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Stereo Integrity's new HT Subwoofer - Page 17

post #481 of 2212
Quote:
Originally Posted by zheka View Post

to summarize.
The real world power limitations for the SI drivers in HT context are dictated by excursion. The power to get the driver to bottom out depends on size and type of the enclosure.
In most cases, 1000 W is a safe match. Smaller sealed enclosures can use even more power.
However the thermal limits can be reached with as low as 600 W long term output signal.
fair enough?

That probably is the gist of it. I am not so certain on long-term power limits, but the coil is only 3".

WinIsd's default .702 qtc box is 3.85 cu.ft.. With 1100 watts, SI's xmax rating of 23.5 mm is met at 10 Hz.. I suppose some like to design to xmech, but I don't think that leaves enough clean stroke as most any driver is starting to get pretty noisy by that point. It's interesting to note that SI lists xmech as 43 mm; whereas Josh put it "closer to 30 or 35mm inward." That's 20-30% less available travel than the manufacturer's spec before the ugly noises occur. I wouldn't want to put any more than 1100 watts into it (even with the small sealed enclosure); I realize we don't listen to sine waves at reference when watching a movie, but it's probably best to leave a little margin for error.

Gear mentioned in this thread:

post #482 of 2212
this is what they list now. perhaps it is still too optimistic.

23.5mm Xmax (one-way linear)
36.2mm Xmech (one-way)

http://stereointegrity.com/index.php?id=60
post #483 of 2212
Looks about right to me.
post #484 of 2212
The revised/current Xmax and Xmech figures are from Klippel results. smile.gif
post #485 of 2212
Quote:
Originally Posted by Electrodynamic View Post

The revised/current Xmax and Xmech figures are from Klippel results. smile.gif

And that's good enough for me. smile.gif

I too have never understood the need to overpower the drivers. Unless space is at a premium, I'd rather run more drivers, with less power, than vice versa. You gain similar output with much less excursion, which results in cleaner sound.
post #486 of 2212
Quote:
Originally Posted by zheka View Post

this is what they list now. perhaps it is still too optimistic.
23.5mm Xmax (one-way linear)
36.2mm Xmech (one-way)
http://stereointegrity.com/index.php?id=60

The 43 mm xmech I referred to was the preliminary manufacturer's number from Data-Bass...I did take a quick peek at the SI site to see if it was still current before posting, but didn't see the family parameters for the HT line off to the right.
Quote:
Originally Posted by Electrodynamic View Post

The revised/current Xmax and Xmech figures are from Klippel results. smile.gif

Well, that's a pricy little machine! Do you guys own your own or send stuff out (if so, to Erin)?
post #487 of 2212
Quote:
Originally Posted by Aaron Smith View Post

Well, that's a pricy little machine! Do you guys own your own or send stuff out (if so, to Erin)?

Who is Erin? Our results come from directly from Patrick at Red Rock Acoustics.
post #488 of 2212
Are we still at 6 cu ft for 18" sealed after the revised data?
post #489 of 2212
Quote:
Originally Posted by d_c View Post

Are we still at 6 cu ft for 18" sealed after the revised data?

Man, this is confusing...I just ordered 4x of SI18's and am still lost on what size of cabs I should build.
In my case, I will power all of them connected to a bridged EP4000 at a 4 ohm load. So roughly 500watts per driver.
I'm thinking a 4.5 cuft cab. Does this sound right?

Thanks
post #490 of 2212
Quote:
Originally Posted by Electrodynamic View Post

Who is Erin? Our results come from directly from Patrick at Red Rock Acoustics.

