Dual UXL 18 Sealed Plans - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 72 Old 04-19-2016, 01:06 PM - Thread Starter
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Dual UXL 18 Sealed Plans & Build

** Note: actual build starts at post 42 **

It looks like I was able to just squeak in to the group buy for a pair of UXL 18s, and I jumped on it before I had a chance to do much research or planning. I took enough time to assure myself that the price was right, and that they were still solid performers, and the local Canadian source (no need to re-ship/drive to border/etc.) was what sealed the deal for me.

I had been planning for a long time to use a pair of sealed 18s in our theatre build, so there’s no deviation there. I was considering the SI HT18 before they disappeared, and then looking at either the new DS4-18 or possibly an Ultimax 18, both a step up with a corresponding increase in price. When I saw the chance for a pair of UXLs, I did some quick googling and determined that they seem to have more output capability than the other 2 (at least a higher Vd), were well regarded, and perform well in small sealed enclosures. That’s another plus for me, because I wanted to keep mine under 2x2x2 to hide behind a tight screen wall. Price will be reasonably comparable by the time I get them all to my door, though they are still likely a little more than the SI or Daytons would have been.

Now... what to do with them!? As I said, I had been planning for a pair of sealed 18s. Right now I’m running a large ported (original) Tempest tuned to 19Hz, and a ported SDX10 tuned around 25Hz. By my calculations, those two combined still fall well short of the Vd of a single UXL, so I think I’ll be in for a noticeable upgrade. I’ve been very interested in trying a Linkwitz Transform design for a long time, and I think that’s the route I’d like to take with these. I like the idea of a small sealed sub with a very capable driver given a good amount of power and EQ to achieve optimal results. My planned amp so far is an inuke 6000DSP based on the performance per dollar ratio. I get the impression that the UXL is a hungry beast, and I want to make sure they have enough power to really get moving. With that said, my room is less than 10x20x8 (1,600 cubic feet) so I don’t anticipate the need to drive them very hard to get enough output.

So, where do I start? It seems that the UXL likes small sealed enclosures, so let’s start with about 3.5 cubes, which seems common. A 20x20x22 enclosure made from 3/4" material with a double front baffle, less about 1/3 cu ft for the driver gives me 3.566 cubes (internal). Minimal bracing won’t hurt that too much, and stuffing will help to offset.

If I’m modeling that correctly in WinISD, that gives me an f3 of 46Hz, and an f6 of 32 Hz. Now I’ll need to improve on that. If I wanted to do it quick and simple, I could use the DSP from the inuke6000 and dial in a few bumps. Alternatively, I still have my BFD (Behringer DSP1124P) that I could use for simple EQ and not need the DSP model inuke. OR... if it actually provides a better solution, I’d be happy to skip the DSP model and pick up a MiniDSP, which I could program with the Linkwitz Transform tool and do it properly. I have a few problems here.

First, I don’t really have a specific target frequency, I just want to maximize my useable low end response. Second, I’ve been playing with the LT in WinISD and it seems to take the cone excursion beyond Xmax pretty quickly with well under the 3,000W theoretically on tap (as expected, really). Building in a 10Hz high pass seems to help, but I really don’t know how to properly model this and integrate real world amplifier power.

I guess that’s where I am right now. Maybe not as completely lost as I thought, but in need of some serious mentoring to make what will be my last (?) sub build as epic as it can be.

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post #2 of 72 Old 04-19-2016, 02:00 PM
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6k @4ohm s will be more like 11-1200wpc according to bench tests, I think brief periods or only 1 channel will do ~1800w. Maybe I'm mistaken.

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post #3 of 72 Old 04-19-2016, 02:02 PM - Thread Starter
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Thanks muzz. I haven't been able to get the details on actual output yet. I think that sounds reasonable for these drivers (I hope)...

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post #4 of 72 Old 04-19-2016, 02:12 PM
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Here is a bench test of the 6k so you get a better idea of what you can expect, pay attention to the test duration and the frequency tested, low frequency is more taxing as you'll see.
notnyt from here also has an amplifier test thread with the NU46000 I believe, he's tested 2 berries I THINK.
Take a look at this thread for the 6k, pay attention to duty cycle and both channels vs 1.
http://forum.speakerplans.com/behrin...opic69202.html

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post #5 of 72 Old 04-19-2016, 02:32 PM - Thread Starter
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Awesome info, thanks muzz! I'll give a read and incorporate that into my model. The UXL's are specced for 1200w rms, so they seem to be well suited, at least on the surface.

