Reality check on my little system for club use

[Shovelhead]

I've been putting together a small system to use in small clubs. To be run from the stage. Does this look adequate to you?

 

Mixer: 16 Channel Carvin with 4 200-watt amps built-in (to be used for 4 monitor mixes on stage)

 

Monitors: 4 Yamaha SM12V

 

Subs: Two 1x18" Reflex cabs loaded with Eminence Omega Pro A. Powered by a QSC RMX2450.

 

Tops: Two Yamaha SM15V cabs, powered by another QSC RMX2450.

 

Crossover: DBX 234XL

 

Eq for monitors: Two DBX 215 units

 

Eq for FOH: DBX 231

 

Compressors: One DBX 166XL and One DBX 160

 

Power Conditioner: Furman M8 Spike protector

 

Multieffects: Soon to be T.C. M-One. Right now I have a couple of older Digitech effects units and the on-board Carvin crap.

 

 

I know this is an extremely modest system, but what am I missing?

[InACanProductions]

 

I've been putting together a small system to use in small clubs. To be run from the stage. Does this look adequate to you? Mixer: 16 Channel Carvin with 4 200-watt amps built-in (to be used for 4 monitor mixes on stage) Monitors: 4 Yamaha SM12V Subs: Two 1x18" Reflex cabs loaded with Eminence Omega Pro A. Powered by a QSC RMX2450. Tops: Two Yamaha SM15V cabs, powered by another QSC RMX2450. Crossover: DBX 234XL Eq for monitors: Two DBX 215 units Eq for FOH: DBX 231 Compressors: One DBX 166XL and One DBX 160 Power Conditioner: Furman M8 Spike protector Multieffects: Soon to be T.C. M-One. Right now I have a couple of older Digitech effects units and the on-board Carvin crap. I know this is an extremely modest system, but what am I missing?

 

 

That 2450 might be a little much for those Yamaha Clubs, an 1850HD would be a better match, though if you're confident in your ablilities and have some limiting in place you can run them with that 2450. Or if you daisy chain them off one channel they'll see 350watts which is just under 1.5x the RMS rating for those cabinets.

 

Unless you plan on bridging the sub amp and running your sub cabinets parallel you're a little light on power there. The general opinion here is not to bridge an amp, I'll admit with my old passive rig I would bridge an RMX1450 for 1400watts@4ohms into two 8ohm subs rated at 750watts program, but knowing what I know now I would have bought a bigger amp with the appropriate amount of power per channel to run those speakers with out bridging.

 

I'd say go for 31 band EQs on all the monitor channels vs. 15 band. The narrower bandwidth will be more usefull for notching out problem frequencies with the 31 band. It's like using a scalpel vs a hatchet when performing surgery.

 

Otherwise looks fine for a generalized small club system. You're not going to run the amps off the Furman right?

[Shovelhead]

 

That 2450 might be a little much for those Yamaha Clubs, an 1850HD would be a better match, though if you're confident in your ablilities and have some limiting in place you can run them with that 2450. Or if you daisy chain them off one channel they'll see 350watts which is just under 1.5x the RMS rating for those cabinets. Unless you plan on bridging the sub amp and running your sub cabinets parallel you're a little light on power there. The general opinion here is not to bridge an amp, I'll admit with my old passive rig I would bridge an RMX1450 for 1400watts@4ohms into two 8ohm subs rated at 750watts program, but knowing what I know now I would have bought a bigger amp with the appropriate amount of power per channel to run those speakers with out bridging. I'd say go for 31 band EQs on all the monitor channels vs. 15 band. The narrower bandwidth will be more usefull for notching out problem frequencies with the 31 band. It's like using a scalpel vs a hatchet when performing surgery. Otherwise looks fine for a generalized small club system. You're not going to run the amps off the Furman right?

 

 

Thanks for the advice! I already have the amps. I was eventually going to get a bigger sub amp and use one of the 2450s for a monitor amp.

 

I plan on using the Furman for everything but the amps. I'll probably run those to a separate circuit.

 

Thanks again!

[jrlaudio]

Another opinion ...

 

As a general rule of thumb in the industry you want to have at least 2x the rated RMS for the loudspeaker in question. The 1.5 times figure is a cost effective compromise number used for install systems and large touring rigs as a weight and space saving compromise. This was due to when amplifiers were generally underpowered compared to rack spaces used and weight. Nowadays amplifiers pack alot of power for their weight and size.

 

The RMS rating for Yamaha SM15V is 500W (with a peak rating of 1000W) and your amplifiers are rated for 450w/ch @ 8 ohms. I'm not sure where the other gentleman got his figures but they appear to be incorrect.

