Subwoofer - RSW12 vs Sunfire

[TVodhanel]

couple quick thoughts,

1)the Aerial and the current SVS Ultra drivers have almost nothing in common except the build house.(TC Sounds) Comparing the Ultra driver to the SW12 driver(both are 12" drivers) is like comparing 500hp blown 454 to a stock 270hp 454 in a new GM truck and saying---well...they are the same size and GM built both....so....

2)the THD readout in Spectra won't be affected by 60hz line issues unless you are using a multiple of that number. Use 25hz if you can't use 20hz for example. If you can, try measuring the subwoofer outside ,2meter. Measuring in room,1 meter will ultimately be tough for anyone else to duplicate down the road as each room will affect the performance capabilities differently. But even if you cant go outside...doing some basic THD is more than 99% of internet sub wunderkins do...props! I would eventually do 1/3 to 1/6th octave spacing,and say...2,5,10% THD limits for each Freq. Chart it out and you'll have some really cool info.

3)One of the many problems that cause THD in a subwoofer design is when the cones(active or passive) begin to dynamically offset....moving more in one direction than the other.(same thing with ports that compress btw) The potential reasons why this begins to happen are many...and those bench-racing simulations won't be of much help here. Build,measure,tweak,repeat...build,measure,tweak,repeat...

4)Somewhere on the SVS site we have a SPECTRA shot shwoing a single Ultra swept at 95,100,105,and 110dBs using a 2m groundplane method. If you can find it(i don't have the time to look)...you'll see the port compression kick in starting around 25hz.

5)3 3" ports have >21 sq-in area, 1 4" has 12.5 sq-in...about a 70% difference.

6)a 6" non flared port would move about as much as as 3- 3" flared ports.

TV

[Dustin B]

So you're saying a TV12 will outgun a SW12 driver and you estimate that a single Ultra would fair better than well against a SW12?

Gotta love internet direct

[Manuel Delaflor]

quote:

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Originally posted by TVodhanel:

2)the THD readout in Spectra won't be affected by 60hz line issues unless you are using a multiple of that number. Use 25hz if you can't use 20hz for example. If you can, try measuring the subwoofer outside ,2meter. Measuring in room,1 meter will ultimately be tough for anyone else to duplicate down the road as each room will affect the performance capabilities differently. But even if you cant go outside...doing some basic THD is more than 99% of internet sub wunderkins do...props! I would eventually do 1/3 to 1/6th octave spacing,and say...2,5,10% THD limits for each Freq. Chart it out and you'll have some really cool info.

4)Somewhere on the SVS site we have a SPECTRA shot shwoing a single Ultra swept at 95,100,105,and 110dBs using a 2m groundplane method. If you can find it(i don't have the time to look)...you'll see the port compression kick in starting around 25hz.

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Tom,

Thanks for the tips on how to measure. I was seriously considering the outside readings, but that was BEFORE I assembled my Tempest Sonosub! this thing is big and heavy and difficult to manage!

Anyway, I know my readings will be not really useful for anybody else, still, for me it is an important measure to really qualify my job in trying to get a good sounding sub out of my DIY capabilities.

I didn't know that the THD on Spectralab is not affected if I throw some frequency with not traces of a 60Hz armonic. Now, do I need to overcome the peak with higher volume in order to have the right number?

In my tests, I read around 110dB at 20Hz at about 10% THD, but I don't want to take that number as final until Im completly sure on how to overcome the 60Hz noise. I will follow your suggestion on doing 1/6 scale testing (avoiding, for now, any 60 multiple).

On the graph you mention, I will certainly look for it!

This message has been edited by Manuel on 08-16-2002 at 01:37 PM

[TVodhanel]

>>>So you're saying a TV12 will outgun a SW12 driver and you estimate that a single Ultra would fair better than well against a SW12?<<<

There was a lot of data on the SW12 driver posted on AVS a while back. The source was extremely reputable...but I don't know if he was supposed to detail things in the manner he did so I won't mention his name (i have since confirmed his text with someone who had plenty of hands on with the SW12 driver/sub)

SW12 is overhung

Ultra is underhung(much more complex and expensive topology)

SW12 uses 1-2 8" spiders(can't remember which,but I believe it is one)

Ultra uses dual mirrored and FEA-d 9.8" spiders

SW12 uses a standard four spoke cast basket

Ultra has move to a basket with more strength and throw potential

Cant remember what the SW12 uses for the VC...I thought it was a 4 or 6 layer unit...somewhat basic.

Ultra uses a brand new TC sounds voice coil design with a 10 layer flat wound coil.BL is extremely high,power handling is extreme and voltage compression is minimal. Although this coil design isn't proprietary to SVS, last I heard no one else would consider using it because it was very expensive to manufacture.

The motor topology on the sw12 indicates 15.75mm of xmax.

The Ultra has well over 50% more than that.

The driver certainly isn't the only aspect in subwoofer design though. a half-assed enclosure with our Ultra driver probably wouldn't approach the performance of the Aerial. The SW12 is a very good,if too expensive unit.