Red Rock was my 2nd guess. Erin Hardison lives just outside of Huntsville, AL and owns the Klippel that DIYMA used to have. I know he wants to get a testing operation going, and figured since he was relatively close to you there might be a synergy there.
post #491 of 2212
Quote:
Originally Posted by Fatshaft View Post

Man, this is confusing...I just ordered 4x of SI18's and am still lost on what size of cabs I should build.
In my case, I will power all of them connected to a bridged EP4000 at a 4 ohm load. So roughly 500watts per driver.
I'm thinking a 4.5 cuft cab. Does this sound right?
Thanks

Here you go. If you're only applying 500 watts, 4.5 cubes is a great size. You could go up to 6 cubes with that power and still be cool with excursion, but the gains are minimal. 4.5 cubes vs 6 with 500 watts applied in a sealed enclosure for one driver:

If you've got the space and want those extra 1-2DB 20hz and below you can go to 6 cubes per driver and get the most out of them. cool.gif

post #492 of 2212
Quote:
Originally Posted by Gorilla83 View Post

Here you go. If you're only applying 500 watts, 4.5 cubes is a great size. You could go up to 6 cubes with that power and still be cool with excursion, but the gains are minimal. 4.5 cubes vs 6 with 500 watts applied in a sealed enclosure for one driver:
If you've got the space and want those extra 1-2DB 20hz and below you can go to 6 cubes per driver and get the most out of them. cool.gif

Gorilla83,

Man, thanks so much for posting that! I really appreciate that you took the time to answer me.
Thank you.

Regards,
post #493 of 2212
Quote:
Originally Posted by Fatshaft View Post

Gorilla83,
Man, thanks so much for posting that! I really appreciate that you took the time to answer me.
Thank you.
Regards,

You're welcome buddy. We've all been there at some point, stressing over box sizes when in reality at this point a cube or so doesn't make a significant difference as you can see. Now you can take this info to boxnotes and plan out your box dimensions. Have fun!!
post #494 of 2212
Right. 600 w is the recommended power from SI. This driver will crash hard if you give it too much power in the deep bass in a large enclosure. That is a suggested limit based on mechanical excursion related issues when used in a large enclosure. SI has to cover their ass for the inevitable guy that clanks one too hard running it off a 2400w amp in a big box. The coil has some sort of thermal limit too but that stuff is based so much on the material, duration and enclosure alignment that it is hard to quantify with a rating. I could probably purposely cook most drivers with a 500w amp if I wanted too but unless you are going to run the sub flat out with compressed dub or techno for 4 hrs straight thermal handling in a home setting really shouldn't be a problem.
post #495 of 2212
So I should be right on target with an 18 at 6 cubes with the iNuke1000DSP bridged for 1000 at 4 ohms, dialing down slightly on gain to find voltage limit?
post #496 of 2212
Got it. Thank you
post #497 of 2212
I would go with a slightly smaller 4.5 cube enclosure with that much power. The larger the enclosure the more efficient the deep bass and the less power it takes to reach mechanical limits. With less power use the bigger box, with more power go smaller.
post #498 of 2212
Quote:
Originally Posted by d_c View Post

So I should be right on target with an 18 at 6 cubes with the iNuke1000DSP bridged for 1000 at 4 ohms, dialing down slightly on gain to find voltage limit?

You do need to be very careful with your gain -- xmax is reached at 21.5 Hz with that setup.
post #499 of 2212
1000 w @ 4 ohm bridged is peak power for NU1000. RMS is listed at 750 W
post #500 of 2212
Thanks for the info guys. I should throttle the iNuke's gain to 60% to see the efficiency of 6 cubes then. Max spl is not my concern for this project, just some deep, delicious bass
post #501 of 2212
True...was going to bring up that it probably couldn't do 1000 watts into 4 ohms at 20 Hz anyway, but when I went looking for the hard data on their site and couldn't find it, I figured Behringer just didn't want people to know the truth. biggrin.gif Missed that silly drop-down box...it should be displayed better, but I can see why they don't want it easily visible. wink.gif 750 watts drops the modeled xmax excursion down to 15 Hz.
post #502 of 2212
Quote:
Originally Posted by Aaron Smith View Post

True. Zheka mentioned he wanted to put an LT on the SI's though...I don't have much experience modeling LT's, but the excursion seems to go through the roof when doing one on these drivers. Although that is probably largely mitigated as it somehow didn't register to me that he plans to run the 2 drivers off of one channel of the NU3000DSP, so they would only see 500 watts or so apiece instead of the 1000 I was figuring. The Behringer stuff may not do so well with low impedance loads at low frequencies, but that may be another story... wink.gif
Also missed that you were keeping the CHT and also didn't realize you had the Epiks...you have the modal thing covered quite well. Has anybody seen my coffee? Perhaps I should keep my 'help' to myself in the future. redface.gif I bet in the real world the extra excursion from the LT would probably be a non-issue even at 1000 watts per driver with the headroom provided by all of those drivers.
But hey, I think I got the D2 config right!

