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About stomashek

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  1. An XLS 402 that we use for monitors is clipping this morning. Last weekend it was working fine. What is strange is that it is clipping with any input level. The input gain on the amp is set to about 50%, and in this case, the only signal is bass guitar. Even if I drop the output from the mixer, it's still clipping no matter how low the input level is. The only time the light isn't on is if there is no signal present. This is happening on both channels. Normally the amp just sits in a fixed rack at the church. Once a year we do and outdoor picnic and we bring it to that. That was last week. So maybe something got beat up in transportation. Has anyone else seen this issue?
  2. Will the USP4 cards work with older amps? Specifically Macro Tech MA5002-VZ, MA-2402, MA-1202
  3. This weekend we did an outdoor service for our church. We have two PRX-618 XLF subs. We ran the audio to the subs, then on to the powered tops. Everything was run off a generator. Everything powered up and worked except the subs. The light was on, the signal light was flashing and it was passing audio to the tops. We tried a bunch of stuff and could not get them to work. The location had one 15 amp outlet so on a whim we plugged the sub into that outlet and it worked. So everything ran off the generator except the two subs. I'm trying to figure out why this happened. Is it because the generator isn't grounded so there is no ground reference for the power supply? The voltage at power strip for the subs was around 130 according to the guy helping me. He had put a meter on the outlet, but I wasn't right there when he did it, so I can't verify that the number is correct.
  4. Is there a document that shows the ammount of dB reduction for each of the "clicks" of the front panel attenuation knobs on XTi and CDi amplifiers? The CTs series has a chart in the manual. I haven't seen one for these amps.
  5. I went to open my file for a setup with just two amplifiers. An XTi1000 and a CDi2000. I loaded the file from the laptop and it still said "New File" at the top. If I double click the file itself the computer shows a pop up that it is looking for "System Architect 2.10.msi" file in a temp folder. Thinking that the program was messed up, I downloaded the installer again and ran it. It also tried to find the same .msi file. So I can't seem to load my file. In the process I wiped out all my settings on the amps. I was able to get that reloaded, but I don't have the custom panel I made since I can't seem to get the file open. Any ideas what's going on? The only other thing I did was accidentally opened Band Manager first this morning. That shouldn't cause a problem, but maybe it did. Scott
  6. Best Methods

    It would be easiest to to switch the 3000 to 26dB but is that the best way? I'll go and reset the Hi-PEQ and then verify with Smaart in the room if necessary. You had kindly responded to a bunch of posts I had done a while ago about voltage gain. We didn't talk much about the 26dB setting and what it does. I'm assuming that it's not limiting the 3000 to the same output levels as the 4200 (both being set at 26dB). So what does this specifically reference in its comparison of voltage levels? Scott
  7. Best Methods

    I have a setup with four JBL VRX 928s that I'm powering with a CTs4200 for the HIs and a CTs3000 with each side powering two of the boxes for the lows. I have a BSS Blu-80 for processing and downloaded the tunings from the JBL site. The settings are designed for all the amps to have the same voltage gain. My amps don't. So, which method would be best: 1. Switch the amps to the same voltage gain. 2. Modify the filters in the parametric EQ setting of the HI outputs by adding 11dB of gain (the different between the 26dB gain of the 4200 and the 37dB of the 3000) 3. Modify the gain levels of the crossover section by either reducing the low output or raising the Hi output. I am leaning toward modifying the Hi PEQ by 11dB but it's using a low shelf 12dB/oct at 11KHz at -13dB. Since there are other filters there, I'm afriad it will mess up their relationship. I could boost each of the four filters by the same 11dB... Thoughts?
  8. If I send one cobra net bundle to a CTs8200 USPCN amp, I can assign each of the eight audio streams from that bundle to each of the eight amp channels right? Technically, it looks as if the amp can see four different bundles allow the choice of 32 possible channels of audio routed to any of the 8 amp channels.... Just making sure I'm doing this right. Scott
  9. I would like to use a Terk XM6 antenna with a 180MAx system. The XM6 comes with RG6 cable. Other sites seem to recommend 50OHM cable. The odd thing is the jack on the back of the unit is an 1/8" jack. What is the recommended way to connect up this antenna to the receiver?
  10. System gain and Input sensitivity

    Thanks again. Hopefully this has helped others understand exactly what goes on inside amplifiers as much as it has helped me. Scott
  11. System gain and Input sensitivity

