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Epik Empire Data-Bass test results

post #1 of 204
Thread Starter 
Here it is The results for the final subwoofer out of the 5 commercial subs I tested early in the spring of this year. The Epik Empire!



Let me go ahead and say that this one was saved for last due to there being quite a bit of extra effort and work involved with reviewing it. Most of this due to it being a dual opposed subwoofer. I wanted to make sure it was right. Not soon after I mentioned that I would be testing one I received a pm from Chad the founder of Epik wishing to speak with me about what would be taking place. He was justifiably concerned about it getting a fair shake in the tests due to the dual opposed design of the subwoofer. I already had some concerns about this myself and had been talking with some notable subwoofer designers about how to handle it.



At this point let me explain the issue simply. A dual opposed subwoofer will always have one or both of the drivers further away from the microphone than a regular subwoofer which usually has a single driver and maybe a port or 2 radiating from a single surface. If you take 2 drivers and mount both on a single face of the subwoofer you can then aim that face at the microphone and the drivers end up roughly 2 meters (In our case) away from the microphone. Now take the same 2 drivers and place one of them facing the other direction on the back of the enclosure and about 20 behind the other. Its contribution at the microphone will be somewhat diminished. Even though you have the same 2 drivers, amplifier, and enclosure volume and alignment the SPL delivered to the single measurement point will be less than the subwoofer that is allowed to aim all or at least most of it's radiation at the microphone. If you have both drivers side firing so that they are equidistant from the microphone you will have the same issue still with advantage maintained by the subwoofer that can aim most of its radiation directly at the microphone. Now this holds true, if you take a single point measurement. However if you take many measurements at various points around the subwoofer the results will even back out as the dual opposed subwoofer will have more uniform 360deg power distribution. Unfortunately there is simply no feasible way for me to do a full polar response work up on every sub I test. It would be ideal but will simply be way too much work. Any subwoofer with radiation from multiple faces is subject to this issue. However ports or passive radiators contribute most of their output over a fairly narrow range, while a dual opposed sub has all radiation from both points covering the entire useful range of the device, so this is a much larger concern in that case. After quite a few emails back and forth with various people I decided on a course of action to investigate the issue and if need be develop a compensation factor for the Empire and other dual opposed subwoofers. What followed was a large amount of work that eventually lead to me becoming convinced of the necessity of and the development of a compensation file for the Empire in order for it to get a fair shake in the output testing. That effort is far too involved to go into here. It will end up being an article unto itself that I will put together in a few days time and will end up hosted on Data-Bass.



One other thing that delayed things a bit was that the first Empire that I purchased ended up developing a buzz or rattle somewhere along the line that was excited by frequencies near 90hz at loud output levels. I determined that it was not the drivers, a driver dust cap, a loose mounting screw or 2, or anything to do with the amplifier. Nor was it some internal wiring or other part making contact with the back of the cones. It appeared to be the enclosure itself although I found it to be very inert and solid feeling and I could not find any obvious issue with any bad seams or anything loose inside. Thankfully Chad sent a replacement under warranty, which technically he did not have to do since I had disassembled it while looking for the problem. (I never did hear what it was.) The second unit was without issue. Kudos to Epik for standing behind their product and honoring the warranty. Thanks.



Alright with that out of the way let's get down to the tests and review.



The Epik Empire is a sealed subwoofer design utilizing 2 long throw 15 drivers in a dual opposed configuration that places one driver on each side of the enclosure. Epik calls this Parallel Drive. Both drivers operate in phase with each other and cover the full useful frequency range of the subwoofer. This type of driver configuration has one large benefit in that the opposing forces of the 2 drivers on the enclosure cancel out each other which results in an almost vibration free subwoofer even when the subwoofer is working very hard. The amplifier is an efficient class D design rated at 600w rms and 1500w short term. It features the usual controls: On/off/auto switch, adjustable crossover 50-150hz, a crossover bypassed LFE input, a phase control and input gain adjustment. It also features balanced XLR inputs which I particularly like and even offers both 120v and 240v operation. It does not however have onboard user adjustable EQ or room compensation. Many subwoofers rely on today's advanced software built into a receiver to take care of that though. The enclosure is 1 thick material as are the cloth covered detachable grills. Both sport a nice looking 1 radius edge. The finish is a simple black laminate. The whole deal weighs in at a hefty 120lbs or so and the external dimensions are 22H x 18W x 24 D. It is not a comfortable 1 man dead lift and carry for most due to not only the weight, but also the size and large smoothly rounded over corners. There is a user applicable Epik logo that comes with the subwoofer and it is listed as designed and assembled in the good old US of A. Epik lists the response as 20-300hz +/-3.5db The price is $799 in singles or you can get a solid discount if you buy in multiples. My cost to my door with freight shipping came in at $799 plus $139 shipping for a grand total of $938. The subwoofer is delivered by freight truck and the packaging is very thorough, with little likelihood of damage occurring in transit, barring some catastrophic event or pure negligence by the shipper.



