Question about Clipping and Blowing Speakers

Discussion in 'Amps and Cabs [BG]' started by dgoof911, May 29, 2012.


  1. dgoof911

    dgoof911

    May 17, 2012
    Hey all,

    First time post so I hope I'm in the right area.

    Recently bought a new rig: Genz-Benz Shuttle 9.0 and an Avatar B410 Neo at 8ohms.

    I got everything set-up at my house when the amp and cab arrived in the mail and was instantly pumped over the sound. The cab had tons of tone and great low-end for a 4x10.

    Anyways, I brought it to my practice space and after a small session with the band I notice that there was some buzzing/fuzz coming from the cabinet. Instantly my worst fear seemed to have come true: It sounded like a blown speaker. After sitting down with the cab the next day clearly the speakers were distorting even at low volumes. Both the left speakers and the bottom right speakers sounded blown.

    When I had first set up the cab I drove it pretty hard but was only hitting the limiter on sharply hit notes and slap/pop style playing. The speakers did not sound distorted and I was not concerned that I was continuously clipping the amp. I probably hit the clip a few times but I have hit the limiter on such playing styles on many different amp and cabs without ever blowing the speakers. The speakers had to have been receiving clean signal and I could not hear any distortion coming from the cab. During the practice session I was not driving as hard as the initial set-up. The amps runs a 500 watts and the cabinet, according to Avatar, is rated for 1000 watts. So if the amp was sending non-clipped signal I find it very hard to see how I could have blown these speakers so easily.

    This has led me to two conclusions: Either 1) there was a defective coil in one of the speakers and therefore it blew out easily thereby perhaps damaging the other speakers (not sure how or if it possible to do that) or 2) that I somehow pushed the speakers passed their x-max and physically damaged them. The Shuttle 9.0 has a low end voicing shape that really made the cab pump out low end but I never heard any distorting what-so-ever.

    I removed the front grate and slowly pushed in the cones to see if I could feel any coil rubbing/scraping. Nothing.

    I'm just shocked at how easily these blew out considering what I've read about Avatar making a quality product. I A/B'd the resident Ampeg SVT-CL 200T and it is most certainly the cab.

    The unfortunate thin is that Avatar is leaning towards the fact that I blew out the speakers whereas I think it might be that their product (or at least the Eminence Drivers) are $hit. My father has been a profession audio technician for over 30 years and says that you would really have to have a note sustain a clipped frequency for a long time to blow out speakers on any solidly built 4x10. Speakers should be made to take a certain level of abuse and in my case I feel I was hardly doing so.

    Any insight and/or recommendations about how to approach Avatar's thus far hesitant customer service and any insight into what I may have done would be great.

    Thanks guys!

    - Carl
     
  2. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Let me suggest that you discuss this with Avitar, have them look at the drivers to see if maybe what you experienced was a defective driver rather than the effects of overpowering. The other thing that I would ask is for them (or your tech) to verify that it is really an 8 ohm cabinet and that a simple error wasn't made that you were unaware of. I would also recommend that they check to be sure the cabinet wasn't dropped in shipping possibly damaging one or more of the drivers themselves. Another thing to checl is that an interconnection wire is not touching the back of a cone causing this symptom (a trivial fix).

    I would expect that this seems like a very reasonable match on the surface, though I do not know specifically how Avitar rates their products. I think there is a sticky at the top of the forum where I discussed some of the details and mechanisms of speaker failure, perhaps there might be some useful information there once you find out what happened.

    If you need some additional help, feel free to PM me.
     
  3. dgoof911

    dgoof911

    May 17, 2012
    Thanks for the response.

    Avatar had me check out the cab and make sure all wire connections were intact and that none of the wires were touching the back of the cone. Still waiting on a response from them about possibly sending me out new speakers. They seem hesitant to have me ship back the entire cabinet (which I am all for and I even offered to pay for shipping).

