Axiom Home Page Forums General Discussion Technical Questions Ultrasonic rumble on music with EP500

Got new EP500 today and I am getting ultrasonic rumble on music even with the subsonic filter on. Have crossover set on 80 on the sub and on my amp. I have 2m22s up front with 2qs8s and the VP100 center soon to be the VP150 (on its way)

I asked on your other thread if you calibrated the sub to the other speakers, normally 75dB's? In other words, maybe you have the volume (gain) cranked to high.

Ya I have lowered it alot and calibrated to the best of my ability. I am having a problem boosting the 40Hz to 80Hz range when I try I get too much low end. The new design has no trim control (replaced with subsonic filter) And in the instructions it said to use the trim to boost that 40Hz to 80Hz (Instructions were for old design and need update)

Did you run frequency sweeps to verify this?

No I havent but my ears notice that hole in the sound. I have fine mid and high end and very low end. I am just assuming it 40 to 80 range. What do I have to do to boost that range if thats the problem? And the other thing I dont like about this new design is I have to turn on the subsonic filter when I listen to music. Being in a wheel chair and because where I have it means I have to yank it out to listen to music. What is the cut off of the subsonic filter? If I leave it on will I lose alot on movies? But regardless I need to know how to boost the 40 to 80Hz range

The "old" design is like having the sub-sonic filter off, so turn it off on the "new" design and you'll end up with the old. It is an additional cut off for LP rumbling (that you cannot really hear as it is below the physical capability of human ears except for newborn babies and even then) so you don't HAVE to have it on.

The fact that you lack some range mean you do not have the correct placement for your sub. Invite some friends and have them do the sub crawl (look into the video section on the "advice" secion of this site for more information on that).

Don't worry, it will get there in the end! It is not always easy to find proper placement for a sub.

Ya thats what I have been doing I was on the phone with JC yesturday when the instructions didnt have the update and he explained it so I have it off all the time but still the trim boosted the 40 to 80 hz signal when setting it to half or full how do I that now? Is turning off the filter the same as having the trim set to full? Well at least I dont have the low rumble I just had the volume all the way up and didnt notice. I am having a pro come over and configure everything correctly so if he says somethings wrong then I will worry if not then great

Your problem is most likely related to sub placement and/or listening position.

The sub is next to the TV on the floor pointed towards the listening area

Try it in different areas of the room. There is a nice trick that is well explained in Axiom's video (putting the sub where you will sit and you move around the room), but which might be a problem if you are in a wheelchair. That is why you might want to invite people over to get it down more easily.

Guy, I was surprised to learn that the current EP500s don't have the Trim adjustment, since the information on the site still shows it and I found it to be quite useful in the locations that I tried for my EP500. I wouldn't have praised it to you in a previous reply if I'd known this.

The subsonic filter has nothing to do with what Trim did previously. I understand that the earlier EP500s such as mine had a fixed subsonic filter at about 18Hz. Now that filter can be selected or not on the latest versions. Making it optional isn't related in any apparent way to the boost which the Trim adjustment gave in the second octave of bass from about 40-80Hz.

You mentioned the manual parametric equalizer on your 772 as a possible solution, but in looking at the 772 manual I see(pp.62-63)that the 772 isn't one of the receivers where the equalization can be applied to the subwoofer channel. So, if your room does in fact make a mid-bass boost desirable this can't do it.

Well living with it for a week now I still think I have a problem with my sub or the amp. The stand bye mode quit working completely on the sherwood so there is some kind of problem there. The thing is its in a small bedroom I should not have to turn the volume past 12 to even see the driver moving with me right next to it. And if I crank it too high it distorts with that rumbling. It should blow that little bedroom away but it doesnt at all. I have the sub on bypass and all my xovers set at 80hz on the amp. I am going to try a diff amp to see. They told me it isnt a diff design just a modification and to just turn the filter off and it is the old design whjich I dont get because I HAVE NO TRIM to adjust.

Look, just because they removed a switch and replaced it with a straight through connection, (thereby making it permanently on the default) it doesn't mean they changed the core design of the amp.

Look,I really dont care if its a new design or not I am just saying I have a problem. It is not normal to have to turn the volume up past 12 o clock on the EP500 on everything just to get the driver moving and to hear it. And this is in a small bedroom with me right next to the sub. Its either the sub itself or the amp. That EP500 should blow that little bedroom away right? I welcome your input though, thanks.

Have you tried a different cable?

Hey Guy,

Sorry you're having problems. I've had a similar issue with my EP350 when I got it back in Jan this year. I've always felt "something just wasn't right". I've always had to turn my sub volume knob to 80% and receiver is set to +3.

Placement was a huge issue for me and I was experiencing some cancellation of low freq. But even then I thought it should put it out more. So much so, that I run 2 subs (an old JBL 10"). Even now with just the JBL 100watt 10" sub, losing the EP350 hasn't made that much of a difference.

Well, yesterday the amp finally went out completely. One call to Axiom and a new replacement amp is on the way. I'm really curious to see if the new amp puts out more. I hope the EP350 becomes more of a performer with the new amp and I don't have to crank the volume to 80% to even hear it perform. Who knows? I'll find out in a week or so...

I know you have your sub in a small room, but make sure you experiment with moving your sub around, if you can. You might be experiencing some cancellation.

Dana