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Question about an Ultimax 15 I just built.

3K views 28 replies 15 participants last post by  BassThatHz 
#1 ·
Hello guys,

Been a long time waiting for funds for a build.

Anyway. I purchased I kit from PE with the 3 cu ft flat pack and the Ultimax 15". It's a sealed, and from what I've read sealed are not as loud as a ported sub. I built it to spec on the PE site. It's stuffed with 3 lbs of there acoustic stuffing. And completely airtight with almost 3 tubes of silicone. So I've not detected any leaks.

I'm using an Aventage rx-a2020 avr. Crown XLS 1500 amp. 550 watts stereo and 1550 bridged. I did have to use a line level converter to get enough signal from the avr to the amp. Cable wise I'm using RCA to the LLC, the. Xlr from the llc to the amp and speak on from the Crown to the sub.

So, What it boils down to is, I'm a tad underwhelmed with the output volume. I was expecting more!! I've ran it in stereo and bridged with a Dbx driverack pa+ to keep it from damaging the sub while in bridged mode. I'm certain it getting the power as the excursion is impressive.

I'm used to brand name ported subs. But, nowhere near the power I'm putting to this one. Is this simply the nature of a sealed sub? Don't get me wrong, it will go low compaired the the store bought subs I've used.

So, To my question. Before I complete the sub with an exterior finish, should I modify the PE box and up the cu ft and go ported ??

Thanks for any help.

Jerid
 
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#2 · (Edited)
I'm used to brand name ported subs. But, nowhere near the power I'm putting to this one. Is this simply the nature of a sealed sub?
It is. You have 86dB sensitivity with an f3 in the vicinity of 35Hz. In comparison the RSS390HO driver in a ported cab is capable of 88dB sensitivity with a 24Hz f3. The downside is that the 390HO cab is 4 cut ft plus the volume of the port. But if you want to go low and loud you have to go big.
Also be aware that many commercial subs will get even higher sensitivity by tuning the cab high. They do so at the expense of low frequency extension, and very often the result is also boomy response.

Before I complete the sub with an exterior finish, should I modify the PE box and up the cu ft and go ported ??

The UMax 15 isn't suited for ported cabs, unless you go with an LLT, say 15 cu ft (exclusive of the port) tuned to 16Hz.
 
#4 · (Edited)
Are you only using 1 channel of the Crown XLS1500 to power it?

I have an Ultimax 15 and I ended up using 2 channels of my NU4-6000 before I started feeling I got the performance I was used to. I also had to turn up the gain quite a bit on my receiver (I maxed out the gain on my amp). It has more output...

Right now I'm using bridged with gain turned up on the subwoofer channel but I'm only at like 70% on my amp. 100% on the amp is too much, I all of a sudden realize "hey, this is too loud, I actually can't handle this".

Just to piggy back on what Bill said regarding the roll off at 35Hz. with sealed subs EQ is necessary to boost the signal down low so you get out put below the roll off.

P.S. big excursion doesnt always mean there should be a lot of sound. it could be very low frequencies that you just cannot hear and not have enough output or room shaking to feel them, or you could be in a null and the frequencies are being canceled out
 
#3 ·
Are you only using 1 channel of the Crown XLS1500 to power it?

I have an Ultimax 15 and I ended up using 2 channels of my NU4-6000 before I started feeling I got the performance I was used to. I also had to turn up the gain quite a bit on my receiver (I maxed out the gain on my amp). It has more output...

Right now I'm using bridged with gain turned up on the subwoofer channel but I'm only at like 70% on my amp. 100% on the amp is too much, I all of a sudden realize "hey, this is too loud, I actually can't handle this".
 
#6 ·
Yeah. I have the same subs. I would check the gain on the crown and or the gain on the reciever. Probably low. What size room you have?

These subs do go loud and hard.
 
#7 ·
I felt the same way about my Ultimax 15's in the same box as yours with an iNuke 6000 for a couple hours. I ran 2-3 CD's through it and then it really came to life. I did move them more towards the back of the room where I had them 1/4 from the front and side walls. Play a few CDs and then evaluate. See if they change.
 
#8 ·
Thanks a bunch for All the advice.

as far as store subs go. I'm talking cheap cheap subs. 150
To 200 watts.

I'm mean I pushing this thing with a max of 1550 wAtts. I sure don't damage what the ultimax. Honesty I was hoping for much Moore. And isn't much louder than the 150-200'watters!!!!

Again I'm have it set up full pro. As far as eq goes I've tried 90-30htz. I Iniluding PEQ. I'm at a loss. I'd love to build another. But I. need more volume.

Any chance I have a bad driver??

