Stereo Integrity's new HT Subwoofer - Page 16

Isn't it better to connect any DVC speaker in series so that if a voice coil fails the amp is protected from a sudden drop in ohmage?

For this reason I always connect in series my speakers.

I decided to go with a dual drive enclosure. Now I have to decide which version of the drivers I should get.
At least for some time I will have to power my CHT CS18.2 (4 ohm) and the newly built SI sub with single NU3000DSP amplifier

The amp can do approx 600W per channel @ 4 ohm and 1000W @ 2 ohm.

So the question is should I get a pair of D2s for 2ohm total or a pair of D4s for 4ohm total.
Going with the 2ohm version will allow me some headroom for LT.
On the other hand If I ever buy second amp or upgrade to nu6000 (2000W @ 4 ohm, the sweet spot for these IMO), the 2 ohm load may become a problem.

What would you advise me to do?

This is a quote from Nick made on another site:

"The purpose of these woofers is to not require that much power. They can safely handle, and are rated and warrantied for, 600 watts RMS. In the end we can't stand over everyone at their houses and tell them to be careful every time they apply too much power, but we do know exactly what the woofers are able to handle. I strongly suggest sticking to the 600 watt rating that we give them."

This was in response to somebody asking if they could put 2100 watts into the driver. The 600 watt rating is a mechanical limit, not thermal, and the Data-Bass tests made it pretty clear that this driver had a very compliant suspension and was pretty clean in it's stroke right up to the point where it taps the back plate -- xmech related damage is the next stop. I do believe it could easily survive with 1000 watts if you don't get stupid with it, but (with your amp) holding it to 500 watts per and then adding another pair to the mix seems like a real winning situation.
Edited by Aaron Smith - 12/29/12 at 5:07pm

Thought some might find these useful. I am simulating the 2 new SI HT drivers vs. the Dayton RSS460HO-4. Keep in mind I have the High Pass filter/boost and the Low pass filter on these, so it's not entirely applicable to every situation. O Audio 500W amp, High-pass engaged 20 Hz setting, User SOS Q =1.72 Fc = 17.33 Hz.

I am impressed with how the SI drivers model, even the lowly 15 which uses a pretty small enclosure.

SEALED: these sealed boxes are near perfect Q (0.707), I did undersize the SI HT18D2 enclosure a little because 6.5 cubes is huge.


Impressions: Seriously, these are all impressive drivers and similarly priced. For a small room, the 15" sub is pretty adequate. The SI driver is a little louder and a little lower, and will handle more power. The tradeoff of course is the huge enclosure. The Dayton holds it's own pretty well.

so your choice would be the 2 ohm config which would deliver roughly 500W per driver, correct?

With the intent of ending up with 4 18's, that is what I would do. For the next 2, I would do individual enclosures so you have the response smoothing advantage of having the bass emanate from 3 different locations in the room.

I was hoping the new sub will blend nicely with the CHT. They model surprisingly similar. That's the main reason I am doing the dual drive enclosure.


yellow - dual CHT, red - dual SI, no EQ, 600W per cab.



I'd prefer not to do any more subs for some time if i can help it ( i know, i know...) . But the amp upgrade may be an option.

I am using a pair of Epik legends for modal smoothing.

More Stuff. Here's ported. We really see the Dayton and the SI screaming for larger enclosures with such a low tune, but this is kind of at my limits. The high-pass filter/ boost has a huge impact on port velocity. I was originally going to go with (2) 4" ports with elbows, but (2) 2x5" slot ports looks a little more appealing and the velocity is in check. I also tested these with different amplifier inputs should I get an iNuke down the road. It works well with that as well.







The only concern at this point I supposed is I think I'll be VA limited by the amp around 18 HZ or so, if only by a little bit.

Most impressive to me is that the 15" SI really holds it's own ported. If this simulation is accurate, it will provide reference levels of bass down to 16 Hz. The enclosure size is smaller and you're only giving up about 2-3 dB on the big boys.

7.0 cubic feet frankly is too large for me but that's where I have the limit right now. The Dayton really wants 7.5 and the SI wants 8.5.