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post #6 of 72 Old 04-19-2016, 02:40 PM
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Probably just set the limiter for voltage peaks and be done with it.
Folks tend to set a limiter on the Berries just to keep it under control/ not shut down, even if the driver can handle it.
I figure just a bit below max.
It even mentions that in that thread I linked I THINK.
Good Luck, glad to help!

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post #7 of 72 Old 04-19-2016, 02:51 PM
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Sweet to see another Canadian build!

Sounds like you have everything thought out, should be wicked!

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post #8 of 72 Old 04-19-2016, 03:45 PM - Thread Starter
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Quote:
Originally Posted by uniquepattern View Post
Sweet to see another Canadian build!

Sounds like you have everything thought out, should be wicked!
We'll see... I know just enough to make a complicated mess of things.

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post #9 of 72 Old 04-19-2016, 04:55 PM
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Quote:
Originally Posted by OJ Bartley View Post
We'll see... I know just enough to make a complicated mess of things.

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Lol...
You're in good hands here bud.. There should be enough guys local to you if you need any hands on help too.
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post #10 of 72 Old 04-19-2016, 05:29 PM - Thread Starter
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Thanks fatty. The hands on stuff I'm confident with. I'm not half bad working with wood. It's just the simulation and arcane driver - amp - enclosure relationships that I need the all knowing AVS gurus for. 😆

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post #11 of 72 Old 04-20-2016, 04:59 AM
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I felt the same way before I started my build...

The guys here are wicked cool, and the collective knowelege base is freaking unreal!

Dont sweat a thing!

And there are a few guys local too, Im about an hour or so drive north of Toronto...
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post #12 of 72 Old 04-20-2016, 05:32 AM
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I'll be keeping an eye on this thread.. I am another Canadian doing a dual UXL build soon! I'm doing the full martys . I'm pretty bad with electrical/the theory behind everything too so I'm hoping when I hook everything up I don't blow up the NU6000 with the wrong settings..
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post #13 of 72 Old 04-20-2016, 10:37 AM - Thread Starter
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I'll do what I can to clear the waters for you, systemlayers!

uniquepattern, careful, you're tempting me to drive up your way to audition your 24" monsters!

OK, I've been at it again. I like the idea of designing everything, including the LT in WinISD, because it lets me see the effects of my EQ, rather than just adding +6dB of boost at 20Hz after I get it in-room and wondering why it went CLANK. I know I'll still need some tweaking after setup, but my plan is to maximize low extension within safe Xmax limits, and then if I have to EQ in-room I can stick to making cuts to flatten my response.

Here are 2 graphs from my experimenting. Sealed enclosure (3.566 ft^3), Single UXL-18, using 1,200W input power. Yellow is the original model, and blue adds the LT filter specified. At this point the LT was just a result of playing with numbers, there was no hard reason behind what I used.

Clearly I need to work on the excursion in the LT model, and I'll try out a high pass at 10Hz or so, but is this generally how people manage the details? Just trial and error? I really like muzz's point about a voltage limiter, and I need to do more reading about them.
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post #14 of 72 Old 04-20-2016, 10:59 AM
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When I get them, and they are all dialed in, for sure!

Pizza, Beer and some serious bass anyone??????
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post #15 of 72 Old 04-20-2016, 05:48 PM
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A 30A breaker will be needed to get 1200watts RMS x2 without tripping it. (Assuming the amplifier is legit.)
A 30A breaker would support roughly ~1500watts RMS x2. A 20A breaker is 33% less power, and a 15A breaker is 50% less power.

That's just the laws of physics talking.

Burst power is usually <1 second and even just a 15A breaker can support many kW's of burst-power.

Most music and movies only contain/need burst-power. (Unless you are listing to sinewaves, techno bass, and heavy dubstep, then you'll need lots of RMS juice.)

