Members Phantasm Posted July 6, 2009 Members Share Posted July 6, 2009 Cross posted in the Live Sound forum, but I know a bunch of you here are the bass-playing PA keepers of their respective bands... Okay, so today I went to Guitar Center and they had their List sale. I went looking for new PA tops as I've currently got two (2) Yamaha S115IV's and two (2) Yamaha 118 Subs to go with them. It's getting the job done but we're having to push it to get what we need. I've got two (2) power amps, a QSC RMX 850 and a QSC RMX 2450. I've been using the 850 for the tops and the 2450 for the bottoms, tops in stereo and subs on 1/2 of the 2450. I bought two (2) JBL MRX515 tops and the salesguy suggested that I use the 2450 to push 500W into each one stereo. Then he suggested I bridge the 850 to push 830W into both the Yamaha subs I've got. Well, since it was no interest for a year and there was a good deal on the MRX518S subs too, I bought two (2) of them too. Well, now that I'm home, the MRX518S cabs are 4 ohm. This wasn't what I expected... and now I can't bridge the RMX 850 since it can't operate at 2 ohms bridged. So now for my question... should I: 1) Use the RMX2450 to push 750W into each sub, and bridge the RMX850 to push 830W mono into the tops. (Pro: Nothing else to buy. Con: Mono Mains) 2) Bridge the RMX850 to push 830W into a single sub, and buy a second RMX850 later for the second sub. (Pro: power matching to the tops. Con: More things to buy and carry later) 3) Return the subs and just use the Yamaha subs. (Pro: Save $1200. Con: Are the Yamahas good enough, or are the JBLs a lot better?) 4) Do neither and take your suggestion: ________ (fill in the blank) Link to comment Share on other sites More sharing options...
Members dravenzouk Posted July 6, 2009 Members Share Posted July 6, 2009 I'll chime in with some points, if not solutions. I've got a fair bit of experience with the same equipment you've got. First - Mono mains are no problem. Honestly, it's a pretty rare situation that you NEED stereo mains, and a lot of the time you're actually better off going mono. Unless you've got some very specific effects that have to go stereo, just about any venue that your particular sized PA is appropriate for would be better served by mono mains. That said, being able to run stereo is better if you can. I'm just saying that if your solution means that you have to go mono, don't worry too much about it. Second - The Yami subs are actually pretty decent, and better than some folks might expect, and they should certainly be "good enough". I've used them (same mains and subs as yours, powered by RMX2450s) in a ton of different situations, and I've always got lots of compliments and happy patrons. But, yes the MRXs are a noticeable step up. My suggestion - and this assumes that you were buying the JBLs as replacements for the Yamis, as opposed to adding on to your rig: - Sell the Yami mains and subs, use the money to buy another amp to power the MRXs appropriately (two 2450s should do you just fine). Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 Excellent points, thank you very much. And, I believe you play rock oriented music so you'll be thinking from the same point of view that I am. It's a whole lot different running for rock vs. country or church music. I had been hoping to sell the Yamahas to subsidize the purchase of the JBLs. I agree a second RMX2450 would be ideal though. Right now I'm trying to calculate what I should be able to sell the Yamaha speakers for. They're in good shape, just I wanted to step up in sound quality. Link to comment Share on other sites More sharing options...
Members gonzobassman Posted July 6, 2009 Members Share Posted July 6, 2009 That is a step up.Do what you can to get the other 2450.I would sell all the Yamaha speakers(FOH) to do that.I am assuming you probably have a couple of Yamaha ClubIV monitors as well?Great wedges. Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 You could run the tops off of one side of the 2450 and the subs off of the other side. Although, I'd probably just run the subs off of the 2450 in stereo and the tops off of the 850 in stereo. My guess is that it will sound great that way and you may end up with a little more sub than top, but that's a good thing. Then sell off the yamaha stuff and pick up another 2450. That way, if you break an amp, you know that you can run the entire rig off of one amp if needed. The 850 will make a great monitor amp, unless you're one of the cool kids who has already made the jump to IEMs. Link to comment Share on other sites More sharing options...
Members ezstep Posted July 6, 2009 Members Share Posted July 6, 2009 I could never recommend running an amp bridged...that is the max...nothing left. Think of running your car at 100+ mph. Four hours non-stop. It can do it for short bursts, but for how long at a steady pace? Glad you caught the 4-ohm minimum before your bridged it. Sell the Yamaha tops...keep the subs. You will find plenty of times where one pair of subs is simply not enough. Link to comment Share on other sites More sharing options...
Members jonjohn Posted July 6, 2009 Members Share Posted July 6, 2009 I could never recommend running an amp bridged...that is the max...nothing left. Think of running your car at 100+ mph. Four hours non-stop. It can do it for short bursts, but for how long at a steady pace? Bridged Is fine . It is really only maxed if you are driving it to the max. Mixers have a volume Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 I don't think I'd want to run my subs off of a bridged RMX850 if I had a 2450 available. Even if the subs were 8 ohm, that's running that amp at its limits and something in that chain will fail sooner than later. Link to comment Share on other sites More sharing options...
