• Content count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About roughkiwi

  • Birthday 09/21/1959

Profile Information

  • Gender
  • Location
    North Island, New Zealand
  1. Very pleased that you have it sorted. It is a nervous situation at the start, but sooner or later you gotta go for it. Take care of those speakers friend. red light spells danger and all that stuff lol All the best.
  2. Help needed in buying the right amp

    JBL MRX515 Specifications: Frequency Range: 52 Hz - 20 kHz Frequency Response: 65 Hz - 20 kHz Sensitivity: 98dB @ 1m (3.3 ft) Nominal Impedance: 8 ohms Power Capacity: 400 W / 800 W / 1600 W Rated Maximum SPL: 130 dB SPL peak Coverage Pattern: 70 x 70 nominal Dimensions (H x W x D): 692 x 432 x 470 (27.25" x 17" x 18.5") Weight: 19.5 kg (43 lb) High Frequency Driver: 1 x JBL 2408H 37.5 mm (1.5 in) annular polymer diaphragm, neodymium compression driver Low Frequency Driver: 1 x JBL 265H 380 mm (15 in) Differential Drive woofer Nice speakers, you need to look at an amp in the range of 650 - 1000 per channel watts @ 8ohm. There are a few choices available in the Crown range, you have to decide re your budget. Perhaps you may want to factor in for a sub in the future when choosing your new amp. Your Cerwins freq response starts at 40hz and the JBL's slightly higher and my guess would be that once you hear the added low end to those MRX badboys, you will make room in the van for the sub at any cost. Someone more qualified will hopefully step in with some amp choices for you, I believe you are looking for an amp that will be rated somewhere around 900 x 2 @ 8ohm. Because of the power involved, it could be a better option to dedicate a seperate amp for a sub should you go there in the future, lets see what the pro's say, good luck.
  3. Hi Gary, I am sure that you wont find a "readymade" pro ?" cable, but they are simple to make up. I can relate to your caution which is a good thing. I will try to help you using old fashioned no tech instruction, and you of course can choose to use it from there. Take 2 identical XLR balanced cables. Cut approx 180 mm off the amp input ( male ) end of both leads.Cast aside one of the longer leads with the female connector. Now strip back approx 50mm of insulation on all 3 leads ( 2 short, 1 long ) taking care to unweave sheilding copper without breaking. Once you have all 3 leads stripped, you will see typically a red + and a white - , and of couse the surrounding copper sheild. After unwinding the sheild wire, strip back approx 20mm of insulation from the red and white signal wires on all 3 leads. Now join the long lead up to any one of the short leads as if you were simply wiring it back after cutting it by mistake. Now mark in some way the remaining male XLR plug with CH 2 ( some permanent method of label a good idea ). Now join the last short lead but put the red wire to the white, and the white to the red. join the sheilds together and form there carefully as you can, kepp them seperated and use a good quality tape to wrap up. Good idea to make a few loops and keep taping so that if pthe lead is pulled it is not on the connections. How you join the wires is down to choice I guess, but I have found that simply twisting together, care keeping the different connections seperated, and clever taping is best. Whew, I realise that appears fiddly and time consuming but as you are finding out, you cant buy a flash bright shiny new one. There are a couple more things, naturally, remember to put the labelled ch2 XLR plug into CH2 input on your amp, and set the front of amp level knobs to exactly the same! Once you have made your Y cable, you now have to either modify ( change location of - wire ) or use only the red binding posts to supply speaker/s. This is hard explain simply but I will try. Firstly, once again label the plug that you are going to wire for bridge mode. ( saves you unscrewing them all the time to see which