Members JMS 2 Posted December 3, 2009 Members Share Posted December 3, 2009 Referring to my previous post here there's some news :The amp we are using is actually the Behringer EP2500 not the EP1500. Looks like we're overpowering the Behringer B1520 speakers and that might be the reason the HF drivers keep melting :450W/channel 8ohms into a pair of 200W RMS 8ohms speakers(Don't shoot me, I'm not the one who bought the system) We never use the entire available amp power, the gain control goes to +34dB while our usual setting is in the +24 to +28 dB range.Is it correct that +34dB gain delivers the maximum 450W here and half the dB means half the power ? If that's the case then we have a problem. At +17dB gain (225W would be safe right?), the volume would be too low. Would it be a solution to add speakers in parallel (going from 8 to 4 ohms) ? This way we would add SPL while leaving the amp at the +17dB (225W) mark and speakers would be safe. Or not ? Link to comment Share on other sites More sharing options...
Members TimmyP Posted December 3, 2009 Members Share Posted December 3, 2009 The amp's control setting has no bearing on the power that the amp can put out. It merely adjusts how much you have to push the mixer to get a given amount of power out of the amp. Adding more speakers will give you a little more volume, but likely a worse (with luck only slightly) sound. But if you don't turn down, you'll likely then be blowing four drivers instead of just two. Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 3, 2009 Author Members Share Posted December 3, 2009 What are my options then ?Sell the B speakers and get some 500W RMS ones instead ?Ouch, that'll get me slipping towards the $2K mark for the speakers alone ... Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted December 3, 2009 CMS Author Share Posted December 3, 2009 If you wish to keep the speakers, why not get an amp with more appropriate power? But frankly I'd opt to upgrade...speakers are the weak link in any system so money spent to upgrade is a wise investment. Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 3, 2009 Author Members Share Posted December 3, 2009 Ironically, in my previous thread, the poweramp was the only gear I intended to keep ... Behringer states in their manuals that their speakers should be driven by poweramps with twice the rated "continuous" speaker power ...Then I see in a different manual that all their "setup examples" show the B1520 speakers connected to an EP1500 poweramp (260W/channel), NOT the EP2500 ... Pffff .... I'm lost As for upgrading, I played with the idea of getting the Yamaha S115V's which are rated 250W (compared to the 200W of the B1520) and 99dB SPL (compared to 95dB in the Behringers) but I doubt now that it would make much difference regarding reliability. The Yamaha's have a built-in limiter on the HF drivers though ... AND I can get an incredible deal on them at a local store right now. I don't know what to do, $2K for speakers is really not feasible. Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted December 3, 2009 CMS Author Share Posted December 3, 2009 Ironically, in my previous thread, the poweramp was the only gear I intended to keep ...Behringer states in their manuals that their speakers should be driven by poweramps with twice the rated "continuous" speaker power ...Then I see in a different manual that all their "setup examples" show the B1520 speakers connected to an EP1500 poweramp (260W/channel), NOT the EP2500 ...Pffff .... I'm lostAs for upgrading, I played with the idea of getting the Yamaha S115V's which are rated 250W (compared to the 200W of the B1520) and 99dB SPL (compared to 95dB in the Behringers) but I doubt now that it would make much difference regarding reliability. The Yamaha's have a built-in limiter on the HF drivers though ... AND I can get an incredible deal on them at a local store right now.I don't know what to do, $2K for speakers is really not feasible. Those Yamaha Clubs would be a nice improvement. The 4dB increase in sensitivity amounts to doubling the amplifier power (actually 3dB is double; I'm assuming we should be conservative) for the same output, so that alone is worth the price. The Clubs are a bar band standard. The contradiction you see in the manuals is neither surprising nor unique to Behringer. It's how marketing gets caught in its own lies. For whatever it's worth, I recommend no more than 1.5x rms ratings unless you really know what you're doing and are able to replace blown components in the event of an unexpected problem. Link to comment Share on other sites More sharing options...
Members 1960LesPaul Posted December 3, 2009 Members Share Posted December 3, 2009 Yep!! Peavey told me anywhere from 80 to 125% of the RMS rating would be good. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted December 3, 2009 Members Share Posted December 3, 2009 We never use the entire available amp power, the gain control goes to +34dB while our usual setting is in the +24 to +28 dB range.Is it correct that +34dB gain delivers the maximum 450W here and half the dB means half the power ?This can actually cause your HF drivers to blow - run the amp up full and reduce your mixer output. By turning down the amp 10db you can clip the mixer and the resulting distortion can fry the HF drivers. Are you sure the clip limiter on the amp is engaged? If you never "flash" the clip limiter lights on the amp you shouldn't be in too much danger of blowing the HF drivers unless something else in the signal chain is clipping. OTOH Synth and Sax can have a LOT of highs. Maybe you're practicing just too f'in loud? Link to comment Share on other sites More sharing options...