Quote:
Originally Posted by zheka View Post

i do not know what the proper approach is. I am still learning. Should I model on based on the amp peak ratings or RMS?

Quote:
Originally Posted by zheka View Post

Yeah, once I get second Inuke I will hit the 1kW per driver sweet spot. Perfect.

Quote:
Originally Posted by zheka View Post

to summarize.
The real world power limitations for the SI drivers in HT context are dictated by excursion. The power to get the driver to bottom out depends on size and type of the enclosure.
In most cases, 1000 W is a safe match. Smaller sealed enclosures can use even more power.
However the thermal limits can be reached with as low as 600 W long term output signal.
fair enough?

Quote:
Originally Posted by Ricci View Post

Right. 600 w is the recommended power from SI. This driver will crash hard if you give it too much power in the deep bass in a large enclosure. That is a suggested limit based on mechanical excursion related issues when used in a large enclosure. SI has to cover their ass for the inevitable guy that clanks one too hard running it off a 2400w amp in a big box. The coil has some sort of thermal limit too but that stuff is based so much on the material, duration and enclosure alignment that it is hard to quantify with a rating. I could probably purposely cook most drivers with a 500w amp if I wanted too but unless you are going to run the sub flat out with compressed dub or techno for 4 hrs straight thermal handling in a home setting really shouldn't be a problem.

This is exactly why I've advocated controlling excursion with the air spring. You maintain a 2nd order roll off, protect the driver, have less in enclosure costs and construction, more placement options and can safely apply enough power to use both ends of the driver, all for the price of some additional 2HD down low.

With that out of the way (because it's a no brainer), I have to say I think there's a lot of confusion in the CEA 2010 results, IMHO, because Josh inputs 11,000W at 80 Hz and 800W at 20 Hz to get those results. Obviously, if you're using 1KW per driver, you aren't going to see anywhere near the results in your system that you see in the max burst output results from DB.

The CEA 2010 methodology is for a system only, not to see what the max output of a driver is at each of the frequency centers of the 1/3 octave tone bursts with unlimited amplification. IOW, why doesn't Josh make the PB-13 Ultra sub passive and connect his K-10 to the driver for the CEA 2010 tests? Because the results would be irrelevant to anyone buying the sub.

It's my opinion that the same holds especially true for a DIY system.

If 1KW is the reasonable limit for amplification, 1KW should be used to get the max burst results. Posting +10dB higher results is irrelevant data and misleading, especially in the case of a sealed L/T system, where the opposite of that methodology is the reality. Since there is no such thing as a frequency specific, variable output voltage amplifier and, with an L/T you use less power up top and maximum power at the low end, not the other way around, there's no way you'll see 125dB at 80 Hz and 106dB at 20 Hz in the finished system.

1KW with an L/T of 6dB boost means you can only run the driver at 250W, keeping the rest of the reserve power for the <30 Hz transients. If you're going to design your sealed, L/T system based on WinISD, use +6dB of L/T boost and input 250W. Adjust enclosure size to that metric (because it is a fixed piece of the puzzle) regarding excursion and stop your model graph at 10 Hz because everything below that in the model is incorrect information.

The idea offered by many folks that somehow the 1KW is available for the top end as 'headroom' is errant, like saying black is white. The only way you can use the extra power above the L/T is to change the frequency response of the system. There are 2 ways to do that; 1) aggressive limiting, which changes the FR infinitely on-the-fly or 2) HPFs, which change the FR predictably for the desired output level up top.

Once you've gotten past that, take your model result numbers and do the math for desired output by multiplying the system times 'X' multiples.