end goes in the amp ) now undo the plug so that you can see the terminals. The real techos are going to laugh at this next bit but, in the hope that this helps many and coupled with the fact that I have real bad eysight, here is a simple way to double check your work. holding the speakon plug in front of you while looking at the wiring terminals, there are 2 positioning tabs formed in the moulding. One wide and one narrow. hold the plug ( looking at the terminals ) with the wide tab at the top. On a 4 pole speakon plug, ch1+ is at 11 o?lock,------ ch2- is at 2 o?lock,------- ch2+ is at 5 o?lock, ----- and ch1- is at 8 oclock. You will find that 1+ and 1- are used in your unmodified Speakon lead. Now you simply take 1- (8 o?lock ) and put it into 2+ ( 5 o?lock ). Use top speakon out only on amp. Some xls amps have only 1 spealon out below the binding posts, in this case the same lead as described here is used. Do not modify opposite end and dont get the new lead mixed up with other standard leads. Gary, I apologise if teaching you to suck eggs etc, but I'm thinking this may help others as well. Re- your other concerns, hopefully now you can see that speakon cables will actually be easy. As for power matching 1680 watts at 4 ohm into a 4ohm 1600 watt programme rating is ok. But peaks in signal could quickly clip the amp especially given the frequency dedicated. Hopefully, someone more experienced than me might hop in and advise a good crossover setting for you which I think is very important with your set-up as described.
  4. Thanks for the reply Mr Glass. I'm sure we all greatly appreciate your time and advise. Cheers.
  5. Yes, This question is so common. I wont provide my source as such because I feel that it is and will be better outlined by a Crown staff member, but I can tell you that my first xls amp was the 602 and the manual that came with it included specs for power output to 4ohm in bridge mode. This was rated 1680 watts. I have since purchased 1 more 602 and 4) 402 amps and run them all in bridge and have done so for many many hours over more than 3 years with zero problems. I do understand that the xls range has been upgraded through the years with A, B, and D series being the models that I am aware of. Also the newer D series offer slightly more power than the former models. I am reasonably sure that the specs for 4ohm bridge were dropped from printing after the A series. It is worthy of mention here, that in NZ where I live we are blessed with a 240 volt 50-60 hz standard power supply which from what I have read affords a better scenario for 4ohm bridging. Anyway, like I said, it would be good if a Crown master put their comments to this allbeit yet again.
  6. Hi, if you look through this forum you will see that double the RMS rating of a speaker is a pretty good guide to go with. The ?cceptable" range for your subs is between 640 & 1200 watts for each speaker. At the lower end of that scale, you would be working the amp most frequently particularly given the frequency range for subs and you would need to guard against clipping closely. At the top end of that scale, you have essential clean power with a good amount of headroom for peaks in the delivery mix. Once again though, you still maintain the watch over constant clipping ( or any really ) as you would be now be clipping severely during those signal peaks. If you connect your subs in parallel, then you will have 1600 watts programme at 4 0hm which will in my opinion be a very good match with your xls 802. The 1050 watts into each cone is correct, but it is the average maximum rating at 1khz so I would always think of that as a safe 950-1000 watts for terms of system matching. Set this up a little shy of the peak leds showing up and you will soon know your own answer. Hopefully, a few pros will get it in here as well and either confirm or give alternatives that would suit. Good luck, XLS amps rock.
  7. bridging query