 

The minimum power I would recommend for the SM15V would be an amplifier rated at 750w/ch @ 8ohms. To recommend less power is poor advice. You may discover that with the power you have now, and if you are mixing loud rock music in a packed club, you may end up driving the amplifier into clipping often.

 

Generally, running to little power is worse and more damaging to loudspeakers than running to much. To over simplify, an amplifier which is under-powered for the application and driven into clipping, even just on peaks, causes square waves to be produced on the outputs of the amplifiers and causes voice-coils to heat excessively and prematurely. This is an over-simplification but is essentially a correct statement of fact.

 

Bridging or not bridging an amplifier does nothing to change the amount of total energy applied to the same load. While the combined impedance and apparent output numbers change, the total energy involved per driver remains the same. What does change is the efficiency of the amplifier. Personally, not knowing what the efficiency of your sub-woofers is, it is difficult to gauge (other than driver rating) what would be appropriate power for you subs. My feeling is you are also under-powered and should probably have at least twice as much power as you do now.

 

Powering issues are tantamount to performance and reliability. Do not take them lightly or brush them off. A common mistake.

 

Understand, long-term reliability of the system, and the ability of the system to produce the dynamics desired with headroom, are directly related to (1) the volume of the room (2) total combined power capacity (3) the efficiency and number of loudspeakers. More power is always preferred over choosing less. I cannot tell you how many times I have seen people assemble a system and then find it doesn't have the ability to produce what the person expected. For instance, a tight and thunderous bass drum, or clear and clean vocals that get out over the mix, and almost always it is the result of too little power in the system. Not recognizing or ignoring powering issues, people then spend more money trying to find a quick-fix, like compressors and limiters, and other processors; which do nothing to help the core problem: Not enough power for the application.

 

I do agree you should use 31 band EQ's on monitors since EQ in monitoring is used primarily for controlling feedback. Two-third octave filters (15 band EQ) are simply too wide for this purpose. You will find when you pull out a frequency to reduce feedback, other unrelated frequencies are removed and tone suffers severely.

 

The system is a nice one and will work well if you do not push the system beyond its limitations. I would plan on doubling your overall power over time, especially if you find clipping or distortion, or even blown drivers, becomes a common occurance. I suspect it might if you're playing rock, funk or fusion or any high-level music in a normal club environment.

 

John LeVasseur

JRL Audio Consultants

New York

 

http://www.myspace.com/jrlaudio

[Luigi]

[soul-x]

InACan's numbers look right to me.

 

The SM15V is rated at 250W RMS. It's a 2.5" VC OEM Eminence driver.

[jrlaudio]

http://www.yamahaproaudio.com/downloads/data_sheets/speakers/Club_V_monitor_datasheet.pdf

[soul-x]

 

http://www.yamahaproaudio.com/downloads/data_sheets/speakers/Club_V_monitor_datasheet.pdf

 

 

Thanks. 250W RMS (EIA RS426) confirmed.

[Al Poulin]

Yamaha's Club 15 is not a 500 watt RMS speaker. 500 watts is the program power which generally means DO NOT APPLY MORE THAN THIS MUCH POWER TO THIS SPEAKER. 250 watts is closer to the RMS power and the speaker is fine (and will last longest) powered at between 250 and 400 watts. Al - Party-Time! DJ Services

[Al Poulin]

Another opinion ... As a general rule of thumb in the industry you want to have at least 2x the rated RMS for the loudspeaker in question. The 1.5 times figure is a cost effective compromise number used for install systems and large touring rigs as a weight and space saving compromise. This was due to when amplifiers were generally underpowered compared to rack spaces used and weight. Nowadays amplifiers pack alot of power for their weight and size. The minimum power I would recommend for the SM15V would be an amplifier rated at 750w/ch @ 8ohms. To recommend less power is poor advice. You may discover that with the power you have now, and if you are mixing loud rock music in a packed club, you may end up driving the amplifier into clipping often. John LeVasseur JRL Audio Consultants New York http://www.myspace.com/jrlaudio

 

 

Sorry to tell you but...There is so much misinformation in your post, I'm not sure where to start... 750 watts is the least you recommend for a Yamaha Club 15? Seriously? Oh boy...

