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Triticum Agricolam

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Everything posted by Triticum Agricolam

  1. I agree with CJ18 and I think some type of slot ported box is going to be your best bet. You have a lot more design flexibility with slot ports so you should probably be able to fit enough port area in there vs what you can do with an aero port. Also, due to the way common wall slot ports work, a slot port will be shorter than an equivalent aero port of the same tuning.
  2. Honestly, I think you should sell the one 12" you have, and then buy two 10"s. That will fix both your space/port area problem, and your impedance problem. If you are determined to stick with 12"s, you are going to have to make design compromises somewhere. Ideally you should use at least 80 sq in of port area, with 3 cubes of net airspace, tuned to the low 30's. Since you don't have space for that, you are going to need to sacrifice somewhere and it is going to cost you performance one way or another. First thing I suggest is you don't use a triple baffle, a double baffle will be fine. Since the box is narrow that actually makes it stronger. Getting rid of that third baffle should gain you some space.
  3. I picked the Sundown sub as an example because Sundown is one of the few companies that gives an actual port area recommendation, not just the typical "x sq in of port area per cube". I picked the Zv.4-12 because its a roughly equivalent sized sub in terms of RMS power handling. I know it's not a perfect comparison, but 14 sq in of port area (using one 6" port for two subs) isn't anywhere near the 40 sq in Sundown recommends for their sub. This isn't the only information I'm going off of for my recommendation either. I'm also going off of my experience, and I also use box modeling software to see what kind of port velocities the OP is going to get. With a single 6" aero velocities peak at almost 80 m/sec, above 33 m/sec is when bad things start to happen and lower is better. Even if software is off by 25% (which I doubt) port velocity will still be way, WAY too high. The reason this affects daily use is primarily, you aren't getting what you pay for. If you lose 5 db to port compression, you are paying for a 4000 watt system, but only get roughly 1500 watt performance, if that even. Also there is a really good chance you will get port noise like crazy, so not only are you not getting the performance you paid for, you get some really annoying port noise you didn't want. Now the 5 db loss is just a number, I can't tell you exactly how much output is going to be lost to port compression, I wish I could. I do think that 5 db probably isn't unreasonable though.
  4. So next question, have you bought the subs yet? Given your space constraints you would probably be better served by 10"s. Another thing to think about, based on the amount of power you are going to be running your box really should have a double baffle and some bracing. Both of which are going to further eat into the amount of net volume you have available.
  5. Well that's better than a single 6" port, but is still significantly undersized. Have you built this box yet? Is it possible to just make the box bigger so you can use the proper amount of port area?
  6. Your box is a perfect example of why "port area per cube" rules don't always work out. I've built plenty of boxes with over 20 sq in of port per cube, it all depends on what the application requires. You are going to be putting 4k watts into this box, that's going to move some air and you need to facilitate that or your output is going to suffer significantly. To put things in perspective, Sundown recommends 40 sq in of port area per sub for their Zv.4 12"s. A single 6" aero port is 28 sq in, so you have 14 sq in per sub. Does that sound like a recipe for success? I know there are other people here who are saying they've run similar setups with a single 6" aero, but here's the problem, how do you hear the output you aren't getting because your port is too small? You can't. Port compression isn't always audible, but you would sure as hell hear the difference if it wasn't there.
  7. Nowhere near enough port area IMHO. Even two 6" aeros would be a bit on the small side.
  8. Sub choice matters too. If you have a sub with a really stiff suspension (low VAS) you are going to have a hard time getting anything other than peaky frequency response out of it.
  9. Real power. Zapco z-3kd. Hearing a 1db increase just from swapping the sub makes me want a ns3.... Keep in mind you can't actually hear a 1 db increase.
  10. That would probably be my recommendation. Two E10s in a small box to keep the frequency response smoother.
  11. Well the problem is what's "pretty loud" to one person may not be loud at all to another. Also I prefer ported boxes vs sealed boxes because I like a little amount of rising low end response. What it really comes down to is I can't tell you what you are going to be happy with.
  12. The E12 are going to have a lot smoother sound than the ported SA-12 will. The SA subs have fairly peaky output in reasonably sized ported boxes. They would not be my first choice for even sound. As far as which is louder, there isn't a simple answer. Around the tuning frequency the ported box will most likely get louder, partially due to its peaky nature. Above and below tuning the two sealed subs will most like beat it. As a side note, I have a single E12 in a small, low-tuned ported box and I love how it sounds, very smooth and even. It get loud enough for me, at least most of the time, though my desire for loudness is probably a lot less than most folks here.
  13. +1 to what CleanSierra said about bandpass boxes. However if you would like to try one anyway, here are some things to think about. The reason people (like me) said to ignore bandpass box "ratios" is because they don't really tell you anything. Having a high aspect ratio does not guarantee you will end up with highly efficient box, and having a low aspect ratio doesn't guarantee you will have a wide bandwidth. These is because those attributes are not determined by the relationship between the two chamber sizes. Those attributes are both mostly a function of front chamber size. So if you have a box with a 3 cube front chamber and a 1 cube rear chamber, you have a 3:1 ratio. Now if you were the double the rear chamber to 2 cubes you now have a 1.5:1 ratio which by common (incorrect) wisdom would make the box have a lot wider bandwidth, but in practice its not going to make the box sound that much differently. As far as sizing the rear chamber goes, I pretty much agree with CleanSierra. Larger is better. Making the rear chamber larger will improve you low end performance by reducing the sealed resonance frequency and the QTC. What limits how large you can make it is mechanical power handling. As you make the rear chamber larger your cone excursion below tuning also increases. You don't want to go too far. Modeling software can help give you an idea of whats going to happen.
  14. Your install looks so clean! You have some awesome fab skills and serious attention to detail, I'm jealous! How does it sound?
  15. Don't worry about it. I just like to see how other people design their bandpass boxes.
  16. That looks awesome!! Do you know what the specs are on the box? Chamber size & tuning?
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