2 x Ultimax 18's Unrealistic expectations or something wrong?

[duanebro]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Looking at your fr graph looks like you have a hpf at 20hz.

[rhodesj]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

What content are you actually playing that has 30 Hz material in it? Most music doesn't go anywhere near there, and movie stuff is generally all effects... not sure how one would describe an explosion as "floppy". How large is the room? Open floorplan, or closed?

Can you tell more about how you measured. Through L/R stereo, or HDMI straight to the LFE channel? Are you using the stock UMIK calibration file, or do you have a CSL-calibrated mic? What volume level on the AVR? Given that the sub-15Hz and over-90Hz part of the sweep is under 60 dB, you might be closer to your noise floor in the room, which could be influencing the sweep. Might help to crank the volume up for the sweeps.

Do you have anything configured in the Behringer? How did you integrate the two subs? If phase/delay aren't set well, you could be losing a lot of output that way. There's a good tutorial here: http://www.avsforum.com/forum/155-di...ow-thread.html

FWIW, I've got four SI HT18 D4s running on an NU6000. No complaints about the sound at all after I EQ'd the hump out of it.

[fbov]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Looking at your fr graph looks like you have a hpf at 20hz.

+1

I did a filter setting series on mine, single sub, no other filters. Your response looks a lot like mine with the 25Hz filter selected. I use 16Hz. (These are not real HPF as they include boost, that's why I call them settings.)


Have fun,
Frank

[---k---]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

but a highpass at 20 hz wouldn't make it sound like pooo . It would just take away the low frequency. My guess is room positioning. Move them around. Start with one or co-locating to verify.

[corradizo]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

How much stuffing did you put in each?

[Blenton]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Here is a post that might be helpful in extending the LF extension using the iNuke DSP settings. The iNuke doesn't let you set a HP filter below 20 hz, but this is a quite simple way to do that...

http://www.avsforum.com/forum/155-di...z-dcx2496.html

but a highpass at 20 hz wouldn't make it sound like pooo

That depends on your definition of pooo :D Using a plate amp for HT18 that had a built in HP around 30 hz, I wasn't happy with the sub 30 hz performance. It even affected above 30 hz performance because of the discrepancy between the two; I wanted more low end, so I would turn the gain up a smidge but that would make it too boomy up higher, so I would turn the crossover filter down which would make me turn the gain up a bit and so on a so forth.. I wouldn't quite say it all sounded like poooo, but it certainly had qualities that I didn't like and it started driving me nuts since it was getting quite peaky. Getting rid of the HP filter entirely made it sound soooooo much nicer (at the obvious risk of over excursion, though below 500 watts I was below Xmax all the way down the spectrum). Not that I'm suggesting that's what the OP does...

[Pete Basel]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

It sounds like you know what you're doing but did you put the dual 2 ohm coils in series?
I'm sure that 1 ohm is too low for that amp.

[corradizo]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Why would you high pass a sealed sub? What you may want to do an ls12 @ 20hz +15db combined with a Peq @ 20hz Q=2 at -12db on your inukes dsp. The inuke UI settings limit you to 20hz but the filters effect below 20hz. You can model this in the REW EQ and it aligns pretty closely. Use the preset for the dcx2496 as the equalizer in REW.

[Face]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

I agree with above, no need for a high pass if you're sealed. I've clipped a Crown X4000(1350w @4ohm) on a pair of sealed(7cf) UM18s and didn't hear any nasty noises come from them.

[Jeff B.]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

+1

I did a filter setting series on mine, single sub, no other filters. Your response looks a lot like mine with the 25Hz filter selected. I use 16Hz. (These are not real HPF as they include boost, that's why I call them settings.)
[ATTACH=CONFIG]60716[/ATTACH]

Have fun,
Frank

I am so glad I have two Oaudio 500's and so bummed that I know I can't get any more of them. Those switchable settings on the bottom end really set that amp apart if you want deep bass. The best sealed subwoofer amp I have ever found.

[jonpike]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

I have flipped polarity, no better.

I know it's been asked a few times, but have you tried flipping/checking polarity of EACH sub to each other, as well as flipping the polarity of the pair to the mains? It wasn't clear to me if you did that in your earlier checking.

If that isn't it, I'd try measuring the response out of the amp, if you've got the gear to do it, to check for a unexpected HP filter (as has been said shouldn't cause lousy sound higher up) or maybe only one channel has a filter and the other dosent, or there's some defect, etc... (which possibly could)

Added thought: Clear out all DSP settings in the amp and elsewhere. Take measurements of each sub separately, both together in phase, and both out of phase. That should tell you a few things...

[Pete Basel]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

I am so glad I have two Oaudio 500's and so bummed that I know I can't get any more of them. Those switchable settings on the bottom end really set that amp apart if you want deep bass. The best sealed subwoofer amp I have ever found.

Do you have or know where to get a schematic for it?

[Jeff B.]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Do you have or know where to get a schematic for it?

Sorry, I don't know where to find one of those.

The combination of the adjustable 4th order lowpass, a parametric EQ, and multiple adjustable high pass settings, really offers a lot of flexibility - and the ability to get deeper than almost any other sub amp. And mine has no turn on thump and has been problem free for years.

[fbov]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

Pete,
Physically, the O-Audio amps were identical in many respects to the PE BASH 500, but with different features like PEQ that set O-Audio apart. Screws are in the same places, power boards look the same... control boards differ, as expected.

They measured one back in 2007... BASH architecture prevented the amp from reaching full power in steady-state use, but it sure has the extension! ([email protected], with the 12Hz setting I suspect.)

Have fun,
Frank

[hardeng]

Re: 2 x Ultimax 18's Unrealistic expectations or something wrong?

If you eq it flat from 20 to 75 Hz, it will sound a lot better. I'd aim to have it flat at the 80dB line on your graph. Right now, the output in the 20 to 40Hz range is about 15dB too high. Those frequencies might rattle the couch and flap the pant leg, but they don't sound very good, can be sore on the ears.