Last call for advice - articulate music dual subs

[Steve81]

It doesn't matter if the sub is 10", 12", 15", or 18". What matters is the quality of the sub and power compression and dynamic output of the sub. 18" can be just as "musical" as 10" subs and vice versa. Some 18" subs are not as musical, and some 10" subs are not as musical.

You're just biased since you own unmusical 18" subs

 

[pbc]

Data-Bass

#6

... and probably 3, 4 and 7 are relevant here as well.

I've always been curious about the addition of the GR line of drivers (F12 vs F12G) on the Rythmik site and how big of a difference there is between say the F12, F12G and F12SE (not sure if the only diff is gloss black between SE and non-SE). Makes it somewhat confusing as a customer to choose given the price isn't very different...all is says is "the difference is the paper based GR driver" and clicking on the link, then the store, then clicking on the driver I assume is used you get ..

The SW-12-04 gives new meaning to the terms fast bass. Fast bass has been a debatable term but really refers to a drivers ability to return back to a resting position. Any other sub must rely on the suspension alone to allow it to return back to a resting position. Any sub capable of playing down to the 20Hz range will also need a very heavy cone and a really low Fs. The heavy cone and its stored energy from the inertia of its movement make it difficult to quickly return to the resting position. The Direct Servo controlled sub can make use of a much lighter weight cone as the servo system will virtualize the parameters and add output as needed to maintain a flat response to below 20Hz even with a light weight cone that has a higher Fs. Not only does the light weight moving mass minimize the inertia but the Direct Servo control system effectively slams on the brakes electrically to much more quickly bring the woofer back to its resting position.

Does this imply the SW-12-04 is "faster" than the regular 12 offered in the F12? Or is the implication that the "paper" cone makes the difference. Or simply the fact that the T/S are different resulting in a different system Q?

The FR graphs appear to be scaled a tad differently on the product pages, but they are both 14-100 when using the Line-in.

Anyhow, was just curious if anyone had direct experience with both systems F12 and F12G in the same room and experienced this.

 

[AcuDefTechGuy]

You're just biased since you own unmusical 18" subs

Damn you!

Why must you make me feel bad about my unmusical 18" subwoofers?

Ignorance is bliss.

My dual RBH SX-1010N subs (each sub has dual 10" aluminum drivers) are very musical.

When I bought my 802D2, the dealership people said 18" subs are just not very musical at all- too big and slow. They said my Blue Jeans cables are not as musical as Kimber either.

Oh, yeah, passive bi-amping and bi-wiring also increases the speed and musicality of the drivers. Also, some amps are slow and some amps are really, really fast.

 

[Tomorrow]

Data-Bass

#6

Thanks for this link, Steve. Please note that I said I may be wrong.

But also note that the D-B site has a big caveat regarding the subs' relative performance. He assumes a larger cone on a smaller motor. I assume he means a larger cone 'relative' to a smaller motor. While he says that it's because manufacturers tend to do this, it likely is not universal. I'd like to believe him, but I'd need to see some data.

I don't think it unreasonable to expect that from a technical aspect, the F15 would deliver output with less distortion and compression than the smaller and less efficient F12. However, given that you're planning on running a pair of subwoofers in a medium sized room at more moderate levels, I'd expect either would do the job quite well.

Could you elaborate a bit on this? I assumed that the 12 paper cone with relevent motor would be more efficient that the metal coned F15. Here is something from the Rythmik website. (Sorry, the plot referred to below won't copy and paste, but here is the link...Rythmik Audio • Servo subwoofer products) Both the F15 and F12G use 370w A/B servo amps, but the 12G has a lighter cone.

Reducing cone mass by itself will move the mass-controlled region up (which essentially improves the efficiency in this region), while increasing cone mass will do the opposite. The above plot shows the comparison of lighter and heavier cone mass as compared with the original curve. We can see the corner frequency will move higher (lower) with reduced (increased) cone mass. While a lighter cone will move up the corner frequency of bass roll-off, sometimes it actually gives a more musical and dynamic sound (not because the lighter cone is "faster", but because lighter cone has lower distortion in the mass-controlled region).

