Axiom Home Page Forums General Discussion Home Theater My EP800s are HERE!

Guys,

I decided to start my own thread for my EP800 experiences. I'll be tweaking today (without REW, I left my laptop at work), and I'll post pix and comments later in the day.

First pic though... Theater full of subs!

Mighty fine looking setup you have there! Congrats. It will be a fun filled weekend I'm sure.

Nice start Steve! Have fun!

That rug really ties the room together...
Oh yeah, and "The Dude Abides."

You should call your Home Theatre, your BASS-ment!!

I posted this on the other thread, but I'll ask the question again on mine.

Jason/CV - On the back of your speakers, what is the power draw of your sub amps? Mine say 675W (same as the EP500s). This seems strange to me since they are supposed to be 800W subs, and should therefore draw well over 800W. By the way, the picture in the instruction book shows 675W also.

Steve

Haven't checked yet... I'll take a look today.

Nice looking set up.

Very nice! Steve did you say you are keeping the 500s?

Hi S.Roode,

I checked with Tom Cumberland, Axiom's chief electronics engineer, who reports that at average music listening levels, the amplifier will draw about 675 watts. At full output, however, it does draw 800 watts. Both dual-voice coil drivers are wired in parallel, so we have a very low impedance "seen" by the subwoofer amplifier, hence it produces greater output into the very low impedance.

Regards,

Alan

This doesn’t follow, please correct me if I’m mistaken but in Canada, and the rest of North America, is it not the maximum draw, in watts and/or current, that an appliance is rated at and not the average draw?

Rick - No. I'll be boxing them up this weekend to send back

Alan - Thanks for the info! I have no doubt from my initial tests that they are more than doing the job!

Tuning the system now with my SPL Meter and my test tone disc. The disc only goes down to 20Hz though! The initial curves were pretty flat (better than the EP500s). I am in the process of manually adding two filters on my BFD to get rid of my 66Hz room hump, and a little boost around 24Hz. I am tuning the room to 75db in the >100Hz range, and 80-81db on the <100Hz range (like I had with the EP500s). MUCH SLOWER without REW, but doable.

-Steve

Is there some kind of tutorial on determining how to get your room "flat" or getting rid of a "hump" (whatever that is)?

I feel like I might be missing out on really getting the most out of my system after reading a few threads lately, especially with the new M80's.

Thanks, and sorry to hijack.

Wow!

Nice set-up.

Vasillios. If you are using REW, this software creates the filters for you so all you have to do is enterthe numbers into the bfd and you're done. I was quite surprised that the predicted response was pretty much exactly what I got.

I would imaging doing it manually would be an itterative process. You would have to figure out the center fewquency, amount of cut or gain and the Q.

I think that the dual EP800's look stupid. In fact, I think that everyone's EP800 look dumb....











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So why not box them up and send them my way! Then I can put one in every room in my house and have bass utopia!!!! YEAH BABY!!! I can FEEL it now!!!!

(Disclaimer: To take advantage of this limited time "Don't look stupid" offer, carefully pack up your EP800(s) in their original Axiom packaging and send them prepaid, by you, to Nick Buol... PM for shipping address. Act today. Batteries not included. Not valid in Puerto Rico or Guam.)

Hi,

Incidentally, the stand-by draw of all of Axiom's DSP subwoofers (EP400, 500, 600 and 800) is 12 watts. When the subs are "On", no signal driving them, that rises to 15 watts.

Regards,

Alan

Hey Guys,

Okay, I've had about 5 hours to tune and audition the changes to my system. For those of you who do not know, I previously ran two EP500s, and now running two EP800s. I'll start with my initial impressions from last night. After just hooking up the EP800s to replace the old subs (AND keeping the old BFD parameters in place), there was very little bass. I was so disappointed! Even my wife noticed it. I then tuned the BFD off... No Bass whatsoever.

I remembered that the BFD adds about 3-4db of gain by being in the loop, so I left it on and then cleared out the programs. Okay, but still not there. I had initially set the EP800s to the same setting as he EP500s (about 7 o'clock). I brought them up to about 10 o'clock to get the same perceived gain (Looking into the future, after Alan's response, it makes sense. It's the same amp driving two drivers in parallel, therefore, more gain is required.)