A 4 X SI 18 sealed, L/T system with 4KW is a perfectly reasonable system that should give excellent results. 4 drivers ups the sensitivity to 95dB making the 1KW above 30 Hz formidable (within 3dB of Josh's single driver results) and the 4KW for <30 Hz gives a safe delivery of the 20+ available liters of displacement.

If you want to utilize the +6dB above 30 Hz, apply a HPF at around 20 Hz and there ya go, giving up some flat in-room extension for higher playback level.
post #503 of 2212
Thanks Boss - you glued together all the random info flying around in my head.
post #504 of 2212
I appreciate yor advice , BB.
Can you explain how the power is "reserved" for certain frequencies? I understand that input power in WinISD must be lowered to offset the power requirements of LT. But if the LF signal does not contain any material within LT frequency range, why would not all power be available for its reproduction?

Thank you

Quote:
Originally Posted by bossobass View Post

This is exactly why I've advocated controlling excursion with the air spring. You maintain a 2nd order roll off, protect the driver, have less in enclosure costs and construction, more placement options and can safely apply enough power to use both ends of the driver, all for the price of some additional 2HD down low.
With that out of the way (because it's a no brainer), I have to say I think there's a lot of confusion in the CEA 2010 results, IMHO, because Josh inputs 11,000W at 80 Hz and 800W at 20 Hz to get those results. Obviously, if you're using 1KW per driver, you aren't going to see anywhere near the results in your system that you see in the max burst output results from DB.
The CEA 2010 methodology is for a system only, not to see what the max output of a driver is at each of the frequency centers of the 1/3 octave tone bursts with unlimited amplification. IOW, why doesn't Josh make the PB-13 Ultra sub passive and connect his K-10 to the driver for the CEA 2010 tests? Because the results would be irrelevant to anyone buying the sub.
It's my opinion that the same holds especially true for a DIY system.
If 1KW is the reasonable limit for amplification, 1KW should be used to get the max burst results. Posting +10dB higher results is irrelevant data and misleading, especially in the case of a sealed L/T system, where the opposite of that methodology is the reality. Since there is no such thing as a frequency specific, variable output voltage amplifier and, with an L/T you use less power up top and maximum power at the low end, not the other way around, there's no way you'll see 125dB at 80 Hz and 106dB at 20 Hz in the finished system.
1KW with an L/T of 6dB boost means you can only run the driver at 250W, keeping the rest of the reserve power for the <30 Hz transients. If you're going to design your sealed, L/T system based on WinISD, use +6dB of L/T boost and input 250W. Adjust enclosure size to that metric (because it is a fixed piece of the puzzle) regarding excursion and stop your model graph at 10 Hz because everything below that in the model is incorrect information.
The idea offered by many folks that somehow the 1KW is available for the top end as 'headroom' is errant, like saying black is white. The only way you can use the extra power above the L/T is to change the frequency response of the system. There are 2 ways to do that; 1) aggressive limiting, which changes the FR infinitely on-the-fly or 2) HPFs, which change the FR predictably for the desired output level up top.
Once you've gotten past that, take your model result numbers and do the math for desired output by multiplying the system times 'X' multiples.
A 4 X SI 18 sealed, L/T system with 4KW is a perfectly reasonable system that should give excellent results. 4 drivers ups the sensitivity to 95dB making the 1KW above 30 Hz formidable (within 3dB of Josh's single driver results) and the 4KW for <30 Hz gives a safe delivery of the 20+ available liters of displacement.
If you want to utilize the +6dB above 30 Hz, apply a HPF at around 20 Hz and there ya go, giving up some flat in-room extension for higher playback level.
post #505 of 2212
For every 3db increase you need to double your power or add an additional driver.
The models show about 9db difference between 10 and 20hz so you can L/T it out and then lower the overall gain of the system.



oh and behringer ep2500 is flat to 5hz, not sure about the inuke gear but someone here measured the ep2500 with a load (not chucky) and found it was flat to 5hz.



regarding the reserved power, the old iron like the ep2500 do not track the signal. It delivers power at the maximum level at the peak as it does at the low level over a couple of peaks and valleys. Smart tracking amps like the LG clones (when they aren't poping) are able to deliver the correct ammount of power at the leves that are required. Bosso has a graph of it somehwere.
post #506 of 2212
Quote:
Originally Posted by Aaron Smith View Post

Red Rock was my 2nd guess. Erin Hardison lives just outside of Huntsville, AL and owns the Klippel that DIYMA used to have. I know he wants to get a testing operation going, and figured since he was relatively close to you there might be a synergy there.