Looking for education here.

 

[Steve81]

Thanks for this link, Steve. Please note that I said I may be wrong.

Not to worry. Someone like Josh Ricci could come right along and smack me down any second as ill informed. Just part of the process.

But also note that the D-B site has a big caveat regarding the subs' relative performance. He assumes a larger cone on a smaller motor. I assume he means a larger cone 'relative' to a smaller motor. While he says that it's because manufacturers tend to do this, it likely is not universal. I'd like to believe him, but I'd need to see some data.

He assumed a larger cone with a smaller motor as a worst case example. After all, if you were comparing a small cone with a regular motor to a large cone with a commensurately more powerful motor, your argument wouldn't hold water to begin with. However, if you'd like data, here's a waterfall and spectrogram of a subwoofer with an 18" driver.

http://www.data-bass.com/images/measurements/89/A vs18.1 sub1 waterfall.jpg

http://www.data-bass.com/images/measurements/89/C vs18.1 sub1 spectrogram.jpg

Here's one with a 12" driver

http://www.data-bass.com/images/measurements/59/B lfm1ex 2 port mode waterfall.jpg

http://www.data-bass.com/images/measurements/59/D lfm1ex 2 port mode spectrogram.jpg

Could you elaborate a bit on this? I assumed that the 12 paper cone with relevent motor would be more efficient that the metal coned F15.

From Rythmik's website:

Rythmik Audio 15" servo driver• DS1500 Direct Servo driver

Compared to our 12" drivers, these achieve 2 db greater efficiency and 4 db greater transient output. For bass frequencies, a 6 db increase in output sounds twice as loud.

 

[Tomorrow]

From Rythmik's website:

Rythmik Audio 15" servo driver• DS1500 Direct Servo driver

Thanks for the links, Steve. I'll peruse them later, when I have more time. It looks like some good information.

But the link included here...I think they're talking about their aluminum 15" driver (F15) vs. the aluminum 12" driver (F12) and not the OP's question about the F12G that sports a paper cone.

It seems like the lighter paper cone with identical drive components should be more efficient than the F15....but I dunno......

 

[Steve81]

It seems like the lighter paper cone with identical drive components should be more efficient than the F15....but I dunno......

I wouldn't bet money on it; a 2dB increase in sensitivity isn't piddly (even though it sounds like it). Putting it into perspective, if one of their 12" drivers needs 160 watts to reach a given SPL, their 15" driver will only need 100 watts.

The only difference Rythmik notes on the F12G page is

What is the difference between F12 and F12G?

The main difference is the paper-based GR research driver.

That's it... Not exactly a lot of fanfare for something that is offering a significant increase in sensitivity (and thus should lead to increased output capability since the F12, F12G, and F15 all use the same amplifier).

 

[KEW]

Thanks for the great discussion, I have been researching the Rythmik subs for awhile but my path had not covered a good bit of the info you two are discussing.

The only difference Rythmik notes on the F12G page is

What is the difference between F12 and F12G?

The main difference is the paper-based GR research driver.

That's it... Not exactly a lot of fanfare for something that is offering a significant increase in sensitivity (and thus should lead to increased output capability since the F12, F12G, and F15 all use the same amplifier).

This is the net sum of everything I have found on the two drivers:
The Rythmik site offers:

The main performance difference is in the drivers. F12G uses a paper driver designed by GR Research. The paper driver is lighter than our standard aluminum drivers and has a more extended response. It can handle a higher crossover point, however, this is only significant when crossing above 80 Hz If a higher crossover point is desired, F12G is the subwoofer of choice. Please note: when crossing this high, localization can become an issue and dual subwoofers are recommended. Regarding the lower mass, this results in slightly better dynamics at low to moderate output levels. The downside with the paper cone is that it is not as stiff as our aluminum drivers.