The overall build quality of the cabinet and the amplifier were very good. The amplifier in particular had a solid and high quality look and feel. The cabinet is heavy and inert. The drivers I examined and they appear to be of good quality as well. They are not particularly flashy with modest foam half roll surrounds, black Kevlar impregnated paper cones, a stiff inverted dust cap, and a stamped steel frame, but the motors are fairly hefty and of large diameter. There is what appears to be a 2 diameter voice coil and a single moderate sized spider. There is no pole vent since the drivers are virtually back to back once mounted in the cabinet. These are cost effective drivers but it seems that the money in them was spent where it counts, a strong motor with plenty of force and the cone and suspension system. Of course the other thing to note here is that there are 2 of the drivers in the cabinet. Multiple drivers can many times outgun a single much more expensive and heavy duty driver simply because the sharing of the load reduces the demands on each tremendously.



Overall the first impression I got from this subwoofer upon receiving it was that it was a solidly built and engineered product, using quality components, with the money spent where it counts most.





Please excuse my photography skills or lack thereof everyone....





post #2 of 204
Thread Starter 
All measurements were taken at a distance of 2 meters from the nearest enclosure face in an outdoor ground plane setting as per the usual Data-Bass test procedures.



Here is the compensation file that was developed for the Epik Empire in order to better represent its true output. This compensation is added to the CEA2010 results and also the max long term output and power compression results. Again i will be doing a short article on the how's and why's of this later...










This is the response of the subwoofer with the drivers side firing versus front and back firing towards the mic. There is less than a db of difference between the 2 orientations below 80hz. The side firing orientation provides 1-3db of extra output at the mic above 80hz so I decided to keep with that orientation.











This is the effect of the crossover control on the basic subwoofer response shape with it set at minimum, 12 o'clock, maximum and with the crossover bypassed using the LFE input. All tests were done with the crossover bypassed.










Here is the basic response as tested for the Empire. This is a sealed subwoofer and should exhibit a smooth corner transition into what is ultimately a nominally 12db octave roll off if there is no electronic manipulation of the signal. We can see that this is not the case so there is some shaping of the signal. It looks like there is some boost centered at about 22hz or so. There is also a high pass filter inserted below 20hz. It appears to be an 18db octave filter which combines with the natural 12db roll off to result in roughly a 30db octave final acoustic roll off. The measured response fits within a roughly 9db window from 19-300hz, which is fairly close to the factory published spec.











Time domain measurements.





post #3 of 204
Thread Starter 
During the power compression sweeps the sub acted fine up until the second highest sweep level at which point there was a hint of over excursion flutter from the drivers between 16-25hz where they were being asked for a lot of excursion due to the EQ boost. The next higher sweep level produced more exaggerated grumbles from the Empire's drivers over the same frequency range and there was virtually no improvement in output in this band, so this is where the test was stopped. The Empire exhibited very good compression performance indeed, up until the last and loudest sweep level, which produced a very large amount of compression where there is EQ boost used to extend the response.









Spectral Contamination 100db





Spectral Contamination 105db




Spectral Contamination 110db










Looking at the THD measurements taken at the same levels as the power compression sweeps the Empire remains very clean and low distortion above 30hz even at the loudest levels. There is an increase in distortion below 25hz followed by a reduced level again once below 20hz before the response falls down in level to the point that the noise floor is corrupting the results excessively at the lowest frequencies. The increased distortion centered near 20hz corresponds with the EQ boost. Examining the harmonic make up of the distortion reveals that above about 30hz the distortion is dominated by the second harmonic, which is good. Where the EQ boost takes effect and results in much higher driver excursion the 3rd harmonic is the predominant one. Overall I'd consider it a pretty good performance still despite the higher levels near 20hz. If you aren't driving the sub to its limit it even has decent THD at 20hz.










103db THD Alone





103db THD sweep by harmonic component






108db THD Alone





108db THD sweep by harmonic component






113db THD Alone






113db THD sweep by harmonic component
post #4 of 204
Thread Starter 
Looking at the maximum long term output which is derived from the highest level sweep completed during the power compression tests, the Empire tracks right about the center of the all time results in the low bass range and then trends closer to the all time maximum recorded levels once above 63hz.





