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

[Pete Basel]

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

I'd take the wires off the back of the amp and test polarity with a battery just to be completely sure that something didn't get flipped. Or did you try this already?
They could be moving, because there is enough clipped voltage to do that but if it is clipped then it will be distorted.

[Whitneyville1]

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

Placement issue? I had a big problem with my Titanic MkIII 12" with a Dayton 500 w plate amp after I moved it into the living room about that. The "Norge" sounded super in the shop and sounded poopie in the house against a wall. Fix, move it away from walls some. I too had the "sloppy" low bass freq. SQ. I'm drawing a few dozen watts max with a tiny bit of EQ to get the smoothest response with Audessey.

I have no idea if this will be of any help, but I hope it is. Best of luck to you.

[Rory Buszka]

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

The Ultimax 18s are great in the 4 cubic foot enclosures, but they are still subwoofers, and not woofers. They will not perform well with a crossover frequency above 80 Hz, and if crossed over too high they will begin to sound muddy, as will most subwoofers with extremely long throw suspensions and very heavy cones. These things enable deep bass from small sealed enclosures but do not enable "upper bass" and "midrange" output of any acceptable quality. What main speakers are you using, and what crossover frequency do you have selected?

[killa]

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

Have you tried flipping the polarity of both subs? Sometimes polarity needs to be reversed to blend correctly with the mains. You might be able to reverse polarity in your AVR settings. It will make it easy to switch back and fourth to hear the difference.

[joshp214]

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

The Ultimax 18s are great in the 4 cubic foot enclosures, but they are still subwoofers, and not woofers. They will not perform well with a crossover frequency above 80 Hz, and if crossed over too high they will begin to sound muddy, as will most subwoofers with extremely long throw suspensions and very heavy cones. These things enable deep bass from small sealed enclosures but do not enable "upper bass" and "midrange" output of any acceptable quality. What main speakers are you using, and what crossover frequency do you have selected?

I think maybe you misread my post....I'm not worried about frequencies above 80 hz, I'm talking about down below 30

[joshp214]

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

Have you tried flipping the polarity of both subs? Sometimes polarity needs to be reversed to blend correctly with the mains. You might be able to reverse polarity in your AVR settings. It will make it easy to switch back and fourth to hear the difference.

I have flipped polarity, no better.

[JasonP]

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

I assume you ruled out stuff in your room making noise in response to the high amount of low end being pumped out? I know when the deep bass kicks out from movies in my system I can really hear my room, which sounds bad at real volumes.

[Chris Roemer]

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

All I can say is (IF you're low-passing them around 80Hz?) in order to get output similar to an unboosted 16cf vented box (Fb near 16Hz), you'd have to EQ your 4cf closed box with +15dB of boost around 16Hz.

UN-boosted, your box should be peaking near 60Hz naturally. Add a 60Hz hum issue and I'd guess they could sound kinda poopy.

[generic]

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

Are you sure you don't have any air leaks in your boxes? What did you use to seal the subs to the box?

[bullittstang]

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

All I can say is (IF you're low-passing them around 80Hz?) in order to get output similar to an unboosted 16cf vented box (Fb near 16Hz), you'd have to EQ your 4cf closed box with +15dB of boost around 16Hz.

UN-boosted, your box should be peaking near 60Hz naturally. Add a 60Hz hum issue and I'd guess they could sound kinda poopy.

+1 ... I just finished a 12" sealed DVC310 build yesterday (1.0-ft3 net Vol). Cranked it up for the first time and.... POOP!! What the??? Then turned the music down and what do you know a 60-Hz hum, even though the previous sub didn't have a hum. Fixed the hum...and now it sounds Fantastic! Sort out the hum first, then lower the XO to 50-60 Hz max and add EQ to taste. Only my two cents, though.

[fbov]

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

...I do have a UMIK-1, and looking at the graphs tell me the same thing my ears are hearing. Severe roll off after 30 hz, and under 20 hz it almost looks like a sin wave lol.... ...

I have two sealed 15's, in 1/3 the room, and this is what I see in a circle around the MLP, before room correction.


Our subs should have similar native FR, but I'm using an O-Audio plate amp while you've got an Inuke. Consider testing the amp, as your description of your measurement looks nothing like mine. If you did a sine wave sweep down in frequency, what's the amp output voltage look like across the load? If voltage follows the SPL trend, you could have an amp problem, not a speaker problem.

Have fun,
Frank

[Blenton]

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

What xover and DSP settings are you using on the receiver and on the amp? With the DSP in the inuke, I suggest that after you follow up on the aforementioned issues, then try adding some boost in the 20 hz region while subtracting a few db in the 50-60 hz region. You shouldn't need a HP filter below 20hz, but check to see where the LP filter is set (if at all). Try eliminating the LP filter on the amp or moving it up to 200hz or so; the filter on your receiver should be sufficient.

[joshp214]

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

I added this to the OP, but I will add it here as well.

[killa]

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

Attachment doesn't work for me. I usually just post screencaps.

[joshp214]

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

Attachment doesn't work for me. I usually just post screencaps.

Should be working now