Axiom Home Page Forums General Discussion Technical Questions Connecting EP500 to line output of receiver.

I have a really basic problem. I just bought a used EP500 subwoofer, but I don't know how to connect it to the subwoofer line output of my receiver. I looked at the "manual" on Axiom's product page for the EP500, but it's not all that helpful. It refers to an XLR to RCA adapter, but I don't have such a thing. Any suggestions would be welcome.

Greg, unless there's some complication that you haven't mentioned, you simply connect a standard coaxial cable with RCA plugs on each end from the sub out of the receiver to the line input on the sub.

Only the very, very newest EP500s (and all Axiom subs) use the XLR to RCA adapter. If it's used, the current manual probably doesn't apply, and the sub has a regular ol' RCA input (and a regular old RCA output). You can use either one.

Was trying to figure that out too, cuz in the new EP500V2 pics on the main Axiom site, I couldn't see any RCA inputs nor outputs. May I ask why they were omitted? Thanks!

Call Axiom, they might now.

On the new amps for the EP500 the RCA and XLR are one in the same. Axiom should have sent an adapter for this purpose. If you need to use RCA you use the RCA adapter and plug into the XLR imput on the back of the sub. If using XLR just plug in your cable and your off to the races.
Mel

There are line-in and line-out jacks, and I disconnected the RCA connector from my current (working) sub and plugged it into the EP500 line-in jack. But I hear nothing. There are various possibilities of course, but now I'm exploring the possibility that there's something about the connections I don't understand. There are small holes at the right of the line-in and line-out jacks -- what are those for?

I could try the high level inputs, but there are no high level outputs, so how is that supposed to work?

Is the XLR to RCA adapter a standard part? I have no experience with XLR connections. [Never mind this; I see there are adapters and XLR male to RCA male cables.]

Thanks for any clues.

Axiom often makes changes to their subs midstream, your best bet would be to call an actual Axiom employee (Jc, Brent, Alan, etc.) at the 800 number, they man the phones until late. Since they are priveleged to this information, than can give you a factual answer.

The "small holes" are, I guess, the 1/8" 12v triggers (which can be used to control power on/off for the sub).

Oh, I see. The manual diagram for the current model has them in different places.

I moved my right speaker connectors temporarily over to the EP500 high level inputs, and I am hearing some bass, now. So that's a relief. Most likely, the line-level input is just broken -- it feels a little loose. So I guess I'll order a male XLR to male RCA cable (I hope that's right).

Thanks for the help.

The new subs with the combo XLR/RCA jacks don't use an XLR to RCA adapter anyway. There's just a 1/4" phono hole in the middle of the XLR where an RCA-female to phono-male adapter is inserted.

There's no way to adapt an unbalanced RCA (which is what receivers put out), into balanced XLR (which what the Axiom subs use) with just a cable. You need active electronics--the sub has those electronics inside when you use the RCA input.

If the RCA inputs are not working, there's a chance the sub is broken. You said you bought it used? While Axiom will more than likely provide some testing ideas on the phone, you won't have any warranty support.

Oh. But then what are the XLR to RCA adapters and cables I see on sale used for?

It's possible to go from an XLR signal source, to a device expecting an RCA input with just a cable. But not from an RCA source to an XLR input.

XLR has two signals on it. One normal, and one electrically inverted. When going from XLR to RCA the inverted signal can be ignored. But from RCA to XLR, you need something to generate the inverted signal--thus the active device.

The current manual says: "Your subwoofer is shipped with a supplied 1/4” Phone-to-RCA-jack adapter already installed in the XLR female input. Connect a shielded coaxial cable, with male RCA plugs on each end, from the A/V receiver or A/V preamp processor’s Subwoofer Output jack to the RCA female jack on the 1/4” Phone-to-RCA adapter."

If an active device is needed, how can Axiom do it with an adapter? Or maybe they're not referring to a physically separate adapter here ...

It is a physically separate adapter, but the plug they use is a combo XLA and 1/4" plug. The 1/4" plug is wired separately from the XLR and is unbalanced.

I don't quite understand that. An RCA connector is going to be unbalanced in any case, isn't it? Are you saying that if I use a passive adapter to plug RCA into the XLR input it will be an unbalanced connection? Or that it won't work at all?

The XLR is balanced. The 1/4" plug is unbalanced, as is an RCA connector.
You don't have a 1/4" input on your EP500, so...

And it's not an adapter from RCA to XLR, it's RCA to 1/4" phono.