    Thank you very much for the reply, I had wondered often if splitting a channel via the Y cable would effectively half the signal strength at each input ( compared to standard stereo hookup into one amp from both mixer outputs ) thereby providing the amp with only half the signal strength to start with. I do now understand the importance of using an exact source for bridging 2 channels of the amp. All of your advise is very much appreciated. One reason why there is no mention of if you should use one or both of the mixer outputs is because there are several different ways the amp may be used in Bridge-Mono. First is the amp may be powering only one side of a system and in that case it would be fed from only one source either left or right. The second is it may only be handling a portion of the audio band for a side and being fed from an x-over. For example: it is only doing the subs frequencies for a side. The third is that the only amp is powering the speaker(s) with full range audio in mono. The fourth the system is mono but the amp is only doing a portion of the audio band and is being fed from an x-over. For example: it is only doing the subs frequencies of a mono suytem. The third case is what you were describing. In this situation the amp would only need to get the signal from one side of a stereo board. It doesn't matter which side, Left or Right, as the pan controls should be either straight up or panned all the way to the side feeding the amp(s). When the pan controls are in the straight up position the board is running with Mono outputs. Mono output in this case means that everything is going out the same to both outputs there is no difference in the outputs - there are just two mono output. So…. there would be no need to use both outputs of the mixer as one side has all the mix that the other one has. With that said there is nothing wrong with using one side of the mixer to drive one BM amp (with a “Y” cable) and the other side to drive another BM amp (with a “Y” cable). This would be like case 1 mentioned above where one amp is doing one side of a system and another is doing the other side. In this setup you could still be stereo as the amps are just larger Mono outputs one driving one set of speakers the other driving another. You mentioned using both outputs of the mixer and sending them to the two inputs of the amp and then inverting the signal of the channel 2 input this is not recommended. The reason the “Y” cable is used is so that the “exact” same signal including amplitude is sent to both channels. Remember one side of the amp is just amplifying the opposite polarity or mirror image of the signal and deviations in the signal on one side could cause an inbalance in the amplifier output and cause issues with the amplifiers operation. So this setup would not be recommended In amplifiers that have a Bridge-Mono switch the switch routes the signal from channel 1 to channel 2 bypassing the channel 2 input level control. So you only need use the channel 1 input and level control. The inverted signal is then fed to the channel 2 side of the amplifier. Not that long ago there were no switches on amplifiers to do Bridge-Mono configuration and it had to be done manually. For amplifiers that do not have a Bridge-Mono switch they need to be set up for BM the old fashion way and to do this you need to use a custom “Y” cable on the input. Since there is no switch to bypass the channel 2 level control the input signal level controls on the amp need to be level matched as well. Not doing this could cause damage to the amplifier.
  8. Here is a question for you experts that I would appreciate greatly any input. We all know the implications surrounding the actual connection procedures for this mode of operation, particularly in the cases where you require the use of the infamous Y cable for the XLS amps. All of my manuals suplied with my XLS amps ( 6 of ) have the same directions. In each case, the diagram shows clearly the single xlr exiting the mixer, then split to the inverted config for channel 2 input. That is not too hard to achieve and the understanding of what this does is easily found on this and other websites. However, it is not stated in any manual I have as to whether or not the output from the mixer is a summed mono output or simply either ch1 or ch2. I personaly use the ch1 output Y cabled into one amp, and the ch2 output Y cabled into a second amp which works fine. Upon reading through this site and consequently studying my own understandings etc, a question I have is, for those unsure about Y cables, what is wrong with using both ch1 and ch2 mixer outputs making sure of course to invert the ch2 xlr at the amp input. Is it that the signal strength is compensated internaly on the amps thereby making this unsuitable?? Just one more quick note, I have seen conflicting views on the correct level controls, Every xls manual I have states specifically to match as close to identical that you can. Would love some feedback on this, Regards, Warren.
  9. Hi all, I couldnt help but get into this site. Have been reading through hours and hours of forum threads and could not help but notice how many novices/newbies there are out there prepared to spend huge money on fab gear like Crown and Jbl. Thank heavens for the experts making themselves available to help out!!! BUT, I also believe that very very often the gap between the seasoned "techo"and the poor blighter desperate for help is far too great. Smaller steps are what the new guy needs and can handle, so I'm here to encourage more "newbies" to answer more "newbie questions on this forum site. When I see all the tech specs and factors etc, it surprises me that anyone without a degree actualy gets to have a decent go with their Pro Audio gear. You may notice my username is RoughKiwi, well thats because its true,-- the proof, my system is simple -- 4 x JBL JRX 125 each powered by a bridged xls 402, 2 on the left and 2 on the right. 2 x Mackie s410s each powered by a bridged xls 602. This system is my mobile DJ rig and it just WORKS. Hey, love this site and although probably none of you experts will ever talk to me after what I just owned up to, I hope you carry on the priceless job you do on here.