Ear your Driver has arrived (SunFire, eat your heart out!!)

[fire pinch]

Tom,

Sure, we cant rely only on the Vd in order to know if a sub "A" will be better than a sub "B". I just wanted to point out how much air approximately that TC Sound 12" driver can move, just by curiousity For the distortion produced by each driver, we can see in the Adire website that the Tumult at 28mm of excursion one way produce 3% of THD (which is quite very low for today woofers IMHO) so we can say a "very" clean 4.2L of air displacement. But I just talk about air displacement, not subwoofer overall performance number. And now, what is the distortion produced by that TC sound woofer when it reach 42 mm of one way Xmax? Please, please, I dont want you to think that I bash this TC Sound woofer, this is the most awesome 12" woofer Ive seen "in action -] pictured"! A 18 incher with that much excursion would be GODLIKE!!!

[TheEAR]

Tom V.,

Man you better make sure this prototype works and design new higher end subs around it.Because I grow impatient,I really want to buy the best 12" sub on the planet and I know you guys at SVS can mnake it all happen.

So please give us someting better4 than even the impressive TV12.

Thank you

[TVodhanel]

>>>Tom,Sure, we cant rely only on the Vd in order to know if a sub "A" will be better than a sub "B". I just wanted to point out how much air approximately that TC Sound 12" driver can move, just by curiousity For the distortion produced by each driver, we can see in the Adire website that the Tumult at 28mm of excursion one way produce 3% of THD (which is quite very low for today woofers IMHO) so we can say a "very" clean 4.2L of air displacement.<<<

Just as Vel has servo, MK has push-pull, BW talks about the dimpled porting,ect...every manufacturer is going to point to something they consider a big deal and say this is the best thing since sliced bread..

You can reference several xbl 12-15" drivers that have been compared to other products using distortion limits and the xbl units have performed well, but nothing revolutionary. The latest is the big 15" unit...$1350 I think?

Average SPL 25-62 Hz: 111.3 dB

Maximum Output: 115.2 dB SPL @ 32 Hz

20hz...somthing like 93?

for comparison...the 20-39cs($429 passive, $599 powered) SVS sent Nousaine almost 3 years ago now hit 109.5, 114.9 and 91 respectively...or it is about even to within 2dBs in all aspects. That is with a decent 12" driver with about 13-14mm of xmax (i'm guessing, we don't bother with dumax stuff much). Our unit also had a measured frequency response down to 25hz in TN's huge 7600 cu-ft room. The other units FR isn't made available for some reason?

So the xbl unit is a very good performer, no doubt. But with a decent(by todays standards) 12" driver with maybe 14mm of xmax and a total cost at about 44%...being within a couple dBs with a strict distortion limit shows a non xbl driver can perform very well even with distortion limits in place.

>>>But I just talk about air displacement, not subwoofer overall performance number. And now, what is the distortion produced by that TC sound woofer when it reach 42 mm of one way Xmax?<<<

That will depend completely on the rest of the system it is bolted too. The quality of the enclosure(both design and construction), the amp, the porting/PRs, ect. Instead of looking at a manufacturer's marketing claim, it would be more accurate to look at the measured performance of the completed subwoofer by an independent professional in the field I would reckon?

>>>Please, please, I dont want you to think that I bash this TC Sound woofer, this is the most awesome 12" woofer Ive seen "in action -] pictured"! A 18 incher with that much excursion would be GODLIKE!!!<<<

Not at all firepinch...we aren't trying to say this will be the best thing since sliced bread or anything. It is just a *interesting* driver with interesting potential..

Tom V.

SVS

[TheEAR]

"being within a couple dBs with a strict distortion limit shows a non xbl driver can perform very well even with distortion limits in place."

Well said the distortion figures and great deal made about XBL is a bit of hoopla,even if Dan Wiggins is correct about XBL implementation helping lower distortion.

The best woofers that are not "XBL enabled" have so low distortion any reviewer and audiophile can close his eyes on.Sure even lower distortion is even...better.But take some Japanese power amps that claim .0005 distortion and American and Canadian made high end amps with "very high" distortion of 0.5%...does it make the former sound lesser...NOT

In fact a Mark Lvinson No33 sounds way better than ANY Japanese amp boasting some 0.0005% THD BS.So what is all the hoopla about??? Just hoopla

If SVS next generation of woofers implement XBL the better,if they do not and distortion is kept low...fine.

[fire pinch]

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On 11/23/2003 6:53:46 PM TVodhanel wrote:

The latest is the big 15" unit...$1350 I think?

Average SPL 25-62 Hz: 111.3 dB

Maximum Output: 115.2 dB SPL @ 32 Hz

20hz...somthing like 93?

for comparison...the 20-39cs($429 passive, $599 powered) SVS sent Nousaine almost 3 years ago now hit 109.5, 114.9 and 91 respectively...or it is about even to within 2dBs in all aspects.

