**burningdemons** wrote:

Ah. That makes more sense. Lower hz means the woofer reproduces it at a slower rate? Or just the woofer moves slower to reproduce it, therefore more air is being displaced. I believe the 'kick' in the chest frequency is between 50-80hz, so the Yorkville's will produce more of that kind of thump by a significant amount. Different kinds of air displacement have different effects. Makes sense now. But overall the ZV28's are the best in that regard.

I did some math on the DBH218, this is the graph I came up with. I have added it to yours.

http://imageshack.com/a/img923/1593/lp0Ecr.pngNow, the DBH218 outputs as much as 2 ZV28's and it gets almost as loud as 6 LS801P's. Since the powered DBH218 would cost as much as 2 ZV28's, while weighing and being less cubic feet, would it not be the sole box the could keep up with the ZX5's? That was only at 1000 watts too. It can take 4000 but that will only add 4 more decibels (if that, given compression loss).

I believe my math is correct given that the Danley response graph is 93 db @ 20 hz with 1 watt (2.83V) and 1 meter in 1/2 space, 105 @ 30hz, 112 @ 40hz, and 115 @ 70hz. I tried to match the graph more closely to the one provided by Danley and it crescendos in the same peaks as the Yorkvilles. The air displacement of this single box will be more than 2 ZV28's and it will within barely noticeable SPL output as 6 Yorkville LS801P's. This is true unless Danley forged their numbers. This is, of course, a horn loaded enclosure. The path might have added weight but it is truly remarkable that it takes 4-6 of some dual 18" enclosures to equal the same SPL and displacement. Then you have the TH221 which has 103-105 db @ 20hz with 1 watt (2.83V) and 1 meter in 1/2 space. 110 @ 30hz with 1 watt (2.83V) and 1 meter... Then it fluctuates between 108-110 until 70hz where it is a massive 116, just like the DBH218. This, of course, removes the necessity for multiple cords and multiple trips and more felicitous usage of space. But twice as loud is 10db more and the TH221 would be twice as loud at 20hz and about 50% more loud at 30hz.

So my only question left is which would you suggest for my pair of ZX5's? The ZV28's? The DBH218? Or the TH221? The latter seems to have the most full sound, most displacement, but it's not the loudest for the least money. I believe the DBH218 is. A pair of LS1208's wouldn't be the worst choice either I guess.

105@70hz,105@60,105@50,104@45, and 101@40. Add 6db for a pair of them and that's 111@70, 111@60, 111@50, 110@45, and 107@40. You can buy 4 (you need to double the amount of speakers to add 6db I believe) and an amp for less than the ZV28 pair, 6 LS801P's, DBH218, or TH221.. So that's 117@70, 117@60, 116@45, and 113@40. That beats all of these other boxes mentioned but I don't know about under 40hz cause I don't have the graph. I presume it would drop off below 30 but still leave a respectable sensitivity at 30 that would compete or beat them for the price.. But, as you said, that's more cabs and more weight.

You have given me a great deal to think about. I appreciate all the information you have provided. I'm still curious as to which to go with though for my tops in a mobile setup (for school dances with 1000 people). I want to turn those high schoolers stomachs with bass they have never felt, you know? I want them to ask to have it turned down so I know I have the headroom to run them at full throttle if I wanted to.

Thanks again for your thorough response, I'm really eager to start building my own boxes now and see what sensitivities I could reach by capitalizing on greater efficiency and greater manipulation of physics to increase output in the areas I am curious of recreating. 2.83v at 4 ohm is 2 watt, should have used 2.00v. DBH218 has a switch either 2 or 4 ohm load.