Just to clarify, I actually have my own Klippel from Klippel directly. I don't know what happened to the one that DIYMA had. I sent it back and a couple months later struck a deal with Klippel to get my own along with supporting modules.


Any testing I do can be found on my site @ http://medleysmusings.com. I don't do it as a business means; I'm just a hobbyist. I take donations to help me purchase new drivers to test and equipment needs (ie: I need a higher SPL capable mic for subwoofer testing I want to start doing). For people wanting design analysis from the best there is in the industry, Pat @ Red Rock is the man to see.

That said, if SI ever wanted to send me something to test and post on the site/forums, I'd be happy to do so.

- Erin
Edited by bikinpunk - 12/31/12 at 9:45am
post #507 of 2212
Quote:
Originally Posted by bikinpunk View Post

Just to clarify, I actually have my own Klippel from Klippel directly. I don't know what happened to the one that DIYMA had. I sent it back and a couple months later struck a deal with Klippel to get my own along with supporting modules.
Any testing I do can be found on my site @ http://medleysmusings.com. I don't do it as a business means; I'm just a hobbyist. I take donations to help me purchase new drivers to test and equipment needs (ie: I need a higher SPL capable mic for subwoofer testing I want to start doing). For people wanting design analysis from the best there is in the industry, Pat @ Red Rock is the man to see.
That said, if SI ever wanted to send me something to test and post on the site/forums, I'd be happy to do so.
- Erin

Appreciate the update Erin -- I knew you had the DIYMA one (not too long ago), and knew you wanted to get into testing -- so I put 2 + 2 together and came up with 99. biggrin.gif

That's pretty hardcore to have one of those and not aspire to using it as a source of income. cool.gif
post #508 of 2212
Interesting Erin..cool.gif .I thought you still had DIYMA's. I have talked with the German folks over the last few weeks but damn that is some expensive hardware and there isn't much return on investment to justify the expenditure in my case, so I pretty much shelved that idea. Plus Patrick sort of owns that niche already and his prices are reasonable. I still really want one though.

I have all kinds of drivers laying around doing nothing if you just want something big and brash to play with.
post #509 of 2212
That sucks. I didn't realize people associated my hardware with DIYMA. Grrrrr.

Yep, I've got my own DA, mic, and every module klippel offers. I'm a beta tester for them as well. It just all fell in place after some discussions between myself and Uta.

Patrick has the analysis end of it covered. My only goal is to be a 3rd party reviewer and provide the most accurate data as I can. I definitely don't want to even appear to compete with Pat. I can't match his knowledge for one and mainly because he was so helpful to me when I first started out there's no way I'd want to take money from him.

Shoot me an email with what you have. I'm always down for testing drivers. I sometimes go on dry spells for a couple months for my sanity but I usually Ce back strong. Lol.

Hardisj@gmail dot com


Erin
post #510 of 2212
Quote:
Originally Posted by zheka View Post

I appreciate yor advice , BB.
Can you explain how the power is "reserved" for certain frequencies? I understand that input power in WinISD must be lowered to offset the power requirements of LT. But if the LF signal does not contain any material within LT frequency range, why would not all power be available for its reproduction?
Thank you

There's the rub... assuming your sub is for soundtrack reproduction, you don't know what the signal contains until you give it a spin. Recent STs (Total Recall, Wrath Of The Titans, The Amazing Spiderman, The Dark Knight Rises, etc.) have very high level 2-20 Hz content. Run the L/T'd system for max output >30 Hz and LMK what the results is with those titles. cool.gif

Source with no content below 30 Hz is irrelevant and does not require a subwoofer of multiple 18s.
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