Aguilar phase issues; amp or cables or?

Discussion in 'Amps and Cabs [BG]' started by SLO Surfer, Apr 11, 2022.

  1. SLO Surfer

    SLO Surfer

    Jun 3, 2009
    Los Osos, CA
    Ok, so I've got an Aguilar AG700 running an SL210 and SL115. Each cab sounds great on its own and when piggy backed together, but not when I run them simultaneously with the amp's two Speakon outputs. The rig all of a sudden has no low end and you can almost hear a stereo delay type effect, like each cab is firing a millisecond apart from each other. This only happens when using two Speakon cables, and has been this way since I first bought the rig.

    NOTE: I did the 9V battery check, and all three cones push outwards.
    NOTE: The cabs do run in phase with each other and sound GLORIOUS when I run one Speakon cable out of the amp, and then piggy back the cabs together using a 1/4" speaker cable from one cab to the other. (The AG700 only has two Speakon outputs total, no 1/4" outputs)

    So I think I've narrowed it down to one of my Amazon bought Neutrik Speakon cables being miss wired, or one of the amp's Speakon output jacks being miss wired. I can swap around my two Speakon cables and 1/4" cable with either cab and get the same results in every order and configuration; two Speakons = out of phase, one Speakon plus 1/4" piggy back speaker cable = in phase. Either Speakon cable to either cab by itself sounds great.

    Any advice on simple ways to figure this out? Is it potentially something other than phase cancellation? I'm just kind of OCD and would like to use both Speakon outputs to run one cable directly to each cab. It looks cooler on the back, where only I can tell the difference. :thumbsdown: Plus, I'd like it to work the way it's supposed to work. :thumbsup:

    Thanks for any thoughts or ideas!
     
  2. Redbrangus

    Redbrangus Supporting Member

    Nov 19, 2018
    Under The X In Texas
    One of the two Speakon cables being mis-wired would be a viable explanation of what's happening. Depending on the type of Speakon connectors that are on your cable, it should be fairly easy to unscrew the cable strain-relief chuck and slide the back shell off of the connector to visually inspect the connections. With the two connectors from each end of the same cable oriented in the same direction, you should be able to see if there has been a reversal of the polarity from end to end. Or there are cable checkers with the capacity to check Speakons -- maybe your local retailer or repair shop might have one and would check them for you.
     
    Last edited: Apr 11, 2022
    Al Kraft, SLO Surfer, wcriley and 2 others like this.
  3. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    By any chance are the SpeakOn plugs not genuine Neutrik parts? This would be a clue that the builder of the cables was interested in price only, not quality and this same strategy could be responsible for mis-wiring.

    Non-Neutrik plugs cause more problems than anything I deal with on a regular basis, often (but not always) used by lower quality cable manufacturers due to cost. When they come apart and tear up the mating connector (especially if they get stuck), the cost savings in nothing compared to the cost of now repairing something that's harder to repair because it needs to be dissected to prevent further damage.
     
  4. Wasnex

    Wasnex

    Dec 25, 2011
    My understanding is when you connect everything like this, you get the phasey lows.
    upload_2022-4-11_23-7-17.png
    Could be a crosswired speaker cable, a crosswired output jack on the amp, or a crosswired speakON on one of the cabs. FYI one of my amps had the wiring reversed between the 1/4" out and speakON on.

    Try connecting everything like this if you can. Both cables are speakON.
    upload_2022-4-11_23-7-53.png


    If it sounds good swap the cables.
    upload_2022-4-11_23-10-23.png

    If it still sounds good, the cables are fine. Most likely one the speakON outputs on the amp is wired backwards.

    There are still other possibilities, but I won't go into that now.
     
    Murch likes this.
  5. SLO Surfer

    SLO Surfer

    Jun 3, 2009
    Los Osos, CA
    Thanks for the replies so far! I checked the connectors at each cable end, and they all appear to be wired correctly. (more detail below) I will say that I had two SL112 cabinets previously, used with a different amp head and cables no longer with me, and one of the cabs was wired backwards. I had to change the polarity at the speaker cone so the red wire connected to the black terminal and vice versa to get the cone to push outwards with the 9V battery test. So my faith in Aguilar leads me think it's not unlikely there's a mix up in the amp connectors. I'm afraid to open my amp, but it's out of warranty and those Speakon connectors just have two small screws holding them in on the back of the amp... tempted to see what I find if I remove those screws.