TV

This message has been edited by TVodhanel on 08-16-2002 at 10:13 PM

[TVodhanel]

>>>Thanks for the tips on how to measure. I was seriously considering the outside readings, but that was BEFORE I assembled my Tempest Sonosub! this thing is big and heavy and difficult to manage!<<<

I hear you,

It takes us 60-90 minutes just to drag all my equipment outside...dolly all the subs we want to test,and power/calibrate all the gear. Then another 60 minutes when we are ready to put everything away. So we are in for 2-2.5 hours just moving equipment.This summer I'll have logged in about 800-1000 hours just measuring and rebuilding subs over and over.

>>>Anyway, I know my readings will be not really useful for anybody else, still, for me it is an important measure to really qualify my job in trying to get a good sounding sub out of my DIY capabilities.

I didn't know that the THD on Spectralab is not affected if I throw some frequency with not traces of a 60Hz armonic. Now, do I need to overcome the peak with higher volume in order to have the right number?<<<

No, you shouldn't have too. I just got the new 4.32 version of spectra at soundtechnology though.(1/96th octave resolution baby!---$3500~heavy sigh) So I'm not sure if my capabilities are any different than yours though.

Don't forget to do the mic-compensation chart for the RS meter.

>>>In my tests, I read around 110dB at 20Hz at about 10% THD, but I don't want to take that number as final until Im completly sure on how to overcome the 60Hz noise. I will follow your suggestion on doing 1/6 scale testing (avoiding, for now, any 60 multiple).<<<

110/20hz is very powerful...most likely better than anything available commercially for the price of the DIY components

>>On the graph you mention, I will certainly look for it!<<<

http://www.svsubwoofers.com/images/ultraresponsechart.JPG

The port compression actually starts around 28hz...the top trace is a 110dB sweep---2meters,outside. This would be equal to approximately...124-126dB inside,1 meter from the sub I would guess(6dB when we halve the distance and 8-10dB for boundary reinforcement/room gain).

This is also with the first generation Ultra driver,I would expect the new drivers to reach into the 111-113dB range,but the ports would still compress the same.(hell-better than PRs though,

TV

[Dustin B]

Interesting. I would have thought the SW12 driver was more capable than that. I also would have thought it was underhung as well, guess not.

Given that info it would appear a well designed Shiva based sub could come extremely close to the SW12's performance. And a Dayton 12" Titanic based sub could surpass it. Almost $5000 list for something that could be matched by less than $500 with DIY

You sure you've actually heard one theEARs?

Thought you hadn't played much with PRs Tom?

This message has been edited by Dustin B on 08-16-2002 at 10:20 PM

[TheEAR]

Dusty,

"Almost $5000 list for something that could be matched by less than $500 with DIY"

Matched if you only value raw SPL,the Aerial is much more then just raw SPL.Its finesse and build quality your($500) DIY does not touch.

When I purchased my Aerial and my Dynaudio Contour 3.3's I was not going for blind SPL.

I could just purchased Klipsch KLF30's and had much more output.I have much more finesse the brutes cant touch and this is music,not plain noise.

The SW12 driver is very capable,the new SVS Ultra/SS is more potent no doubt.And...and I am sure you wish you had an Aerial Acoustics SW12 or even a Revel B15.

TheEAR(s) Now theears

[Dustin B]

Lets recap then:

theEARs:

quote:

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Aerial SW12(the king of the HILL,no question about it)

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Dustin B:

quote:

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I see you mention the Aeriel SW12 as king of the hill no question. Is this in output as well as sound quality or just sound quality?

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theEARs:

quote:

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Bass quality and quantity.The Aerial has nothing to fear from the SVS Ultra.Solid to 16Hz it delivers where most fall and has very few peers in output down low.

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With the info Tom has provided I'd put a $500 DIY sub (if the alignment came from somebody like Dan Wiggins or ThomasW/JonH) up against an Aerial SW12 any day. If the pre/pro being used wasn't up to snuff I'd have to up that budget a little bit to go with an HS series amp that would give the necessary connectivity to allow it to blend with the mains properly, but it would still be under $750.

And I certainly don't wish I had an SW12. I wish I had a Crown K1 or K2 powering 4 Tumults in an infinite baffel with an LT chip giving it a Q of somewhere between 0.5-0.6 and an F3 of around 14hz. With a nice EQ to tame any room peaks my wished room treatments didn't take care of. Some day

I'd still like that port/leg measurement on the Studio if you don't mind though.

[Manuel Delaflor]

Alternatively, Im sure you wish you had found SVS or DIY before spending all that money on your Aerial.

No no. I almost forgot. Most people buy thinking that expensiveness is related to quality. Besides, we can't forget snobbism, the Aerial surely sports a lot of that. Two good reasons to have it.

[Manuel Delaflor]

quote:

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Originally posted by TVodhanel:

So we are in for 2-2.5 hours just moving equipment.This summer I'll have logged in about 800-1000 hours just measuring and rebuilding subs over and over.

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Lots of work. Still, sounds like fun! I have a scientific background, so I can tell you I know exactly what are you talking about.

quote:

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Originally posted by TVodhanel:

No, you shouldn't have too. I just got the new 4.32 version of spectra at soundtechnology though.(1/96th octave resolution baby!---$3500~heavy sigh) So I'm not sure if my capabilities are any different than yours though.