    I really appreciate the in depth answers to my questions. I was able to create a simple spreadsheet in excell that compares a lot of these values and I ran my hypothetical situation of using all MA-5002s to tri-amp my speakers, and everything looks like it is lining up. The only thing I noticed was that if I took the voltage gain to calculate maximum voltage (based on .775 sensitivity), then used that to calculate max power based on load, I got about 2379 watts into 4 ohms, and 1189 watts into 8 ohms. That's close to the specs, but a little off. Is this just real world vs. hypothetical, or does this take into account other design factors? Scott
  12. System gain and Input sensitivity

    Since dB is a measure of the difference in two values, what specifically does the voltage gain of an amp refer to? Is it just the difference in the in input voltage to the amp and it's output voltage (measured into a specific impedance)? Basically, what does this tell me (from the 5002 spec sheet): 132:1 6% or 42 dB 1 dB gain at 0.775-volt sensitivity. I think it is saying that the output voltage is 42dB higher than the input voltage, when the sensitivity is set at 0.775. It also seems that that number would vary depending on the impedance of the load (thus the spec of 1K@8ohm) and that the only way of getting an accurate voltage gain for, say 4 ohms, would be to measure that setup and see what the voltage is.
  13. System gain and Input sensitivity

    I'd like to make this more complicated. We have EAW KF750s in our cluster. They are tri-amped with an MA-5002 for the lows, MA-2402 for the mids and MA-1202 for the hi's. I think I've asked this here once before but basically, what's the best way to balance the amps for a triamp situation? Now that I understand that each amp has a signature voltage gain, I'm sure that figures into the equation. Hypothetically, with my speakers and amps, a unity signal (.775) would cause the 5002 to output 2000 watts into the 4 ohm load of the lows, 520 watts into the 8 ohm mids, and 310 watts into the 8 ohm highs. The speakers are rated at 1200, 400, and 200 watts respectively. The way I understand it, the fact that it's over powered isn't that big of deal, it's actually good to have the headroom. But the amps should have the same dB ratio of headroom correct? 2000 watts is 2.218dB over the 1200 watt max for the lows while 520 watts is 1.139 dB over the 400 watt max for the mids. That would seem to be an imbalance and the lows would have to be attenuated. Since the human ear can only differentiate volume changes of around 3dB, does it matter since the values are so close? In a hypothetical situation, what if I had a rack of all 5002 and wanted to tri amp the same speakers? I would certainly have to attenuate the mids and highs so they wouldn't get blown. I feel I'm on the right track, I'm just missing the last few steps. Scott
  14. System gain and Input sensitivity

    In the article I read, if you just had a mixer and an amp, you would attenuate the amp down the difference between the max output of the board, and the input sensitivity of the amp. For instance, our mixer has a max output of +26dBu (clipping). If the amp clips at 1.4 volts which is about 5dBu, the amp level should be attenuated -21dB so that it clips when the board clips. In reference to the previous post about the CD clipping, it's all the transient signal above unity that is causing the problem. By setting the amp level at the maximum, it will clip when the board reaches unity. It seems that some would argue that you are not maximizing the amp since you have "turned it down". But the key here is that the amp is seeing 1.4V when the board hits it's max output and so the amp is as loud as it can get. If that is not loud enough, get a bigger amp...right? In a way I'm embarrased that I didn't understand this a long time ago, since I work with sound systems all the time. But being self taught, I'm sure this isn't the only gap in my understanding. Thanks for the education! Scott Tomashek
  15. Bridging mono a Crown CE 2000 A amp

    Bridge or mono mode uses both sides of the amp to provide more power to a speaker. Most amps, and the CE series included require you to use signal from both channels, but it requires special wiring. One the amp you have channel 1 outputs as a + terminal and - terminal, same for channel 2. It should say on the back of the amp, that in bridge mode, the positive terminal of the speaker gets connecter to the amp's ch1 + terminal, and the speaker's negative terminal gets connected to the amps ch2 +. If you have the red and black binding posts on your amp and that's what you are using for your speaker cable, you just plug the bannana connector across the two red terminals, making sure you are getting the negative wire on the ch 2 side. If you have a neutrik speakon connector, you will have to take it apart and rewire it. The NL4 has four poles so it's easy to do. If you have a speaker cable with the NL2 connector, you will have to by the NL4. The problem here is that your speakers are 4ohms. Since the amp is now mono, meaning both sides of the amp are being used to amplfy one signal, you are going to have to run the speakers is a daisy chain fassion which would be parallel wiring. Long story short, when you run speakers in parallel, it drops the impedance. Your bridge mono amp would see 2 ohms if you connected both of your speakers. That's below what the amp can handle in bridge mode and you will fry the amp. What are the power ratings for the speakers? I gather that these are your mains, not subs? I have a rack of CE1000s and 2000s running all in mono to power 1000W at 4ohm mains (one amp per speaker) and 2000W subs. What is your goal? Is it that the speakers are not loud enough but can take more power?