DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 Mainly music and video games but movies every now and again. I'm not expecting it to sound like a high end HT sub Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted November 23, 2015 Report Share Posted November 23, 2015 Ok, so here are some things to think about. There are two reasons why I recommend avoiding the Dayton plate amps. The first is because they are really expensive for the power they put out compared to other options. For $200 you can get a Behringer NU1000DSP pro audio amp that should put out roughly the same power, but it comes with very sophisticated digital signal processing and is MUCH more flexible in its usage. Or for $270 you can get an NU3000DSP amp that has all the same advantages, but puts out 2.5x as much power. There are other pro audio amps out there that will beat the plate amp for price/performance too. The other reason to avoid the Dayton plate amps is they aren't terribly reliable. I have two of them, though they aren't the same model as the one you are looking at, and I'd had issues with both. I had to send one back to get it replaced and it still isn't working 100% correctly. I know a lot of other folks that have had issues with Dayton plate amps as well. If you must stick with a plate amp I hear the Bash ones work well for people. I looked over the specs for your sub and box, the box design the manufacturer gives you really is intended for car audio use and isn't very appropriate for home audio. Home theater sub enclosures need to be designed differently than car audio boxes and there are a couple reasons for that. The biggest difference is in a car cabin gain boosts the low frequency performance of the sub significantly and in your home you don't get that anywhere near as much. The other difference is for movies you want to be able to play a lot lower. For music 30 hz is usually about as low need to go (with some exceptions) but for movies the magic number is 20 hz. It may not seem like big difference between 30 and 20 hz, but it is. In fact, getting good output to 20 Hz with most 12" subs is very hard to do but you want to get as close as you can. So the largest glaring problem with your proposed sub box design is port area. You don't have even 1/3rd as much as you should have. If you change nothing else you REALLY need to increase your port area or all you are going to have is a leaky sealed box. I would suggest at least 32 sq in (200 sq cm), you will need to lengthen your port significantly to keep your tuning frequency the same. Port area is extra important with subs that will be in your home since port noise is MUCH more noticeable. Since you are going to be using your sub for movies from time to time you will really get better performance if you make the box larger and tune lower, I'd suggest 75 liters (2.65 cubic feet) tuned to 26 hz with at least 35 sq in (225 sq cm) of port area. This should get you decent output down to around 23 Hz or so. In addition to getting you better low frequency output, this lower tuning will help save your sub from destruction due to over excursion the first time you watch a movie with content below 30 hz. This is a serious possibility with the amount of power you would like to be running and a 35 hz tuning. You also should use an amp with an adjustable high pass (subsonic) filter to help protect your sub. The SPA-1000 has a high pass filter at 18 hz, but that's much too low to help you, which is another good reason not to use that amp. The pro audio amps I suggested do have this function and you can set the high pass filter where you want.. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 Thank you for your advice. I will take your advice and redesign and look into a pro amp with adjustable high pass filter. What do you suggest the port length be if the area is 36 inch^3 and I make the Vb 2.65 ft^3 like you suggested? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted November 23, 2015 Report Share Posted November 23, 2015 Its going to need to be about 42" long. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 Its going to need to be about 42" long. Damn, okay. Does bending it change it's tuning? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted November 23, 2015 Report Share Posted November 23, 2015 Nope, bend it all you need, less bends are better for airflow, but they don't affect tuning, just measure the length of your port down the centerline. Depending on the size of your box, you may need to only put one 180 degree bend in your port. Here is an side view of a home theater sub I built recently and how I did the port. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 That picture actually helps a lot, thank you! Well, I have a few questions. 1.) Seeing what you did there, should I put some sort of dampening material on the inside like you have there? 2.) So, now that i'm using an external amp, how do I go about getting the power to the driver? As in, how do I connect the leads to the amp with out compromising the integrity of the box? 3.) What material should I use? I was thinking baltic birch, but i've seen you talking about some other wood. 4.) What kind of glue should I use? What do you recommend? 5.) How should I go about making the corners? Just glue them or do some kind of joint (like a box joint)? Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted November 23, 2015 Report Share Posted November 23, 2015 1. The purpose of the felt is to absorb any out of band noise that can come off the sub. 99% of the time, it won't matter and you won't be able to hear any of that noise anyway. I have the felt and its easy to do so I do it, if you don't have any felt I wouldn't worry about it too much. 2. For getting power into the box I use a terminal cup. There are good terminal cups and there are cheap ones, the cheap ones often leak. Here are the ones I use: https://www.parts-express.com/parts-express-round-speaker-wire-terminal-cup-2-7-8-gold-spring-loaded--260-276 There are other ways to get power into the box that work equally well, binding posts are a good example. 3. For materials, there are lots of choices. MDF works fine, or any 3/4" plywood with 7 or more plys. I use arauco plywood because its a good compromise between cost, performance, and weight. If cost didn't matter I'd probably use baltic birch for everything. 4. For glue I use TiteBond II. Any aliphatic resin wood glue should work equally well. If you aren't completely confident in your ability to get really tight joints, you can use a polyurethane construction adhesive. It expends as it cures and will seal just about any imperfect joint. Its a little more expensive and can be messy though. PL Premium is a good example. 5. Simple butt joints are more than sufficient for speaker cabinet construction, you don't need to do anything fancy. The glue does all the work. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds: Link to comment Share on other sites More sharing options...
DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 I see that those cup terminals accept up to 8 gauge wire. Will 8 gauge wire be able to support the power i need/want to push to the sub? Also, I think I'm just going to stick with Baltic birch, it looks nice and I was wanting to just put a nice stain on it. Keep it simple Link to comment Share on other sites More sharing options...
DLHgn Posted November 23, 2015 Author Report Share Posted November 23, 2015 Also, how would a mitered butt joint hold up? It would definitely look cleaner Link to comment Share on other sites More sharing options...
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