There is enough room in the center of the 3 pins for a female phono jack. It wouldn't be possible to have a female RCA there. So the adapter from the more common RCA to the less common phono is used. But an RCA male to phono male cable could be used in that case without the supplied adapter.

None of that matters to you, as this only applies to the newer subs, where the unbalanced (phono) and balance (XLR) inputs have been combined into one physical interface, but are still electrically separate.

The older sub, as you have, has the RCA and XLR both electrically and physically separate. I'm sure they were combined to save a little on parts and labor (plus the combined jacks are what the A1400-8/2 amps are using, so there's some standardization across the lines).

Okay, I guess I'm with you. I'll do a little rewiring of my system to use the high level inputs of the EP500, for the time being. But if I want to use my other subs with the EP500, I'll lose any LFE channel input to the EP500, so it's less than ideal.

Have you tested the high level to make sure they work? I'd do that with some temporary cables before you rewire anything.

I see you did test them already. Good. Did you try the RCA "out"? While they are labeled input and output, they're both hooked together inside the amp, and go to the same place (they basically form a Y).

Oh, that's another reason for the RCA adapter with the XLR. People kept breaking the RCA inputs which went straight into the back of the sub. The RCA adapter is 90 degrees, and can point down, thus less likely to break.

Also try plugging the RCA cable into the line-out jack--the line in and line out are actually the reversible--electrically, they're the same thing.

Yes, I did test the high level inputs, and they work.

How about running into the Line Out jack?

I know it's been said already but you realllllly need to call Axiom. They are very friendly and helpful. At the very least, if the RCA jack on your sub is broken, they will arrange a fix for you.

Using the high level inputs negates all the bass management you can do on the receiver. I would want the RCA jack fixed, if that is indeed a problem.

Thanks to both of you -- that's a very useful suggestion. Well, line out sort of works a little. There's some sound, but it's very faint, even with the sub volume up all the way. Maybe some faint sound was there using line in, also, and before I just didn't notice it.

Greg, there is more than one individual on this forum (rvrrat and argon) that have this same issue. Normally, unplugging the AC to the sub and plugging it back in fixes the issue temporarily, but after a short term goes back to the symptoms you describe.

If you call Axiom, they will resolve your issue. We are all tweakers, but sometimes you can't tweak that what is broken.

A known issue, eh. That's good, and I'll try unplugging the power, as a diagnostic. I'll call Axiom soon, but for a little while, I'm going to be listening. The person who sold this to me seemed to think it was an EP175. Should I feel guilty?

Not if he sold you a faulty sub.

Caveat venditor!

If this is the system you mentioned over at AVS and you can get the sub working properly you got an awesome deal.

that bad thing is it won't be under warranty since your not the original owner, if there are issues...

Yes, I'm pleased with the speakers, even if the sub turns out to be less than fully functional. I also got four QS8s in place of the the QS4s that were advertised.

A couple other questions: Is there somewhere I can find an older version of the manual? This sub is model "EP-500", serial 5050001, bought in 2006 according to the seller. And, related, what do the settings on the Trim control do? (Remote, Flat, Half, Full, Load)

Was the guy you bought them from even the original owner? How could you not know what speakers you have especially if only about 3 years old.

The trim control adjusts the frequency response of the sub kind of like using EQ but with preset settings. Flat is a flat FR, where Half and Full are designed to help compensate for subwoofers in general having FR issues in small rooms. Load is supposed to be for firmware updates though I’ve never seen one yet.

I’ve used the Half and Full settings to boost the FR at around the 40Hz range in two rooms where I had large dips due to room modes.

Wow, that's definitely an old EP500 amp.

It was a gal, and I gather her ex bought them. Well, I think what happens is that folks not really interested in audio and video gear categorize equipment by brand and general functionality. But sometimes not by model or year. I see quite a few listings on Craigslist for "Sony 5.1 speakers", e.g., as though Sony only ever made one 5.1 speaker set. "A nice 42 inch Samsung flatscreen."

Thanks for the info on Trim.

By poking around, I found an older manual version: Older EP500 manual.

So many changes I've noticed to the ep500v2 amp. First the 3 accessible round fuses were omitted, then the crossover was changed from bypass (100hz) to 150hz, then the volume level knob was desensitized (is that a word?), then the replacement of the trim knob with a subsonic switch (which the older ones already had the subsonic roll-off program built-in), and now a totally new look for the amp, which now requires an rca-phono adapter jack that plugs into the xlr?

Greg,

Did you find that system locally? Just wondering.

Brian

Yes, locally, on Craigslist Hawaii/Oahu.

This is what they replaced my amp with. I just bought mine and received May 2009 - so these updates have happened between then and now.