Need advice for an amp for this setup...

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So I've got my hands on 4 of these:

Rockville RSG15.28 Dual 15” 3000 Watt 3-Way 8-Ohm Passive DJ/Pro PA Speaker - Rockville Audio

That would seem to be a straightforward statement, but there were a couple twists and turns in there - anyway, this all starts with me having 4 of those units (brand-new).

What I need to do is have a setup for events, where there will be an announcer doing his thing as the event goes on, with music also playing (generally from a laptop). I've had a PA system for this use before and it all worked well...until someone offered me a certain amount of money to buy it all from me after I loaned it to them, and I couldn't say no ;) So I'm not exactly an audio professional, but for the most part I have a basic understanding of what's going on. But I may have a noob moment here or there.

So the plan is to have those 4 8-ohm speakers, daisy-chained 2 per channel so there's 4 ohms on each channel. The amp (with or without a receiver - nice to have perhaps, but not required) will need to push a single output signal to 2 channels - including input from the mic and from the computer audio. Those speakers have 1 speakon connector and 2 1/4" connectors each - I've got speakon and speakon-1/4" cables to facilitate said chaining and connecting. It would be nice if the amp natively had speakon and/or 1/4" outputs, although naturally I can just convert to banana or whatever.

Amp needs to be big enough to drive those speakers correctly...but naturally money isn't exactly unlimited. When I first got those speakers, I bought a Gemini XGA-5000 amp to use with them, which appeared to be a significant step up from the Pyle amp/reciever I had with my previous system...firstly, the amp was terribly defective - whole channels would fade in and out, so it got returned. But during this process I discovered that that amp really wasn't what I needed - and I think this is true typically of a standard power amp - it had 2 channels in, and 2 channels out - each output tied just to it's input. That's not what I need - I need a couple inputs for mic and the laptop as noted, and then everything that's coming in needs to go out to all speakers. The Gemini unit did have a bridge mode - but it looked like then everything went out on one output, so I have no idea how I'd hook up 4 8-ohm speakers to one output channel without dropping the load to 2 ohms and probably blowing everything up anyway.

So...sorry for the long blurb. Basically can someone point me to an appropriate amp for such uses as noted above, for not a huge amount of money? The Gemini amp was $200 - although I can afford more than that if necessary. Thanks in advance!
 
Power amps are just that, power amps. What you need is a mixer and a power amp. You can get those combined into a "powered mixer". Every PA gear company makes them. Of course you can also get them separately. A power amp of the size you want then a small mixer, sounds like you don;t need a large one.

For example, here is a basic mixer with two mic inputs and several stereo line level inputs, $70:
Behringer Xenyx 1002 Mixer | Sweetwater

The 3000 watt rating is wishful thinking.

MAy I recommend looking at real PA gear rather than "DJ" gear. Stuff aimed at the DJ market tends to be low end stuff.
 
Power amps are just that, power amps. What you need is a mixer and a power amp. You can get those combined into a "powered mixer". Every PA gear company makes them. Of course you can also get them separately. A power amp of the size you want then a small mixer, sounds like you don;t need a large one.

For example, here is a basic mixer with two mic inputs and several stereo line level inputs, $70:
Behringer Xenyx 1002 Mixer | Sweetwater

The 3000 watt rating is wishful thinking.

MAy I recommend looking at real PA gear rather than "DJ" gear. Stuff aimed at the DJ market tends to be low end stuff.

Hey thanks for that...that appears to be exactly the kind of direction I need to be given. So granted that you get a mixer like that, and you still need an amp, do you have a suggestion for an amp to go with all that? And yes, the "3000 watts" is rather optimistic. You've already been quite helpful Enzo!

As for all this stuff being junk...I acknowledge that it's not "real" gear that a professional would use. I'm not a professional. I need something to use a couple times a year, and that otherwise is going to sit around unused. And to the point of having junk - the stuff I had before was all Polk audio stuff - a name that I think used to mean something, but lately has all turned to "junk" as far as I can tell. All parts of my last system were cheesy Polk junk - and it worked so well that someone offered to pay me more for it than it cost me to buy it originally. So if Rockville speakers strike professionals and audiophiles as "junk," I'm just simply not going to lose any sleep over it. With a few more hundred dollars I'm certain I'll have a system here that will blow everyone away for the needs we have for it.
 
