Members desertzj Posted November 3, 2009 Members Share Posted November 3, 2009 I have a dilemma, I have used the QSC HPR181i's before and liked them. But I was looking at the new PRX718s and have not had a chance to hear them. What experience has everyone else had with these subs? How do they compare to the QSC's? Thanks Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 3, 2009 Members Share Posted November 3, 2009 I would expect them to easily keep up at less weight. Link to comment Share on other sites More sharing options...
Members dangordan Posted November 3, 2009 Members Share Posted November 3, 2009 I've been using 4 MRX518's for 2 years now (same drivers as PRX) and have been very satisfied. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 3, 2009 Members Share Posted November 3, 2009 I've been using 4 MRX518's for 2 years now (same drivers as PRX) and have been very satisfied. Very different drivers than the PRX-718 though. The 718 is more substantial. Link to comment Share on other sites More sharing options...
Members 1tribe Posted November 3, 2009 Members Share Posted November 3, 2009 Theres a thread on PSW about the PRX718 subs and the user seems to really like them. Ive used a set of VRX918SP subs and liked the sound and performance. (as well as passive SRX718s) Yes it is a bit different in the size of the box but does have the same driver and just about the same size power amp. Personally, even if the db's were down a few from the HPR's the weight difference alone is enough of a difference to go with the PRX718's. Link to comment Share on other sites More sharing options...
Members desertzj Posted November 3, 2009 Author Members Share Posted November 3, 2009 Ive noticed everybody agrees the QSC HPR181i kills the PRX518S, but I have yet to see a comparison with the PRX718s. I have always liked the SRX subs and that is part of the reason I am looking at the PRX718s. Which are closer in price to the 181i's. On paper they look better than the QSC, but we all know that paper and gig are two different things. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 3, 2009 Members Share Posted November 3, 2009 Ive noticed everybody agrees the QSC HPR181i kills the PRX518S, but I have yet to see a comparison with the PRX718s. I have always liked the SRX subs and that is part of the reason I am looking at the PRX718s. Which are closer in price to the 181i's. On paper they look better than the QSC, but we all know that paper and gig are two different things. Everybody does not agree. A little more output, about the same on LFE, but not "killer" difference, and when the size/weight is factored in, the PRX-518 has some definate advantages, even if more boxes are needed. For example, if there are stairs or a tough load-in, more lighter, smaller subs is my preferred route. A 125 lb sub is unmanaeable in some situations where an 80 lb box is ok. There's a 45 lb difference between the two products. I don't think there's all that much weight difference between the PRX-718 and the 518 either, making the 718 an even better choice where additional low outout levels are needed. Link to comment Share on other sites More sharing options...
Members dangordan Posted November 3, 2009 Members Share Posted November 3, 2009 Very different drivers than the PRX-718 though. The 718 is more substantial. Gotcha, looks like the same driver as SRX. So this could be the first in a PRX 700 series. Link to comment Share on other sites More sharing options...
Members allexcosta Posted November 3, 2009 Members Share Posted November 3, 2009 I believe the PRX518 is the powered version of the MRX518, which is a good speaker. The PRX718 would be the powered version of the SRX718, which is an outstanding subwoofer. Link to comment Share on other sites More sharing options...
Members dcastar Posted November 3, 2009 Members Share Posted November 3, 2009 Copied from a previous thread: You're not completely correct on the comparisons... there are subtle, yet important, differences. MRX518 has the 2044G - Single Voice Coil 4 ohm 18" WooferPRX518 has the 2044E - Single? Voice Coil 4 ohm - 18" WooferPRX718 has the 2268FF - Dual Voice Coil 8 ohm 18" WooferSRX718 has the 2268H - Differential Drive (Dual Voice Coil) 8 ohm 18" Woofer and shares the same cab as the VRX918VRX918 has the 2268FF - same driver as the PRX718, same (smaller) cab as SRX but adds rigging points on the cab. As far as comparing just the PRX 518 to the 718, the 718 is far superior. What I'd REALLY like to see, is someone coming in and posting a real world A/B comparison the PRX718S vs the (SRX) VRX918SP's ----- As for comparing it to the QSC HPR181, that's a great question. I'm looking to upgrade to an all VRX setup next year... as noted above, the VRX sub would have the same driver as the PRX718s... so performance should be similar. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 3, 2009 Members Share Posted November 3, 2009 Note that there appear to be errors in the above JBL woofer part codes... The 2268 is a dual VC differential drive woofer. Some products use both VC's brought out and others use it wired as though it were a single coil (electrically). IIRC, the FF is a dual 2 ohm coil and used in powered products only. The equiv. rating would be 4 ohms and the amp would be rated at 4 ohms accordingly. JBL generally poweres their powered cabinets at close to the RMS level which improves reliability greatly in the hands of the masses. The E suffix is, I think) an even lower impedance (net wired load) but I don't have info on what it actually is. It's not uncommon for powered speakers to utilize an internal amp optimized for a very low impedance. I am going to look through my JBL updates to see if I have this. If anybody knows, would they please post it. Link to comment Share on other sites More sharing options...
Members jwlussow Posted November 3, 2009 Members Share Posted November 3, 2009 Ive noticed everybody agrees the QSC HPR181i kills the PRX518S, ... I don't agree either. I'd take 518s over the 181is any day. I have to move that stuff. Link to comment Share on other sites More sharing options...