    Avatar rated this cabinet at 1000 watts which I believe is probably the peak power. Each of the drivers inside (Eminence Deltalite Neos) are rated at 250 watts. My estimate of the RMS is around 500 watts?

    I understand there is a significant debate over clipping amps and the potential damage it may do to a speaker. For years now I have used amps where certain playing styles have sent a spiked signal through the amp (such as slap/pop and hard finger plucks) setting off the limiter light. In fact, the little practice rig in my jam space is an Ampeg SVT-CL 200T with a big 8ohm Carvin 15inch. I slam into the limiter on this guy all the time and occasionally can hear a bit of distortion as we are pretty loud but the speaker is in fine condition albeit sounding muddy and flat.

    As a Genz Benz guy, could you tell me if the limit light and O/L red light for the pre-amp on the Shuttle 9.0 are both flashing initially during strikes on hard playing styles am I sending a dangerous level of clipped signal? I have been running it with the gain at around 10AM pre-amp volume around 3PM and the master around 1PM. I usually have the low-end voicing button on but I don't hear any distortion besides the blown fuzz. At this level, most of my playing style never hits the yellow limiter unless I really pluck hard or slap/pop in which case it lights up but very quickly disappears after the initial strike and is not on in between strikes/plucks. I also know that the Shuttle 9.0 has a soft clip mechanism (not exactly sure what that means) and when the limiter light flashes you have about 6dB extra before true max clipping occurs

    Everyone talks about clipping and thermal failure but no one really describes just how much or how little clipping is safe/dangerous. My pops (30 years head audio technician: The Band, Susan Vega, Aerosmith) is set on the belief that speakers can and should be able to take a certain level of abuse, including clipped signals, and that to really and quickly thermally fail a speaker you have to send a pretty sustained clipped signal for significant damage to occur. He made the pretty valid point that if speakers readily failed with occasional clipped signals or even temporary clipped signals, which may be the case in my situation, then musicians would be blowing their speakers constantly.

    Anyways I thank you for you advice and help.
     
  4. will33

    will33

    May 22, 2006
    austin,tx
    Shipping damage may be a real factor here. That said, just having a clipped signal won't destroy woofers like that, any type of overdrive, etc. is clipping of some sort, but overpowering them will. Amps are usually rated at some % distortion, running them into clipping in the power section can make them put out a good deal more power.

    The acoustics of your practice space may also be at play here. If things are positioned as such that you end up in a null zone, you can seemingly turn up and up but not get any louder, the directional nature of a 410 sitting on the floor hitting you in the knees doesn't make it any easier. Could be a few things at work there.
     
  5. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Syracuse NY
    Endorsing artist: Dingwall Guitars
    Discussion of clipping is a red herring. As Will says, clipping doesn't kill speakers, overpowering does. The 1000w of the cab is a thermal rating, not peak or RMS (which are amp ratings). The more important rating is displacement limited power handling.

    Also, exceeding Xmax doesn't damage drivers... It's exceeding xlim that does it.
     
  6. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    That's probably a reasonable guesstimate as almost all 410's start to fart around 400-500w worth of power. And your dad is pretty right, except it doesn't necessarily take a sustained clipping signal to take out a cab. One really good short burst that overpowers the speakers can do it. And that's whether the amp is clipping or not.

    Not really sure what happened here to be honest, but with the info given, I'm leaning toward the idea that you have one defective driver. Have you tried the voice coil rub test? GENTLY push with even pressure around the dustcap, and if you can feel rubbing, the voice coil is shot. A working voice coil will not have any rubbing.
     
  7. B-string

    B-string Supporting Member

    "I usually have the low-end voicing button on " Here is the key. Speakers get rated for power, but not at low bass frequencies. At 250 "RMS" expect more like 100-125 watts with bass boosted making it a 400-500 watt max cab. The amount of power a speaker will handle goes down sharply with frequency.
     
  8. will33

    will33

    May 22, 2006
    austin,tx
    That size of gear, run up loud, bass boosted, etc., in the typical smallish practice space, you just plain "overun" the room, sound quality suffers, it's hard to hear speakers in distress, etc. Not to mention the spl in there is at a level you shouldn't expose yourself to for a length of time.

