Members trynmybest Posted February 10, 2011 Members Share Posted February 10, 2011 Just want to put it out there that i'm new to all this jazz, and this is my first post. I've got one Peavey 215 Dual 15" PA Speaker Cab. To power it I use a Yamaha EMX 2000 Powered Mixer. I'm pretty sure I'm not really milking the speaker for what it's worth with the powered mixer I've got. The speaker has 4 ohm nominal impedance, program power rating (700 Watts), peak power capacity (1400 Watts). The powered mixer is 200W/4 ohms. The good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating??? My speaker has a continuous IEC of 700Watts right? So the powered mixer obviously doesn't have enough power to power the amp adequately? Do i just need to buy a power amp with 1200 Watts/ 4 ohms to hook up to my powered mixer (200W/ 4 ohms) for a total of 1400W?? Or do I just need to ditch the powered mixer and get an unpowered mixer to hook a power amp up to? Or what??? I'm just confused with the whole thing Thanks for being pateient and helping me with my noobish question everyone. Link to comment Share on other sites More sharing options...
Members heath_eld Posted February 10, 2011 Members Share Posted February 10, 2011 OK... you're missing a fair few things here. I'll try to address them. 1. In answer to your heading question: can you use a power amp with a powered head, yes, you can. However 2. You can't combine the 2 power amps into one speaker (remember that a powered mixer is essentially a mixer, and an amp, in one box). You would have to take an output from the mixer (that is whats called a line level signal) and put it into the power amp. At that stage, you'd be using only the power amp's amp, and not the on board amps on the powered mixer. There is nothing wrong with that (that is for transistor amps. Tube amps, like for guitars, are very different). You could possibly use the amps in the powered head for foldbacks. 3. BUT I suspect you're hugely overstating the capabilities of your speaker. There are many discussions on this forum about what rating to use when powering a speaker. They are rated as RMS power, Program power, and peak power. RMS power is generally half program, which is generally half peak power. That means that, give or take, the RMS of that speaker is 350w and peak about 1400. For a beginner to intermediate operator, you should use about the RMS rating. You could plug a 1200w power amp into that speaker - yes, say a Peavey PV3800. But as soon as you got near the capacity of the amp, you would be seriously risking blowing the speaker. If you did it long term, you would almost certainly eventually blow the speaker. You might well read in a brochure (from a speaker company) that you should use double the Program power in your amps - however, that is going to result in you often needing to purchase new speakers or get old ones reconed. I would not recommend that you do this!! let me make that clear. 4. Ideally therefore you would power that speaker with 350w at 4 ohm. Or a little more. I would stay well under 500w. So yes, i suppose you could say that your amp (200w) is underpowering that speaker. It won't do you any harm to underpower as long as you don't clip the amps. Basically that means "avoid the little red lights". Moving up to 350-400w won't make a lot of difference to the volume, but there would be some. 5. There are a variety of ways you could upgrade. You could get a desk and power amp, or better, powered speakers and a desk. They would both work. But the more important question is what are you doing now, what are you aiming to do, and why do you need to upgrade (that is, whats wrong with your current set up) Link to comment Share on other sites More sharing options...
Members GCDEF Posted February 10, 2011 Members Share Posted February 10, 2011 The good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating??? So the powered mixer obviously doesn't have enough power to power the amp adequately? The rule of thumb is nonsense. Adequate depends on the situation. If you're getting sufficient output from it now, don't worry about it. Link to comment Share on other sites More sharing options...
Members Unalaska Posted February 10, 2011 Members Share Posted February 10, 2011 IIRC the EMX2000 will bridge to 400w @ 8 ohms. BUT this amp will not bridge to a 4ohm load! You've got a bit of a problem, the speaker cab is not great and the power amp section of the EMX is small. I'd recommend replacing both if volume (SPL) is still an issue. Link to comment Share on other sites More sharing options...
Members Shaster Posted February 10, 2011 Members Share Posted February 10, 2011 I've got one Peavey 215 Dual 15" PA Speaker Cab.To power it I use a Yamaha EMX 2000 Powered Mixer.I'm pretty sure I'm not really milking the speaker for what it's worth with the powered mixer I've got.The speaker has 4 ohm nominal impedance, program power rating (700 Watts), peak power capacity (1400 Watts).The powered mixer is 200W/4 ohms.The good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating??? My speaker has a continuous IEC of 700Watts right? Hi, welcome to the forum. Starting with the last question, your speaker has a program rating of 700 watts, not an IEC rating.... http://en.wikipedia.org/wiki/International_Electrotechnical_Commission What are you presently using this system for? Is volume an issue or are you just concerned that you're doing something wrong? If it's the latter NO you're not. Nothing wrong with "underpowering" a speaker unless you clip your amp - then there could be trouble. If you double your amplifier power you're only going to get another 3dB - that's not a whole lot if you're already falling quite short of your desired mark. And that speaker could only take double your current power. It's roughly rated at 350 watts RMS. Generally without experience and/or limiters you shouldn't power a speaker beyond it's RMS rating. So for you, 350 watts would be good. If your gear suits your needs then carry on as you were. If you need to improve things then I would get rid of it all and start over. Link to comment Share on other sites More sharing options...