Members The Chinese Posted November 3, 2009 Members Share Posted November 3, 2009 The link referred to on PSW has exhaustive info on this - they seriously beat it to death... I dunno about posting that link in this forum tho... is that oK? Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 4, 2009 Members Share Posted November 4, 2009 Don't see why not. Of course read between the lines, some of the guys there are quite aware of (and understand the mechanics of) overpowering and have addressed it in their own rigs even though they operate with more power than even some of them recommend themselves. Then there are also those who don't quite get it yet (based on their comments and math understanding). they also do address JBL's powered version's power level which IMO is a good, safe level and will result in a long service live with low warranty claims. Speaker life is similar to tires, if you race your vehicle and are going fast sliding around the corners, your 40,000 mile tires may last only a few hundred miles before failure from tread wear, fatigue, or mechanical failure. If you take it a little easier you may get a few thousand miles, if you drive normally you may get 40,000 miles. Link to comment Share on other sites More sharing options...
Members The Chinese Posted November 4, 2009 Members Share Posted November 4, 2009 Yes, I have noticed that. There are guy espousing running 2400w into an SRX718. Yikes. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 5, 2009 Members Share Posted November 5, 2009 Yes, I have noticed that. There are guy espousing running 2400w into an SRX718. Yikes. and when they have accidents, they are expensive ones too. I wouldn't buy speakers that were pounded with that much power, the liklihood of fatigue damage is pretty high. Link to comment Share on other sites More sharing options...
Members KF650SB1000 Posted November 5, 2009 Members Share Posted November 5, 2009 Copied from a previous thread:You're not completely correct on the comparisons... there are subtle, yet important, differences.MRX518 has the 2044G - Single Voice Coil 4 ohm 18" WooferPRX518 has the 2044E - Single? Voice Coil 4 ohm - 18" WooferPRX718 has the 2268FF - Dual Voice Coil 8 ohm 18" WooferSRX718 has the 2268H - Differential Drive (Dual Voice Coil) 8 ohm 18" Woofer and shares the same cab as the VRX918VRX918 has the 2268FF - same driver as the PRX718, same (smaller) cab as SRX but adds rigging points on the cab.As far as comparing just the PRX 518 to the 718, the 718 is far superior.What I'd REALLY like to see, is someone coming in and posting a real world A/B comparison the PRX718S vs the (SRX) VRX918SP's Lets add one more cab using the 2268 driver:VPSB7118DP uses the 2268G driver with a 1800 Watts Continuous/3600 Watts Peak power amp. Much different cab than any of the others. Link to comment Share on other sites More sharing options...
Members KF650SB1000 Posted November 5, 2009 Members Share Posted November 5, 2009 Note that there appear to be errors in the above JBL woofer part codes...The 2268 is a dual VC differential drive woofer. Some products use both VC's brought out and others use it wired as though it were a single coil (electrically).IIRC, the FF is a dual 2 ohm coil and used in powered products only. The equiv. rating would be 4 ohms and the amp would be rated at 4 ohms accordingly. JBL generally poweres their powered cabinets at close to the RMS level which improves reliability greatly in the hands of the masses.The E suffix is, I think) an even lower impedance (net wired load) but I don't have info on what it actually is. It's not uncommon for powered speakers to utilize an internal amp optimized for a very low impedance.I am going to look through my JBL updates to see if I have this. If anybody knows, would they please post it. The 2268 drivers and other Vertecs drivers are neats as they have 2 Voice Coils on one cone. Some have 1 pair of power input and other have 2 power inputs like a true Dual Voice Coil driver. JBL "typical" lettering:E - 1 ohmF - 2 ohmsG - 4 ohmsH - 8 ohmsJ - 16 ohms Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 5, 2009 Members Share Posted November 5, 2009 Lets add one more cab using the 2268 driver:VPSB7118DP uses the 2268G driver with a 1800 Watts Continuous/3600 Watts Peak power amp. Much different cab than any of the others. I guarantee that there's some really heavy processing and limiting in that box, time integrating, and excursion control as well as the effects of the bandpass box itself. Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 5, 2009 Members Share Posted November 5, 2009 The 2268 drivers and other Vertecs drivers are neats as they have 2 Voice Coils on one cone. Some have 1 pair of power input and other have 2 power inputs like a true Dual Voice Coil driver.JBL "typical" lettering:E - 1 ohmF - 2 ohmsG - 4 ohmsH - 8 ohmsJ - 16 ohms I can't say that I remember ever coming across a E voice coil, it must be unique to a specific application of the differential drive unit. Link to comment Share on other sites More sharing options...
Members 1tribe Posted November 5, 2009 Members Share Posted November 5, 2009 What kind of performance gain will a dual voice coil have over a single VC? One reason I would guess it has something to do with less heat so better overall performance? Link to comment Share on other sites More sharing options...
Members agedhorse Posted November 5, 2009 Members Share Posted November 5, 2009 It's not as simple as that... The heat is distributed better for removeal but also there are in effect 2 seperate magnetic circuits and the idea is to help minimize the saturation of these circuits which increases the motor strength and power handling. Of course it's not as easy as it sounds since this requires good control of the magnetic field(s) and I imagine this is made better by the use of the N-Dym material since it's not as large for the field produced, meaning there are more options for progressive geometries. Link to comment Share on other sites More sharing options...
Members 1tribe Posted November 6, 2009 Members Share Posted November 6, 2009 Thanks Andy. Link to comment Share on other sites More sharing options...
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