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Awesome setup. NICE. Scott(Fi) makes some killer subwoofers!!
 

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Discussion Starter #22
Yeah, I must say they perform above what I expected already, and I haven't even started on any finetuning yet. There's alot of potential there, and I'm already convinced about the IB configuration. I was afraid it would be underwhelming without the usual box distortion, but it really is very visceral and physical in addition to sublime and discrete.
 

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Discussion Starter #23
The excursion at 7Hz at reference level is very reassuring. That pulse REALLY pressurize the room. It feels like my couch is actually moving on the floor. My old LLT sonotubes din't do anything useful at that lowest pulse. I've read somewhere that those pulses are at 7Hz.

Never mind the rattles, I hadn't cleaned up my back room after the build....

https://www.youtube.com/watch?v=f7XmmmzPhaQ&feature=youtu.be
 

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So that was your wall rattling?
 

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Discussion Starter #25
No. That was a ladder leaning against the wall, and a shelf full of screws and clutter. :)

In the cinema there are very few rattles, even with the cacaphony in teh back room. I'm confident I'll get it totally quiet.
 

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Oh ok. Well thats good to hear. :T:sweat:
 

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Discussion Starter #29
In the video I was at reference volume (MV at 0dB) and my couch was dancing. There was maybe 1/2" of total excursion at the 7Hz bits... Don't think headroom is an issue, and I don't think I need a HPF. I watched the subs during the "Pacific Rim" inro sequence, and they moved less than in the video, at reference. I think I'm good. :)
 

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Just something to consider - words of caution. i would hate to hear that a fellow IB'er had issues. We are a rare breed.

There have been those that have only one ep4000 that have bottomed out with specific content. It is all a matter specifics....what material are you watching, what is the boost/tune at the frequency, what volume, gain settings it can all come together in a few seconds to cause a bottoming out event. You'll see what I mean with movies scenes like WOTW, BHD Irene and many more. They will cause WAY more excursion than that song at the same volume. The rocket ship take-off in Ender's game may be a new reference.

That said, if you are careful, you should be ok. I don't use a HPF, but I keep the volume really low and only use one ep4000. I have tapped only maybe 50% of the potential and that is enough for me. I have also wired the subs so that the max wattage matches the drivers. So theoretically, I would have to have everything maxed out to bottom out at 16Hz or lower. I also spent the first few months with the sub working up the volume and understanding just how much excursion can be caused by some of these movie scenes.

Anyway, even with my somewhat minimal setting I have see excursions that scare me and am considering adding the HPF. Just saying ----- If I had 2 ep4000, I would be scared when trying to impress your friends that are used to distortion subs.

Have you modeled this out with winISD just to see at what frequency excursion limits may be breached with 2 ep4000s?
 

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Discussion Starter #31
I have, and it's easy to reach excursion limits even with one amp. Which is why I want two, to be honest. I feel amps driven well within their limits keep better hold on the drivers and will limit excursion a little.

I watched the important scenes from WotW yesterday, and excursion wasn't dramatic at all. The level was a little less than I've heard from oter system too, though, so I might just be running them a little lean. I haven't measured them yet, I think there may be some listening position issues (I've moved my couch during the build, it's very picky about distance from front wall in my particular case), and maybe even some integration issues. I've done a quick Audyssey run and haven't even looked at it after that. I'll use them for a few more hours to loosen them up a little, and then do a proper calibration. I might just be too used to box distortion still. :)
 

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Discussion Starter #33
Just read your thread, Blitzer. I'm a little relieved since I saw the same dropoff in the low end as you did, even if it SOUNDED like it was outputting significant energy way below 15Hz. I've boosted the low end a bit and cut my very similar 24Hz node significantly. I'm now a little worried about overexcursion since I've boosted the VLF part pretty significantly (6dB)

How did you end up wiring your amp? You got the 4S drivers as well, right?
 

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Just read your thread, Blitzer. I'm a little relieved since I saw the same dropoff in the low end as you did, even if it SOUNDED like it was outputting significant energy way below 15Hz. I've boosted the low end a bit and cut my very similar 24Hz node significantly. I'm now a little worried about overexcursion since I've boosted the VLF part pretty significantly (6dB)

I can pretty much claim flat to about 11Hz after EQ. What I ended up doing is eq'ing down the HUGE hump down to the level of the 11Hz level. The worked very well. If I start turning it up a lot, the room nodes and nulls(of course) start winning again, but for 90% of the listening volume I use i am good. Maybe this is why I am getting so much excursion.

Also, before the eq, I had that 20db bump at 30Hz and it was doing a number on my ears. My ears actually were aching for a day or two after watching the latest bond film - the gunfire and explosions in that movie can be particularly loud. I tamed that and don't feel like i am risking my ears during movies anymore, but lost some of the gut punch.

I am actually buying a couple nice subs to experiment with for extra upper base punch. I know purists will goff, but, I feel like the IB compresses my whole body - I feel like I am inside the explosion or the sound wave, etc, but sometimes I do mist the particular solar plexus gut compression in the mid bass that a good box sub can produce. So, going to play a bit with trying to add a couple SVS PB13s to even out my room response and to see if it gives a little of that back without screwing up the IB sound and the bottom end.

Can you post your REW graphs or MDAT?
 

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Discussion Starter #37
I will when I have them available and they are "presentable". :)

I have very capable mains, so "gut impact" is not an issue in my particular case. I think the IB does this better than the "box" subs I've had previous, maybe with the exception of the four JBL 4645 subs I had. But those did nothing under 20Hz. If you're curious you can check out my build thread for my mains, the link is in my signature.

I haven't had time to experiment alot with the setup yet, and I want to give the drivers a few hours more to loosen up before I go to any lengths to get it set up properly. Also have a wall rattle I need to address.
 

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Did you get the 2 ohm or 4 ohm drivers? How much power is each driver getting? I have 4 of the 2 Ohm IB3 18's and am planning to get a Crest Pro-Lite 3.0 which will give each driver 415 watts.

Sent from my LG-H901 using Tapatalk
 

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Discussion Starter #39
4 ohm drivers in series, two per channel for an 8 ohm load. I might not use all the potential in the drivers, but then, I'd like to keep my house a few years too. It's certainly an easier load on the amp and there's plenty of output. 415W to each driver is overkill, and there's nothing better! :)
 

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Sounds good. I do worry about over excursion so I am also consdering a Berhinger inuke 3000 since it would deliver 320 watts RMS per sub. Combined SPL at reference should still be a couble dB above the mains I plan on getting. Of couse getting the Crest might allow for more of a house curve to be dialed in. Hmmmmm.
 
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