Maximum Long Term Output Comparison








Maximum Long Term Output Excel Comparison Chart and Averages




Attachment 218984
LL
post #5 of 204
Thread Starter 
Here are the CEA2010 output results. This sub has good output levels if not huge ones over the 25-50hz octave where it will many times be compared with vented subs which will often be tuned somewhere in this range. At 20hz and below the maximum recorded levels are pretty good and in room this sub could probably provide a real and useful 16hz if called upon to do so. I could not get a clean 10hz result to pass CEA2010, partly due to the high pass filter built in and the difficulty in getting enough 10hz level to get up out of the background noise floor. I should have captured the maximum output result even with excessive distortion just to show what the sub would do dynamically, but alas I did not. I will do this with future sub tests though. Up above 50hz this sub will get very loud indeed and does so cleanly at the same time.













CEA2010 Distortion Results at Each Center Frequency.


















CEA2010 Output Comparison and Averages Excel Chart





Attachment 218985
LL
post #6 of 204
Thread Starter 
To wrap up this reviewThis is a pretty good sub. I spent a little more time actually listening to this one at home compared to some of the others and I thoroughly enjoyed doing so. One thing I really like about this sub is the fact that the drivers used have a very good top end without the typical roll off above 50-60hz that can sometimes be severe in subwoofers with a lot of inductance and a heavy moving assembly. I don't know if they employ shorting rings in the drivers but the signs point towards that probably being the case. The drivers also have a pretty light cone and voice coil from what I could tell which also helps out too. It seems that they are sort of a cross between the light moving mass and high motor force of a pro woofer and a long throw woofers increased xmax, which is a difficult thing to pull off well especially in a cost effective design. To see what sort of difference this makes look at the CEA2010 or the max long term output composite graphs and compare the Empire's max output above 50hz with the black trace indicating the minimums, which is a sub with a peaky rolled off response. At 50hz the difference isn't that big, but by the time you follow them both out to 125hz the difference is huge. This is not only max output but an indicator of efficiency as well. You might think that you don't need all of that output but I am a fan of as much headroom as possible and 50-125hz is a very critical response range. Anyway this extended response and high output capability, combined with the very good distortion performance above 30hz, tells me that the Empire has the potential to be one very good sounding unit once integrated well. No MBM is needed here that is for sure. The sub also has enough headroom to provide useful output down to probably 16-20hz in most rooms.



If I have a gripe it is with the 20hz boost. There is nothing wrong with including it and in fact the resulting response will probably match up with typical room gain pretty well, but I wish that it was defeatable, for smaller better sealed rooms, or simply to increase headroom for those that like to really crank their system up. Other than that from what I could tell the Empire could stand to either lose the high pass filter all together or at least have the sharpness of the slope decreased to maybe only 6db octave. The drivers are operating in a very small airspace which should control the driver excursion very effectively already and the sub has shown itself to be capable of pretty good output even recording a passing CEA2010 result at 12.5hz.



The build quality and components of the sub are good as is the performance. It isn't the prettiest or flashiest subwoofer I have seen, but that sort of thing costs extra money. It is also a robust subwoofer that overloads predictably and without damage. The 20hz area is the weak spot in headroom due to the EQ boost built in but when the sub reaches it's limit there there is some overload noise from the drivers but otherwise the sub clamps down and compresses further output. With the discounted price a pair of these is a cost effective deal that should handle even a large difficult space or a cranker if you are one of those types , very well.



That is all for todayTill next time.
post #7 of 204
Great job Josh! Keep them coming. Any chance of seeing a review of the Submersive for comparison?
post #8 of 204
Thanks!
post #9 of 204
The review that I was waiting for. Excellent. Very promising sub. I think I will get rid of the idea of DIY and get one of this. Ricci, only one more sub to review on your journey should be the HSU-VTF15H.
post #10 of 204
Thanks a lot Josh, excellent and very thorough technical test study on the Epik Empire and the other subs you included in the test . Reinforces what EPIK Empire owners know and love about this sub We already knew this sub had the guts to dig low, but that midbass slam output from 50hz-125hz sure looks good on paper GREAT JOB man!
post #11 of 204
Thanks another great review. Any other reviews in the works?
post #12 of 204
how about some internal pics I'm always curious how these things work....
post #13 of 204
Quote:
Originally Posted by Ricci View Post

One thing I really like about this sub is the fact that the drivers used have a very good top end without the typical roll off above 50-60hz that can sometimes be severe in subwoofers with a lot of inductance and a heavy moving assembly.