Okay, so now I had the same perceived gain, but it sounded "muddy". Most likely because I was comparing a non-tuned pair of subs to a tuned pair of subs. Since I did not have my laptop with the REW software with me, I would have to tune it old school with my SPL meter and paper and pen. I wanted a sub tuning about 5-6db hotter than my full range for preference.

But it was late and time for bed... Part II next.

Good start, MORE MORE!

Threads with cliffhangers?!?!

SRoode,

That is a very nice setup. In fact, your theatre setup matches up very closely to what I have been imagining for my future basement theatre (hopefully sooner rather than later). I've been spec'ing out some equipment and taking measurements of my basement to determine screen sizes and overall layout. I really like what you've done and it mates well with my initial designs. Do you mind sharing some of your measurements? For example:

- Room dimensions - particularly width across the front of the room accommodating the screen/speakers/entertainment unit, along with ceiling height.
- Screen size?
- Dimensions of the screen on the wall (i.e. top/bottom/sides in relation to height on the wall)?
- Dimensions of the black entertainment unit underneath the screen (which, btw, I really like - did you purchase or build?)
- Seating distance from front wall (to 1st row of seats if you have multiple rows)?
- Throw distance of projector?
- Any other measurements you believe would be relevant.

Thanks in advance! I'd really appreciate your help but it is not required immediately as I don't plan on doing the basement for some time. Either reply in this thread or by PM - your preference.

Thanks again and awesome setup!

Bryan

P.S. Originally thinking, I was going to put two subwoofers the size of the EP500 up front (I currently own the EP500 in my bonus room setup). However, seeing the two EP800s may change my mind

um, oooookay. Nevermind. I think what I have now sounds pretty good.

I would also really be interested in knowing your projector/screen setup because I would like to get one far down the road.

Thanks also

I would also like to know your bank numbers because I too would like an EP800.

Part II:

To sort of cut to the chase of tuning, I did a 20-100Hz plot of the room before any BFD tuning. Below you will see a graph (hand plotted, no REW) of the results, as well as the results after BFD tuning with only 3 filters. I probably could have gotten by with 2, but I added one more at 33.1Hz to make it flatter.



As you can see, the pre BFD tuning was very good. It was +/- 3.5 db across the 20-80Hz spectrum (80Hz is my crossover point on my receiver. I have the subs crossovers set at 150Hz). The post BFD tuning was amazing. Just a hair over +/- 2 db across the same spectrum. Keep in mind that this was done by hand, and by using only the SPL meter. When I can get my laptop here and do a proper calibration with REW (like Jason did), I'm sure I can do even better!

Impressions - I brought the family down to the "Bass-ment" to listen to the new speakers. I chose to listen to music first, and picked songs we were all very familiar with. I have to say, the changes for music were very subtle. The EP800s sounded musically very similar to the EP500 setup I had before (which is a good thing!). I noticed that the music seemed to be "tighter" (for lack of a better word) in the low end. The bass was not overpowering, but is was definitely there, and definitely tight and fast. My wife said she noticed very little difference as well. The kids of course just ran around in circles and danced. After several songs, we both agreed that the new speakers performed just as well, and a bit better, than the EP500s.

Next, we chose a couple of movies to check out the differences in LFE. THIS is where the big changes occurred. I picked "Apollo 13" and "V for Vendetta" as our two test cases, again because we were both very familiar with these movies. For "Apollo 13", we played the takeoff scene. Even moments before the ship took off, there were points where I could feel my seats shake. This is a first for me in this theater because, since it is in the basement, it sits on a concrete foundations. I've had no problems in the past getting my walls, furniture, and dishes upstairs to shake, but getting the floor or seats in the theater to shake was next to impossible! My wife noticed the difference right away. I told her that the extra 8 or so Hz the new speakers were providing were mostly in the subsonic range, but definitely in the range that would provide the "shake" and "punch" that we were missing from the old setup (I would like to provide a small caveat on the EP500s. They are fantastic speakers! In most any other setup, they would provide a bunch of shake or punch as well. Basement theaters are tricky however.)

Next, I played the domino scene in "V for Vendetta". Again, the floor and seats shook when the LFE effects were played. I pulled out the SPL meter and read peaks of approximately 100db during the scene. There was never a distortion of sound, it always seemed tight and punchy, and for the first time (well, second now), the theater seemed to actually shake during the scene. I asked my wife what her impressions were, and she agreed that the new setup (and sensory feedback) added a greater sense of realism because you felt more like you were in the scene.