GR Research also has the following comments in their ad copy for the paper cone driver:

The SW-12-04 gives new meaning to the terms fast bass. Fast bass has been a debatable term but really refers to a drivers ability to return back to a resting position. Any other sub must rely on the suspension alone to allow it to return back to a resting position. Any sub capable of playing down to the 20Hz range will also need a very heavy cone and a really low Fs. The heavy cone and its stored energy from the inertia of its movement make it difficult to quickly return to the resting position. The Direct Servo controlled sub can make use of a much lighter weight cone as the servo system will virtualize the parameters and add output as needed to maintain a flat response to below 20Hz even with a light weight cone that has a higher Fs. Not only does the light weight moving mass minimize the inertia but the Direct Servo control system effectively slams on the brakes electrically to much more quickly bring the woofer back to its resting position.

Here are the specs on the F12 Driver:

Model DS1200
Enclosure size 2 cu ft sealed
3-4 cu ft vented
fs 26 Hz
BL 11.24
VAS 88 L
Qms 7.42
Qts 0.472
Sd 530 cm2
Re 2.80 ohms
Le 1.0 mH
Cone finish Anodized aluminum
Rythmik Audio servo subwoofer 12" F12

Here are specs on the F12G driver (note that enclosure size is not the same):

Enclosure size 1.5 cu ft sealed
fs 21 Hz
BL 13.7
VAS 137 L
Qms 4.308
Qts 0.279
Sd 490 cm2
Re 3 ohms
Xmax 16 mm

Here are additional specs from GR Research for the F12G driver:

SW-12-04 parameters:

Mechanical Parameters:

Fs = 21.3 hertz
Qms = 4.308
Vas = 4.849 cu.ft or 137.3 liters
Cms = 0.071 in/Ib
Mms = 4.903 oz or 139 grams
Rms = 9.495 Ibs/sec
Xmax = 18 mm
Sd = 76 sq.in or Dia = 9.83 in or 250 mm

Electrical Parameters:

Qes = 0.298
Re = 3 ohms
Z = 4.0 ohms
BL = 13.7
Pe = 200.0 watts (conservitive rating)

Combination Parameters:

Qts = 0.279
Sens = 88.4 dB (2.83 V)

If anyone sees anything in these specs worthy of highlighting, please do so.
I'm clueless!

 

[Tomorrow]

Well, I still admit to being a little confused...but at my age, that's called being in good shape.

I wrote Rythmik and asked the question about efficiency. Steve seems to be correct in his assessment. Here is Rythmik's answer.

"We recommend the F12G for most Music than HT. The F15 perform very well in both scenarios. The F15 is +2dB louder than the F12G."

Hahahaaaa...what's it to be, Kew? You more cornfused then ever, too? I still think you ought to give the Aperions a listen...then try a brace of 12" Rythmiks if you don't like the Bravus gear.

 

[jcl]

I'm surprised the SVS SB12-NSD hasn't gotten more consideration. I would think at $1150 pr shipped it meets the OPs criteria and cost is well below the others.

Is there a reason why they are being passed over for the others?

 

[Steve81]

I'm surprised the SVS SB12-NSD hasn't gotten more consideration. I would think at $1150 pr shipped it meets the OPs criteria and cost is well below the others.

Is there a reason why they are being passed over for the others?

FWIW, in this case, I think being a well known quantity is as much a blessing as a curse. The SB12 can certainly deliver sufficient output with reasonably low distortion. On the other hand, it's performance in the time domain (most notably that its group delay is already hitting 1.5 cycles by 40Hz) might give it a black mark for those looking for the "ultimate" music subwoofer.

 

[KEW]

I'm surprised the SVS SB12-NSD hasn't gotten more consideration. I would think at $1150 pr shipped it meets the OPs criteria and cost is well below the others.

Is there a reason why they are being passed over for the others?

I think the Legato dual sub system from SVS is probably their best competition in this arena. B stock runs right at $2000. It is the only sub system I know of that is only sold as a pair (though I am sure there are others).

