First build - Octo SI 18's with flat packs. - Page 10

It also looks like you are dropping off like you are outside. These are not max outputs so it could just be the sensitivity increase. Max power would be a 6 dBs difference. Your room is big right? You are down 12 dBs from 20hz. Luckily if you want to be flat to 5hz you have the displacement to do it. People wonder why we buy so many. BTW, the subs look fantastic! Now move them around airflow to see the response change and see what works best. I would bet dual stacked going across the front stage may help.

12hz @ 125db?

Hey Carp. Sorry if i missed it, or just forgot.. did you use any sort of stuffing/damping material in each one of these? Im about to start ordering stuff, so I thought I would ask. Ive never done this. What should I get, what would be easy to work with in this box? Or do you even need it? Thanks for the help man

Not bad. What kind of EQ device are you using or going to use?

A simple shelving filter ~30hz will bring up the bottom end significantly.

Awesome. thanks, thats about a quarter of the price as what i was looking at. Pretty clever way of making sure you got four pounds in the box, too

Sure wish I could hear what 8 of these guys sounds like. Enjoy it, man.

It will. You're still in a good spot though. When will you think you'll have the MDSP installed?

Well, the graph is not detailed enough to say exactly, the midpoints are 70 and 80dBs so it looks to me like 10 dBs from those graphs. Here is my graph with no EQ, down about 3-3.5 dBs at 10hz.

I am just saying there seems to be more rolloff than expected. Still not a big problem with lots of dispalcement.

Can you try a certain setup? Can you place the noesis on one of the subs and then put a sub on top of that(only if stable). The remaining subs can go in front of the screen besides the center, try that out.

you killed your dog with bass

meh.. well, ill take pictures of course, (who isnt proud of anything they put together!?).. Seems sort of redundant to have a thread of my build when its literally a fraction of you, gorrila, and several other's builds..

But hey, why not. Im sure I will, just for Sh*ts and G*ggles.. if anything, I could probably get some more advice and knowledge from you guys along the way if i do, so i guess i probably will.

Not to mention, i see myself going the same route as you guys.. Where one was a good idea, but only for starters. lol. Im guessing with the slow and steady removal of coffee tables, end tables and other assorted unnecessary furniture, i could probably fit quite a few of these in my rinky-dink place

Honestly I like that blue curve the best. To me it shows a broad peak at 40hz or so. You are only 2 dBs down at 10hz and once cutting that peak being flat from 5hz to 200hz is easy! Same for the orange trace.

I think you're gonna find the yellow, blue and green traces together, with the added height of a second sub under each surround, will be awesome placement. That's close to what you said you'll prolly be going for, and that seems like it will provide both the best 5-20hz performance, and smoothest performance above that.

Then, you just EQ down the peaks at 30hz, 50hz, and maybe reduce the upper midbass from 70-100hz via a shelf filter. It's usually better to pull down than to push up. Also, the yellow trace tells me you may not need an L/T.

Have you played around with phase (delay) at all, too? I don't recall seeing you mention it, but, as others have said, it can have a potent effect.

Also, try running the sweeps at higher levels, but wear ear protection.

As an aside, miniDSP shipping takes from 10-14 days from when it leaves Hong Kong, although I didn't get the shipping notice from them until the day before it arrived, so ymmv.

well, ive got my list of everything ill need to make it happen now (i think). Now i think im down to the very last thing.. actually, two little questions.. What kind of screws exactly should i get for one of these builds? Those hurricane thingermerbobbers sound like something i can screw up, so i was thinking normal screws.. any preference?

last question (ive asked before here and there, but i dont think ive got an actual answer yet, so it must be a really stupid question to ask) : the wire that goes from the driver to the binding posts.. do you have to worry about it making noise and vibrating? In other words, exactly where do you mount that wire. do you let it hang freely, or tack it along the bottom or what? I would jsut hate to make a silly mistake on something like that.. also, i was thinking of getting some monoprice 12 gauge for this.. That should do, correct? (If it matters, i think ill have the amp for this sub placed quite close to the sub, instead of near the rest of my gear, so i dont have to run a long-ass run of wire).

Im pretty sure i couldnt possibly have any other questions as far as simply building this thing goes. lol. Just wait until i try to start figuring out the meters, and the testers, and DSP's and all that but, im going to take gorilla's advice and get it set up, built and hooked to my system, and jsut see how happy i am there with audyssey.

Wood screws work fine, but make sure you have everything ready before you drill and screw because frequent removal/replacement in MDF can cause the hole to strip. I prefer black oxide, but you can use black spray paint on anything, pretty much.

I actually had a problem with excess wire slapping inside the boxes and fixed it by zip tying all extra wiring to the speaker baskets. You'll want zip ties anyway to lower the drivers into the box. 12awg wire will be fine, yep.

I'm still trying to wrap my head around PVG as bosso mentioned in your thread earlier. I wonder if that is a factor in you seeing such a significant gain in that region.


Kevin, do you have a build thread or a writeup some where regarding your miniDSP Box build? I'm probably one the few idiots who wasted money on purchasing a boxed version, but I'd love to see what I could pickup from your write up.


Seems like the SI's simply can't dig as deep as some of the other heavy hitters. Some of my favorite demo songs on my old LMS-U's just arent the same on the SI's. Not necessairly a bad thing...just means I'll have to find other favorite demo songs...lol


Keep leaving that door cracked open buddy. I've seen Scott talk people out of thousands of $$$ just by soneone leaving the door open. Don't be his next victim...lol

Don't come to any conclusions until you add boost down low. The LMS5400's rolloff less than the others so naturally will play louder and deeper. My subs rolloff little as well so they will play lower but not as loud as I need more of them to catch up on displacement. I have had more displacement from my 18's before but they had mor rolloff down low and without boost my little 13's seem stronger down low. I can make all of them sound equal with the right amount of boost and EQ. My 18's were at least 10 dBs down but had more displacement than my 13's. After measuring the THD on my subs the 13's have less THD at higher spl's at 10hz. So it is just not about displacement but how linear it gets down low, The LMS5400 and REXXX are the best at this. Now I am just going on my own experience in my room. I compared F-20's, CHT 18's, eD 190v2's, DTS10's, and my 13's. The DTS10 cheat because they are horn loaded and act like a boost down low(10hz in my room) so they don't count. Let me dig up the graphs for each to compare. PVG just means that any room should have some added free boost down low when comparing to outside. This raises the spl and lowers the THD naturally. He was showing that even though every room was different the profiles were pretty close so when people say they have no boost or when they say I have magic boost this is not true.