Triticum Agricolam
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Posts posted by Triticum Agricolam
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2 hours ago, Acura tl said:
My bad, I was going to run them at 2 ohm and the 1.75 per sub
Ok, in that case I'd probably go for a total of 45 sq in of port area. I still thinks Skars recommendation is a little low.
Assuming the net volume is 3.5 cu ft total, and you want to tune to 34 Hz, a 45 sq in port is going to need to be around 23-24" long. Keep in mind the layout of the box is going to change how long the port needs to be, but that should get you close.
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So, couple questions for ya.
You said the subs are dual 2 ohm, are you going to wire 2 ohms to the amp or .5 ohms?
How tight are you going to be for space? I assume you are going to go with Skar's recommendation of 1.75 cu ft net per sub tuned to 34 Hz? Since you are running above RMS power (which is fine), you should probably increase the port area a bit from what Skar recommends, but it will take up more space.
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How much power are you going to be running?
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1 hour ago, Artiflex said:
What I was wondering is will the 4th still be able to play down into the 20s like the slotted design will that I posted?
This is exactly what the "SPL" graph with tell you.
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Try switching the WinISD graph you are looking at from "Transfer Function Magnitude" to "SPL". The TFM graph is for looking a frequency response, but isn't good for comparing how much output you will get when comparing two enclosures.
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The best thing to do would probably be to model the subs in box simulation software. A larger rear chamber will get you more output below your front chamber tuning. It also increases cone excursion though, so it’s going to depend on how much power you are running.
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You said you have the box modeled in WinISD? You should be able to see what your front and rear port velocities are in WinISD. When it comes to port velocity, less is better, but larger ports come with their own design compromises. 30 m/sec is my hard limit, if I can get things closer to 22 m/sec that's a lot better.
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2 hours ago, Hopesndreams said:
Sorry i forgot to say I was doing a parallel tuned box and yeah I'll take any help I can get because some of this is a bit confusing
Sounds like you are off to a good start, just let me know with any specific questions you have.
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I'll try to help you as much as I can.
First off you need to decide if you want a series-tuned 6th order, or parallel-tuned 6th order. Parallel-tuned boxes are easier to do IMHO, but series-tuned boxes push all the output out one port and that can be useful depending on your situation. The two types are VERY different in how they are designed and WinISD ONLY models parallel-tuned boxes.
As far as the port area per cube suggestions you have come across, those are referring to series-tuned boxes and if that is what you decide to build I would strongly encourage you to NOT make the rear chamber small. In my experience making the rear chamber port small will get you a little more middle range output, but at the expense of just destroying your low frequency output. I can show you my testing if you are interested in seeing it. -
Growing up on the farm, I've always done all my own vehicle maintenance and I'm distrustful of anyone else doing it. That stripped out oil plug only confirms my fears.
A few years ago I had a Dodge truck with the 5.9 Cummins. I never changed the oil, at least not in the traditional way. I ran an bypass oil filter and I changed it out every 3K, about a quart of oil got replaced along with it. I did used oil analysis every 10K to keep an eye on how my additive package in the oil was holding up and how much soot was in the oil. The bypass filter was effective enough that the oil never got that dark diesel engine black, you could still see the dipstick through it. I ran it for 100k miles that way without any problems. That being said, messing with the bypass filter was kind of a hassle and I haven't bothered with the bypass filters on any of my other vehicles. Though I still am very picky about the oil I use (high quality full synthetic) and I use oversized oil filters everywhere I can.
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1 hour ago, SnowDrifter said:
Went through the log of some of the dashcam shenanigans
Pullman drivers are horrendous. I don't know how many times I almost got hit in a crosswalk when I was there.
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16 hours ago, SnowDrifter said:
Nice ZJ! Is that out by Moses Lake?
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1 hour ago, image91 said:
Thanks for the reply bro. That's a significant difference in porth length O_o Will have to add approximately 0.43 ft^3 to cater for the addition. Also, I will have to wrap the port in a "U" for it to fit probably. There was a distance of 11.5" between the port openings inside the box.
I used a random port calculator online. One of the very few that I found which asks for the number of slot ports. This leads me to the question, how do I know which calculators will give me an accurate port length? The calculator gave me a similar length to one of the persons who helped with the specs. I'm guessing he used a calculator of his own as well. If it's not too much trouble, did you use one as well? & if yes, which was it? Wouldn't mind fiddling around with it to see for myself.
With regards to the SA vs the E, did you mean the SA was the right choice 1 sub vs 1 sub? Or the 2 E-15s vs 1 SA-15?
Thanks again = )
So the proper way to calculate port length with two ports is to plug the numbers in for one port and divide your box volume in half. So for a 3.2 cu ft net volume box with two 2" x 15" ports you would calculated it like a 1.6 cu ft box with a single 2" x 15" port. In your case, if you are tight on space my suggestion would be to use one port if you can. It takes up less space due to having less internal panels. Also 60 sq in of port area is a bit more than you need. There is nothing wrong with having more than you need and with multiple ports its better to be on the high side for port area since multiples port are less efficient, but if you switched to a single port, 45 sq in (3" x 15") would work just fine.
With regards to the SA-15 vs E-15, I didn't see that you were looking at TWO E-15s vs ONE SA-15. Either of those would work well in terms of power handling, but the two E-15s would have needed a box twice as big.-
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You box net volume and tuning should be fine, though your port length is short if you want to tune to 34 Hz. To tune to 34 Hz I calculate your ports need to be 35" long each. You will have to adjust your external box dimensions to keep the net volume the same.
As far as an E-15 vs a SA-15. Here is a comparison of the two in the same size box. SA-15 is the green line and E-15 is the yellow:
Their frequency response is pretty similar. Note that this graph is raw output, cabin gain is not included and will boost the low end significantly. Based on the power you are running I think the SA-15 was the right choice.
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X8s aren't a good choice for 4th order bandpass boxes anyway.
SA8s would work. SA10s would work better.
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Go with what fits your space better. All else being equal I'd probably lean toward two 12"s over one 15".
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Your current setup will most likely be louder.
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DC recommends 1.5 cu ft per sub.
You would probably get more responses if you posted this in the Subwoofer/Enclosures section.
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A 2000 watt amp definitely won't be too much for a Xv2, as long as your gains are set right. You could put it on a 3k amp as long as you were paying attention.
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1 hour ago, Skullz said:
Does that not border on or cross the line for anti loan shark laws?
You print 26% and charge 100%. wtf
Nope, its 26% per year for six years. That's how it ends up being over 100% interest.
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2 hours ago, Karkov said:
A friend just bought this, now I need a new SUV..........
if this one doesnt work then I give up
FIFY
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Pictures no worky.
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1 hour ago, Colby88 said:
True haha. Well let me ask y'all one more question. If a ported box gets you the most output then why does 2 "ported boxes" together not do the same?
The parallel-tuned box should pretty much perform identical on low frequencies to ported box with a similar box specs as the low chamber. So with a 5 cu ft low chamber tuned to 28 Hz the 6th order should be like a ported box with 5 cu ft tuned to 28 Hz. At higher frequencies the 6th order is going to have more output than a ported box because of its second chamber.
Sub box spec
in Sundown Audio - GREAT Amps/Subs! GREAT Customer Service!
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No. That's net volume, which is what's left after you account for sub, port, bracing, etc.