Members RoadRanger Posted December 3, 2009 Members Share Posted December 3, 2009 The Yamaha's have a built-in limiter on the HF drivers though ...So do the Behringers. Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 3, 2009 Author Members Share Posted December 3, 2009 Doubling ? Not trying to fire up that debate again but I know +3dB is mathematically doubling the volume, but I believe it takes +10dB to trick the human ear into "thinking" it's twice as loud as previously Anyway I'm talking myself into those clubs, look : The HF drivers in the B's are melting, so it's an overheating problem. Better sensitivity (+4dB in the Yam's) means better efficiency (I'm certainly going from 4% to 6%) means 2% less thermal loss, means 2% less heat, means "wow what a huge difference that makes GET THOSE YAMAHA SPEAKERS DAMMIT !!!" See ? Easy ... Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 3, 2009 Author Members Share Posted December 3, 2009 So do the Behringers. REALLY ??????I didn't know that ... and I don't see that stated in the manual Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 3, 2009 Author Members Share Posted December 3, 2009 This can actually cause your HF drivers to blow - run the amp up full and reduce your mixer output. By turning down the amp 10db you can clip the mixer and the resulting distortion can fry the HF drivers. Are you sure the clip limiter on the amp is engaged? If you never "flash" the clip limiter lights on the amp you shouldn't be in too much danger of blowing the HF drivers unless something else in the signal chain is clipping. OTOH Synth and Sax can have a LOT of highs. Maybe you're practicing just too f'in loud? Nothing is never clipping anywhere.The mixer LED's show anywhere between -20db to -10dB but never above 0dB.Never had the clip limiter blinking on the amp either.I've been in a couple bands, this one is by far the quietest. I really don't know what's going on ... Link to comment Share on other sites More sharing options...
Members RoadRanger Posted December 3, 2009 Members Share Posted December 3, 2009 REALLY ??????I didn't know that ... and I don't see that stated in the manualYour link from the other thread:http://www.behringer.com/EN/Products/B1520.aspx7th bullet item. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted December 3, 2009 Members Share Posted December 3, 2009 I've been in a couple bands, this one is by far the quietest. I really don't know what's going on ...Did whoever "fixed" the speakers check out the crossovers to make sure they weren't somehow cooked? Do you mic the sax? How loud is the synth? Any of those in combination with running the speakers on an amp rated at 2.5x their rms is going to cause problems. Moving down to an EP1500 would probably help and would be cheaper than buying new speakers? If you were in the states I'd trade you one of my RMX1450 clones for your RMX2450 clone . FWIW I have run my Peavey PR10's (200wrms) off an RMX2450 run near clipping before but don't blast the synth or lead guitar through them. I usually use one of my RMX1450 clones instead but this wasn't my amp rack I was using and I was too lazy to haul my own . Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted December 3, 2009 CMS Author Share Posted December 3, 2009 Doubling ? Not trying to fire up that debate again but I know +3dB is mathematically doubling the volume, but I believe it takes +10dB to trick the human ear into "thinking" it's twice as loud as previously Yeah, I miswrote that; 3dB increase in sensitivity is the equivalent of doubling amplifier power, not output volume. So you get the same level using 50 watts into a 99dB speaker as you would using 100 watts into a 96dB speaker. Sorry for the confabulation.... Link to comment Share on other sites More sharing options...
Members malcatron Posted December 3, 2009 Members Share Posted December 3, 2009 Sorry to jump in on this, but something in the thread I noticed raised a question. Is it safer to run your amp flat out and ease back on the mixer level or is it better to get a strong level coming from the mixer and then set the amp so it is not clipping? Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted December 3, 2009 CMS Author Share Posted December 3, 2009 Sorry to jump in on this, but something in the thread I noticed raised a question.Is it safer to run your amp flat out and ease back on the mixer level or is it better to get a strong level coming from the mixer and then set the amp so it is not clipping? Doesn't really matter. Theoretically you would increase signal-to-noise ratio by increasing mixer level relative to the amp sensitivity, but in practice most amps are very quiet. In all cases it's important to avoid clipping any segment of the signal chain. Link to comment Share on other sites More sharing options...
Members Coaster Posted December 3, 2009 Members Share Posted December 3, 2009 what HF protection do the clubs have? i've been through the crossovers and the only thing i see is the polyswitch - but that doesnt seem to directly protect the HF driver. i can tell you this - when the tinsel lead of the 15" went to hell, the HF kept right on going. also, when the cap exploded in the LP filter the HF kept right on going. i'm not so sure about any HF protection, only a couple resistors and a choke. Link to comment Share on other sites More sharing options...
Members agedhorse Posted December 3, 2009 Members Share Posted December 3, 2009 what HF protection do the clubs have? i've been through the crossovers and the only thing i see is the polyswitch - but that doesnt seem to directly protect the HF driver. i can tell you this - when the tinsel lead of the 15" went to hell, the HF kept right on going. also, when the cap exploded in the LP filter the HF kept right on going. i'm not so sure about any HF protection, only a couple resistors and a choke. The polyswitch engages a HF driver pad that reduces the power to the HF driver under "overload" conditions, IIRC it's somewhere around -6dB. This is going from memory. Tinesl lead failure is almost always due to exceeding Xmech from too much power. Link to comment Share on other sites More sharing options...