 

[Tomorrow]

I think the Legato dual sub system from SVS is probably their best competition in this arena. B stock runs right at $2000. It is the only sub system I know of that is only sold as a pair (though I am sure there are others).

Another (99 bucks over your target cost, though).....ULS-15 DualDrive Packages

I really like the wireless feature of these dudes. Makes placement issues so much easier for those of us with WAF issues.

 

[KEW]

Well, I still admit to being a little confused...but at my age, that's called being in good shape.

I wrote Rythmik and asked the question about efficiency. Steve seems to be correct in his assessment. Here is Rythmik's answer.

"We recommend the F12G for most Music than HT. The F15 perform very well in both scenarios. The F15 is +2dB louder than the F12G."

Hahahaaaa...what's it to be, Kew? You more cornfused then ever, too? I still think you ought to give the Aperions a listen...then try a brace of 12" Rythmiks if you don't like the Bravus gear.

I think I'd have to stick with the F12G's over the F15's. It seems they will do the job fine and the more compact size and lighter weight makes for more and easier sub placement options (not to mention the cost savings).

It doesn't show until they are in the cart, but you get 10% off when you buy a pair of Rythmiks plus $114 shipping putting the F12G's at $1688 vs Bravus 12D (x2) at $1800.
For me the concept of buying a pair of Bravus, then deciding if they are good enough doesn't work. I would define "good enough" as "better than the Rythmiks"
Unless I can A/B them side by side, I would never know if the Rythmiks would have been a better option. The shipping costs for most sub brands tends to kill off casual in-home comparisons.

I think it would be a better gamble to buy the Rythmiks, then trial order a Bravus.

 

[Archaea]

My vote is for a pair of Epik Empire subs. They do very well in all the shootouts for music and come in under budget.

Welcome to Epik Subwoofers

 

[KEW]

Another (99 bucks over your target cost, though).....ULS-15 DualDrive Packages

I really like the wireless feature of these dudes. Makes placement issues so much easier for those of us with WAF issues.

If I ever thought these would do double duty in HT, I'd be all over this!

 

[FirstReflection]

Ha! I didn't know the Legato were still on the table

KEW and I traded a few PM's on this subject, and I thought he had shied away from the SVS Legato system! But if they're back on the table, that makes for a VERY interesting possibility!

Here's the thing, you don't need the sheer output capabilities of dual Plus subs, nor the sheer deep bass extension. But the Legato package offers one particularly neat feature, which is the ability to set both the high pass filter out to the speakers and the low pass filter to the subwoofer!

Feed the outboard Legato amp a full range stereo signal. The STA-800H can then apply a perfect 4th order low pass filter at, say, 80Hz to feed the dual Plus subs, and then also apply a perfect 4th order high pass filter to the stereo outputs that feed the speakers!

This is particularly attractive in the case of the Solo6 Be. Being self-powered, the Solo6 Be can easily accept the high pass filtered signal coming out of the STA-800H amp. But more than that, the Solo6 Be have a bass response where they're basically flat down to about 50Hz, they sort of heffalump their way down to 40Hz due to the port tuning, then they basically fall off a cliff! That makes them rather difficult to properly bass manage. If you try to cross them over where they naturally start to roll off at about 50Hz, you run into the boosted port output at 40Hz and end up with a hump in your frequency response. If you drop the crossover way down to 40Hz, you lose the dynamic advantages of allowing a subwoofer to handle that region of the bass, and you wind up with an almost brick wall filter below 40Hz once the steep roll off of the Solo6 Be cascades with the 2nd order slope applied by any receiver or pre-pro. And if you cross them over up at 80Hz with just the receiver or pre-pro's bass management, you'll only have a 2nd order slope since the Solo6 Be are pretty darn flat to well below 80Hz!

So using the outboard STA-800H amp provided in the Legato package isn't just about the dual Plus cylinder subs. They're fantastic. But it's also about the crossover!