I've heard the SDX-10 in person and I've heard the UXL-18 in person, and I've seen videos of the tempests.
The SDX-10 is like a tweeter compared to the UXL-18. LOL
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post #16 of 72 Old 04-21-2016, 05:47 AM - Thread Starter
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Quote:
Originally Posted by BassThatHz View Post
A 30A breaker will be needed to get 1200watts RMS x2 without tripping it. (Assuming the amplifier is legit.)
A 30A breaker would support roughly ~1500watts RMS x2. A 20A breaker is 33% less power, and a 15A breaker is 50% less power.

That's just the laws of physics talking.

Burst power is usually <1 second and even just a 15A breaker can support many kW's of burst-power.

Most music and movies only contain/need burst-power. (Unless you are listing to sinewaves, techno bass, and heavy dubstep, then you'll need lots of RMS juice.)
Thanks for stopping in, BTH! Glad to have any input from you in here. First, I'll have you know I find listening to sine waves very relaxing...

I had been doing some reading about real world power requirements and output, and had been planning to run a dedicated 20A line for the sub amp, but I don't think it will be much more trouble to make it a 30A. A quick look online suggests 10ga wire should handle that I think, but what about the receptacle? Most of what I see in the 30A range look like they're for appliances and heavy equipment. Is 30A overkill, especially if I plan to voltage limit the amp? Or would it be a sensible precaution to avoid going into protection when running hot?

Edit: I've been rereading and I think I should be safe with 20A for standard movie and TV duty, but any feedback here is welcome.

Quote:
Originally Posted by BassThatHz View Post
I've heard the SDX-10 in person and I've heard the UXL-18 in person, and I've seen videos of the tempests.
The SDX-10 is like a tweeter compared to the UXL-18. LOL
LOL... now that's good to hear. I think I'm being a little naive about the output I'm going to have when these are done. I just can't really picture it, because what I have now is my only reference. And it has been fairly impressive for the last 10 years or so. Logically, I think I'll be capable of about 4x the displacement I have now between the 2 current subs, but can I actually expect it to SOUND and FEEL that much different?

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post #17 of 72 Old 04-21-2016, 06:11 AM
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30amp does have a different receptacle. They actually make an adapter to go from "RV plug" to standard 15/20amp style. I did that in my old house at the suggestion of Harmon.


http://www.amazon.com/Prime-RV201801...ilpage_o06_s00




If I was doing it today, I'd just install the 20amp.
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post #18 of 72 Old 04-21-2016, 09:31 AM - Thread Starter
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Thanks John. I'm leaning towards 20A, for simplicity and as a precaution to not overdrive too much.

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post #19 of 72 Old 04-22-2016, 08:58 AM - Thread Starter
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I've been doing more reading, and it seems like there are a lot of people successfully running quite a lot of gear (including multiple amps/AVRs) off even a single 15A circuit, so I think I'll be in good shape with a 20A just for the inuke, and a dedicated 15A for the rest of the gear. Volume seems to be the key factor in power consumption, and this room is going to be tiny, so I can't see us cranking things up to ear splitting levels. At least not on a regular basis.
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post #20 of 72 Old 04-22-2016, 09:04 AM
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I think you'll be good. I was tripping the 20amp breaker just before clipping on a CV-5000, which is why I put in the 30amp circuit. You shouldn't have that problem with the iNuke.


Edit for clarification...I was running the CV-5000(old school iron) at 2ohm stereo
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post #21 of 72 Old 05-03-2016, 07:54 AM - Thread Starter
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While I'm waiting for Mark to cut into some raw metal and get these puppies built, I thought I'd post some idle musings I had on my commute this morning. I've been using ported subs for a long time (again, a ~6cube 19Hz tuned original Adire Tempest and a ~1.5 cube 24Hz tuned SDX-10) and I'm pretty used to the sound. I haven't properly calibrated them or set any EQ in our current living room, so there can be a little boominess at times, but they do a good job of rumbling as needed down low.

I've never heard a powerful sealed sub in person. I convinced myself a long time ago that I wanted to try something like that for my next sub project, and it looks like I'll be able to carry out my plans with a pair of UXL-18s. And now is when the hesitation kicks in. What if I'm a "ported guy"? I know that, all things being equal, ported subs will have an advantage in output down to their tuning frequency. More is better right? Should I be directing my efforts to just make "the most sound" that I can?

