Members BIGB Posted July 15, 2003 Members Share Posted July 15, 2003 Has anybody use this amp it? Especially on Subs. How does it compare to Crown's and Yorkville. Thanks Jerry Link to comment Share on other sites More sharing options...
Members J the D Posted July 16, 2003 Members Share Posted July 16, 2003 I've been doing my research for the subs I am trying to get and have compared the specs on this amp to various others. I have determined that, even though my tops are running on a QSC amp, I am going to get the Yorkville AP4040 to run the subs under an 8 ohm load. Equivalent or better specs and $300 cheaper. The Yorkie also takes up two spaces instead of three and weighs less. The QSC is rated at 800 wpc at 8 ohms and the Yorkville is rated at 750 wpc at 8 ohms. Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 16, 2003 Members Share Posted July 16, 2003 That's an awful lot of power to any single 8 ohm driver. I would look at an amp that delivers between 500 & 600 watts personally. What sub are you trying to drive? Link to comment Share on other sites More sharing options...
Members BIGB Posted July 17, 2003 Author Members Share Posted July 17, 2003 I am driving the JBL SR4715X Dual 15's. Cabinet rated at 1200 watts RMS. The cabinet is a 4 ohm load. I really don't want to bridge a MT2400 because it will take 4 of them ( 4 cabinets) and that is more money than I want to spend. So I looking at least this kind of power. I hope I will never use all of it, but what power is there should be clean. Link to comment Share on other sites More sharing options...
Members J the D Posted July 17, 2003 Members Share Posted July 17, 2003 Originally posted by agedhorse That's an awful lot of power to any single 8 ohm driver. I would look at an amp that delivers between 500 & 600 watts personally.What sub are you trying to drive? The Yorkville LS1208. It is rated at 1200 watts and I figured that 1.25 the estimated RMS rating (750 watts) would be OK for me. I know that Flanc is running 1500 watts into his off two bridged RMX2450s. Am I trying to put too much power through it? Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 17, 2003 Members Share Posted July 17, 2003 Originally posted by J the D The Yorkville LS1208. It is rated at 1200 watts and I figured that 1.25 the estimated RMS rating (750 watts) would be OK for me. I know that Flanc is running 1500 watts into his off two bridged RMX2450s. Am I trying to put too much power through it? I was seeing concern over the 8 ohm rating and assumed it was for a single 8 ohm driver. For the dual 15" JBL, the RMS is about 800 watts (assuming you high pass at about 40Hz!!!) so I would recommend between 800 and 1200 watts into 4 ohms. I would not exceed this amount as failure rates increase dramatically on those drivers. I think the 4050 would be plenty of power. If you were to bridge an amp (not my recommendation), an RMX-1850 would be an good choice as well. Link to comment Share on other sites More sharing options...
Members bassknave Posted July 17, 2003 Members Share Posted July 17, 2003 IMO, the AP4040 offers better bang per buck than the HD4050. The power split is nearly perfect for the speakers in question (1200WPC@4 ohms)--1.5x true RMS. Link to comment Share on other sites More sharing options...
Members Kennykeys Posted July 17, 2003 Members Share Posted July 17, 2003 Uh, Gentlemen, the LS1208 sub IS a single 18".... 8 ohms, rated at 1200 watts program. That's roughly 600 watts RMS. It's a B&C, 4" voice coil, designed for this cab which is a expanding horn, and yes, this type of sub horn gets great reviews. From what I've heard, good sound (no one-note response), and max SPL per cu. ft./ $$. I believe that a Yorkville tech told Flanc to go ahead with 1500 watts per driver, properly controlled I'm sure. Yes, it seems like a bit much, but then again, he hasn't blown one (yet), has he?......Flanc???? Any problems bridging that 2450 into an 8 ohm load? ?? No?.... me neither."Let's live for today.";) Link to comment Share on other sites More sharing options...
Members flanc Posted July 18, 2003 Members Share Posted July 18, 2003 Haven't blown one yet ...and I did call the guys at Yorkville to get their thumbs-up! It's mostly headroom for me since I don't push those amps into clipping and I still have plenty-o-thump. Since I'm bridging into an 8ohm load, the RMX2450's don't get very hot at all. I also have my DRPA limiting my sub's incase something awful happens (God Forbid)...but what the hell...they are still under warrenty!! Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 18, 2003 Members Share Posted July 18, 2003 If you are hard-limiting the DRPA before clipping the amp (or limiting at the amp) then that's power that is not being used, can't be used, but you did pay for! It's like buying 100 mph tires for a race car... then putting a govener on the car to limit yourself to 100 mph. As a manufacturer, I can't possibly understand how Yorkville can expect the speakers to hold up under 1400 watt amp... any oops and it's toast. I am familiar with the driver... it's a good driver but not that good! Link to comment Share on other sites More sharing options...
