I Need HELP with a cabinet!

Jimmy Stump · #1 04-28-2010, 09:16 PM

I'm looking for some assistance here from some knowledgable cabinet people.

I just took delivery of a USED Epifani UL2-410 today. I plugged my new head in (a Markbass F1), and it sounded a little empty in the low end to my ears.

I noted some damage to the rear of the cab where the plastic housing for the horn attenuator and inputs are. I also took the grill off to inspect the speakers. Speakers are all intact. Both 1/4" / speakon inputs work on the back of the cab.

OK, here's where I need help. When I hit a low note, there is speaker excursion from all four speakers. However, there appears to only be SOUND coming from two of the four. If you're looking at the front of the cab, the top left and bottom left are the ones with an audible tone. The top right and bottom right do not appear to actually produce an audible sound.

Anyone have any experience with this sort of thing? I am an electrical novice so I'm not sure I would know how to test anything.

I can not take it to the place I bought it because it was an online retailer in the US (I'm in Canada). I will be able to send it back, but I'm trying to determine with certainty if there is something wrong with the cabinet first.

Is it also possible that there is something wrong with the Markbass F1?

You guys seem to know your stuff, I'm hoping someone can help.

Thanks!

Calaverasgrande · #2 04-28-2010, 09:41 PM

You can use a battery to check the speakers as well. Just take a speaker cable and put a 9v battery across the tip and sleeve of the cable (or + and - if its a banana, if its a speakon uh?).
When the battery contacts meet the cable you should see all of the speakers move together in one direction. All out if you are in polarity, all back if you are out of polarity. If they dont move they are blown or disconnected.
Unscrew that speaker cup in the back and use a flashlight to verify that wires are connected to all of the speakers.

Jimmy Stump · #3 04-28-2010, 10:11 PM

Thank you, Calaversagrande. I just tried the 9v battery trick. Clear excursion on the 2 producing a tone. But, there is SOME movement from the other 2, but nowhere near the full excursion. Speakers are connected as far as I can tell...

Can I conclude anything from this?

korngold · #4 04-28-2010, 10:27 PM

Did someone try to wire it in some sort of "x stereo" formation? Did you try the other inputs to see if the opposite speakers work? Did you look inside to see if all 4 speakers are the same brand/models? Also, make sure all 4 speakers are wired the same. It sounds like you could have two wired out of phase (backwards, basically), so they would go in while the other two go out, which does cancel some of the sound and may be the cause of your low-end issues.

Either way, it sounds to me like someone got "creative" inside & miswired it somehow.

Some additional info:
http://www.stevehoffman.tv/forums/ar...p/t-39109.html

and

"You can check the Phasing of multiple speaker cabs' drivers, by connecting a 4.5 volt battery to the positive input terminal and checking out what the cones do.......they should all move in the same direction......If one doesn't, then it's out-of-phase, and it's connections should be reversed. "

..from this site:
http://www.dancetech.com/construction.cfm (see "Electrical Connections" about 1/2 way down)

Jimmy Stump · #5 04-28-2010, 11:14 PM

Quote:

Originally Posted by korngold

Did someone try to wire it in some sort of "x stereo" formation? Did you try the other inputs to see if the opposite speakers work? Did you look inside to see if all 4 speakers are the same brand/models? Also, make sure all 4 speakers are wired the same. It sounds like you could have two wired out of phase (backwards, basically), so they would go in while the other two go out, which does cancel some of the sound and may be the cause of your low-end issues.

Either way, it sounds to me like someone got "creative" inside & miswired it somehow.

I tried both outputs of the amp into both inputs on the cab. No change there.

All 4 speakers are Eminence neos.

As far as the wiring goes, I really don't know. There's quite a few red and black wires in there. Some appear to be daisy chained.

This seems pretty crappy any way you look at it. I shouldn't have to rewire a cabinet bought from a reputable (?) dealer. I'm going to call about a return tomorrow.

rbonner · #6 04-29-2010, 12:19 AM

Yeah they sure didn't check out the cab.

BOB

Calaverasgrande · #7 04-29-2010, 12:51 AM

Sounds like two of the speaks are either not wired up (it only takes one loose wire) or are blown.
If two of em are moving and the others only kinda move they could just be blown and are only moving from the air pressure of the good ones.
fixing it is really simple if its just a wiring prob. It's hard to explain over the internet, but easy. Might want to try removing each speaker so you can check
A )that the wires connect to the terminals.
B )that the terminals connect to the VC.
those are common places I have seen failure. It is less likely but one of the wires that connect between speakers could be shorted or broken. It's hard to take from there as each company wires their cabs differntly.