The regular PB12 or PC12-Plus subs don't have the high pass filtered output going to the speakers. Only the Ultra series subs include the high pass output aside from the STA-800H outboard amp in SVSound's lineup. So even though dual PC12-Plus subs offer double the amplifier power and don't cost a heck of a lot more than the Legato package, in a case like this, the Legato still offer a unique value

 

[djreef]

Ha! I didn't know the Legato were still on the table

KEW and I traded a few PM's on this subject, and I thought he had shied away from the SVS Legato system! But if they're back on the table, that makes for a VERY interesting possibility!

Here's the thing, you don't need the sheer output capabilities of dual Plus subs, nor the sheer deep bass extension. But the Legato package offers one particularly neat feature, which is the ability to set both the high pass filter out to the speakers and the low pass filter to the subwoofer!

Feed the outboard Legato amp a full range stereo signal. The STA-800H can then apply a perfect 4th order low pass filter at, say, 80Hz to feed the dual Plus subs, and then also apply a perfect 4th order high pass filter to the stereo outputs that feed the speakers!

This is particularly attractive in the case of the Solo6 Be. Being self-powered, the Solo6 Be can easily accept the high pass filtered signal coming out of the STA-800H amp. But more than that, the Solo6 Be have a bass response where they're basically flat down to about 50Hz, they sort of heffalump their way down to 40Hz due to the port tuning, then they basically fall off a cliff! That makes them rather difficult to properly bass manage. If you try to cross them over where they naturally start to roll off at about 50Hz, you run into the boosted port output at 40Hz and end up with a hump in your frequency response. If you drop the crossover way down to 40Hz, you lose the dynamic advantages of allowing a subwoofer to handle that region of the bass, and you wind up with an almost brick wall filter below 40Hz once the steep roll off of the Solo6 Be cascades with the 2nd order slope applied by any receiver or pre-pro. And if you cross them over up at 80Hz with just the receiver or pre-pro's bass management, you'll only have a 2nd order slope since the Solo6 Be are pretty darn flat to well below 80Hz!

So using the outboard STA-800H amp provided in the Legato package isn't just about the dual Plus cylinder subs. They're fantastic. But it's also about the crossover!

The regular PB12 or PC12-Plus subs don't have the high pass filtered output going to the speakers. Only the Ultra series subs include the high pass output aside from the STA-800H outboard amp in SVSound's lineup. So even though dual PC12-Plus subs offer double the amplifier power and don't cost a heck of a lot more than the Legato package, in a case like this, the Legato still offer a unique value

This is how I have my 2-channel rig set up. The SB-12pluses have an internal crossover built into the amp that allows me to pass off the HF to the powered Airmotives through their balanced outputs. I can't say I have any regrets wiring things up this way.

DJ

 

[shadyJ]

KEW if you only have one listening position, I think you would be better served with a single high end sub since your priority is articulation. If it were me, I would give Funk Audio a call and see how their 15" subs are going, they might fall in your price range. After all, if acudeftechguy is selling his Rythmiks in favor of his Funks, that must mean something. If you want to avoid single sub localization, just cross it over low, providing your mains are capable down to 60 or 70 hz. Barring that, I would go for Hsu ULS or Rythmik subs, or, if you can make the stretch, a Seaton submersive. You might also look into JTR's sealed captivator, it supposedly sounds very good. The thing is, you may not think you will need some real dynamics right now, but I think there will come a time in your music listening when you wish you had it. Think about throwing in an album and in there is a track that when it hits and grabs you, you just have to crank it. Also, if you just get one high end sub now and still pine for duals, save up and get another and you will have a bass system that is truly enviable. But, if you are certain you will never need the big dynamics, I think the Rythmik F12s are the ones with your name on them. The advantage of that is if you ever want more output than what your Rythmik subs can give, just buy two more F12s and stack them.

 

[GranteedEV]

If the XBL^2 HSU ULS-15 is anything like my XBL^2 maelstrom, that's what i'd do.