Well, that's my initial impression in a nutshell. I'm extremely satisfied with the new speakers. Sending the EP500s back is sort of bittersweet however, because it's sort of saying goodbye to good friends. They were fantastic subs, but the EP800s are musically equivalent to them, and on a different level when it comes to LFE.

Bryan,

Nice to meet you. Some pix of my theater (with the old subs) are here:

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showgallery&Number=206049

Room dimensions: 16ft wide by 18ft deep.

Screen size: 126" diagonal 16x9 Carada screen

Dimensions of the screen on wall: 9'-9" wide and 5'8" high. This includes the 4" border all around.

Entertainment unit: It was custom built into the wall for the theater. I hired an Amish carpenter to build it to the exact width of the screen. I think it was only about $700-800.

Seating Distance: It's a perfect triangle to the main seating position. Speakers are 11 ft apart, main seat 11ft to each speaker, main seat about 12 ft to screen.

Throw distance of projector: About 13'

Other relevant measurements: Main seat is about 10 ft from each surround, and about 9 ft to each rear speaker.

For music, I would be happy with the EP500s. For LFE, the EP800s are in a different league.

-Steve

Steve - that is exactly how I would describe the change from the 600 to the 800. For music, really not a difference at all (and I didn't expect one), but for movies, YES, the shake and rattle is there at levels that I'd never experienced with the 600. The EP800 finds LFE in places that you'd never know existed with other subs. It's been fun to listen to familiar movies again and feel the difference with the new sub.

Thanks for posting your thoughts!

Jason

IH, no, the power consumption rating on an audio receiver or amplifier typically is an average consumption rating unless it's specifically termed "maximum", "full power", etc. This results in some screams of fraud when it's noticed that, for example, a 7x100 watt receiver has maybe a 500 watt power consumption shown on the back panel. Having heard that class AB amplifiers are maybe 50% efficient, they think that if the power output rating was true that the consumption would have to be around 1400 watts.

Well, the power rating is true(has to be so as to not be in violation of the FTC amplifier power regulations)but the consumption rating can also be accurate. An average usage number might be taken with 1 channel driven at full power and the other 6 at 1/8th power, which also happens to be the standard that Underwriters Laboratory uses when testing for overheating, since that's considered to be roughly the average usage that occurs in home audio. The channel driven at full power runs at about 50% efficiency in a class AB amplifier, but the efficiency drops off at lower power levels and might typically be around 25% at 1/8th power. So, the consumption would be about 200 watts for the channel driven at the full 100 watts with 50% efficiency plus 300 watts used for the other 6(1/8th x 100 x 6 = 75 watts total output, using about 300 watts at about 25% efficiency), and that's why the plate on the back shows 500 watts consumption.

SRoode,

Thanks for the measurements. Once again, nice setup. I have two more questions if you don't mind. First, what is your ceiling height and secondly, what is the bottom height of the screen from the floor (or conversely, the height of the entertainment unit)?

Thanks again!

Bryan

Ceiling Height: 9 ft
Entertainment Unit: 3 ft tall on the ends.

V for Vendetta!! One of my favorite movies for many reasons but I really think it's a masterpiece; very thought provoking. I can't get enough of how V talks in iambic pentameter, just the idea of having a character talk like that is pretty cool. There are numerous meaningful quotes in the movie, but my favorite is "Vi veri universum vivus vici" translated "By the power of truth, I, well living, have conquered the universe".

SRoode, do you remember that part in the movie?? Quizzing you LOL.

I'm not sure I remember that scene exactly. Was that in the beginning when he first met Evie and spoke for about 30 seconds where every word he spoke started with a V?

My wife and I both love that movie, and she loves the way he speaks as well! She was surprised when I told her it was Agent Smith from the Matrix.

The scene is when Evie is cleaning off the mirror in one of the rooms and that quote is imprinted along the top of the mirror. Just after cleaning it off V walks in and asks for her assistance.

Hi John thanks for the response

If your explanation is correct, and I don’t believe it to be accurate, a person would be required to guess the maximum current draw on a house circuit, or even a simple power bar. I’ve never heard of manufacture of any electronic device, or any electrical device for that matter, giving an average rating as apposed to the maximum rate for current draw.
But because I’m not an electrical engineer I called a couple of electronic shops here in the region and all tree indicated it’s the maximum draw rating. Maybe their all wrong.
I would be interested in learning what your background is as it pertains to electronics in general.
It’s just a hobby for me.

this should be interesting.

