Some Basic Sub Questions

[atm98]

I have some questions regarding a sub.

I am looking to add a sub to create my 7.1 system. At first I was going to do an IB. However, my job has me moving next year, so I don’t want to add a large hole in the ceiling (see my ambitions in photo). I am planning to use SS RL-P18.

Using unibox, it looks like about 14ft3 ported box is the best option. My wife will never go for this. So if I go smaller, say 6ft3 range, the sealed box looks like the best option as I can better capture the sub-20hz sound.

I have a DEQ2496 (This thing is awesome –I am new to pro gear) and will soon have the mic along with a QSC PLX1602. This should be enough to get me started.

I am new to this sub building so I request some help on the following questions:

1. Am I correct about the sub-20Hz performance of the sealed smaller box compared to ported?
2. If I am looking at a small enclosure, could I achieve the same bass and sound quality by using a 18” pro audio subwoofer? I am traveling a lot this year and my wife does not want me to start a new speaker project.
3. The amp I have provides 1600W in bridged mode at 4ohm. If I purchase a 4 ohm SS sub with dual coils, how do I hook it up. A. Parallel – Will the amp handle 2 ohm. B. Series – I assume it will not be as powerful. C. Provide the same signal from the DEQ to both sides of the amp and hook up both channels?

Thanks for the help.

Austin

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[Gir]

1. Am I correct about the sub-20Hz performance of the sealed smaller box compared to ported?

The ported box will get much better low end extension than the sealed will. This is why ported subs are so common.

[Dennis H]

Sealed is your only choice for a box that small. Get the dual 2 ohm and wire them in series. Use one channel of the DEQ to your bridged (mono) amp.

[atm98]

Thanks for the info. Does anyone have any experience with pro subs, such as a DJ uses. How would they compare to something I could build?

Also, I have seen a number of recommendations on this site to use the 4ohm version. Including the recent post:

https://www.htguide.com/forum/showthread.php?t=25565

How are these being wired? I am still a little confused.

Austin

[---k---]

A pro sub typically roll off pretty early and don't give you much in the 20hz range and nothing in the sub 20hz range (unless you live in a concrete bunker). Some people have thrown a lot of EQ at some of them to get the low end, but you better have plenty of excursion to do that.

I think you'll be real happy with a sealed unit and the DEQ. I base this on my experience with dual seal RL-p15 and a DEQ. The DEQ you can get great low end. Just build the sealed box as big as you can, brace the piss out of it, and you're good.