    They appear to be genuine; they look like any Neutrik connector I've seen, they say "Neutrik" on them, and are made with GLS Audio professional series speaker cable 12AWG. If there are fake look-alikes out there I can upload a pic of mine for comparison. It's reading your comments here on TB that lead me to try to only purchase genuine Neutrik parts. I am grateful for your input!

    I checked out the inside of the cable connectors, and all of the white wires connect to 1+, and all of the black wires connect to 1-. This, along with the fact that each cable acts normal by itself with a single cab means I think the cables are fine? (I guess the only next step to verify this would be to use a cable tester or electrometer)

    That is correct.

    I can't connect my speakers and amp as shown in your second or third photo because my SL115 (and SL210) only has one Speakon input jack. Each cab has one Speakon input and two 1/4" inputs. This lack of a second Speakon connection on either cab is the only reason I use a 1/4" speaker cable for the daisy chain.

    ...how about....now? :woot:
     
    Murch likes this.
  6. Wasnex

    Wasnex

    Dec 25, 2011
    :rolleyes:

    If you have confirmed the speakON cables are wired correctly my guess is one of the panel mount speakON jacks on either the amp or one of the cabs is wired backwards.

    If you have 1/4" to speakON adapter, plug the cable into each cab. Next use the adapter to do the 9V battery test on each cab.

    If both cabs and cables pass, it's the amp.

    I use this Hosa adapter.
    upload_2022-4-12_0-15-18.jpeg

    However, I believe the AG700 has a differential output, so it's important that you do not allow the metal of the 1/4 jack to touch the chassis of the amp. Because of the hazard, consider an adapter with a longer chord.


    Also from Hosa:
    1593600305_IMG_1382135.jpg
    :cigar:
     
  7. SLO Surfer

    SLO Surfer

    Jun 3, 2009
    Los Osos, CA
    Thanks! I don’t have a Speakon to 1/4” adapter. But after looking at the inside of my Speakon cable connectors, I’m thinking I can just unscrew and remove the wires from one connector and try the 9V battery test with those exposed wires. This would be just for testing the cabs. Still not sure how I would test the amp, and I hope it doesn’t come to that.
     
    Wasnex likes this.
  8. SLO Surfer

    SLO Surfer

    Jun 3, 2009
    Los Osos, CA
    Ok, I had a chance to take the connector off one end of a Speakon cable and use it's bare wires to do the 9V test with each cabs' Speakon input. Sure enough, the SL115 has the Speakon panel mount wired backwards (cone moves inward with 9V), even though the two 1/4" inputs on the same cab are wired correctly (cone moves outward with 9V).

    I took the back panel off the SL115 to see if I could just swap the two wires on the cab's Speakon connector without any soldering. Sure enough I could easily pull the wire connectors off the tabs and swap them, witch fixed my phase issue! Now all inputs (1/4" and Speakon) on both cabs push the cones outwards with the 9V battery test, and any audible phase issues are gone when playing my bass through the rig in any cable configuration.


    So this is now my second Aguilar SL cab with an internal miss-wire issue creating phase cancellation. In both cabs (SL115 and SL112) the red and black wires appeared to be connected to the correct color terminals on the speakers, and correct + - tabs on the jack connector, but not soldered correctly to the circuit board/crossover. I wonder how many other cabs with the same issue have gotten passed their QC... I've found two out of four, in my personal experience.

    Thank you @agedhorse, @Redbrangus, and @Wasnex for your invaluable support in guiding me through this! I owe you each a beverage of choice next time you're in the San Luis Obispo area or I'm in your area!
     
  9. It's really surprising and disappointing that you've now had two Aguilar cabs with incorrect internal wiring. I've owned dozens of cabs from cheap to expensive manufacturers over the years and none were wired incorrectly. I'd put Aguilar in the expensive category and consider reaching out to Aguilar to see how they respond. They owe you a few beers!
     
    SLO Surfer and BasturdBlaster like this.
  10. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    This is a good example of how troubleshooting leads to the real root cause without wild ass guessing, obtuse speculation and internet absurdity.
     
  11. You engineers take the fun out of everything. And I was just going to suggest replacing all the caps in the amp. :D
     
  12. Interesting thread—good read!