I have to be the most unlucky guy in the world when it comes to this sub! I was making adjustments on the receiver because I just didn't feel I was getting enough out of the sub. so I set my sw volume on the receiver to 8.0 and the sub starting droning... I had to turn down all volumes then turned the sub off...

A few moments later I turned the sub back on, turned on the receiver, tried again to turn up the sub volume on the receiver, and now the subs started sounding like there was a helicopter playing on the TV, but there was none... once again, I turned down all volumes and it kept doing it until i powered down the sub again... only know there's a pop whenever I shut it down!

I don't know if it gets damaged in the delivery or what, but this is just ridiculous. I pay good money for a sub that can give me some power... but as soon as I crank up the volume it's starts having problems?? Can anyone tell me if the denon 3808 receiver is strong enough to push the 800? How can I check if it's the receiver or the sub that's doing this? I need to find a solution to this problem because I'm about to go Crazy!

Any amp would be good enough to drive the sub since it is only taking a line level signal. The EP800 does the amplification. A +8 setting on the receiver seems way to high to me. The amp could be distorting the line level signal at this level of gain.

Thanks for the input while turning down the sub volume on the receiver prevents the issues of droning and that "helicopter effect", it also prevents me from getting any thump from the sub! I did a test and at the level i have to keep it (sub volume on the receiver at +2), I get WAY, WAY more thump from the m80s! that isn't normal, I know this because others are in awe of their 800.

I'm beginning to wonder if there's an issue with the sub out on the receiver...but with the last 800 i tried it on onkyo and 800 blew (smoke coming out of the back)... I'm at a loss here.

Hi majik,

Did you run auddessy? If so disable it for now.

Majik,

Just remember that the gain settings are in db, and therefore logarithmic. That is to say, every +3 db doubles the gain of the signal. A +8 db setting on the receiver tells the receiver to gain the signal by 6.3 times! You should always try to have all channels within +/- 3 db.

On my EP800s, I have a +1db setting in the receiver, and my dials are turned to about 10:30 on the subs. At these settings, the drivers extended so much during the fishbowl scene in Finding Nemo that my wife jumped back when I asked her keep her hand next to the driver.

Set the receiver to 0 and turn up the sub volume on the EP800 if it needs more gain.

Hi House, no, I didn't run audessy I think you're the one that told me about that with the first 800. So I had the sub volume on the receiver to 0.0 just now, and when a scene came on with some rumble (watching Transformers), the drone came back again, had to power down the sub's amp.

i'm going to visit axiom and bring the sub and the denon (and maybe even the Onkyo), and let them test everything out to see if the problem is the sub or the receiver.

In the meantime, is there anything I can do to try to figure it out?

Try turning the sub volume down on the receiver to -4 and see if you get any rumble on that same scene and if it doesn't drone (I do not know what that means btw), start turning up the volume on the subwoofer slowly and see what happens.

Thanks for all the input. I tried everything and yep the sub droned again, i.e. made a continuous low humming sound or rumble(sorry House, I should have written it as a verb, not a noun).

When it's a rumble in the scene, the sub drones until i power down, when it's a sudden thump, or blast it goes into the "helicopter effect" - sorry that's the best way to describe it.

Roode, my drivers aren't extending much at all... I will put in finding nemo after the movie is done and check it out. Can you tell me more about the fishbowl scene you are referring to?

Thanks everyone!

Is there a constant humming sound when the sub is on? Could be a groundloop which is causing issues. Do you have a cable or satellite receiver for your television? What 3 prong devices are hooked up to your system?

After reading all this I was thinking the same thing, possibly a ground loop causing some weird issues.

if it's droning and a scene comes up with a big thump... then it switches over to the the Heli effect but not vice-versa...

What should the LFE level be on the receiver?

I've set frequency level to 80
channel levels are now at 1
sub level is at 0.0

In the user guide, when using the manual setup, then going to audio setup up, then ext. in it recommends setting sub to +15db?? is this right? What is Ext. In anyway? What is it for?

Your settings seem fine. Disregard the Ext. In settings, that deals with hooking up a multi-channel device such as a SACD or Blu-ray through analog cables. When using Ext. In, the sub needs atleast a 10db boost hence the recommended 15db. These settings have nothing to do with your other subwoofer settings, they are completely separate and are not the issue.

I would recommend trying attaching a 3 prong to 2 prong adapter to the power cord on the EP800 and see if those strange sounds go away. You can pick them up at a hardware store for a couple of bucks. They look like this (link below). This is not a permanent fix if it works because it defeats the ground but it is worth trying as a troubleshooting measure.

http://www.enjoythemusic.com/SuperiorAudio/equipment/0107/plug.jpg

Like the others, this seems like some sort of ground loop thing. Once you figure that out, then run Audyssey correctly, go back and fine tune the receivers settings and leave the sub settings alone.