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The big 15 at $1350... I dont know of which sub you are talking about. Oh... I think I know which one! Is this the one which is powered by a 1000W amp + finished with a black piano finish? I dont remember how it is named thought... Well, IMHO, that sub is under-powered and moreover it is sealed. So we dont expect to have a lot more of performance than your Pci subs. Im sure than before reaching the true 10% THD limit of the Tumult woofer, they often cliped their amp. So most of the distortion came from the amp because it was pushed to its limit all the time during max SPL at 10% of THD tests. I suppose this for the moment. Most people use a 1000W amp with a Tumult, and its not enough if you want it to reach its limits IMHO according to many simulation softwares. But, to be even more sure, Im gonna do an experience once my Tumult will be done, so I will know if this is definitvely true that it can take more power than 1000W, 1500W, why not 2000W in a low to mid-Q sealed box. Here is how I will do the test:

I have presently a QSC 2400W amp. Im gonna try to use only one channel of the amp into 4 ohms, so it will give 825W of power to the Tumult (voice coils wired in series). I'll fire some test tones, and I'll record the maximum output delivered. After, I will set the amp in bridged mono mode, so 2400W into 4 ohms. I'll do the same thing, measuring the maximum output without audible distortion and finaly, I'll see if the Tumult can definitively take more than 1000W of power. The woofer itself sure can take more power, but I talk about a Tumult in a low to mid-q sealed box (Q in the mid 0,60s). Do you know the approximative Q of the Tumult sub you are talking about? A higer Q alignment can even take more power...

So in the end, I just wanted to point out that with double the amp power, see those performance numbers of the Tumult sub as 3dB higher except between 20 and 25 Hz, where the Tumult woofer will probably produce 10% or more of THD. OF course, the price of that sub would be higher and would be even worse for the performance/$$$.

Your SVS subs are very damn good subwoofers for the price. When I go to audio stores, I wonder why they dont sell subwoofer like yours Its a pity we have to use internet in order to know that quite a lot of subwoofers can outclass subs found in commercial stores for less money !!!

Oh... and if you answer my post, I have a question for you and well, other people if you can respond you are welcome Suppose that I measure 110 dB at 20 Hz in a 1500 cubic ft room. How much outpout will I have in a 7500 cubic ft room? I would like to know at the same time what formula you used. Suppose also that the 2 rooms have the same characteristics, I hope you understand. A 7500 cubic ft room with a sub placed in the middle of the room instead of in a corner + a different L X W ratio, + things which are placed differently wouldnt be fair.

Thanx in advance for any answer, and that discussion is really cool. I just want to add that I wrote quite a lot of opinions about the Tumult with twice the power etc etc (what I thought true). So take it easy, when I think that something is wrong or must be explained or must be added, I show up my thoughts. I try to be as civilized as I can

[fabulousfrankie]

"The big 15 at $1350... I dont know of which sub you are talking about. Oh... I think I know which one! Is this the one which is powered by a 1000W amp + finished with a black piano finish?"

That's the right one.

http://www.diycable.com/main/default.php?cPath=24_94

"Do you know the approximative Q of the Tumult sub you are talking about?"

It's ~.7

[fire pinch]

Frankie,

Do you think that this Tumult sub (the DIY Cable one) is underpowered with a 1000W plate amp? Many tell us that you dont absolutely need the maximum possible power the Tumult can take in order to extract every bit of its performance, for example, 1600W for a certain design. They say that 1000W is plenty for having clean deep bass performance. But still, I beleive that some alignment needs really more than 1000-1200W in order to reach the full potential of the Tumult and Im the one who like to have the every most of what the woofer can do. What is your opinion on this?

A sealed mid-Q alignment of 0.7 like the DIY Cable one could take twice the power of what its amp can deliver, so we would have a nice boost of 3 dB, which is somewhat well noticable. Still, I understand that its hard to find a 2000-2400W plate amp on the market for DIYer like us, I dont know of any. Plus, this is not every people who like to have a passive sub + an external amp.

By the way, many people say that 2400W is too much for the Tumult, 1600W of power beeing the thermal limit of the woofer. Someone in the HTF forum use a 2400W amp like me for his Tumult subwoofer (vented with 4 Adire PR15s) and he have 0 problem for the moment and he pushed hard his subwoofer sometimes. He told me that the 1600W of power is rated for 1 hour continuous and 4800W, yes, 4800W is for one second Unless you fire the same 40 Hz test tone for more than 15 seconds, 20 times per day, I think that 2400W is really not dangerous at all for the Tumult.

[formica]

I'd agree with you Burning pinch... I don't think the 1000W amp is enough for the tumult in such a small sealed enclosure.... and if I recall it is mentioned somewhere (on the web site or the forums?) that the amp did reach it's limit before the driver in those posted tests.

I believe rumors already have it that DIYcable will increase the power and probably integrate a bass boost in the next revision, but it will remain sealed.

