eD - A7S-450 vs. Epik Empire subwoofers - Page 2

Baltic Birch has a higher resonant frequency and is well suited to subwoofer enclosures, it is also a good material for drum shells.

BB certainly isn't used because it is a cost cutting measure. Most speakers are made of MDF because it is an economical solution. BB is a little more difficult to finish, as we have seen.

A lot of the DIY crowd uses BB, check around.

Uh, oh, We do NOT want a fair fight between those two. Many fanboys might not like the outcome when performance is the bottom line not taunts.

actually I'd LOVE to see a one on one of those 2!

Below90hz and his bro already posted their initial impressions after the first meeting between these two brutes.

A repeat performance would be.......

http://www.youtube.com/watch?v=X8PyTo6NyXA

Aha! A drummer in the forum..cool. I have vintage Sonors drums from -67, red stripes. Lovely creatures, they are..

Sonors are a big step up from my current classic Ludwig 5 piece trap. I was happy as a clam when my brother needed a place to store his Tama Rockstar for a while.

Sorry for the hijack, Mike. Flam to swell exit....

Mike,

FYI a guy on this forum has two Empires for sale at a good price. He's located in the NW burbs of Chicago. No affiliation. link:

http://www.avsforum.com/avs-vb/vbcla...do=ad&id=14531

Go Bucky!

Mike,

I'd wait until the guys post their shootout results between the Empire, CS-18.1, A7s-450, etc.

I have a feeling that eD and CHT will be at the top.


I'm waiting on this to pick!

+1!

Meh. The empire is not even in the equation. Who else is worth talking about besides the 18.1 and the A7s-450? And I already know whose going to win that one.

I would still like to hear an empire. As far as the 18.1 and the A7s-450, I don't care who "wins". I'm just looking forward to having something fun to read for awhile. I think that whoever "wins" it will only be marginally.

Agreed.

Isn't the Empire weak below 25 hz.? Not a lot of amp power for those duals, either. Not a bad sub, well worth the money. Just not a Super Sub.

That assertion from the Epik site seems to not be genuine to me.

Without knowing the specific volume displacement of the Empire's 15" drivers, or their excursion capabilities, this comparison simply cannot be made.

Mathematically, eD's 18" 19.Ov2 in their A7s-450 has 40% more surface area than their 15" driver used in the A5-350 (this was per several long-winded online chats with Alex and Matt). With nearly identical excursion capabilities (22mm on the 18" and 23mm for the 15"), the correlation between actual surface area and volume displacement basically carries over.

Without ANY of this information on the Empire's drivers (or amp, for that matter), a 1:1 comparison like the above simply cannot be made about the Empire's drivers.

It also makes me wonder how the CS 18.1 in the other thread could possibly outclass the A7s-450 so greatly, using less amplifier power, a smaller cabinet, and a driver of equal or lesser excursion capabilities. I own an A7s-450 and am quite pleased with it (call it bias). I'm also sure that that 18.1 is a damn good sub. But the math doesn't add up that you get an almost 3db volume gain from one sub to the other. An instrumented test is the only way to know. We all know how volume plays tricks with the human psyche. If I got a nickel for every time I asked a hifi dealer to let me ensure his product demo was level matched before I auditioned and got turned down....I'd be a rich man. Thread drift over.

At face value, the argument is valid.

The surface area of two 15" drivers is:
2*Pi*15^2 = ~1414in^2
The surface area of one 21" driver is:
Pi*21^2 = ~1385in^2

But I agree, it is marketing talk to compare solely based on driver size.

I agree that the math you did adds up. BUT, where to find a 21" driver with linear excursion of a relatively equal value? The maelstrom is a great driver, but is uber expensive. And, again, we still do not know the xmax capabilities of the Empire's drivers (or any figures on linearity).

Also, since we're dealing in 3 dimensions.....The curvature of the cone could certainly affect the actual surface area of the radiating surface. Cones aren't just flat discs. I would wager that the curvature of my A7s-450's 18" driver is different (it appears to be deeper) than the curvature of the last A5-350 15" driver I saw. This could be quickly estimated by measuring the depth from the edge of the surround to the middle of the dust cap (if it's inverted). If it's a non inverted dust cap...well, that's where my math ends.

My only point being....without knowing ANY specifics about the Empire's two 15" drivers....the only question remains: to what 21" driver are they being compared?


Now, I'm not slamming the Empire at all. It's a great sub and it sounded very good to me when I auditioned one a while back in a buddy's home. I found the A7s-450 to handle upper mids and bass below 30hz with more authority...but the Empire did sound great. This is not, by any stretch, an Epik/Empire bashing issue. It's an unrealistic claim made by god-knows-who on the epik forum. They probably didn't even work for epik. Epik is a great subwoofer company (if it weren't for the ridiculous CS i got from eD pre-purchase, I damn near bought an Epik Empire), and they add a lot to our 'sub-woofing community'.


EDIT: I just measured my A7s-450's cone to be slightly less than 3" from the edge of the surround to the center of the name in the dust cap. Remember, we're not measuring circles here... we're measuring the interior surfaces of the 'slices' out of a sphere.

A7s-650, can do a kit

Since the displacement is a linear piston stroke, AFAIK the swept displacement (Vd) doesn't change just because the cone is a cone instead of a flat disc, if the 2D cross section areas were identical among both. The cone is an inherently stronger and more rigid structure, however.

It'd be good if someone smart could chime in.

FWIW, if you read the quote again, since it doesn't mention displacement, it is technically an accurate statement. I think the idea was to just give folks a rough idea of the Sd of two 15"s - not to claim that they displace as much as one of the 21" drivers on the market (which is how you seem to be taking it).

I was taking it pretty literally. After re-reading it, it doesn't appear to be a literal claim.

As far as the air that is displaced by cone movement....well I'm not an expert in wave propagation. I agree...but my whole point is the statement is based on a chain of "if's". I agree it's hard to impune...but I would articulate that, without it being verified it can appear to be misleading. At least it does to me. I think it would be better to list an actual volumetric displacement figure like several other makers (or at least have it at the ready should someone ask). A number is more difficult to stretch.

Mike, I didn't realize it came from Epik. IMHO, if a manufacturer is gonna make claims like that...they need to have something to substantiate the claim. It is an estimate...but, seeing as how out-of-this-world a 21" driver is to most people (I've seen a naked Maelstrom X 21" in person...it is INDEED impressive), it leans more toward hyperbole than a real analogy. BUT, this is all pretty subjective and it could certainly be taken a different way.

In 2D. Now, somebody wanna do the math and break this down into a hard number? Two 15's vs. single 21".

Geez, I went right over this. I do agree, it is a claim made mostly for marketing purposes.

Two sealed double magnet 15's ought to do the job. Two vented 18's with more power would probably top it though, especially if the floor plan is open.

Think of the classic definition of displacement and picture the sub pointing up filled with water. The water that is displaced is only a function of the diameter of the sub, and the stroke since the cone shape doesn't change. Same would be true for a car's piston (and head or dome shape) - again, displacement is only a function of diameter of the piston and stroke.

Since we don't have a defined Xmax in either situation, the 21" equivalency is all we can say.

Also, be very careful trying to infer anything about the difference in amplifier power. You can easily find drivers that are 10db different in efficiency which would require 10 times more amp power to produce the same output!

Also, we want to take into account speaker enclosure alignment.

The Empire's 15's are sealed, splitting 600 watts RMS.

The eD's are ported with 1300 watts RMS.

My bad, I was looking at the A7-450.

I still lean towards dual eD's, if nothing then for the FR extension.