Well, let's take a step back first. First, I have a quick WinISD comparison of my two current subs and a single theoretical sealed UXL, as planned at 3.556 net cubic ft, getting approxinately 1,200W from half of an iNuke6000. (Ignore the orange lines, that was for my brother's project).



As I mentioned way earlier, looking exclusively at displacement, I think a single UXL (yellow) has more than twice the displacement capacity than my existing subs have combined. I'm not sure how to mentally sum the output of the pink and blue subs, but I think that even a single sub in this configuration would provide an upgrade. Would it SOUND like an upgrade? I'm not sure. I'm sure that from 20Hz and down it would be improved.

BassThatHz mentioned that he's heard the SDX-10 and the UXL-18 and that, comparatively, the SDX is like a tweeter, which I was glad to hear. There would be no question if it was my only sub that I would be crushing it with this upgrade. At least I'm glad to see that the UXL is significantly higher at the Tempest's tuning frequency, and well above it at it's peak of 70Hz. More reassurance. I won't even add EQ to this model, because it seems to be a clear win (even without adding the second UXL). OK, good.

Now my second issue... how much am I leaving on the table by going sealed vs. ported? Let's see. Now, I don't have unlimited space to put these things, so LLT is not an option. I did a quick model using about twice the size (7 cubes) and tuned to 16Hz.



The ported sub seems to have an advantage from about 48Hz and down, which is kind of an important area. Cone excursion just squeaks over xmax in the ported model at 10Hz, so that shouldn't be a major concern. Now, my secret weapon with the sealed sub... EQ. Theoretically (let me know if I'm getting this wrong), the sealed sub can handle more power by selectively applying some EQ to shape the response curve more to my liking. Ideally, I'd like to figure out a Linkwitz Transform that suits my subs, but I'll wait to measure in room before getting too far into that. Even using just 2 PEQ filters (as shown in the model), I'm able to bring it up to a more comparable result. The filters both keep boost to only 3dB, and cone excursion just barely comes above xmax at around 16Hz then dips back under.



The ported sub still has a 3-4dB advantage between 11 and 26Hz, but we're a lot closer. And working with half the size. I'm still getting 7dB more than I was from the Tempest at 20Hz, and I'm not even modeling the pair of UXL's. I was able to obtain a very similar result with an LT and a high pass at 10Hz to keep excursion reasonable. I guess what I have to ask myself now is "is that good enough?". I suspect that it will be. Does the sealed model's advantage above 26Hz mean it will feel "tighter" or give it more "punch"? Those traits are typically assigned to sealed subs (or that they sound more "musical"), are those attributes just typical of sealed enclosures in general? Do they exist at all? I know, this is getting flaky. And I'm about out of mental capacity.

TL;DR - will my big ass sealed subs sound better than my current menagerie of mismatched ported subs, and will I be happier with the smaller sealed and EQ'ed enclosures rather than going ported again? I hope so. Does sealed have a "better" sound quality? Does a sealed setup provide more "punch" or "slam"? I'm drifting again, I need to step away...
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post #22 of 72 Old 05-03-2016, 09:16 AM
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@BassThatHz


breakers tend to pass a little more than that. for example, here is a ge 15 amp breaker time current curve:




on top of that, the VA of the amp will vary based on the impedance of the driver (though below about 15hz, it does start to approach v/re) as well as both the efficiency and the design of the amp.


edit: here is an explanation:


the green shaded area is roughly where the breaker will trip.

the left side represents the minimum time-current, the right side the maximum time current.

the minimum is the side of interest, for the most part.

the breaker is rated for 15 amps.

so if you go across the x-axis (the bottom axis) to "1" that represents 15 amps. then you go up until you hit the green. when you hit the green, then move over to the left side (the vertical axis) to see how much time the breaker will allow the 15 amps to pass.

if you go to "1" on the x-axis, that is 15 amps. if you go up the chart, you never hit the green. so that means that the breaker will allow 15 amps to pass pretty much indefinitely which is what you want from a 15 amp breaker.

if you go to "2" on the x-axis, that is 30 amps. go up the chart until you hit the green. then go to the left and you will see that it indicates about 15 seconds. this means that the breaker will allow 30 amps to pass for a minimum of 15 seconds.

of course all of that is based on the breaker being cold. success hits will reduce those times. the key point is that a 15 amp breaker isn't a brick wall at 15 amps. for short bursts, more current can be attained without tripping the breaker.