Members flanc Posted July 18, 2003 Members Share Posted July 18, 2003 As usual Agedhorse, you are right, but I happened to have those amps, so I put 'em to use (with Yorkvilles blessing). The limiters give me peace of mind and protection from those accidents you are so quick to bring to our attention. Sometimes killing a fly with a hammer sitting next to you is better than going out a and buying a new fly swatter.....awful analogy, but you get the point. In the perfect world, I'd have one of these driving both subs in stereo. A perfect 1100watts/channel and saving me:1) about 50lbs in my amp rack2) considerable power draw3) a couple rack spaces4) Peace of mind The problem is spending $2800 to fix something that ain't broke. Even if I sold the two RMX2450's...it's about 2K out of pocket; not feasible right now but on the ole wish list! Lab Gruppen FP3400http://www.mia.dk/usr/mia/mia.nsf/0/658DCBCCA3B50F75C1256BA000403856?OpenDocument Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 18, 2003 Members Share Posted July 18, 2003 Originally posted by flanc As usual Agedhorse, you are right, but I happened to have those amps, so I put 'em to use (with Yorkvilles blessing). The limiters give me peace of mind and protection from those accidents you are so quick to bring to our attention. Sometimes killing a fly with a hammer sitting next to you is better than going out a and buying a new fly swatter.....awful analogy, but you get the point.In the perfect world, I'd have one of these driving both subs in stereo. A perfect 1100watts/channel and saving me:1) about 50lbs in my amp rack2) considerable power draw3) a couple rack spaces4) Peace of mindThe problem is spending $2800 to fix something that ain't broke. Even if I sold the two RMX2450's...it's about 2K out of pocket; not feasible right now but on the ole wish list!Lab Gruppen FP3400http://www.mia.dk/usr/mia/mia.nsf/0/658DCBCCA3B50F75C1256BA000403856?OpenDocument Yes, as long as you don't break something valuable with the hammer! This is a good example of where compromises are necessary. Not everybody understands that more is not always better though. Link to comment Share on other sites More sharing options...
Members OMNIFEX Posted July 19, 2003 Members Share Posted July 19, 2003 agedhorse, Wouldn't you say that RMX 4050 is nothing more than the EX 4000 with a stronger power supply. I've been reviewing both spec sheets, and, this looks like a modified EX 4000 Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 19, 2003 Members Share Posted July 19, 2003 I haven't seen the schematic for the 4050, but generally, QSC tends to stay with familiar topologies, like the Series 1 ---> USA ---> RMX progression, that we are familiar with. It's a smary way to proceed from a manufacturer's perspective. As power levels increase, it becomes impractical to use a conventional class AB topology and must go to class H to achieve better efficiency ana power draw. This is where the lines begin to blur. I would expect that the RMX 4050 is based on either the MX-EX technology, or some revision of it via their PLX/PL line... but I don't know for sure which. Link to comment Share on other sites More sharing options...
Members Unalaska Posted July 20, 2003 Members Share Posted July 20, 2003 I guess the 4050 is a three tiered amp w/ 3 voltage rails on it. I dunno if the MX3000 (EX4000) is that way also... pete Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 20, 2003 Members Share Posted July 20, 2003 The 3000 is two tiered, I don't recall the 4000's type. It's all a function of efficiency and cost. Link to comment Share on other sites More sharing options...
Members OMNIFEX Posted July 20, 2003 Members Share Posted July 20, 2003 When I picked up my first 4000, I was pretty confused, when the manual spoke about Dip Switches, and, minedidn't offer any. Then after talking to Bob Lee (QSC) I found out, that the EX 4000 had two versions, and, I had the newerversion with the old versions guide. Old Version, 20 - 20Khz 0.1% THD 720 watts per channel @ 8 ohms 1100 watts per channel @ 4 ohms New Version, 20 - 20Khz 0.1% THD 800 watts per channel @ 8 ohms 1200 watts per channel @ 4 ohms Both offered 3 step High Efficency Circuitry MX 3000a, 20 - 20Khz 0.1%THD 800 watts per channel @ 8 ohms 1200 watts per channel @ 4 ohms This one also offered 3 step High Efficency Circuitry. This is why I feel the RMX 4050 is nothingmore than the predecessor of the EX 4000 with a beefier power supply. Of course there is the same power consumption,weight, and overall appearance. (With the exceptionof the face plate) And, all these models are class H. Sounds Possible? Link to comment Share on other sites More sharing options...
Members agedhorse Posted July 20, 2003 Members Share Posted July 20, 2003 I stand corrected, the change from 2 step to 3 step rails occurs between the MX-2000 and MX-3000. I was thinking specifically of the MX-1500 actually. There are other differences, such as octal socket compatability (none w/ MX line), DIP switch programing, speed/bandwidth of semiconductors, packaging etc that cam make up the differences also. Bob Lee is a very well educated resource... I think he just received an IEEE appointment (or award?). I respect him and his work very highly. Link to comment Share on other sites More sharing options...
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