I'm afraid I tend to agree--not having the maximum rating on the unit wouldn't make sense. How else would one plan?

I bet there is a lot of current going through those keyboards

Okay,

Since my own thread has been jacked in several directions I'll put in my opinion. This is my opinion, as an Electrical Engineer with almost 20 years of experience.

The power rating of a device is the maximum power draw of the unit. It should take in to account inefficiencies, power factors, etc. As an example, a motor rated at 100HP is the maximum rating. Most of the time, it will consume much less, but 100 HP is the maximum output of the unit. In all of my experiences with equipment (and I commission VERY large pieces of equipment in my field), the power rating of devices are always identified with their max draw.

The amp used in the EP800 appears to be the same amp used in the EP500 (rated 500W) and the EP600 (rated 600W). This amp has an identified power rating of 675W. Fine for the EP500 and EP600, but raises eyebrows for the EP800.

As we all know, amplifiers are a different animal. Typically, an amp's power rating is for an 8 ohm load. Since there are two drivers in parallel in the EP800, and according to Alan's response, the impedance of the EP800 is most likely 4 ohms (I'm assuming the drivers are 8 ohm). Therefore, if the amp is capable of driving a 4 ohm load, it will in fact draw more than the stamped 675W.

In my tests with the new speakers, I have no doubt that they are in fact pulling more power than the EP500s. I cannot verify this without plugging in an in-wall wattmeter, but from my listening experiences, the speakers are far more powerful. Also, even at 110 db, I have yet to trip them out.

What we have to keep in mind is that we basically have prototypes here. These speakers are not available to the general public yet, they were only made available to loyal customers. My guess is that when they are ready to be shipped to the masses, the amplifier will be labeled with it's proper max power draw for a lower impedance load.

Again, all I can say is that I am quite certain that these speakers are pulling more power than my EP500s with the same amp.

Steve

Here, a nice nude picture to soothe the savage beasts!

Very pretty. That Xbox 360 wants to be an Elite, though, I think.

Beautiful man, simply beautiful setup!!

Color me jealous!!

::runs back into HT cave crying::

Sharing is all about making other people embarrassed.

Steve, great-looking setup. Enjoy your newly monstrous(small m)bass.

IH, this is really a point that should be fairly obvious: power consumption(again if it's one of the few which give a "max" spec)would have to greatly(how greatly varying with amplifier efficiency)exceed maximum power output. As previously stated, most specs are an average rather than maximum consumption spec. The numbers shown in the previous post were of course only to illustrate the principle and come out even, not to represent a particular unit(although all are in the ballpark).

A real-world example can be seen in the Denon 3808 popular here. The power consumption is shown by Denon as 7.2 amperes(note, no "max" specification), equivalent to about 860 watts. The lab tests which have been cited several times here to illustrate the excellence of the unit include all 7 channels continuously driven at 130 plus watts per channel, a total output of a little over 910 watts. With typical class AB 50% full-power efficiency this would consume about 1800 watts. The 3808 is very good, but it doesn't create power out of thin air.

There's no legal requirement(as there is in FTC regs on the power output)that the power consumption be shown as a maximum figure so as to aid the user in "planning" requirements, and most don't include such a number. There's no real disadvantage in this, as full power operation of all channels simultaneously isn't a realistic home scenario.

So, the typical power consumption figure shown may help in estimating the electric bill, but doesn't represent the maximum capacity of the unit.

Hi John,

Thanks for thoughts.

John,

As always, a well thought out and easy to understand explanation.

The Denon amp is a good example. In reviewing my AVR-3806 manual, I see a 7.1A total draw, and each channel is rated 120W. 7.1A x 120V = 852 Watts. 852 Watts / 7 = 121 Watts / Channel. The math works here. The manual also states the amp is capable (dynamic power) of 140W Channel driving 8 ohm loads, and 210W Channel driving 4 ohm loads. This is how I think the EP800 gets rated. The plate on the back of the amp is showing it's 8 ohm load rating, not it's 4 ohm load rating.

I suspect you are spot on Steve.