    Use those same settings in a bar and you'll be told to turn down, that means it's too loud for a practice room. I like to play loud as much as the next guy, but do it within reasonable limits. Take a break and give your ears a rest. You only get one pair, they have to last you the duration.
     
  9. TrevorCJ

    TrevorCJ

    Apr 29, 2012
    So what does the red clip light on my bass head mean?
     
  10. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Good point.
     
  11. BassmanPaul

    BassmanPaul Inactive

    Depends on what bass head it is.
     
  12. will33

    will33

    May 22, 2006
    austin,tx
    Usually indicates clipping. If it's in the preamp, it means your signal is full strength or getting dirty. If it's in the poweramp, you're driving the amp past it's limits.
     
  13. TrevorCJ

    TrevorCJ

    Apr 29, 2012
    So if I'm playing and I see the red light clip alot I should turn something down, probably the gain?
     
  14. will33

    will33

    May 22, 2006
    austin,tx
    Oh, yeah...on mine it simply means it's turned on.:D


    @ trevor. If it's a preamp clipping light, rule of thumb is a little flash when you hit a note hard is fine, constantly on is not. If it's a poweramp clipping light, it means turn down.

    Read the manual for your amp, know what all the indicator lights mean, what's ok and what's not. Not all amps are the same regarding these lights.
     
  15. Stumbo

    Stumbo Guest

    Feb 11, 2008
    This.

    Sound like you need a fEARful cab or similar with extended low range handling capabilities.

    Possibly adding TBr fdeck's pre-amp/adjustable hpf to your signal chain could help you out by eliminating low freq transients and low bass freqs that are not affecting your tone.
     
  16. dgoof911

    dgoof911

    May 17, 2012
    I appreciate the concern Will. Big fan of the Hearos ear plugs. Mind you this is the setting I use in a very large practice/recording place. In my small practice room, I certainly had the volume turned down and took that bass voicing off to allow the mids some room to breath.

    Overdriving/clipping the pre-amp is most often not a bad thing and sometimes desirable (especially with tubes) to get a gritty overdriven "clean" distortion. The power amplifier is where you want to make sure you don't completely overdrive and strongly clip out your signal.

    That being said I am not denying the possibility that I may have blown my speakers but I just feel like with my decent level of knowledge and common sense that something is amiss. My guess is that maybe I pushed the speakers passed their xlim (thanks for the clarification BurningSkies).

    @ JimmyM: I tried the cone test and I cannot feel any rubbing or scraping. They seems to move in and out cleanly.

    Thanks for all the input guys. Hopefully Avatar lives up to their advertised customer service and at the least offers at cost replacement speakers and will check out the blown drivers.

    (PS Anyone know any local speaker techs in the Santa Barbara/Ventura area?)
     
  17. TrevorCJ

    TrevorCJ

    Apr 29, 2012
    I've read the manual and it didn't get very in depth with it it just said what it was. I have an Ampeg B2RE
     
  18. will33

    will33

    May 22, 2006
    austin,tx
    Some of the SS Ampegs need the gain run high to sound good. Advise from some of the Ampeg guys (help Jimmy) is to ignore the preamp clip and set it by ear. B2 isn't that powerful. If you weren't using massive bass boost, we might be back to just getting a bum cabinet.

    My old 800rb doesn't have any indicator lights other than the one that says it's turned on, you set it all by ear. Never understood putting that one light on there either. One of the easiest things there is to discern in any gear is whether or not it's turned on.:D
     
  19. StraightSix

    StraightSix

    Nov 23, 2011
    http://www.ampeg.com/pdf/B2RE.pdf

    Page 4 - which light are you confused about...?
     
  20. B-string

    B-string Supporting Member

    Industrial light and sound in Ventura, don't know if they are still around now though. I left Cal 8+ years ago.
     
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