ibanender

Nobody ever refers to a ported box as a 4th order. I'd bet there are few that know 4th order (without bandpass name) is ported, so when they say 4th order it's assumed 4th order bandpass.

You do realize bandpass tuning isn't he same as ported tuning, right? A 35 hz tune would give him NO passband at all. If the sealed chamber is reasonable, it would play the hell out of about 30-40 hz and nothing else, and won't be loud doing it. The front chamber needs to be tuned much higher, like 55-60 hz.

There is a reason for that. Maybe it's worth paying attention to what they're telling you instead of what you're wanting to do

Yup, outside of a burp application, over 1.75 cu. ft. tends to get sloppy.

Show your math. Remember that the only usable energy stored is that in the voltage between whatever your alt voltage rests at and the battery voltage. That's also in a perfect world where there is no ESR to worry about. I've done the math. Usable energy in a perfect world (no ESR) is 0.5 amp-seconds/Farad. (farads*voltage) / seconds There are a number of "what if's" like ESR, but the math I found back when I was compiling a spreadsheet of equations is what you see above. If I can round up a capacitor this weekend, I'll do a real world test of draw over time to verify.

It's not carrying a load, just isolating the loop. I was using 16 ga as an example of it doesn't need to be large, virtually any size will be sufficient as long as you can make secure connections. If it doesnt' do it on the first try, try another point on that plate amp.

Yes, that's what I was saying. I'm 99% sure it will solve that problem because I had the same issue with a computer in a vehicle used in a similar manner. If you think about it and understand circuits and ground loops, it'll click.

Once you do a 100% steel box, you'll go back to wood. Having to tap holes and bolting in the sub is a PITA. Ask me how I know. Now if you're talking all steel except where the speaker mounts, I can show you an Explorer done that way. It's 1/2" steel.

Better question, what 1700 watt amp do you have? dont have one yet. Then why are you worried about an SA15 taking 1700 watts daily, or getting a sub that will work on 1700 watts?

The way I check grounds without a DMM is as follows: 1. Find ground wire 2. Pull on ground wire till your hand hurts 3. If it didn't come loose, ground is good. If it came out, ground was not good enough/bad.

this... ive read some stuff on how caps can help for 30k+ systems that burp but never saw anything solid on it... If it worked, you'd probably see it in 170+ vehicles instead of 30+ batteries.

Better question, what 1700 watt amp do you have?

Did you actually read the original post at all? If he was doing DVC's he'd need 4 ohm coils and wire it series parallel. If you want 1 ohm with 8 SVC subs, you need 8 ohm coils.

A clipped INPUT is also different from a clipped output. The speaker is dumb, it only plays what you tell it to. You can clip the input and the output power will remain the same as clean. For the people that run 1500 watts daily on their 1000 watt sub without problem, there are 2 things to consider. Is the sub designed to take more than rated because they know the user will exceed it? What's the ACTUAL power going to the driver? I have an SAZ-3500d on a single SA8 @ 1 ohm DAILY, does that mean that sub is getting 3500 watts while I drive around? No.

Not only does wood thickness play a part, wood type does too. Most MDF found now is a low grade, very soft MDF that SUCKS. You can tell by if it's dark or light. Dark stuff = bad. I built a few boxes, identical, out of light and dark MDF and the dark MDF was always 1.2-1.5 dB quieter. The best wood to use that is reasonably priced.... a decent grade plywood. All my 7/8" plywood boxes = louder than 3/4" plywood = much louder than 3/4" MDF. This is with a 1 cu. ft. single 8" box BTW.

Is there a ground loop problem? Yes. Will a ground loop isolator fix it? No. (side note, a ground loop isolator will also cut off low end and high end frequencies on the signal). Now to fix the problem, you need to run a ground wire, 16 ga will be fine, from the chassis of the Behringer amp to the vehicle chassis or battery ground. One of the screws on the plate might do it. The inverter is causing the noise.

Everybody who has said anything about gain setting is 100% wrong. How do I know? You have NO idea what his RCA voltage is. The gain is to match line voltage, not to set a power level or just another dial to set randomly. Based on the fact that it didn't do it till you were likely moving things around, that tells me it's a connection somewhere. Either on the amp, or otherwise. I've only seen a 1200d blow onboard fuses from low voltage due to a poor ground, or a sub going bad. Any other condition it SHOULD go into protect before anything else, including running it below 1 ohm or too high of RCA voltage for the gain setting.

Here's the real deal with caps if you do the math. 1 farad of capacitance is good for 4 amps of current for 3 seconds on 12.6 volts. So, say you went with a 40 farad, you'd have storage for 160 amps for 3 seconds. Keep in mind, that's till full discharge. So, if you have more than 1500 watts, it probably won't do anything for you. Now, in a real world scenario, a friend of mine got eight 50 farad caps to pretty up his install with his 8 Memphis 4kw's. That means he had 210 amps of storage. 4kw's draw over 400 amps of current (don't know exactly, clamp only goes to 400) and has to go directly through the cap. He gained around 1 dB by taking out the caps. This was in an extreme vehicle, burp only.

At some point here I'll be selling my Nightshade 12 d1 from my show truck, I'll part with it if you can put it to use.

I think a BM would be great for that application, but when he's out of stock you gotta go elsewhere. For that I'd say Alpine. I sure as hell wouldn't pay that much for anything JL, especially the 13TW5. SA8's just won't have the depth there to do them, they also won't be real strong around 30 hz where the other subs mentioned could be.

No, it will not produce better results, because they will be dead. It's a 600 watt rated sub. There are people doing 1000 a sub without problems though. A REAL 1700 watts a sub would only be good for a burp. Also an FYI, currently Dual 4's are out of stock at Sundown till February, however woofersetc might have some in stock.

From my testing, you shouldn't need the aluminum coil. They are best suited for SPL applications but not because of power handling. You'll reach mechanical limits before thermal.

+1 for SA10's.

For 1500 watts, a Zv2 would do better than a Nightshade v2, also cheaper.

So I can get 2 of those, put them in small sealed boxes with 600 watts and do 150's?