Okay, so here's what I did to solve the issue... I set the sub dial to 80, then configured the channel levels and the frequency... played the same scenes and no more issues, then I set the dial to bypass and everything seems to be okay.... EXCEPT... for my music playing from the ipod using a cable connected to the cd input on the amp and the 3.5mm headphone jack on the ipod... yesterday when I first set up the sup it was working fine, now, i'm barely getting anything (better thump from the m80s).

Another thing, the bass that DOES come from it seems... distorted some how, more of a vibration/rumble than a thump - Not normal when playing reggae (bog marley). But when playing movies from the ps3, i do get thumps when it's supposed to be. Any ideas?

I'll tell you what I'm going to be one happy camper when all this gets figured out and I can just turn on the receiver and get that bass pumpin' like it's supposed to!

when you say Ground loop, should I try using another outlet? Come to think of it you may be right, because the sub was working last night although, I wasn't to happy with the how little thump it was giving me, then I moved it to a new spot and changed sockets. I'm going to try it out and see what I come up with.

Can I use an extension cord/power bar or can that have a negative effect on the sub's output? I like where it is right now and will have to use one if I want to change outlets

Try changing outlets. I would also ditch the iPod (strictly for portable use) and transfer all the music to the PS3 and use the PS3 as your source for playing all your music and movies.

Do you use any type of equilization settings or "sound enhancements" on your iPod, those settings most certainly can cause distortion.

House, the thing is when I'm playing the ipod.. the drivers barely move until i crank up the volume... then they get going big time. After that I can lower the volume ant the drivers will still be working... it's almost as if something is preventing them from receiving all the info they need to get them moving.

And I checked on the ipod, no enhancement settings are on.

Do you use any preset equilization (rock, jazz, classical) or custom. Check the equilizer on the iPod, turn it off, if you can't turn it off set it flat like a straight line right down the middle.

Also check the volume on the iPod itself which could be a factor in having to crank the volume on the Denon. Set the iPod volume to 90% see if that helps at all.

Has the humming gone away when changing outlets?

Nope, none at all.

As stated above I have gotten rid of the humming sound somewhat, but not from changing outlets.

When playing the ipod, there I can tell that "something" is getting to the subs but not "everything"... so there is somewhat of a continuous rumbling effect that will go to the beat of the music, then, when I crank up the volume, I get the thump the 800 is supposed to give...

once I turn up the volume and get the music bass, i can then turn it down and the 800 will still respond to the bass.

okay, now i'm stumped! If I play a movie in the ps3 I get the bass, if I put in a music cd in the ps3 all the bass passes through the m80s??? wtf??? Does that make sense to anyone? I know it must be a setting, no?

Do you have the M80s set "Small" in the 3808 menu?

Dont use your iPod as the source. Use the PS3. There is probably a setting on the iPod that is causing problems. The PS3 is a much better source to use anyways. So you are getting bass now but is there still unwanted noises such as humming or anything else that sounds strange such as distortion?

What does your receiver say when playing a CD? Mine always defaults to "Direct" when playing a CD on my PS3, and I usually change it to a matrixed multichannel mode after the fact. There may be a way to choose a different default based on what type of signal it's receiving, but I've been too lazy to investigate. It might be something to look into on yours.

yep, probably an input source on the Denon.

yeah, I thought I had solved the problem but put finding nemo in the ps3 and when the bird hit the window the helicopter effect happened again, but then when they did the initiation in the fish bowl (I think that's the scene SRoode mentioned) the sub was CRAZY thumping!! I was seriously impressed!! So I'm kind of at a loss for what causes the problems.

As for the music, that's what I did... popped in a cd and nothing... at all! all the bass was passing through the m80s!

and the m80s are set to small. would the setting change on it's own when it's a music cd?

That helicopter effect that you talk about would you call it a humming/buzzing sound or distortion?

Yeah, it could be bypassing those settings if it's entering a pure direct mode, I believe.

It sure sounds like your PS3 is changing modes.

I wonder if that helecopter thing is some sort of input clipping?

Majik, in the 3808 there is a 2 channel settings mode that needs to be set up, I beleive it is in the options section. Once you find it you have to set up the system for sub and the crossovers for the mains as well. I think this might be causing your lack of bass when listening to music.

Majik, try what jakewash just said. There is another place in the setting menu to set the stereo mode as well.

House the helicopter effect is neither nor.. the drivers extend continuously in rapid succession - as if a the sound of a helicopter was being sent to the drivers... sorry, it's the only example I can come up with. and it happens at medium to high volume levels when there is a big boom (like when a Transformer lands after jumping in the air)...

The humming/vibration happens when there is a rumble... like when the cars are driving by in Tallegeda Nights...

only two things can stop it once either starts:
1- I cut power to the sub
2- I turn the crossover dial on the sub down until it stops.

Do you have sub cable connected to the line level INPUT (Line In) on the EP800? Do you have the cable connected to the subwoofer output jack on the Denon? Make sure to read the Denon manual to double check.

For the music CD you have to go to:

Manual Setup -> Audio Setup -> 2ch Direct/Stereo -> Custom.

The Basic setting will take the settings from your auto setup (or by default), which was probably Large for the M80s.


Edit: This is assuming that it is a Denon setting problem and not the PS3.

