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Discussion Starter #1
Hi guys
I'm building a ported um 18 22 tuned to about 16hz in a 12cubic feet box.
It seems to be less output than a pb13 ultra at 2metres from 20hz and up?
Is this to be expected?
Have I done something wrong?
 

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:help:
I am noticing the same thing. Not as it relates to the 13 but as compared to a side by side I was doing with the tc sounds lmsr 15...... It seems like the low end is good but it rolls off in the upper frequencies fairly quickly.

Are you using the downloadable driver files? I am and I don't know how current they are in relation to this driver. I tried entering them off of Parts Express info but winisd wouldn't take them (for me anyways).

I was finding that the 15 inch driver was keeping up with the 18 no problem. I am curious if I am missing something obvious.
 

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I was using about the same size box as you. 12 cubic feet with about a 39 inch port. I may be doing it wrong though.
 

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:help:
I am noticing the same thing. Not as it relates to the 13 but as compared to a side by side I was doing with the tc sounds lmsr 15...... It seems like the low end is good but it rolls off in the upper frequencies fairly quickly.

I was finding that the 15 inch driver was keeping up with the 18 no problem. I am curious if I am missing something obvious.
I think what you guys are talking about is just the nature of the Ultimax, especially at first, especially up high, not just a little over 20 hz but on up into the midbass. It just rolls off, and at first it is super stiff. I even left a review on the product page 4 months ago that says about the same thing you guys are.

I would recommend playing the snot out of them for awhile, it helps to some extent. If you can generate a sine wave and do a free-air break-in that would probably be good. Took quite awhile for mine to break in. Still not nearly as boomy up top as other offerings, but its all in how you look at it. Get used to these and then switch to something like a Klipsch R-115SW and the higher frequencies get very annoying.
 

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So a bit of break in may help..... Hmmmmm..... Makes it harder to design an enclosure. What do you have yours in lake? ( if you don't mind sharing). Ported, sealed.... Etc
 

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What do you have yours in lake? ( if you don't mind sharing). Ported, sealed.... Etc
Two sealed. They're a little bigger than usual, I split the difference between the recommended home theater size and recommended music size, its a bit over 5 cubic feet. If I did it again I'd go smaller as to have more control for sub-bass. They get kinda floppy on some material.

 

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I know this is way OT, but I have to ask about what seems like some serious toe in on those mains. They look like they actually cross paths. Or is that a trick of my eye?
 

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I know this is way OT, but I have to ask about what seems like some serious toe in on those mains. They look like they actually cross paths. Or is that a trick of my eye?
They are toed in pretty hard, I've been playing around with them and everything else. I also have a serious center channel stand issue going on but that's not necessarily permanent. ;)

Anyway, I don't think they quite cross paths, currently both are aimed at the back of the center of my middle seats, which is typically halfway normal, but my screen size spreads them out pretty good, and my 10' viewing distance has them turned in more than usual. Plus, I have a single row of four seats, and the outside seats are pretty far out there. Have been trying to get the speakers opposite the outside corners to not sound as weak. If I straighten them up, the outside seats get blasted by the outside speakers and the opposite ones can't be heard nearly as well. The halfway short distance and the wide row of seats is messing me up in this regard.

On top of that, yeah you're viewing from the side which makes them look even worse.

Ideally I need to redo my room and have two rows of 3 seats with the mains behind my screen. Alas, I can only do so much. Rewiring my entire room, building a false wall, ordering more seating... can't do it right now.
 

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Discussion Starter #10
I ended up just assuming it is because of low sensitivity of the driver. So I reduced box size from 12 to 10 and the tune from 16 to 18, it gave a touch more spl from 20hz to 45hz. And gonna give it 1200rms aswell.

Or I could wack a second 18 in a slightly taller box to get some more midbass.
Dual driver in single ported box would look unreal.
 

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Yeah I was playing with the idea of a dual 18 as well. I imagine that enclosure would be enormous though..... :yikes:
 

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Discussion Starter #12
Imagine a box that extends to the ceiling with 4 18's on either side of the room. Tuned to 14hz. 1 day before I die I WILL do this. Then some buttkickers to cover 5hz to 14hz. Niiicee
 

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Got an email this morning that reminded me of this thread to a T:

"If you want the kickdrum feel I suggest going with sealed enclosures. I have responded to many many emails asking what the problem is because they purchased multiple 18's and put them in big ported enclosures tuned very low and all they get is rumbling and augmented extreme lower frequencies. Ported alignments look good on paper but many people don't like them because they have too much bottom end which drowns out the upper frequencies. For neutral sound reproduction on the bottom octave I suggest going sealed...especially if you want the feeling while watching live music. :)"

This was from the owner of Stereo Integrity.
 

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Discussion Starter #16
Yer always a compromise I guess. You could just put an eq curve in and roll off from 30hz and down. Easy done with inuke dsp. One for movies and one for music.
 

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Imagine a box that extends to the ceiling with 4 18's on either side of the room. Tuned to 14hz. 1 day before I die I WILL do this. Then some buttkickers to cover 5hz to 14hz. Niiicee
If a room can be built to "hide" this... its my room...

Super weight shaped that could 100% hide 1 quad set and just extend a wall extension and bloch an arch I hate anyway... Suoer tempting... Not sure I can pull off that build with my lack of skills, space and tools. If any room can be livable with this though...

I might think about it... but am sure it would go poorly...
 
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