Please help me choose HO-15, HF-12, Epic 12

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turbodawg

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satx said:
Okay, I read through that thread. It was a little inconclusive. Seemed like most of the guys on there were for dual sealed and the OP went with vented. Never posted any results. Personally in a room his size I would say one or two vented, but his room is about 50% larger than mine.

Here are the plots of the HF in ported (250L), sealed (125L) and sealed (125L) with eq applied (3.25db at 20Hz). All modeled with a single driver

Without a highpass filter the ported HF has amazing extension, but no protection and has the same output (xmax + about 10% limited) as the sealed version. With the HPF in place at 20Hz, which is what the NU3000dsp can do, the output is a good few db higher, but the response is pretty close to that of a the sealed HF with eq.

So the decision seems to be between:

HF vented-HPF @20Hz. More output with the same extension as sealed, Large box and I may not be able to add a second one due to size constraints.

HF vented-no HPF. More extension, but same output as sealed. Large box and no protection on the woofer.

HF sealed no eq. Smaller box, multiple subs possible. About the same output, but with much less extension than vented with no HPF

HF sealed with EQ. About the same extension, but less output than the ported box with the HPF. Smaller box.
Click to expand...

So, to start with, be aware that putting the sub directly next to your listening position will require time alignment to delay it, syncing it up with your mains. Take the difference in distance, divide by the speed of sound, this will give you the delay amount.

Sounds like your mains have good bass response already, so you're really going to need good output below 50hz to make a big impact in your extension.

If I follow correctly, here is the plot of output adjusted to xmax, which is what we should be concerned with:

389516d1387833293-please-help-me-choose-ho-15-hf-12-epic-12-dayton-15hf-comparison-spl.jpg


This looks like the ported is 6db more output at 20hz to me. To get the same with sealed, you will need two together in the same location. Two sealed in separate locations will give 3db more than one. While it may be a similar response curve, having the 6db more headroom will give you much more to work with when EQ'ing to flatten things out.

Keep in mind that's a 2nd order highpass, the inuke DSP can go up to a 8th order, which is much more abrupt. How this interacts with the roll off at port tuning should be considered. The 17hz tuning combined with the 8th order butterworth at 20hz should give very strong response to the low 20's, while the 2nd order will give a longer milder rolloff with more extension. You can try various highpass orders to find the right mix of extension vs. output around the highpass point.

Overall, I would try the ported box next to your listening location, with the inuke in bridged mode into the 4 ohm sub. Delay, highpass, lowpass, and EQ as needed, it should sound excellent, assuming a correctly designed and constructed box.
 
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satx

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Joined 2012
I didn't really get into what port size I needed and if it was feasible. I just threw this together real quick. It actually seems like it would work well in a ported box as small as 6ft, but then the port needs to be even longer I think.

I know that having the sub in the near field will mean some delay and possible phase adjustments. No problem. I'll measure and listen to get it right.

Yes, I know that the output is substantially higher for the ported alignment. I hadn't thought about the headroom that gives for eq'ing. I assume you mean if I have a suckout that needs boosting or does that help to cut too? To me I just figured that I don't listen at really intense levels so 110-112db for peaks should be sufficient. Is this not correct. I don't want to blow out the giant plate glass windows I have in the room and my house is 60yrs old. Not sure if that's a positive or negative in regards to structural integrity, but seriously, I don't plan on flexing the glass, I just want to feel the bass when appropriate.

With that in mind and with the possibility that I wouldn't be able to add a second one if it's 8ft^3 while two or three smaller sealed wouldn't be a problem. Do you still think I should go with ported even if I can only have one?

BTW, thanks for the help guys. People on this site can be so helpful and you guys have helped me to get my head around things that looked way above my head when I started out, and not just for these subs.
 
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satx

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I'm still contemplating. I know that the ported version won't disappoint me, it looks like it has really good output and extension. Step response and group delay are another question, but I suppose it's not supposed to matter too much when talking about sub 40Hz?

On the other hand, I can always try a sealed one and change if I'm not happy, no big deal. At least I know the drivers capable and I have enough power available to get what I'm after one way or the other.

I wish someone with experience with the HF sealed could chime in, but I've read most of the threads and reviews out there so I guess I know all I gonna know.
 
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satx

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Turbodawg, this is a post from you in the above thread. Can you explain the slat/stud part? Is it just the outside wall with strips of ply glued to the inside on end? Or is there a stud in there too?

"I would build with 18mm ply, 1x1/2" slat/stud bracing glued on end spaced every 6" (think of a stud wall), and line with real sound damping fiberglass, owens corning 703 2" thick or more against the slats (not the wall, with an air gap). Internally coat the walls with rubbery roofing mastic if you feel like it. That should max actual internal volume, while the fiberglass is the best you can do for stuffing."

I've got a bunch of the recycled demim insulation (2") that I've used for speaker lining. Will this work as well as the fiberglass. I've also got most of a sheet of 1/2" apple ply that I don't have a use for. Would this be too thin? It's really nice stuff. I was going to use 3/4 mdf, but I don't really like using the stuff. BTW, I always make braces out of ply not mdf.
 
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satx

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Joined 2012
One more thing. If I built this as about a 6ft^3 ported enclosure, could I then use sealed for any addition subs that I might add? Either all of them playing to up to the same main crossover or the ported playing up to say 30-40 and the sealed playing from 40-70 or so.
 
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satx

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Joined 2012
Wiring amp to inuke

Hey, I'm trying to understand how best to connect my two channel amp to the NU3000. I bought an RCA to balanced cable, but then it occurred to me that I would only be getting one side of a stereo signal to the single sub. Do I need to use a Y-cable from the amps' preouts to the rca to balanced that plugs into the behringer?

I'm using a Peachtree Nova which has L/R line out and pre out, but no mono sub out. I connect my receiver to the H/T bypass input of the Nova for tv/movies. For music I use the Nova's dac, pre and amp, for movies I use the receiver's dac and pre and the nova's amps.

Thanks
 
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satx

Member
Joined 2012
On the Behringer, should the signal lights come on when it's being used? As I understand it the bottom three lights (orange) are signal lights and the top (red) light is clipping.

I've only got it to light the bottom light once on loud bass heavy music. I'm worried that I'm not getting enough input voltage to it because I'm unable to get much bass at all or get the cone of the sub moving more than a couple of mm even when watching Jurassic Park last night.
 
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