I read the manual more times than I care to admit! lol! And yes everything is connected to what it should be.

If you have a spare cable I would swap out the one you are using now to rule out a faulty RCA cable and I would also try a cheater plug on the power cord of the EP800 to see if that solves any of the humming/drone/helicopter sounds. Other than that I dunno what else. Time to call Axiom if you have not already.

I'd get rid of the PS3 and IPod. Maybe call Axiom.

The PS3 is an awesome device for Blu-ray, dvd, c.d playback and even SACD. The iPod on the other hand I would use for portable use only driving low impedance headphones (not good for much else).

I don't have any sort of problems using my iPod as a source. But I don't have an EP800, either.

I hate to say it, but I suspect there's still something wrong with the 800.

It is looking like that, a real stumper.

My guesses in no particular order: (1) plugged in to wrong output (but not likely), (2) bad RCA cord (not rare in my experience), (3) problem with the Denon's sub output (so try plugging into another output and see if you get anything - just set sub x-over to ON), (4) another fried EP800 amp, and (5) haunted sub (rare but I'm sure it must happen).

Zimm, haunted subs are very common around these parts..

Majik,

Just for kicks, try moving the sub away from your main speakers and see if you get the "helicopter effect". I seem to remember a problem with the EP600 doing that sometimes if it was too close to the main speakers... I forgot what the affect was called, and why it happens.

Hi SRoode,

That phenomenon is possible only when a subwoofer is connected using the high level inputs.

Majik,

Try taking out the ground screw on the back panel of the EP800. It may or may not help.

Regards,

Alan

Any update on this Majik?

Sorry about the delay in getting back to the post work has been really hectic.

Zimm you suggested I: "try plugging into another output and see if you get anything - just set sub x-over to ON".

Can you tell me exactly what I need to do for this?

I ordered another rca cord, we'll see what happens and I'll post results.

@ Alan: Ground screw??

Spoke with JC today when the sub was in continuous vibration/humming mode, but he couldn't hear it (frequency too low to pass through the phone line). I'm going to try all the suggestions here this week and if nothing then I'm going to take the 800 back. And just do without (can anyone tell me what the return policy is?)... I really want the sub, but I don't have the time to be spending hours trying to figure it out... the way I see it, with the money I've spent on it, it should work straight out the box, no?

I'm just frustrated... sorry.

http://www.axiomaudio.com/troubleshooting_ep500.html#

click on the link and then click on the link that says View Chassis Ground Screw. I know this is the amp for the EP500 but the ground screw should be similar on your EP800.

I would also unplug the sub from the outlet when doing this.

The thing is, if it's a grounding issue, you'll likely find that any other replacement sub will have problems, too.

Agree Mark. Removing the ground screw and or using a cheater plug will tell you if you have a ground loop or not. It is common when adding a 3 prong subwoofer.

k.. i'll look into that.

now what about zimm's other suggestion about the sub out on the receiver? Can anyone tell me what I should do to check this? thanks

I'm using this cable for my sub

http://www.monoprice.com/products/produc...&seq=1&format=2

It was recommended to me either on the axiom forum or the avs forum. Is it okay? or should I be using something else? I read on the monoprice reviews that I might need coaxial cables on both ends (3 review from the top):

http://www.monoprice.com/products/produc...rmat=4#feedback

Maj, the sounds that you've described wouldn't appear to have any relation to a ground loop, which is a continuous relatively low level hum not related to changes in the program content.

The receiver sub output or the cables also wouldn't account for what you describe. The poster at MonoPrice was simply saying that after he ran the coaxial cable behind the wall he connected the receiver and sub with short lengths of the same cable.

From the information that you've given, an internal defect in the sub appears to be most likely.

@JohnK

Yeah, it's looking like that. I'll do what I can to check it out here, and if I can't figure it out I'll just wait until I can bring the sub down and let them have a look at it. I'm fairly certain something happens while in transport. The truckers that come up here drive like maniacs and the road to hear is NOT the kind of road you want to be speeding on; bumps and swells and potholes - it's a dangerous trek! Just my opinion.

That has to be frustrating. I really hope you can get it sorted, as you should be enjoying that sub.

Well, I'll be bringing the Sub back (for SURE this time) august 26th. I'll let them check it out and see what's up. I'll be spending a week in Cuba =) so that should give them the time to work out the kinks! I'll let you know what comes of it (and my week on the beach with bikini clad women! wut wut! lol)

Have fun in Cuba! I would love to vacation there sometime. Relaxin on the beach drinking mojitos and smoking cigars .

Don't mess around to much with them bikini clad women, something of yours might fall off a few months later.

Thanks House! and point well taken, Sirquack! lol! If something does happen should I dbl bag? lol! Naw... just going on a golf vacation with friends... if you like golf, go to Bella costa green fees are waived! just have to pay for the cart (55 cuban convertible pesos).. the varadero course is right in front of the resort and hotel is a 4 star... I was there in May, and decided to go back (got a deal that was too good to pass up)! Beach is wicked!