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Discussion Starter · #1 ·
I just uncrated 2 Earthquake Cinenova 3 Channel Platnum's. I thought I was going to have to rent a cherry picker to get these things out of their crates(which were very impressively protected, considering how "brown" is soo very careful with our precious HT equipment...ya right). None the less I took one 3 channel and hooked up the fronts and center speakers(Klipsch RF-7's,and RC-7) I am using a Onkyo TX-DS777 Receiver as a processor for right now. Checking and double checking all connections I decided that the time has come to hit the "all mighty" power switch. With that said the next sound was a humungus thud that showed love to the mains and center channel. After I came out of cardiac arrest and shouted out some choice words.I started rechecking everything. Everything looked wired right, which left me scratching my head. So I figured some testing would be in order next to pin down problem, and as I hit the power down switch on the amp roughly 20 seconds later my speakers all started talking to me in a strange kind of high pitch"picolo pete" sound that lasted for roughly 5 or 7 seconds. Again after picking up my jaw and starting to believe I'm retarded, I just shut down the entire system until I can resolve this issue. Quick specs on my electrical: living room and kitchen on one 30 amp breaker, and 2 bedrooms and bathroom are on other 30 amp breaker. The place was build in the fourty's(apparently before they had electricity...sheesh)try not to laugh to hard. I don't know where to start to solve this issue, any advise would be greatly appreciated. I would even settle for some lies at this point...If anyone has sure bullet proof way to fix this situation let me know, I could sell some of my kids for the products I would need...jk. Thanks in advance.


Rick
 

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You need to delay the amps coming on until the "processor" comes up. You can do this using a power line conditioner like the Panamax 4300 which has a delay for power amps. Go on line to the Panamax site and you can read how it works. www.panamax.com There are also many other manufacturers of devices like this. Others I am sure will chime in.


Dave
 

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Rick,


Continuing on Dave's point, you didn't indicate exactly what/where the "all mighty power switch" was. Amp switch? Processor? a powerbar?


Typically it is turning the processor/receiver with the amp already turned on that would generate thuds. I have heard some systems make small sounds at the speakers simply from the amp being turned on, however. On shutdown--turning off the processor before the amps have discharged (which may take a couple minutes) might result in pops/thuds again.


Those of us with Feedback Destroyer Pros (often used to EQ the sub region) know real well to turn on that unit then wait a couple seconds before triggering on the amps--else "THUD". And again, the reverse on shutdown--turn off the sub amps, let them discharge, then turn off the BFD.
 

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Discussion Starter · #4 ·
My problem is my amp is indeed sending a thud to speakers just by turning it on all by itself. I even tried stuff that didn't make sense like unplugging all equipment except for amp, and still I get a thud. As far as turning on equipment, I do turn on and off in the order you mention as well as giving amps time to discharge(up to 5 minutes I have tried)and the only thud I ever get is the one that my amps give off when I turn them on. They have 12 volt triggers also. Would that help ? That would give me a great excuse to buy a dedicated processor, therefore hitting 2 birds with one stone(hmmm had my eye on that cinepro too...). Could I just leave them on all the time and never shut them off ? Grrrrrrrr....damn these thuds...


Rick
 

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I have the same problem with my Bryston 4B even with an adcom Ace515 conditioner connected that has delayed amp turn on/off feature. The delay turn on/off didn't help with the thud (turn on) and chirp (turn off) sound I get.


I've been told that this is normal from an amplifier which doesn't have relays on the speaker outputs.


BTW I have Klipsch KLF30's
 

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Discussion Starter · #7 ·
Thanks for the input guys. I guess I'll just leave them on for good, they'll be like night lights in the living room(for my beer trips to the refrig w/o actually having to turn on any lights...lol). A few more bucks spent on my electrical bill each month is much easier to swallow than listening to those annoying thuds.:D
 

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Doggin, might want to check with the manufacturer both on the source of the thuds and if leaving it on 100% is a good idea. Aragon amps, just for an example, specifically say not to leave them on 100%, due to something about the kind of self-cleaning power switch they use and carbon build-up or something like that.
 

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A crude way to stop this is to purchase a speaker selector switch. Wire your amp to it and your speakers to the Pair A (or 1) outputs. Put nothing on the Pair B (or 2) outputs. Then select Pair B and power on your amp. The "thud" will then be sent to the non-existent Pair B. After waiting a few seconds, switch to Pair A and you should be fine.


(Later thought: I guess this is now harder to do with a 5.1 system. I haven't seen many 5 channel speaker selectors. Switching is a lot more complicated, on both inputs and outputs, than it used to be.)


Adcom used to make a couple of good quality external stereo speaker switchboxes, maybe you can find one on eBay.


Another thought, does your amp have channel output level controls on it? If it does, you could try turning them all the way down before powering up.


Tom B.
 

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Discussion Starter · #10 ·
I will check with Earthquake tomorrow about this. Unfortunately there is no gain control on amps. They do however have a high-pass,low-pass,and bypass on the fly crossover switching,along with in-line fuse rails for each moral amp and a circuit breaker for each amp housing. On a lighter note I have least 50 hours on these things so I decided to put them to the test. Ummmm...ya, this is truly the amp setup I have been looking for. There is some serious power with plenty in overhead locked in these things. I run Klipsch Reference 7 line because I personally like horns and the sound they produce(as long as the juice behind them do not make them so bright as to make the audio source sound unrealistic). I could not be happier, of course this is just my opinion and I know there are plenty of people out there that would knock these amps. It is almost like these amps kinda mellowed the horns out a bit(kinda like the reference of "warm sounding" with tweeter setups)I have personally owned a Parasound HCA2205A, and this does not even compare(though I am not ripping Parasound)but we are also talking twice as many watts as well so take it for what its worth, bottom line I'm happy !!:D
 

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If you have a delayed turn on/off already enabled the problem may be elsewhere. Do you have a separate subwoofer amp? Does the subwoofer automatically sense a signal or does it have to be turned on and off either manually or via a trigger?


Dave
 

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You have speakers with a sensivity of 102dB/1W/1M and moved up from a 220wpc amp to a 300'ish wpc amp????


One of the reasons you may be hearing a power-up thud that others aren't reporting is because your speakers are so ultra-efficient that the power up noise is 10-15dB louder than most of the other owners of this amp. If the same thing were happening to them, they might only hear a mild thump and not be concerned with it.


Most people with those speakers would never clip a 20 watt amp (which would drive them to 115dB at 1 meter). Going from 220 to 300 would push up the maximum SPL at 1M from roughly 125.5dB to 127dB. I'm afraid that is extra headroom that I would never discover.


Tom B.
 

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Discussion Starter · #13 ·
I got in touch with Earthquakes tech, long story short leave amps on. I talked to the tech(which was very involved with ground up design of amp line)and he basically stated that there are no inducers,resistors,crap,junk,blah,blah,blah to soften the thud and the high pitch noise from speakers when turned off. He also stated that that is normal especially with Klipsch's high signal to noise ratio. So ON they are, done deal. Tom sorry I should have made myself clear on power ratings of amps. My fronts and center are bi-wired at 4 ohms,giving the Parasound 300 watts per channel, and the Cinenova is pushin 600.:)
 

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Hi,


I used to have the same " thud" problems with my KRELL FPB 200.

What I did was change the power cord to Synergistic Research with active shielding and the" thus" is gone...

Ia m not sure what is the real reason behind the power cord, but I am happy now...


MT
 
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