Listen. It's All Good.

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post #23 of 72 Old 05-03-2016, 09:20 AM
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op,


there are shelf filters in the inuke dsp. the 12db/oct filter is the same as a linkwitz transform with both corners set to q=0.707. that can be modeled in winisd by changing the both of the q's in the filter to that value. then along with change the frequencies, the filter can be moved around. and if that doesn't give you the exact response that you are looking for, peq can be used to finish things off. in room though, you will have both gain and modal effects. the modal effects will botch up the pretty winisd response anyways, so best to measure once you are set up to see what you are working with and go from there.

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post #24 of 72 Old 05-03-2016, 09:28 AM
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"Theoretically (let me know if I'm getting this wrong), the sealed sub can handle more power by selectively applying some EQ to shape the response curve more to my liking."


this isn't correct.


it seems to be a misunderstanding that is going around.


turn off all filters. set the power that the amp can output. that is the max level at each frequency before the amp will clip.


by adding eq to boost some frequencies, the overall level MUST be reduced, or those frequencies will just clip earlier.


if eq were "free", the you could just buy a 1w amp and apply 50db of eq at 20hz and have full reference output.


additional explanation here:


Feedback needed on 6x sealed JBL CS-1214 DIY build
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post #25 of 72 Old 05-03-2016, 11:53 AM - Thread Starter
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Wow, thanks LTD02.

Quote:
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@BassThatHz
breakers tend to pass a little more than that. for example, here is a ge 15 amp breaker time current curve:
I stared at that graph for a while, and felt extremely dumb.

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Originally Posted by LTD02 View Post
there are shelf filters in the inuke dsp. the 12db/oct filter is the same as a linkwitz transform with both corners set to q=0.707. that can be modeled in winisd by changing the both of the q's in the filter to that value. then along with change the frequencies, the filter can be moved around. and if that doesn't give you the exact response that you are looking for, peq can be used to finish things off. in room though, you will have both gain and modal effects. the modal effects will botch up the pretty winisd response anyways, so best to measure once you are set up to see what you are working with and go from there.
That's kind of my plan, I'll build, measure in-room, and then plan my EQ strategy when I see if I'm getting much room gain, or any serious nulls.

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Originally Posted by LTD02 View Post
turn off all filters. set the power that the amp can output. that is the max level at each frequency before the amp will clip.

by adding eq to boost some frequencies, the overall level MUST be reduced, or those frequencies will just clip earlier.

if eq were "free", the you could just buy a 1w amp and apply 50db of eq at 20hz and have full reference output.
This makes sense. What I'm hoping is that these subs will easily keep pace with my mains (probably DIYSG 88 Specials), and that I'll have lots of overall headroom. Then I can boost a little in the low end, and possibly cut higher up to flatten things out. But hopefully I'll have plenty in reserve, because I doubt I'll ever max them out in the tiny room I'm building. If I was pushing 2 UXLs to their limits in a tiny enclosed space, my hearing probably wouldn't last too long.
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post #26 of 72 Old 05-03-2016, 04:58 PM
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"I stared at that graph for a while, and felt extremely dumb."


apologies if it was confusing.


the green shaded area is roughly where the breaker will trip.


the left side represents the minimum time-current, the right side the maximum time current.


the minimum is the side of interest, for the most part.


the breaker is rated for 15 amps.


so if you go across the x-axis (the bottom axis) to "1" that represents 15 amps. then you go up until you hit the green. when you hit the green, then move over to the left side (the vertical axis) to see how much time the breaker will allow the 15 amps to pass.


if you go to "1" on the x-axis, that is 15 amps. if you go up the chart, you never hit the green. so that means that the breaker will allow 15 amps to pass pretty much indefinitely which is what you want from a 15 amp breaker.


if you go to "2" on the x-axis, that is 30 amps. go up the chart until you hit the green. then go to the left and you will see that it indicates about 15 seconds. this means that the breaker will allow 30 amps to pass for a minimum of 15 seconds.


of course all of that is based on the breaker being cold. success hits will reduce those times. the key point is that a 15 amp breaker isn't a brick wall at 15 amps. for short bursts, more current can be attained without tripping the breaker.


edit: I copies the explanation into the previous post so if anybody is confused about time-current curves, the explanation will be right there with the picture.