 

You do realize that going from say 400 watts to 750 will only give you roughly a 2-3DB increase in volume which is barely noticeable? And that with this increase in power, you are putting long term reliability of this speaker in jeopardy? Maybe, and just maybe this would be OK in very experienced hands, but what YOU are recommending here is POOR ADVICE. Al

[Craig Vecchione]

As long as you aren't clipping the amp and you're getting enough volume (the Clubs are pretty efficient, IMO) I'd say you've got a pretty nice system. Be sure to engage the RMX's limiters, and the 50Hz HPF's on both amps (the subs won't do much more than waste power below that).

[Al Poulin]

 

 

Yeah... here we go again.....

[joel77]

I gotta keep an eye on this post ...... this could get interesting!

 

Joel

[jbutler1982]

 

Generally, running to little power is worse and more damaging to loudspeakers than running to much. To over simplify, an amplifier which is under-powered for the application and driven into clipping, even just on peaks, causes square waves to be produced on the outputs of the amplifiers and causes voice-coils to heat excessively and prematurely. This is an over-simplification but is essentially a correct statement of fact.

 

 

For the last time, its not because its under-powered. That has nothing to do with it. Thats like seeing five red cars break down and thinking "I'm not going to buy a red car, they break down constantly!"

 

Don't clip the amp. Thats the cause. Not the underpowering. Its irrelevant.

 

Considering the amount of wattage you are recommending is roughly halfway b/t program and peak, and it is a barely noticable increase in volume, its a stupid risk, IMO. 450W is pushing it. Better would be an RMX 1850HD with a proper limiter engaged.

[soul-x]

750 watts is the least you recommend for a Yamaha Club 15? Seriously? Oh boy...

 

Are you saying I don't need a Macrotech 3600 for my Yamaha Club monitors?

[Al Poulin]

Are you saying I don't need a Macrotech 3600 for my Yamaha Club monitors?

 

 

 

What I'm saying is if 400 watts/channel doesn't get a pair of Yamaha Club 15s loud enough, you need more SPEAKER and POWER. Applying more power to this poor speaker is just asking for trouble... Al

[Al Poulin]

For the last time, its not because its under-powered. That has nothing to do with it. Thats like seeing five red cars break down and thinking "I'm not going to buy a red car, they break down constantly!" Don't clip the amp. Thats the cause. Not the underpowering. Its irrelevant. Considering the amount of wattage you are recommending is roughly halfway b/t program and peak, and it is a barely noticable increase in volume, its a stupid risk, IMO. 450W is pushing it. Better would be an RMX 1850HD with a proper limiter engaged.

 

 

Congratulations! Your are the 1,000,000th customer on this website!!! Click here to claim your prize...

 

Just kidding. Congratulations though, I just noticed you are now a senior member! That was your 1000th post. Al

[twostone]

How big are these small clubs? 2-18" subs and 2-15" 2 way speakers heck I use 1 sub and 2 12" 2way cabs and that's more then enough for our small club circuit.

[Al Poulin]

From Yorkville's professional audio guide :

 

Consider the following; if you reduce applied power by 50%,the SPL will be reduced by -3dB reflecting a decrease in perceived loudness of roughly 30%, possibly less depending on who you ask. If the system was producing 110dB, the SPL would still be around 107dB with 50% of the applied power gone (believe it or not!). And if you think that's unusual, consider the reverse situation - doubling applied power only nets +3dB or roughly a 30 to 40% increase in perceived loudness - more about this later.

 

AND :

 

Back in the 1970's when everybody was learning about sound systems, you might hear someone say, "Oh I know that speaker. The rating is 100 watts RMS but you can hit it with two times that much power." Go around the corner and you might hear someone else say, "RMS times three, that's how much power you sock into that speaker - in fact any speaker." (argh!). Meanwhile speakers, horns and tweeters were blowing up like popcorn and repairmen were the only ones making a profit - at least that's how it seemed. Thankfully, "program" power ratings are more reliable when used the right way. Now, when you see "pgm" you know it means "APPLY NO MORE THAN THIS MUCH POWER". Life is simpler and safer.

 

 

Al

[Craig Vecchione]

 

Understand, long-term reliability of the system, and the ability of the system to produce the dynamics desired with headroom, are directly related to (1) the volume of the room (2) total combined power capacity (3) the efficiency and number of loudspeakers. More power is always preferred over choosing less. I cannot tell you how many times I have seen people assemble a system and then find it doesn't have the ability to produce what the person expected. For instance, a tight and thunderous bass drum, or clear and clean vocals that get out over the mix, and almost always it is the result of too little power in the system. Not recognizing or ignoring powering issues, people then spend more money trying to find a quick-fix, like compressors and limiters, and other processors; which do nothing to help the core problem: Not enough power for the application. I do agree you should use 31 band EQ's on monitors since EQ in monitoring is used primarily for controlling feedback. Two-third octave filters (15 band EQ) are simply too wide for this purpose. You will find when you pull out a frequency to reduce feedback, other unrelated frequencies are removed and tone suffers severely. The system is a nice one and will work well if you do not push the system beyond its limitations. I would plan on doubling your overall power over time, especially if you find clipping or distortion, or even blown drivers, becomes a common occurance. I suspect it might if you're playing rock, funk or fusion or any high-level music in a normal club environment. John LeVasseur JRL Audio Consultants New York http://www.myspace.com/jrlaudio