8.5 Cubic feet + braces + driver + ports = huge enclousure, maybe 36 x 26 x 24.. dunno.

The 5.0 cubic feet Net enclosure for the SI 15" would be 30 x 22 x 20 including ports, driver, and bracing.

just fyi. this has been discussed before. in a sealed enclosed these can take more than 600 watts

I propose a Hybrid Theory...


3D Sketchup..


Anchor the towers to the walls so they don't tip over. As you can see, the boxes on ground are dual opposed to ensure your L/R speakers remain undisturbed.

best yet

dang mr 16 drivers


ULF addiction enabler indeed!

I'd like to understand why this would be the case. can you point me to the discussion?
obviously Ricci tested with higher short term power, but the max long term output chart seems consistent with 600VA / 4.5cu.ft. models.

the lowish wattage is because of excursion. the smallish cab keeps the excursion under control, so you can apply more power.

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...

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. 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!

thank you for chiming in, John.

but if the limit is in fact thermal, not mechanical, then is not the sub constrained by 600W even if it has not reached the xmech yet?

Where are you getting that the limit is thermal?

This is a very good point. Thank you. 4 ohm it is.
300 per driver still models rather well. I won't have much room for EQ but then I may not need it with the room gain and all.

Long term , the limit is thermal.
At peak power - the limit is mechanical.

Ricci found that in 4.5 cu.ft box it can take 1400W peaks before bottoming out.

http://www.hometheatershack.com/forums/diy-subwoofers-general-discussion/60421-new-si-ht-woofer-specs-info-21.html#post560703

Right, I understand that a 1200W sine wave for 13 hours in any size enclosure is probably not the best idea, but I didn't see anything in the data-bass review or in Ricci's post that you linked that limited the sub to 600W due to thermal concerns for normal/program usage. Are you saying 600W just to guarantee you'll be on the safe side, or is there something in there that I'm missing or not understanding?

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?

Here is link to the post by Nick of SI explaining the recommended power. Aaron S quoted it before.
http://www.hometheatershack.com/forums/diy-subwoofers-general-discussion/60421-new-si-ht-woofer-specs-info-28.html#post576033

DISCLAIMER: I am not a representative of Stereo Integrity. With that said, After Josh's test of the 18HT, in a smaller box, Nick did say that they planned on NOT changing the recommended power of the driver, but would adjust down the recommended box size to a little smaller than what is listed on the site. With that said, 1000watts for this driver in a smaller box than 6cuft, more like 4cuft, there should be absolutely no issues with thermal or mechanical overdrive. the airspring of a dual opposed will even compound this. Also, this all assuming you are running high power sine waves through your system.

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

Zheka, Hope I didn't throw you off in post #455. I stated the drivers were thermally limited, not mechanical -- I hope you could tell by the context of the sentence (where I mentioned them having a compliant suspension) that I meant to say mechanically limited, not thermal, but I apologize nonetheless. I had reworded that a few different times and it's too bad that slipped through like that.

How large is your room? You are going to have a superb bass system with 4-18's and 4-12's.

Yes, your post was in part why I asked the question. But you are not the only one who stated that the 600W limit is thermal, not mechanical.

and why would it be mechanical if the sub is way under the xmech at 600W in any reasonable size enclosure ? It hits 37mm at 10Hz in 25 cu.ft sealed box.

I am in 12x22x8 basement. I suspect when all is done I may still have reasons to feel inadequate about my set up by this forum's standards

ricci was running sine waves through the driver with 1400 watts in his long term compression test.

compression began to set in significantly above that.

running real world content with 1000 watts should be fine.

Yeah, sorry about that again. That was 180 degrees out of phase...I was experiencing technical difficulties for whatever reason.

The limit would be mechanical because the suspension travel is the limiting factor; not the coil (which probably describes 95% of woofer drivers out there). Have you read the review at Data-Bass? Excerpt from the Sealed System test: "The woofer specs lend it to use in large EBS vented or even IB installs but mechanical power handling in large enclosures should be kept in check with the highly compliant suspension as it can be bottomed. Thermal handling seems to be less of an issue." You probably have seen those tests, but Josh touches on the power rating a few different times.

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?