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pre or post amplifiers

wrgflyfishwrgflyfish Posts: 9
We have a Driverack 260 sitting between our mixer and our amplifiers. I have a friend who swears that the better place is AFTER the amplifiers. This person has worked with some pro musicians. When I quoted from the manual about it he said "Nope, we toured with the DBX DriveRack, and we ran them through our snake because our speakers were XLR, but it's a very inexpensive and good quality adaptor that can be placed in the XLR jack and plug the 1/4" cable into to". I think it would blow up the driverack and if not it would prevent us from using all the features. What do you think?


  • GadgetGadget Posts: 4,915
    :shock: :shock: :shock: :shock:
    Ummm.. AFTER THE AMPS :lol::lol::lol::lol::lol::lol::lol:
    IMPOSSIBLE...totally and utterly IMPOSSIBLE! The Driverack is the only thing you need BETWEEN the mixer and amps, and is an LINE level device...NOT a speaker level device. Whoever was telling you that is on CRACK! ESPECIALLY since he indicated that the speakers were XLR input... now:
    1. Either those speakers are older than Jessica Simpson, and used the totally unsuccessful XLR input as the amp to speaker connection (mostly because the pro audio community saw the potential for misuse of the this in a multiple platform source... ) IF... you could plug a line/mic level source AND a speaker level source indiscriminately...then you could plug a speaker level source into a line level source BLOWING THE HELL OUT OF THE LINE LEVEL SOURCE!...So NO forget it, he either miss-spoke or is TOTALLY full of :evil: :twisted: :roll: :shock: (crap) :oops: or something to that effect...
    2. He means that the speakers have processing internally? and that the speakers should be able to do the processing?...NO wait... forget that!!! this guy is ... Ok here's the deal...until otherwise instructed, that guy has to come on here and tell US how that works, because We, Dennis, Dra, Mikey, and I and others have worked with A, and B level performers and NEVER have we EVER heard of such a thing.. THIS IS LUDICROUS! BEYOND stupid... unless you are not portraying this properly...

    All in all I have to say this guy seems like a NOB... I wouldn't believe another word he says till he comes here and pleads his case.. :arrow:
    Moderator (that means throwing my non existent weight around... even though I'm REALLY a BIG guy in real life)
  • GadgetGadget Posts: 4,915
    Ok... wait...
    he said "Nope, we toured with the DBX DriveRack, and we ran them through our snake because our speakers were XLR
    Here he is indicating (if I'm not totally giving him more credit than he deserves... and I'm pretty sure I'm NOT) that the Driverack was run through the snake... (the snake is LINE LEVEL ONLY) that the mixer out ran into the snake, then into the 260 (or mixer into the 260 then into the snake) and THEN into the powered speakers... HE is STILL full of :o :shock: :o :evil: (crap) that is still ALL LINE LEVEL signals NOT speaker level, and you can tell him to... " Sit down and SHUT UP!!!"

    We have provided all the info you need here to take the Driverack and RUN with it.. ALL the info hers is proven, tested, and designed to make your experience more gratifying, and simplified...
  • That was my thought too but he was insistent. I'm going to paste the email exchange between us (with a few edits). Sorry it's so long but context always helps. I don't know if J- reads this forum. I doubt he does. If you do jump in!! I want to understand this stuff. If he doesn't what questions can I ask him to get clarity. I really believe he knows what he's talking about most of the time but this one is blowing me away.

    My original email to J-

    B- mentioned that the signal path wasn't right on the driverack.
    I'm going to be at church tonight so if you can give me details I can
    get it changed.

    Note: I thought he was going to suggest a change in the config.

    Reply from J-

    Yeah, the driverack should go after your amplifiers and your speakers come directly after. It's the same if you were to run an EQ rack unit. Because it's all to tune the speakers, in essence.

    Reply to J-

    I disagree completely. Yes, it is an EQ but it does so many other things as well. Putting it after the amps will blow it up.

    From the manual:

    • Connect the output from the sending device (mixer) to either of the two XLR
    inputs connectors shown below.
    • Make output connections from any one of the six output XLR connectors shown
    below to the input of the selected power amps.

    Here's a sample picture: (Edit: I copied one of the pictures from the 260Manual.pdf).

    Reply from J-

    The reason why I'm saying this is because I called my old soundguy who's run sound for about 4 years with a driverack in his configuration, and that's how it's run. I set up a system for a church in Chicago and that's how we ran it to make it work. That's why. I called this guy because he is very familiar with this product and making it work in a complete system, and that's where it works best in all the rigs he's been running.

    Reply to J-

    It doesn't even have 1/4 jacks on the back of it to do it; only XLRs so I don't even know how you would do it. There are several different driveracks (including EQ only products). I'm wondering if he has one of those? The manual is very clear about this one. If you want to check with him about it it is the 260 Driverack.

    Reply from J-

    Nope, we toured with the DBX DriveRack, and we ran them through our snake because our speakers were XLR, but it's a very inexpensive and good quality adaptor that can be placed in the XLR jack and plug the 1/4" cable into to. $12 fix.

    Edit: Of course our amps and speakers are hard-wired so it would take more than just an adapter.
    Reply to J- (Edited to shorten)

    More quotes from the manual:

    Analog Inputs:
    Number of Inputs: (2) Line inputs. (1) RTA Mic input
    Max input line level: +20dBu - an amplifier definitely goes over this

    No disrespect, but I'm not doing it. I'm not risking $800 of the church's money that I can't replace.