But isn't this advertised as a subwoofer? Is output of a subwoofer (not woofer) above 60Hz really important?

Quote:
Originally Posted by Ricci View Post

You might think that you don't need all of that output but I am a fan of as much headroom as possible and 50-125hz is a very critical response range.

from a subwoofer?

Quote:
Originally Posted by Ricci View Post

If I have a gripe it is with the 20hz boost. There is nothing wrong with including it and in fact the resulting response will probably match up with typical room gain pretty well, but I wish that it was defeatable, for smaller better sealed rooms, or simply to increase headroom for those that like to really crank their system up. Other than that from what I could tell the Empire could stand to either lose the high pass filter all together or at least have the sharpness of the slope decreased to maybe only 6db octave.

If it didn't have that boost (about +11db at 20Hz) it wouldn't really sound like a subwoofer in a typical size room. Even with the EQ, based on the Fletcher-Munson curves, it may not sound like a true subwoofer because of how it's EQ'd and because it doesn't have output capability at the low end relative to it's output at the high end. It appears as though this product is more of a mid to upper bass woofer.

Quote:
Originally Posted by Ricci View Post

The drivers are operating in a very small airspace which should control the driver excursion very effectively already and the sub has shown itself to be capable of pretty good output even recording a passing CEA2010 result at 12.5hz.

It's really not a pass/fail measurement. By your criteria, a 5.25" sub can "pass" the 12.5Hz CEA2010 albeit at some inaudible SPL which is of no use to anyone. The only result that matters in the CEA2010 burst test is the SPL. The THD+N limits only define what max SPL number is chosen. That's why, IMHO, the SPL number should really be included with every CEA2010 graph. Otherwise people may look at the spectrum, see that one sub has lower harmonics than the another but not realize that SPLs are night and day apart.


Quote:
Originally Posted by Ricci View Post

The 20hz area is the weak spot in headroom due to the EQ boost built in but when the sub reaches it's limit there there is some overload noise from the drivers but otherwise the sub clamps down and compresses further output.

20Hz is the weakspot due to the design compromises chosen by Epik. The EQ at 20Hz is a good decision up to an SPL level where the amp clips or the driver excursion is reached which happens to be 102dB. After that, you won't have any need for +20dB output at 100Hz if your target is flat frequency response as perceived by your ears. Sure the room gain helps but it's not really enough. The bottom line is the product has more output capability than is needed at the upper bass frequencies and not enough at the low end. Just calling a spade a spade...
post #14 of 204
Thanks for taking the time, Ricci.
post #15 of 204
Quote:
Originally Posted by Sahak94 View Post


But isn't this advertised as a subwoofer? Is output of a subwoofer (not woofer) above 60Hz really important?

from a subwoofer?

If it didn't have that boost (about +11db at 20Hz) it wouldn't really sound like a subwoofer in a typical size room. Even with the EQ, based on the Fletcher-Munson curves, it may not sound like a true subwoofer because of how it's EQ'd and because it doesn't have output capability at the low end relative to it's output at the high end. It appears as though this product is more of a mid to upper bass woofer.

It's really not a pass/fail measurement. By your criteria, a 5.25" sub can "pass" the 12.5Hz CEA2010 albeit at some inaudible SPL which is of no use to anyone. The only result that matters in the CEA2010 burst test is the SPL. The THD+N limits only define what max SPL number is chosen. That's why, IMHO, the SPL number should really be included with every CEA2010 graph. Otherwise people may look at the spectrum, see that one sub has lower harmonics than the another but not realize that SPLs are night and day apart.

20Hz is the weakspot due to the design compromises chosen by Epik. The EQ at 20Hz is a good decision up to an SPL level where the amp clips or the driver excursion is reached which happens to be 102dB. After that, you won't have any need for +20dB output at 100Hz if your target is flat frequency response as perceived by your ears. Sure the room gain helps but it's not really enough. The bottom line is the product has more output capability than is needed at the upper bass frequencies and not enough at the low end. Just calling a spade a spade...

I think what he meant to say was...Thanks for all the hard work! It is greatly appreciated!!
post #16 of 204
Thanks Ricci for another well done, thorough review. They are always appreciated!
post #17 of 204
Ricci, you gotta live the hobby to put this much into it. Your reviews are something that people can get their teeth into in order to make a choice when buying a sub. Thanks for a good review.
post #18 of 204
Quote:
Originally Posted by NicksHitachi View Post

how about some internal pics I'm always curious how these things work....