Members agedhorse Posted December 3, 2009 Members Share Posted December 3, 2009 Referring to my previous post here there's some news :The amp we are using is actually the Behringer EP2500 not the EP1500.Looks like we're overpowering the Behringer B1520 speakers and that might be the reason the HF drivers keep melting :450W/channel 8ohms into a pair of 200W RMS 8ohms speakers(Don't shoot me, I'm not the one who bought the system)We never use the entire available amp power, the gain control goes to +34dB while our usual setting is in the +24 to +28 dB range.Is it correct that +34dB gain delivers the maximum 450W here and half the dB means half the power ?If that's the case then we have a problem. At +17dB gain (225W would be safe right?), the volume would be too low. Would it be a solution to add speakers in parallel (going from 8 to 4 ohms) ? This way we would add SPL while leaving the amp at the +17dB (225W) mark and speakers would be safe. Or not ? Controls on your amp are input sensitity, the drive level the mixer must provide for full rated output. If you reduce the sensitivity on the amp by 10dB and increase the output of the mixer by 10dB, you are at exactly the same place. Most mixers deliver about +18dB on the unbalanced outs and +24dB on the balanced outs. If the amp's rated sensitivity is +4dB for rated output and turned the amp down by 10dB, the new sensitivity would be +14dB and anything above this will clip (or limit) the amp and if you go beyond 4dB into limiting then you will clip the mixer's output and end up with the same clipped speaker signal. Nothing wrong with doubling up on speakers for your application, you will get more volume and sound better for your uses and your amp's power will end up at around 350 watts per box... still more than I would recommend though. I would strongly suggest that you use this experience to make a significant upgrade. The Club's are a nice upgrade, less to carry than 4 of the B boxes, and will sound better, last longer. Link to comment Share on other sites More sharing options...
Members sharnrock Posted December 4, 2009 Members Share Posted December 4, 2009 I use the club 15's. They are an excellent speaker. Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 4, 2009 Author Members Share Posted December 4, 2009 Your link from the other thread:http://www.behringer.com/EN/Products/B1520.aspx7th bullet item. Right you are.Funny, it's only stated on the spec sheet, not in the manual Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 4, 2009 Author Members Share Posted December 4, 2009 what HF protection do the clubs have? i've been through the crossovers and the only thing i see is the polyswitch - but that doesnt seem to directly protect the HF driver. i can tell you this - when the tinsel lead of the 15" went to hell, the HF kept right on going. also, when the cap exploded in the LP filter the HF kept right on going. i'm not so sure about any HF protection, only a couple resistors and a choke. This is what yamaha says about it :club_v_series_featuresNot much I agree Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 4, 2009 Author Members Share Posted December 4, 2009 Controls on your amp are input sensitity, the drive level the mixer must provide for full rated output. If you reduce the sensitivity on the amp by 10dB and increase the output of the mixer by 10dB, you are at exactly the same place. Thank you very much, I think I see how it works now. Nothing wrong with doubling up on speakers for your application, you will get more volume and sound better for your uses and your amp's power will end up at around 350 watts per box... still more than I would recommend though.I would strongly suggest that you use this experience to make a significant upgrade. The Club's are a nice upgrade, less to carry than 4 of the B boxes, and will sound better, last longer. But I would still be using a 2x450W amp into 2x250W RMS speakers and that wouldn't solve anything or did I miss something ? Link to comment Share on other sites More sharing options...
Members JMS 2 Posted December 4, 2009 Author Members Share Posted December 4, 2009 Did whoever "fixed" the speakers check out the crossovers to make sure they weren't somehow cooked? Do you mic the sax? How loud is the synth? Any of those in combination with running the speakers on an amp rated at 2.5x their rms is going to cause problems. Moving down to an EP1500 would probably help and would be cheaper than buying new speakers? They were fixed by a technician, no idea about the xovers, all I can say is the speakers sound right to my ears. Sax is mic'ed but the first time the speakers blew we didn't even have a sax in the band yet. I only see two potential culprits : - The synth/Hammond (that's me). There are no shrill synth/Hammond sounds in Pink Floyd music but who knows ... Now if the woofers blew instead of the HF I'd have no doubt about whose fault it is. The volume of the synth is so that it can barely be heard in the mix. It is for instance much lower than potential culprit #2 : - The electro-acoustic guitars, lots of HF content. One goes through a POD and one goes direct to the board via an active DI. Could it be the lack of compressors inserts and thus dynamics coming from the guitars that stress the HF drivers ? Turning down either instrument is not an option. If anything, the whole band would then have to turn down ... Link to comment Share on other sites More sharing options...
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