    2nd Reply to J-

    I can give several functional reasons not to do it either:

    The built in limiters (meant to protect the amplifiers) wouldn't work after the amps.
    The crossovers wouldn't work well after the amps because then each speaker set would need it's own driverack.
    Anti-feedback suppression wouldn't work after the amps because the feedback loop would already have been created.
    Auto-gain control wouldn't work again because the amps had already boosted the signal and the driverack wouldn't be able to limit them much.
    It also has (but I'm not planning on using) a compressor that couldn't work after the amps.
    Even the Auto-EQ feature wouldn't work after the amps because the unit sends the pink noise signal directly to the outputs and the speakers would get a line level input and not an amped input (meaning they wouldn't do anything).

    I think the only part of it that could effectively work after the amps are the delays and the EQ.

    (Edit: assuming it didn't blow up.)

    Reply from J- (Edit: extra stuff in here but don't want to take anything out of context.)

    I was only answering your question. It doesn't bother me that you won't run the driverack after the amps. Not at all. All I'm saying is that the best place so that you get the best quality sound, and following rules of live sound, EQ and EQ processors go after the amps, including the Driverack. Limiters are a form of Compression. Regulates the signal from the amplifier to the speaker protecting the speaker. Amps don't need nearly as much protection as the speakers. Amps can peak and continue running, speakers can't. You can't learn everything from a manual. The advice I was given about the DriveRack comes from a friend I worked with as a soundman and he was my soundman for a year. He and I were taught by a certified sound engineer who has over 30 years of experience in professional sound applications. That's all. Do what you want. Trust me, you won't offend me. Just trying to answer your original question about what was wrong so you could change it.

    After I type / copy / paste all this I'm wondering if maybe he did have some powered speakers and isn't remembering right. I still disagree that anything is wrong with our existing setup.

    What questions? Maybe ... can you remember which amps and speakers you used? Got a picture of your setup I can look at?
  • DraDra Posts: 3,777
    Borrow your FRIEND'S nicest fx / processor and place it between the amp and the speaker. Then sit back and enjoy the warm glow. You might even bring a few marshmellows. U2 has that on there Tech Rider (writer?)
    2 cases of imported water.
    10 lbs of peanut M&M's
    large bag of jumbo marshmellows
    Klark Teknik EQ (for marshmellow roasting)
    Uncoated wire coat hangers

    :lol::lol: DRA
  • GadgetGadget Posts: 4,915
    Ok first incongruity here...
    Reply from J-

    Nope, we toured with the DBX DriveRack, and we ran them through our snake because our speakers were XLR, but it's a very inexpensive and good quality adaptor that can be placed in the XLR jack and plug the 1/4" cable into to. $12 fix.

    He's talking about running the Driverack signal THROUGH the snake...to the speakers which are powered ... IF he was trying to tell you that they were running speaker signal through the snake... on 22 gauge wire :roll: Ya right...I personally run the driverack IN the amp rack, to get the best shot at a nice high signal to noise and less probability of interference running 6 signals through the snake instead of 2...

    Now why he's telling you to get a $12 (in this case I can guess) impedance adapter (Radio Shack 1/4" to XLR balancing transformer).. I'll never know...

    No, go ahead and disregard what he's saying because he is seriously confused...This 40 plus year sound veteran, and moderator of THE DBX forum (I've been participating here for longer than your friends buddy has been a sound guy, over 7 years...), is telling you that he is mistaken...Invite him here to debate his contention if you wish, but in deference to his feelings start a new thread and lets hope he doesn't find this one...I think once we get him here to clarify his position you will see that he doesn't actually mean after the POWER AMPS but probably AFTER the snake perhaps... (in his example they run the driverack signal THROUGH the snake since the speakers are powered) I guess what I'm saying is that the premise he makes is so ludicrous that I don't really want to embarrass him, just get him the correct info..

    BTW, you equated yourself very well in the emails...your arguments were lucid and point on! Good work!

    Now, what was the question in the email that started this whole mess?

    To summarize:
    1 . best routing, Mixer>snake>driverack>amps>speakers, If your going to provide a tactile GEQ for quick adjustments for visiting BE's then Mixer>GEQ>snake>driverack>amps>speakers. Control the 260 with computer and GUI remotely, this affords the best possible signal to noise and interference rejection...
    2. NO line level equipment can handle today's high power amp outputs at their inputs
    3. The processing needs to be BEFORE the amps, as you pointed out, the signal splitting (crossover)AFTER the amps would be ridiculous!
    4. The limiter is designed to protect the speakers by LIMITING the amps output BEFORE it clips, not after :roll: I have an old device from the past that WAS a post amp clipping eliminator.. that didn't work worth a ^%#!
    5. NEVER run amp signals through a snake! Some snakes are now coming out with power running through them specifically for powered speakers and line arrays
    6. Good job for checking into this further before you made a TERRIBLE mistake! (getting more than one opinion when you suspect the information is flawed... just think what would have happened if you had actually followed his directions!
  • Thanks for the confirmation. I think I'll talk to him about the snake and powered speaker idea and see if that is what he means. That makes lots of sense. If not then I'll drop it.

    We only need to send 3 signals through the snake. Our other signals go to the computer (sitting next to the driverack) for recording the sermon, the video camera (10 feet above the driverack) for the overflow area, and the last is reserved for our yet to be purchased speaker system for the rest of the building. So for us keeping the driverack at the back is probably best since signals go multiple directions.
    BTW, you equated yourself very well in the emails...your arguments were lucid and point on! Good work!

    Thank you for the compliment. I've read your posts often and that is high praise.
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