Which is better for a DBA (Swarm); powered subs or unpowered?


I want to start building a swarm (starting with 2 subs), on a budget.  Starting with $1000, am I better off buying two used powered subs, three less expensive used powered subs, or a subwoofer amp (eg Dayton SA1000) and two (less expensive) used unpowered subs?  What is the advantage of having a discrete subwoofer amp?  Room size is 13'x22'. 
128x128cheeg

Showing 2 responses by audiorusty

How loud do you like to listen? Do you listen to a lot of rock and want gut thumping low end or do you prefer classical or jazz and are looking to just fill in the bottom end?

With powered subs you need proximity to AC and you will need interconnects, unless your subs have wireless calability. If you are using RCA connectors and have some long runs over 10' to 15' that could be an issue. If your system is balanced then long IC runs should be fine. With passive subs you will need speaker cable and if you require big power and a long run then you may need to use heavier gauge wire up to 12 awg maybe even 10 awg.

If you like it loud, a good powered sub will offer better speaker protection. With passive subs and a separate amp you will more than likely get none, so if you hard clip your amp it will probably be re-cone city. The rule of thumb (at least it use to be) is to use an amp that is capable of twice the output power of the speakers maximum handling capacity. So if your subs can handle 200 watts @8ohms then you want an amp that can deliver 400 watts @8ohms and so on.

With powered subs you will have more individual control, which for some will be a good thing and for others not so much. A dba system itself makes integrating easier but as the room gets larger control becomes more important. It will be dependent on how sensitive you are to time domaine issues. You should be fine either way with your room.
Some subs (I think REL is one) allow you to wire them in a way that reduces the burden on the main amp to cover frequencies below a set cutoff, like 80Hz. Does anyone know if that is possible with the Dayton?
Almost all powered subs and I believe this is also true of the Dayton amp, only come equipped with a low pass filter, which allows you to set the frequency cutoff point of the signal that is sent to the subs.  You would need an actual crossover to do reduce the burden on your main amp. 
is it advisable to use all the same brand/model of subs in the swarm, or does it not matter?
There is not a lot of detail when you get below 80hz so in my opinion the subs do not need to match. I use three different brands of subs in my 4 sub dba with no issues.
what is REW? 
I believe REW is a type or brand of room analysis software.
Is it possible to run 4 passive subs off of one amplifier, say like a Crown XLS series? 
Yes as long it has enough power and can drive the impedance load that the speakers are presenting. The load will vary depending upon how the cabinets are interconnected.
Hi Cheeg

I have a lot better understanding of the issues, but am no closer to deciding whether I should buy a Dayton and cheap passives, or buy two better quality actives and save my pennies for 2 more. Maybe the answer is "it doesn't matter"
It kinda doesn't. It's really a personal preference. Your room is not big enough to create any timing issues amongst the subs to be audible unless you are really sensitive to timing issues. The extra flexibility with the powered subs is not a big difference over the passive subs, it just gives you a little more wiggle room if you don't or can't place the subs in their ideal location. It's the number of drivers that make the magic, not whether they are powered or passive. A lot of people have passive and a lot have powered and both camps are very satisfied with the results. They both have pros and cons which is what I was trying to outline, evidently not very successfully. You really can't make a wrong decision, it boils down to which pros and cons appeals to you the most.