[Kevin Haskins]

I get everyone throwing options at me, but I can't tell which one is really the best...because no two suggestions seem to be alike. It doesn't help that I keep on coming up with more options myself. My fiance is pretty open to my building a big box for the theater, it's mostly my own aesthetic that keeps me from building a 20cf ported 21", and my own budget that keeps me from building TWO of them! LOL

That is the way Internet forums work. If you want a plethora of opinions, none of them the same, just ask in an Internet forum. :laugh:

If it were me, I'd just build a big sealed 21". Ignore the people saying you could get more output. The sealed 21" has PLENTY of output and it goes smooth and deep. I love sealed subs but you need a lot of swept volume for them to work well for HT. The smaller drivers NEED to be ported, to give the extra headroom. The 21" has an abundance of output, without the need of porting. It goes subsonic with ease because you don't have the roll-off under the port tuning. It sounds awesome.....

Kevin Haskins
Exodus Audio

 

[Kevin Haskins]

According to the owners manual, the EP2500 will run 750watts @ 4Ohms per channel. I think Kevin mentioned to me that is plenty by itself, let alone 2500watts bridged. So even if the numbers are fudged a plenty on the amp, it should have enough juice to drive the 21".

Once I get mine built, I'm going to try the 21" on one channel, and my current dual 10" folded horn on the other channel. But I'll probably just bridge the EP and run the 21" alone.

The EP2500 (or the EP4000 that has replaced it) is a great bang for the buck amp...otherwise it wouldn't be so widely used by so many DIY builders.

No... the 18" & 21" will eat up all the power you can give them. The EP4000 is listed at 2 x 2000W into 2 Ohms. You won't get that out of it because you would trip the breaker immediately and the voltage on the AC line will drop like a rock, but that is not overkill.

Both the M-18" & M-21" have highish DCR 2-ohm coils. The impedance is always above 2-ohms so you won't have any issue using the EP-4000 with each channel driving a coil. That combination should give you plenty of output.

Kevin Haskins
Exodus Audio

 

[Kevin Haskins]

I must have misunderstood.

I also read (on the intarwebs) that the EP-4000 really doesn't output what they claim. Or maybe that's just typical internet talk.

None of these amps will in the real world. Your AC line doesn't have the ability to do so either.

The EP-4000 should be more than sufficient for the job. When you compare it to plate amps, there is NO comparison. The pro-amps are much more capable and they are much more reliable on average too.

Kevin Haskins
Exodus Audio

 

[Kevin Haskins]

, glad you talked the bloke into doing the 21", thats going to be awesome.

By 'smaller' do you mean anything smaller than the 21"? :gulp:

Sorry... missed this. No... the 18" is a beast too. It is just that the sealed 21" has enough output that most people are not going to be wishing for more. I'm sure there are a couple crazies that will prove me wrong but a single sealed M-21" is pretty tasty.

Kevin Haskins
Exodus Audio

 

[Kevin Haskins]

well the reason you are comparing the 21" sealed to the 18" ported is because you get more output from a ported. So to make a wild statement, if there was a 26" Maelstrom-X, you'd need to port a 21" to be as loud as the 26" sealed

Once you get to "loud enough" any more output is irrelevant.

Kevin Haskins
Exodus Audio

 

[Kevin Haskins]

Can a large sonotube be sealed and be just as effective as a braced box?

Sure... Sonotube is great. There should be no sound quality difference between a properly assembled and braced rectangular cabinet, and a properly assembled Sonotube.

You can pick which you like purely based upon personal taste.

Kevin Haskins
Exodus Audio