Maybe I should swap out to a 2000+ watt Croown? N

As far as room cu ft I'm only working with 1800 cu ft.
 
#11 ·
Scall. May I ask how you had it setup wrong? Could be. Mines the same way.

And I have it on 75% volume.


Perhaps this is why it's down a few db. My cable from the line converter is an xlr on the converter side and RCA going to the amp. I hade preach been thinking of cutting off the RCA and going RCA.

Thank very much for your help.

Jerid
 
#12 ·
little more info.


The room is 1800 cuft.
I am running the sub in bridged mode from the crown. so, its currently getting 1550watts at 4 ohms.
again, Im wondering if the XLR to RCA from the Driverack is killing so DB's I've removed the Driverack and it has no effect on volume level.


Finally, you guys think I should add a couple cuft to my box? according to the Dayton site 3cuft is on the small side for the 15"


Jerid
 
#13 ·
I don't remember how I had mine setup originally. Now I have RCA from my Onkyo 805 to XLR on a Behringer DEQ2496. From the DEQ to the XLS1500 I'm using XLR to XLR. All cables are from Monoprice. The amp is set to bridge bypass mode. I had a ported 10" 300 watt sub before this. There is no comparison between the two. The sealed 15 is louder and digs a lot deeper. My box is the 3 cuft flat pack as well.
 
#14 ·
Yeah, were hooked up almost the same way. except Im running RCA from AVR to XLR to the Drive rack and from the drive rack im running XLR from the D rack with a RCA to the Crown amp. perhaps I need to use XLR from the D rack and XLR to the amp!! to be able to gain the extra DB's??? I think ill rig that up today and see of that makes a difference.. crossing my fingers that will do the trick. Besides that im at a loss why its so quiet


jerid
 
#15 ·
ok Gentelman,


I think I figured it out.


Apparenttly, you cant run a xlr to rca from thre level converter to the amp. I took a chance and swapped the rca to a femal xlr to the amp. and man i cant believe the difference!! the thing is wicked now!! much louder and lower. I have to turn the volume past -40 in hopes of not disturbing the pepps next to me. I cant wait to turn it up!!


now, I just need one more. ):

Thanks for all the help and advice.


Jerid
 
#16 ·
I'm a tad underwhelmed with the output volume. I was expecting more!!
man i cant believe the difference!! the thing is wicked now!! much louder and lower. Now I need two.
I know they are weak, that's why I have 6 of them, they make for really good mains-woofers though, when paired with LMS Ultra subwoofers! :D

Only two 15's? Come on now... 8 UM-18's would put some hair on your chest! hehe :p
 
#26 ·
Thanks for the tip.. right now is says bridged lowpass. I do recall seeing a bridge bypass mode too. Keep in mind thios is a XLS model. so it doesnt have all the bells and whistles.


Jerid


I am using the 1500XLS for both of mine. I did notice a change between Bridge: Highpass, Bridge: Lowpass, and Bridge Bypass being the optimal setting. Curious if your noticed the same results since we have identical setups.
 
#20 ·
Hey Guys,


Just an update.


I got all components working full power. Currently I running the Crown XLS1500 in bridged mode to be able to get enough volume.


Im impressed with the Ultimax 15" it sounds good "albeit a tad low on DB sealed" and a great bargin.


So now the question is, should I build another or sell this sub/amp combo to my dad and step up my LFE game another level.


in closing, It is a sickness to need more low end, at least thats what everyone telling me.


Jerid
 
#27 ·
RLH,


I cant tell any difference between in sound or output between Lowpass or bypass mode on the amp. In bypass mode, I do think I can hear a little bleed through of Freq's above 80 hertz.


Also, whats the name of the sub box software? I used to have it, now I cant locate it.
Jerid.
 
#28 · (Edited)
It all starts with one or two, then goes to three of four, then moves to five or six, then comes seven and eight. Chances are good you will do better fitting more drivers in your space rather than sheer box space.

Also if you do go ported you need to remember drivers are rated for maximum power under manufacturers best sealed conditions. When you go ported your power handling will drop significantly.

If your hearing some bleed threw something is wrong, do not use that setting. It sound like something I encountered in the third outputs on the driverack PA. All the outputs are not completely independent so I got the same effect on the third outputs. Got rid of the driverack and went to the Bunker BPD 1. Much better. You can hook up eight independant subwoofers with it, all with parametric eq, etc. etc.

Also try going old school amp, breaking your back will improve your performance.
 
#29 ·
the excursion is impressive.
Define impressive, got a video of it?

One persons version of impressive, might be only 20% actual output.

This is more like 100%, not that I'd recommend you drive it THAT hard. :eek:
 
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