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Huh, mine have "only" 1/24, but it was cheaper and I still have a lot to learn about all its capabilities. By the way, I have a future proyect regarding sound quality and subjective interpretation, I think this program is a valuable asset.

This message has been edited by Manuel on 08-17-2002 at 12:05 PM

[TVodhanel]

>>>Given that info it would appear a well designed Shiva based sub could come extremely close to the SW12's performance. And a Dayton 12" Titanic based sub could surpass it.<<<

I would bet on neither myself.

>>>Thought you hadn't played much with PRs Tom?<<<

Oh I have several dozen PR designs collecting dust now.All sort of extreme throw PRs, pretty much every design you can think of a few you might not. When you see no PR designs near the top of Nousaine's list(except the stryke box which extended to 30hz I believe?)...that should tell us something.

TV

[TVodhanel]

Two other reasons the Aerial is *cool*,

1)it had extensive input/outputs and remote capabilities along with adjustable *Q*.

2)Aerial seems to take customer support VERY seriously.

Don't underestimate the work involved in that,esp #2.

Manual, I agree...there are ALL SORTS of possibilities for Spectra and subjective listening tests. I have a few of them thought out myself Unfortunately, I doubt I will get around to any of it until 2003 at the soonest. Just too much on the SVS product developement plate right now.

TV

[Jeremy Fallon]

One more reason why the Aerial is cool:

1) It doesn't look like a friggin water heater

just kidding, just kidding, but i like the Aerial finish

[TheEAR]

Manuel Noriega,

"Besides, we can't forget snobbism, the Aerial surely sports a lot of that."

What do you know about Aerial Acoustics?Not much reading your posts.I did not buy my gear to get any "snob" status.

To you if its well built,well designed and musical its...snobish!

Jeremy,

You got that right the Aerial is not just great performance,its built quality and gorgeous finish.The total package.

TheEAR(s) Now theears

[Manuel Delaflor]

CALM DOWN theRears, calm down.

Take it easy.

Be cool.

This message has been edited by Manuel on 08-17-2002 at 07:07 PM

[TVodhanel]

>>>Jeremy,

You got that right the Aerial is not just great performance,its built quality and gorgeous finish.The total package.<<<

I agree, most,if not all HT enthusiasts would take the aesthetics of the SW12 over the Ultra for sure.

TV

[Dustin B]

I wouldn't call Aerial owners snobbish. I'm sure some are though, mind you so are many Bose owners. So money spent on a speaker won't indicate this.

The SW12 is a beautifully finished and well constructed sub. I will however call the Aerial at list price and anywhere close to list price very over priced for what you get.

As for build quality and finish, you mean like this (pictures aren't the greatest though):

All it takes is some research on techniques, time and effort.

This message has been edited by Dustin B on 08-17-2002 at 04:40 PM

[TheEAR]

TVodhanel,

There is no doubt two SVS Ultra(even using the "older" drivers)outperforms the SW12 on HT and musical pieces containing very deep bass.One thing that is quite amusing is peeps who never had the Aerial and find creative ways to bash a great subwoofer.

I am saving for my own Ultras and maybe add two CS-Plus(you know just for change and kicks ).

Dustin B.,

Nice Aerial copycat,I would like to see this sub side by side with the Aerial,the Aerial in bird eye maple has no competition.

"All it takes is some research on techniques, time and effort."

And you forgot to say...inspiration,in this case the Aerial is copied quite well.

TheEAR(s) Now theears

[Dustin B]

ThomasW set out to copy the Aerial's basic layout. But that sub is 2 layers of 3/4 MDF on all sides, the baffel is 3 layers and all the braces are 3/4" MDF. It's about twice the size of a SW12. The driver is the Stryke HE15 (I think he has a BluePrint 1503 in it now though) and the port is 6" PVC pipe with 6" port flares from NewFoam. It weighs well in excess of 300lbs.

That's the great thing about DIY. Whatever veneer and stain/finish you want can be used. How good it can look, as I said before, depends entirely on how much time you spend on it. I've seen pictures of a few enclosures done by Eric M Jones, Brian Bunge and Hank Frankenburg that would do just fine sitting beside a SW12 for finish quality.

And as I said, I'm not denying the Aerial is a great sub. It just ain't the king of the hill as you proclaimed and is over priced. And I don't think my so called bashing is all that creative, it's pretty obvious stuff I've pointed out.

This message has been edited by Dustin B on 08-17-2002 at 06:09 PM

[jonesey]

Here is the true picture of the Aerial. Just beautiful.

http://www.aerialacoustics.com/graphics/images/largepic/sw12/sw12pic8.htm

Sometimes there is more to think about than performance. A Ferrari 360 Modena and a Corvette Z06 will both perform exceptionally well. The Corvette is better value when talking about performance. But the Ferrari looks amazing inside and out, it might be subjectively better than the Corvette, it is very exclusive compared to the Corvette, it has a very high level of prestige compared to the Corvette, and it has a very high resale value compared to the Corvette.

This message has been edited by jonesey on 08-17-2002 at 06:27 PM