anybody have any thoughts on this? Seems like maybe the SDX really doesn't quite have 30mm of useable xmax? Perhaps the distortion just gets way out of hand even though there may be output left? Maybe the enclosure volume was too small? The 100L performed much better than the dual driver that only had 70L per driver... I'm just guessing here.
 

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I enter them in the order suggested by WinISD and with the autocalulate feature turned on. I understand where you are going with this, but the small differences between the auto calculated params and the mfg'r supplied ones will not cause that big of a difference in a sealed box. Maximum theoretical output for a sealed system on the low end is all about VD, which is not affected by the parameters much at all(excluding SD and xmax of course).
 

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Elite Shackster
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Discussion Starter #58
I've come across something interesting in Illka's tests. I was running through the DIY subs that were tested and simulating them with WinISD to see how closely the predicted max output matched up with what was the actual real world results that were measured. Most of them are quite close, which was actually a bit of a surprise.

All of the subs had the most deviation from the theoretical down at the lowest freq's 12.5 & 16hz. The 2TC subs... TC2000 and LMS5400 were extremely close to what WinISD predicts. The TC2000 was short a maximum of 2.1db at 12.5hz from predicted in the 270L vented design. The LMS was off a maximum 0.9db from the predicted max output at 16hz in the 100L sealed:eek:! Seems like what you simulate is pretty close to what you will get with TC's subs.

The SDX subs on the other hand were way short of the predicted max output in both the dual driver 140L and single driver 100L sealed. They are both really close down to 25hz, and the 100L sub is only -2db off at 20hz. The 100L is 4db short of the predicted output at 16hz and 5.9db short at 12.5hz. The 140L dual driver sub is even further off from the predicted output...it is -6.5db at 20hz, -5.8db at 16hz, and -9.4db at 12.5hz:scratch: from what is predicted. I wouldn't think anything of this if the 2 TC drivers weren't so close to what is predicted.

Anybody have any thoughts on this? Seems like maybe the SDX really doesn't quite have 30mm of useable xmax? Perhaps the distortion just gets way out of hand even though there may be output left? Maybe the enclosure volume was too small? The 100L performed much better than the dual driver that only had 70L per driver... I'm just guessing here.
Hi Ricci,

You can't really compare the CEA-2010 max output figures with the WinISD "max output figures" because the CEA-2010 numbers are THD limited (please see this PDF for explanation on the CEA-2010 standard) and are using a burst signal instead of simple sine wave approximation of the WinISD. Also the WinISD approximation is only a function of the maximum power handling of the driver (Pe) or the maximum "linear" excursion (Xmax), whichever is reached first at each frequency. In other words it's EXTREMELY simplified approximation which basically doesn't always (ever) add up with the real word tests, even when not using any THD limiting or burst signals. Simulations are only simulations based on small signal T/S values which change a lot with larger input signals. Also basic simulations don't simulate the effects of any non-linearities (power compression etc.)

But when it comes to the SDX15, the CEA-2010 output down low is limited by the high 2nd order distortion component. This means that the compliance (Cms) non-linearity is quite high i.e. the suspension is causing a lot of distortion which limits the CEA-2010 numbers at the low end. The 3rd order harmonic is quite low which tells that the Bl related distortion is low, thanks to the XBL^2 motor.
 

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Thank you for the explanation Illka. I figured that it was distortion related to the suspension,but I'm no expert.Now I know and knowing is half the battle.

Do you think that the 30mm linear xmax rating for the SDX is a bit optimistic, or would that be unrelated to the distortion issue?
 

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Elite Shackster
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Discussion Starter #60
Thank you for the explanation Illka. I figured that it was distortion related to the suspension,but I'm no expert.Now I know and knowing is half the battle.

Do you think that the 30mm linear xmax rating for the SDX is a bit optimistic, or would that be unrelated to the distortion issue?
Can't really tell without Klippel or similar measurement, but when one remembers that...

------------------------------
Xmag = Excursion limit due to the magnetic limitations of the driver's motor. Xmag is defined as the displacement at which the BL product has fallen to 70.7% of its value at the cone's rest position.
Xsus = Excursion limit due to the driver's suspension. Xsus is defined as the point at which the compliance of the suspension has decreased to 25% of the value at the cone's rest position.

From these two figures, Xmax is then derived as follows:
Xmax = The shorter of the Xmag and Xsus values, in each direction of cone travel.
-------------------------------

...so linear doesn't usually really mean perfectly linear, so there can be a lot of distortion even when still operating under "linear" range. I wouldn't worry about sub 20 Hz distortion that much though.
 
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