Agreed

Im also really excited to see how you came up with the "handicap" that you gave this sub for it being dual opposed. How did Chad from Epik suggest you take your measurements?
post #19 of 204
I been waiting a long...long...long... time to see how this sub actually measures and performs. It seems to due a pretty good job.I was really looking forward to seeing the THD graphs,they look good for the most part.

Very nice review and thanks for all the hard work!

I replaced my Mackie HRS120 with one and I was a little disappointed at first.The Mackie seemed to have better output down low,but would start making cabinet noises and the amp would clip on intense LFE bass scenes.The Empire actually seems to blend better with my 824's than the HRS120 and to me sounds just as clean without the amp clip and cabinet noise problems.

I haven't heard it complain yet!

I also notice less overhang with the Empire.It's is a nice sub,but I miss the lower-end and what seemed like better slam that the HRS120 could muster before it would complain.
post #20 of 204
Hmm, kind of dissapointing down low to be honest.
post #21 of 204
Quote:
Originally Posted by drewTT View Post

Hmm, kind of dissapointing down low to be honest.

It is...seems like it just starts rolling off at 80hz.
post #22 of 204
Quote:
Originally Posted by drewTT View Post

Hmm, kind of dissapointing down low to be honest.

What could best address this.......stronger amp or beefier drivers perhaps?
post #23 of 204
Quote:
Originally Posted by drewTT View Post

Hmm, kind of dissapointing down low to be honest.

down low - I agree, but astounding clean sound quality up high, and I never heard it make a bad note no matter how hard we pushed it at our KC Subwoofer Shootout meet -- that alone was a big selling point! (it alone, in my opinion, was the only sub that managed a clean sound through EVERYTHING we threw at it. When we turned it up at it's limits it just stopped getting louder rather than audibly sounding distressed.) I enjoyed the Epik Empire at our meet, but I also agree it definately didn't really show up for the lowest frequencies compared to some of its competitors that were directly A/B'ed. Despite this potential concern - It placed 4th overall in the music section as you can see in the column on the far right, which is better than it's pricepoint should allow when compared $ to $ to the other subs compared. It was the favorite for one of my friends at the meet - so it isn't without its fans!

BTW - this somewhate validates a subwoofer gathering's value towards realistic subjective impressions, without all the precise measurements being required... Take a look at the KC Sub get together's music score sheet on the Epik Empire for "Deep Notes" This is all subjective rankings by multiple individuals. I think we pretty much nailed it --- with nothing but subjective opinions in this section (based on like level calibration for all subwoofers tested) We didn't have all the incredibly detailed measurement and graph work that Ricci put together, but in our own comparitively 'hillbilly' way the votes showed the Epik isn't a deep hitting sub based on simple collective averaged subjective impressions.



Ricci, I enjoy reading your reviews! Keep up the good work! Your knowledge level is well above mine --- perhaps after continuing to read your reviews I will glean some of your smarts! :P
post #24 of 204
Quote:
Originally Posted by trolly View Post


What could best address this.......stronger amp or beefier drivers perhaps?

A bigger box
post #25 of 204
Quote:
Originally Posted by Mpray1983 View Post

A bigger box

And a stronger amp for better extension.
post #26 of 204
Quote:
Originally Posted by counsil View Post


And a stronger amp for better extension.

A bigger amp would move it way passed the $800 price point tho
post #27 of 204
Quote:
Originally Posted by Mpray1983 View Post

A bigger amp would move it way passed the $800 price point tho

Yeah I know.

A bigger box would make it heavier. As you approach 140-160 lbs shipping costs start to get really expensive.

But you're right... $50 extra bucks in shipping isn't anything compared to another $200 bucks for a beefier amp.
post #28 of 204
Quote:
Originally Posted by counsil View Post


Yeah I know.

A bigger box would make it heavier. As you approach 140-160 lbs shipping costs start to get really expensive.

But you're right... $50 extra bucks in shipping isn't anything compared to another $200 bucks for a beefier amp.

Drivers may not be able to handle more amp anyways
post #29 of 204
I think higher excursion drives would be needed to dig deeper. The reviewer already said the drivers were stressing at 20 hz in high output. But then again, higher excursion drivers mean heavier drivers, which in turn require more power to move. But the sub does pretty good at 20 hz, so I don't see much to complain about there.
post #30 of 204
Better drivers, better amp, better everything, and what have you got? A Submersive. $2100.
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