Members ezstep Posted July 6, 2009 Members Share Posted July 6, 2009 Bridged Is fine . It is really only maxed if you are driving it to the max. Mixers have a volume But the only reason it is bridged is to get more volume, after driving it to the max and finding that it wasn't enough. I would say 95% of the power amp failures I have seen involved bridged amps. Link to comment Share on other sites More sharing options...
Members jonjohn Posted July 6, 2009 Members Share Posted July 6, 2009 But the only reason it is bridged is to get more volume, after driving it to the max and finding that it wasn't enough.I would say 95% of the power amp failures I have seen involved bridged amps. Yeah Ok , I see what you mean, Situations where one is trying to get the impossible via the miracle known as bridging. "man that's twice as loud.... hey why did you turn down the subs?" Link to comment Share on other sites More sharing options...
Members georgestrings Posted July 6, 2009 Members Share Posted July 6, 2009 Although, I'd probably just run the subs off of the 2450 in stereo and the tops off of the 850 in stereo. My guess is that it will sound great that way and you may end up with a little more sub than top, but that's a good thing. Then sell off the yamaha stuff and pick up another 2450. That way, if you break an amp, you know that you can run the entire rig off of one amp if needed. The 850 will make a great monitor amp, +1... What are you doing about monitors??? - georgestrings Link to comment Share on other sites More sharing options...
Members ezstep Posted July 6, 2009 Members Share Posted July 6, 2009 ...Situations where one is trying to get the impossible via the miracle known as bridging.... Good analogy. Amp salesman's best friend - confusion! "Yeah, you can always bridge it and get more watts...." Link to comment Share on other sites More sharing options...
Members moogieotter Posted July 6, 2009 Members Share Posted July 6, 2009 Phant, I have a Qsc RMX 1450 for sale, PM me if you are interested. Great shape, just a backup amp never pushed or giged. Thanks, moogie Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 Thanks for the suggestions guys. I'm looking for a used 2450 today and I sent Moogie a PM about his 1450. I hate digging a deeper hole to solve a problem... but I may have to this time! It sounds like everyone thinks that the JBLs are a worthy upgrade soundwise and it's worth the trouble. That's definitely reassuring. Right now we have two monitor mixes available but we use one. I've got a small powered mixer that we slave for use as an amp for the two wedges we have and that has been working out perfect, just the right amount of power for them to hear with no feedback. THe RMX850 would work too, though. Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 The 850 would be more portable and if you can score Moogie's 1450 or another 2450, you will have redundancy in the PA rack that will enable you to run all of your amps at 4 ohms or higher, which will keep things nice and cool. Those JBLs are definitely an upgrade, but it may not be a bad idea to hang on to the subs for outdoor gigs if you do those very often. Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 Someone local has a Crown Microtech 2400 for $300. Says it's in good shape but the front is bent. Opinions, anyone? Link to comment Share on other sites More sharing options...
Members gspointer Posted July 6, 2009 Members Share Posted July 6, 2009 Someone local has a Crown Microtech 2400 for $300. Says it's in good shape but the front is bent. Opinions, anyone? I would pass on that one at that price. Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 I would pass on that one at that price. Thanks! Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 I recently scored a Crown XTI2000 B-stock off of ebay for $414 shipped by using the Bing cashback program. Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 I recently scored a Crown XTI2000 B-stock off of ebay for $414 shipped by using the Bing cashback program. I'm looking at those now, the B stock on Ebay, and I was about to ask if anyone had experience with them. Would they drive the subs and do as good a job as the QSC 2450? Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 I'm looking at those now, the B stock on Ebay, and I was about to ask if anyone had experience with them. Would they drive the subs and do as good a job as the QSC 2450? Yes, more power(slightly) and it weighs half as much. The onboard crossover is nicer too. Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 6, 2009 Author Members Share Posted July 6, 2009 Yes, more power(slightly) and it weighs half as much. The onboard crossover is nicer too. Do you remember who the vendor was on Ebay? I see some for $425 from a place in NYC but the range of prices for B-Stock varies greatly. Link to comment Share on other sites More sharing options...
Members burdizzos Posted July 6, 2009 Members Share Posted July 6, 2009 I got one of these. I've purchased other stuff from that seller and have had nothing but good experiences. The shipping on the XTI was stupid fast. If you've got a paypal account and an msn/hotmail account do a search for xbox through Bing.co and follow the Bing cashback link to ebay and then search for the amp you want. If you sign up for the cashback program, Bing will give you 8% of the purchace price back. I got a $36 return on my XTI. Link to comment Share on other sites More sharing options...
Members gonzobassman Posted July 7, 2009 Members Share Posted July 7, 2009 Hey Phantasm.I just realized that there is another option,and this is the one I would go for! (In fact,I did). QSC GX - 5 on the tops! 500 watts at 8 ohms,750 at 4 ohms per side. I run a pair of Yamaha 115V clubs and it is great.Would be perfect for those MRXs,and you should be able to get it at the same GC you bought the rest of your rig at,for around $350.00!!! Check it out! Link to comment Share on other sites More sharing options...
Members Phantasm Posted July 8, 2009 Author Members Share Posted July 8, 2009 I bought one today! Haven't opened it yet while reading reviews but so far it looks like these have very favorable reviews! It was $339 with price matching at GC. Link to comment Share on other sites More sharing options...
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