• Content count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About ampnation

  1. Yes, I have the latest firmware I believe. I tried to check that during the last few days and it seems the latest firmware was as of sometime last year when I originally connected the amp to my laptop. I am also running SA 2.2. I will try setting the RMS limiter to the speaker RMS and see what results I get. Am I correct in my assumption that the high impedance and thermal errors are directly related? What does that 200+ figure say to you about the degree of the problem I was encountering?
  2. Okay. Thanks. I'm feeling more comfortable about my setup now and learned a couple new things along the way. Hmmm... I still have some tweaking to do. Long story short, I pulled out a subwoofer very similar in design and specs to an SRX728s, created a slightly modified copy of my all SRX system, then hooked up 2 SRX712M tops to channel 1 and the sub to channel 2. The ratings and nominal impedences for the SRX tops in parallel and the sub respectively are 3200w @ 4 ohm and 3000w @ 4 ohm. I left the input sensitivty at 1.4v and added RMS limiting equal to the program ratings for each channel. I don't think the attenuators ever go past -15db. It sounded great at first. I was watching the clip indicators and the closest I came was a brief flickering of yellow on my mixer and a constant level of -20 on the amp. The sound level was about equivalent to a loud but not extreme hi-fi system IMO. Wish I had pulled out my SPL meter now. At any rate, about 3-4 songs in I started to hear what sounded to me like heavy handed compression so I went to the laptop I still had plugged in and checked out the monitoring section and found it reporting 5 thermal errors so I turned it way down and the thermals kept increasing to about 7, then started slowly decreasing. I only noticed this on channel 1 but it could have been happening on channel 2 also. I thought I was giving this a low volume easy test. Upon reflection I think I know the problem, but want to check before proceeding... My RMS limiting should be closer to the peak rating, not the program rating. Am I right? I'm guessing what I was hearing was the limiter kicking in as the speaker started to heat up. I also noticed the impedence got over 200. I haven't turned the system back on yet. I'm hoping no permanent damage was sustained and that a setting change like a higher or disabled RMS limiter will lead to better results. Regarding the RMS limiting... if peak power is recommended and the peak in these cases is between 6000 and 6400w, does the 4000w rating per channel @ 4 ohms of the amp have a bearing on what should be or not be set?
  3. Okay. Thanks. I'm feeling more comfortable about my setup now and learned a couple new things along the way.
  4. Wouldn't the limiter section in the iTech handle this. And when you say brick wall, I don't intend this to be a solution that presents a zero chance of a larger signal going out... just a 99% solution. I would be using the lowered sensitivity in conjunction with the peak and average limiters as well as compressors on individual mixer channels as well as watching for clipping during operation. I'm not really asking if the sensitivity level will act as a limiter. I'm asking whether or not, given the same input signal which is not clipping at the input to the amp, would result in a lower amp output when the attenuation is the same but the sensitivity is lowered, also assuming that the amp doesn't clip for either scenario. I got this idea after reading this in the application guide at page 9. If the amp is outputting the same level with the attenuators at 0db, it seems to follow that it would produce lower output if the attenuators were then kept at -10db. I was hoping, and it seemed to follow, that adjusting the sensitivity a little lower at this point would lower the output while the attenuators stayed at 0db.
  5. I own an iTech 8000 and have used it to power a JBL SRX700 setup where both top and sub present 4ohm loads and have RMS ratings of 3200w (pair of SRX712M in parallel and a single SRX728S) and so far I have been very conservative in how much power I give them in limited use. Before I get into a situation where I'm wanting as much SPL as possible I'd like to know something. I was on a forum and discussing the input sensitivity feature and I just want to make sure I understand it correctly because they have me second guessing myself. Here is my understanding... Let's say I can measure the output from my amp with a multimeter and I find that when I am setting gain structure, using pink noise, I have optimized all previous stages of the signal chain. Now at the amp I find that as I reduce the attenuation, I start clipping at say 12db. Let's say I measure full output of 4000w per channel with a 4 ohm dummy load. Now I should be able to reduce the input sensitivity by 12 db which in turn will allow me to get to zero attenuation before clipping. Further, if I attenuate now until my output measurement is say 3200w. (coincidentally, same as my speakers) and read the amount of attenuation needed to get there, I should be able to then further reduce the input sensitivity by that amount and be safe within the same limits as if the amp were a 3200w rated amp. True or Not ? And if that is true, one follow up question... would I be able to assume, based on the same formula used to calculate loudspeaker output based on sensitivity, that a certain decrease in input sensitivity would translate into a given output from the amp. In other words to make it easy, let's assume my speakers are program rated at 2048w instead of 3200w. Let's say at 512w they produce 125 db. Now if I increase the power to 1024 they should produce 128 db (in theory, but slightly less than 3 in real life - no one has ever explained to me, what order of magnitude that gap is between theory and real life with typical loudspeakers). It would seem to follow to me that a 3db decrease in sensitivity would make it such that the same signal is now producing 2x the output power assuming the original power level were half or less the rated output for the amp. If my calculation is correct, a decrease from 4000 to 3200w would then amount to just under 1 db decrease in SPL. [10*Log10*(3200/4000) = -0.9691] so if my extrapolation is correct, a 1 db I should be able to get to clipping, see what attenuation is at, then reduce sensitivity by that amount + 1 db to get clipping at zero attenuation and a 3200w output thus eliminating the need to read the output levels with a multimeter. So again... True or Not ?
  6. I have gotten the dialog about 3 times with send and receive options. Pretty sure I've always hit send. The thing is, it tells me it detects the device but then the send/receive dialog does not appear. Also it tells me the device is offline. How is detected, but offline? I keep getting the network troubleshooting dialog and I just now discovered I had entered the IP address wrong, using a 1 in the third set instead of 0. Fixing this didn't seem to solve my connectivity problem though. Am I right that this looks like a case of very limited connectivity with a periodic success causing the send/receive dialog to appear? There's enough connectivity to allow it to detect the device, but not enough for it to bring it online or complete a data transfer most of the time? I've had it connected via ethernet cable for about an hour I'm guessing right now and keep getting the Network Troubleshooter (which seems to be a one trick pony looking for things including a DHCP server which I don't have and then telling me to put in the IP and subnet addresses which of course are now done.
  7. So I just started setting up my iTech 8000 yesterday. I got it running and made some simple settings which if memory serves, basically copied to the iTech without my intervention. Now I've made a couple minor changes to Setting #1 and added a 2nd Setting. Both have been renamed and I'm not seeing them populated to the amp. I'm wondering what the process or processes are by which this update occurs. I can't find any reference to it and so I'm wondering if it is always automatic. Seems there would be an "update device" button. info that might be needed... running SA 2.2 and Windows XP Pro Version 2002 SP3 yesterday was hardwired from laptop to amp. today, using wireless router but amp is hardwire connected to the router while laptop is wireless. SA shows the device as connected.