Listen. It's All Good.

Last edited by LTD02; 05-03-2016 at 05:01 PM.
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post #27 of 72 Old 05-03-2016, 05:34 PM - Thread Starter
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No apologies necessary LTD02! But thanks for the explanation, now it makes sense.

So theoretically, on a cold breaker under the right conditions I could be pushing about 1,600wpc (if demanded) for peaks of around 15 seconds... I think. I'll still stick with a 20a breaker for the subs, but now I understand how even a 15a works for most people.

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post #28 of 72 Old 05-31-2016, 09:15 AM - Thread Starter
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In anticipation of completion of my UXLs, I'm putting together a shopping list for enclosures and setup stuff. I think I have everything sorted except the connections.

I will be going from AVR ----> nu6000 ----> two sealed UXL enclosures.

Right now I have a few pairs of RCA to XLR cables, so that's what I'll start with for the first connection (AVR to iNuke). When I add the MiniDSP I'll insert it with RCAs before the iNuke.

I have some concerns about introducing hum, going from unbalanced RCAs to XLRs, but I'll just see what happens and deal with it later. I've read that using RCA to TS (unbalanced?) might be a cleaner way to do it, so I can do that if I need to.

My main confusion kicks in with the Neutrik Speakon connections. I want to make sure I get it right. So, will 2-pole connections be what I need? One for each run, from amp to sub? And then my enclosure speakon jacks will just be wired red = +1 and black = -1 for each sub. No need to bother with 4-pole at all, right?

Side question: would the MiniDSP with adjustable "Max Input Jumper" be a good idea, and would it ideally be set to 0.9Vrms or 2Vrms in a typical modern AVR to pro amp setup? (Any benefit to using the balanced MiniDSP instead, coming from an unbalanced consumer AVR signal?)
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post #29 of 72 Old 06-02-2016, 08:55 AM - Thread Starter
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OK, I think I have it sorted out. I'm going to pick up a pair of Monoprice "2-conductor NL4 Female to NL4 Female" cables. Then the enclusures will have the Neutrik NL4MP panel mounts installed in them. I think I'm going to install a pair of these for each enclosure, one for the "back" and one on a "side".

I've heard that the Speakons need a few inches of clearance when connected, so I want to make sure I leave some flexibility for placement. This way I'll be able to rotate 90 degrees and still place against the wall if needed.

Next steps to start construction...

1) Can anyone confirm the baffle cutout sizes (inner and outer)? Not that I don't trust Mark's posted numbers, I just don't want to have to recut anything. Website says Outside Diameter - 46.9cm (18 15/32"), Mounting Diameter - 42.4cm (16 11/16"). Is that generous, tight, right on the money?

2) The driver mounting kits from PE seem nice, which size would I want for the UXL frame recessed into a double layer 5/8" MDF baffle... the 1/4"-20 Speaker Mounting Kit?

Once I find some time to go pick up some MDF and supplies, I can chip away at construction here and there until the drivers are built and shipped. It's all starting to come together in my head. I think.
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post #30 of 72 Old 06-02-2016, 09:12 AM
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Quote:
Originally Posted by OJ Bartley View Post
1) Can anyone confirm the baffle cutout sizes (inner and outer)? Not that I don't trust Mark's posted numbers, I just don't want to have to recut anything. Website says Outside Diameter - 46.9cm (18 15/32"), Mounting Diameter - 42.4cm (16 11/16"). Is that generous, tight, right on the money?

Once I find some time to go pick up some MDF and supplies, I can chip away at construction here and there until the drivers are built and shipped. It's all starting to come together in my head. I think.

Hey, OJ! Just finished my own project using similar components. The UXL mounting diameter spec is really tight. 16 3/4" works, you can go up to 17" with no issues. Outside diameter is also right tight, I think 18 1/2" would give you a perfect clearance around the driver.


Good luck with your project! I think you'll be pretty happy with the setup.


Also, if you were lucky enough to get a post- Q2 2015 iNuke, the fans are pretty quiet and inoffensive. The DSP is awesome.
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