 

 

He's already powering them at 2x RMS. You're recommending he go to 4x RMS. This is wrong. You also seem to be assuming the crossover and HF drivers can handle unlimited amounts of power. What do you suppose will happen when someone gets runaway feedback with 1000 watts powering the HF?

 

As I wrote, if he needs more volume than the system provides, he needs more speaker.

[agedhorse]

Silly consultant

 

Power levels look fine, 500 watts is not all that bad in this case because the crossover will remove the sub-100Hz material and driver unloading is now un likely as in mechanical damage, so assuming you don't clip the amp, 2x RMS (in this case because Yamaha's 250 watt "RMS" ratings on this product are good reasonable numbers) is probably ok with a little common sense. Thermal failure is (probably) the most likely failure mode and is easier to protect from with common sense IME. If that's not enough SPL, you need more speakers and power, not just power.

 

Re: the JRL consultant's comments about a bridged amp running more efficiently... bridged mode doesn't improve the efficiency.

 

Anybody wonder why so many speakers fail these days? This is some pretty good insight IMO.

[InACanProductions]

I don't need to beat a dead horse since many other members have jumped in(which I appreciate some of you coming to my defense). I also want to try to keep this thread from turning into a 10 page pissing match (because there are enough of those already). I'll also admit freely that I would not concider myself an "expert" and my knowledge doesn't hold a candle to some of the members of this forum, but I also would not give advice that I wasn't 100% sure of.

 

With that said, I'll stick by my advice. Since he has the amps already he could power the Yamahas off 1 side of a 2450 and give them each 350watts and those cabs will be pleanty happy with less risk to the drivers. The speakers he used in his subs are rated for 800watts, they are 8 ohm drivers, with a sensitivity rating of 97dB (http://www.eminence.com/proaudio_speaker_detail.asp?web_detail_link=OMEGAPRO-18A&speaker_size=18&SUB_CAT_ID=1). That leads me to say that they "could" be powered by the 2450 in bridged mode with both cabinets run parallel. I gave some reasons, as have others, why this might not be desireable but the OP is the only one who can judge his own abilities to determine his comfort level opperating this way.

 

One sort of rule of thumb I've come to understand is, RMS is about 25% of the Peak rating of a speaker. So with 1000watts Peak RMS should be around 250watts, Program is roughly double RMS. I can understand if JRLaudio misquoted the specs mistaking the program for RMS. If the Yamaha's were in fact 500watts RMS I would have suggested an amp that put out 750watts@8ohms. It's also misleading because in almost all the published specs for the Club series that I have seen has not listed the RMS rating only Program and Peak.

 

I think the OP has a nice little rig. If he didn't already know before posting about the issues with powering his speakers, he certianly has some opinions that he can base his judgements off, or not. The advice from different points of view are available with reasoning backing each postion up, and the people with opposing views can agree to disagree. I'm not going to argue either way because my time is more valuable than that. I hope the OP has good luck with his rig and knows he can come back here for advice any time. I hope all of you reading this have a happy and safe holiday this weekend. I'm off.

[agedhorse]

From experience, the Omega 18 sub should not be powered by more than about 800 watts unless time dependant limiting is used and properly programmed. There's no way a typical cabinet will work out well with regard to Xmax, and the constant mechanical damage from greatly exceeding Xmax will really degrade the suspension components. That driver used to be rated at 400 watts RMS and has steadily increased. Some changes have been made, but not 400 watts RMS worth IME. I have reconed an awful lot of them that have been overpowered. Invariably, the suspension of the spider has been damaged.

 

The gains between powering at 800 watts and going beyond that will largely be mitigated by losses due to power compression. There will be a lot of wire out of the gap at the peak power locations (extremes of the excursion) which doesn't help things much.

[6Imzadi]

Congratulations though, I just noticed you are now a senior member! That was your 1000th post. Al

 

Yee haw! Good job.

 

Working on that myself. Seems to take a long time when I really don't respond to every thread.

[Luigi]

Yeah... here we go again.....