Subwoofer Problems

Basically for 180 people your output was too low.

A second ELX 18 could do the job probably and would fit your current setup.

To give you an idea … I have a 2×12″ + 1×18″ setup too. Only my tops are 600W RMS and the sub is 800W RMS.

Same size setup, only I have 2000W instead of 900W RMS! And I think the efficiency of my speakers is higher too not sure though. Meaning that more of each Watt is turned into musical energy. Two speakers with the exact same Wattage can have different sound pressure levels.

This is why it is so hard to compare PA systems, you can’t just look at the size of the drivers (12″/15″/18″) or the power rating in RMS. Not all manufacturers tell you their sensitivity (which represents the number of dB output in sound pressure level measured by inputting 1 Watt RMS at 1 meter from the speaker). You can see how this number, when standardized will give a very true picture of the efficiency of a speaker. And not every manufacturer wants to share that info.

So, I agree with the others that it is mainly a power issue. Adding a 400W sub will lift your bass end, but you will still sit at only 1200W RMS. Calculating with the 10W-“rule”, you’d need 1800 for a 180 people. 10W is the high end of the equation, but 5 is an absolute minimum (which is what you had and you concluded this was on the low side). Realistically I’d say with the extra sub you will be at about 6.7W per person. Which is ok, don’t expect to break any windows though :-).

Greetinx.

I think it is safe to say that when a manufacturer reports max power, without specifying RMS, it more often than not is some kind of music or program power. In which case it is indeed half in RMS. Having said that. 350RMS on an 18″ sub is not very realistic. As I said, my 18″ sub has 800W RMS. So it’s not unlikely that your sub is actually 700W RMS. Your argumentation on the speaker specs makes sense. On the other hand, if the passive version has a passive crossover, this could be the limiting factor, not the actual driver. Hard to tell without more exact specs and, coincidentally, I can’t reach the EV website today. So no way to get more accurate specs from the source. 1000W RMS on active 12″ seems a lot, here I would expect it to realistically be 500W RMS (usually something like 400/100 or 425/75 split between lo/mid and high).

With all that said, comparing speakersystems is a tough nut to crack unless you can run tests on them in a lab and do true A/B comparison on the important issues like max SPL, sensitivity, frequency response, distortion & headroom, etx.

And even then, your ears should pick the winner. Just because something should sound good on paper, doesn’t mean it does so in real life (at least to your ears).

Terry’s advice is solid in getting an extra 18″ (if you can transport it 🙂 ), it will solve the problem of disappearing bass and give you some extra oomph. 400/500W RMS tops should be ok for the situation you described. Be sure to make the high end speakers sit at or slightly above peoples heads. If you have speaker stands or adapters that you can aim the speaker ever so slightly downwards (say aiming at the middle of the crowd) that will help.

Final thought. I always look at the layout. There is a big difference between setting up if the floor is small/large compared to the number of dancing guests. Is the floor square or rectangle. Is it wide (seen from the DJ) or deep?
I will often take an extra set of (in my case Mackie SRM450vs) speakers, so I can set speakers at all four corners of the floor. Not so much to make the total louder, but to be able to disperse the sound more evenly. You know, that it isn’t earshattering up front near the speakers and hardly audible in the back.

Also, in my experience, having four speakers pointing “inward” towards the dancefloor creates more of a low sound level area behind the speakers, which is good so people have a place where they can still talk to each other.

Hope that helps.

Greetinx.