Having a little extra power on hand is never a bad thing, as clipping is usually what blows a driver anyways... but who says you have to drive your sub amp to clipping when you have 2400W? I'd be a little concerned pushing the full 2400W into a ported enclosure (as the driver will unload below it's tuning)... but like you said... those 3db peaks are always short lived in music anyways (ie: 1200W vs 2400W).

Later...

Rob

[TheEAR]

The numbers are not at all that great considering the driver used and the amp that is driving the Tumult.Yes its a sealed box but why waste a Tumult in such a tiny box?

Take a Sunfire Signature and abobe 25Hz with will be very close to this sub,plus at 31.5Hz it will be too close for comfort.Then what is the point,this sub is still a good deal larger and does not cost much less.

The Tumults shine when used with PR's,like the Everest sub.

"Maximum Output: 115.2 dB SPL @ 32 Hz" this is a Revel,Aerial and Sunfire SIg killer!? LOL

My tiny Sunfire Sig. is very close,and my Revel B15(also a sealed 15" driven by 1000W RMS amp)beats that easy.What is the hype about?World beating performance...NOT

Ported SVS perform much better per $.And dont need $500 woofers to do so.

[fabulousfrankie]

Whether it's underpowered or not depends on whether or not the listener is satisfied with the output. It definitely can take more power though. Rob is right with the the amp clipped before the driver reached it's limits, here's a quote from Kevin Haskins of DIYcable.com:

As you can see from the test we have some good output but we think we can get more with a better amplifier. In our testing the amplifier starts to clip before we get any significant distortion from the driver. We are in the process of developing our own amplifier with more power and a two band parametric EQ to allow the user to extend the current low end which is not EQed. From our guestimates we have another 2-3db to add the Nouisane numbers. The amp would also feature a better crossover section (steeper with more variability) and an RF remote controlling both volume and crossover point.

TheEar,

I agree with you that it seems like a "waste" of a woofer and based on all the hoopla about the XBL motor technology I thought it would do better.

[fire pinch]

Yeah, Im quite disapointed by the numbers too, its why I reacted. I hope that my sealed Tumult will not disapoint me. Knowing what my Tempest sub can do, I hope that the Tumult sealed unit will be more powerfull than my Tempest above 30-40 Hz. I saw somewhere in the forum where Kevin talked that there was some leaks behind the subwoofer, where the plate amp is located so hopefully, hopefully for me, another thing which can reduce the performance of his Tumult sub. Now Im affraid that my Tumult sub wont give the bass I expect! By the way, for sure sure, I will let you know about my Tumult when it will be finished, this is a promise And I will have my Tempest as a comparison

[fabulousfrankie]

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On 11/24/2003 12:03:59 PM fire pinch wrote:

Yeah, Im quite disapointed by the numbers too, its why I reacted. I hope that my sealed Tumult will not disapoint me. Knowing what my Tempest sub can do, I hope that the Tumult sealed unit will be more powerfull than my Tempest above 30-40 Hz. I saw somewhere in the forum where Kevin talked that there was some leaks behind the subwoofer, where the plate amp is located so hopefully, hopefully for me, another thing which can reduce the performance of his Tumult sub. Now Im affraid that my Tumult sub wont give the bass I expect!

By the way, for sure sure, I will let you know about my Tumult when it will be finished, this is a promise

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I wouldn't be worried if I were you. The main reason it didn't have better number is because it was sealed. What kind of enclosure are you using with the Tumult?

[TheEAR]

Sealed is fine,but you need a monster amp with proper EQ applied for good measure.And as we all know even the most crafty EQ use will never compensate for the small volume of the cabinet.

I will wait to see the Acoustic Visions Pinnacle subs meaure and perform before ordering a sb like the Everest.The $2500 asking price is nothing BIG its the transport that will cost me BIG!A 400lbs sub takes space and shipping to Canada is ...quite pricey.

As the SVS B4-Plus packaging is much smaller and is only a bit over 200lbs.And we all know it performs like a true champ.

[fire pinch]

Frankie,

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

I wrote:

"Yeah, Im quite disapointed by the numbers too, its why I reacted. I hope that my sealed Tumult will not disapoint me. Knowing what my Tempest sub can do, I hope that<...>"

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Then you wrote:

"I wouldn't be worried if I were you. The main reason it didn't have better number is because it was sealed. What kind of enclosure are you using with the Tumult?"

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

You have your answer

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Ear,

Well, knowing what my Tempest can do sealed (by blocking the 2 rear flared ports), I dont doubt of how the sealed Tumult will extend. I expect it to be flat to 25 Hz without any EQ. And if you remember my results about the Tempest in sealed mode(FR test), I got surprinsingly response down to even 16 Hz, where it was about -5dB down. I suppose that Im lucky to have a room like this! Im in a hurry to know what kind of power I will get with a 2400W amp: not so many Tumult users use an amp this powerfull for their subs.