Members trynmybest Posted February 11, 2011 Author Members Share Posted February 11, 2011 I'm currently just using the system for vocals during band practice, and volume is definitely the issue. I was concerned a little if "underpowering" the speaker could cause any harm, and I'm glad it's not -so thank you, and also thanks for clearing up the RMS, program, peak issue as well. But as for intentions, I'm the vocalist, and I am just not able to use the speaker and amp at a volume where I can hear my self clearly over the guitars and drums. (Granted the drummer in my band plays like he wants to be heard by everyone on my block.) So with the equipment that I've got presently what do I need to add in order to increase my volume PA semi-significantly??? (enough to be heard alongside a very loud drummer and loud guitars) And also if you gentlemen could bear in mind that I'm on a bit of a budget (not to the point where I want totally want to compromise quality though). I really don't want to start from scratch either, but if the speaker or amp are limiting to the point that I must, I'll deal with it. All suggestions will be duly noted Thank you thank you thank you for your help. Link to comment Share on other sites More sharing options...
Members Shaster Posted February 11, 2011 Members Share Posted February 11, 2011 Can you define what is happening at present? Are you getting feedback before your desired volume? Are your vocals muddy? Is the mixer limiting or clipping or distorted before your desired volume? Is the speaker functioning properly. As I said you're not going to need much or any (depends on shelving) of your 60hz frequency. Reducing that frequency could let you squeeze a few more drops of available power and MIGHT allow you to increase your volume - that's assuming you're not on the verge of feedback, and so on. IMO unless you've got things hooked up incorrectly, you shouldn't need more than 200 watts for your vocal monitor in practice. So make sure everything is set up properly and you have proper gain stage. Also, where is the speaker in relationship to your mic? FYI, I often rehearse in a space that has some old EV speakers and a crummy powered mixer. We have no problem hearing the vocals because we keep the volume down. Maybe you can start with reducing the band's volume and optimizing your system. Link to comment Share on other sites More sharing options...
Members heath_eld Posted February 12, 2011 Members Share Posted February 12, 2011 Tell drummer to tone it down. Link to comment Share on other sites More sharing options...
Members trynmybest Posted February 13, 2011 Author Members Share Posted February 13, 2011 The thing is that I'll turn up the PM to the point where I can hear it, but it's buried under sound from the rest of my bands mates. I've tried to tell the drummer to play drums softer, he says he will, than once we get into a tasty groove he's WHAILING! Believe me I've tried and tried to get him to be a little gentler, but it's not happening. So I really just need to get some more volume for my vocals. (Specific suggestions of would be appreciated). And what was meant by "As I said you're not going to need much or any (depends on shelving) of your 60hz frequency. Reducing that frequency could let you squeeze a few more drops of available power and MIGHT allow you to increase your volume - that's assuming you're not on the verge of feedback, and so on." Oh and by the way. The speaker is the corner of a squarish room and the mics headdoesn't face directly towards or away from the speaker. thanks as always Link to comment Share on other sites More sharing options...
Members heath_eld Posted February 13, 2011 Members Share Posted February 13, 2011 If you roll off the lower frequencies on the graphic eq or channel eq, it should allow more amplifier power to be directed to the frequencies you need for your voice. Wont make a huge diff but definitely try it. So is it feeding back? or clipping the amps? Thats what we need to know. Link to comment Share on other sites More sharing options...
Members GCDEF Posted February 13, 2011 Members Share Posted February 13, 2011 In a small space, turning things down works a whole lot better than turning them up. That said, you'd probably hear yourself better with a floor monitor in front of you than with a big cabinet in the corner. If that mixer isn't getting you through a rehearsal, you're doing something pretty wrong. Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted February 13, 2011 CMS Author Share Posted February 13, 2011 The thing is that I'll turn up the PM to the point where I can hear it, but it's buried under sound from the rest of my bands mates. I've tried to tell the drummer to play drums softer, he says he will, than once we get into a tasty groove he's WHAILING! Believe me I've tried and tried to get him to be a little gentler, but it's not happening. Age-old problem. This has to be solved. Practice/rehearsal is to work out bugs in the songs, not display ego. If the drummer can't understand or abide this, eventually you may grow tired of the relationship. Your hearing WILL be damaged. And the band will suffer either way. What you have now should be more than adequate for practice. Link to comment Share on other sites More sharing options...
Members trynmybest Posted February 16, 2011 Author Members Share Posted February 16, 2011 I'm just getting feedback on the pa when I turn up to volumes that match the volumes of the other instruments. Link to comment Share on other sites More sharing options...
Members GCDEF Posted February 16, 2011 Members Share Posted February 16, 2011 I'm just getting feedback on the pa when I turn up to volumes that match the volumes of the other instruments. You can only get so much volume out of a small room. Again, you may have better luck with a wedge on the floor, but turning down is a much better solution than turning up. I wouldn't be very impressed with bandmates that feel compelled to drown out the vocals in rehearsal. Link to comment Share on other sites More sharing options...
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