As for all this stuff being junk...I acknowledge that it's not "real" gear that a professional would use. I'm not a professional. I need something to use a couple times a year, and that otherwise is going to sit around unused.

Look bud I'm not trying to be a snob here I'm trying to prevent you from literally throwing away $600 on speakers that are guaranteed to fail on you, matter of fact you will be lucky if 1/2 of them aren't DOA. I'm not so sure that Gemini amp was your problem with the sound fading in and out, I have a hard time believing these boxes are 8ohms.. dual 15's are usually 4 ohm so 2 of those per channel would be 2ohms and that is a lower impedance than the Gemini can handle. There is an easy test for this if you have a multimeter. Another possibility is that some of the components inside these speakers are already starting to fail causing a short that was loading down the amp and forcing it to protect itself. Without a doubt there are levels of quality with pro audio equipment from entry level up to touring grade but I'm sure you would agree the minimum requirement is simply that the gear performs it's job without failure for as long as you want to use it. Your old Polk speakers did that but I'm afraid these speakers will let you down badly especially if you put an amp with any kind of respectable power output behind them.

If you want inexpensive gear that will do the job buy Behringer, their speakers and amplifiers don't often get high ratings but for the most part you can rest assured something won't die on you for no reason, yes if it is abused you may have trouble but that is one of the things you pay more for with better quality brand names.

Now the other red flag I see here is your selection of dual 15 boxes, I'm sure you are thinking you can get good live vocal projection and relatively full range music reproduction in 1 box, well you can but you have to spend a lot more money. But that's not even the point I'm trying to make, the point is that this format is all wrong for what you want to do, the box is too big to put up on stands so that the mid/high drivers are over peoples heads and can project as far as possible. The right way to do this is with a system where these components are separate from the low frequency drivers, I guess the exception to that would be if you know the only place this system will be used is on a stage where they will be elevated relative to the listeners anyway but that is a pretty narrow scope of use.

So my suggestion would be to instead buy two to four 10"+1" or 12"+1" PA speakers and stands from somebody like Behringer, and buy powered speakers if that format will work better for you. Don't under estimate the advantages this format provides.. you get a lot more than just a speaker with an amplifier built in these days even with boxes like the Behringer B112d. These speakers will not give you a lot of lowend bass but they will do a decent job with live vocals and will reproduce 90% of the music spectrum so people won't have any trouble recognizing a song, and if you want more lowend then add a dedicated subwoofer or two at a later date.
 
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We all start somewhere, Woot. Consider this, if it is something you think you will only use a couple times a year, consider just renting a system for the gig. Music stores and audio production companies usually rent PA systems, and you will get real gear.
 
If you already have them ... you already have them.

If they state 8 ohms ech then I guess they are 8 ohms each after all.

Since your reference budget is $200 , might go "a little" higher which means about the same, you are very limited.

Personally and to simplify things, not to mention saving money, instead of a new mixer + power amp, although that´s the "right· solution, you simply don´t have enough money, so Plan B is try to get a powered mixer, an old but strong Peavey vocal mixer , what used to be a small band only PA system, which will provide you with a few microphone channels for your announcer + some auxiliary inputs for your laptop plus 200 or 300W RMS (the real kind) per channel into 4 ohms, each channel can drive 2 speakers.

Used ones can often be had for peanuts locally, even at GC or similar.

Just check that *everything* works, "waste" 2 hours testing *all* mic inputs, all volume/pan/EQ knobs, all outputs, etc.

"They" won´t like it buy those units are hard to sell, so they will have to stand you.

Make certain everything works before paying because any repair will surpass (used) unit cost.

Store warranty means nothing on old discontinued stuff because they can´t get parts any more, so it either was built as a tank (Peavey), still works and will presumably keep doing so, or forget it and look for something else.
So go do your homework :)
 
Might want to double check the speaker impedance - presuming you already have them. They might state 8 ohms but actually be 4 to make it sound louder. The speakers that are in there literally cost $15 each for the 15's, and won't even approach 90dB/W sensitivity. They almost have to run two parallel 8 ohm woofers to get any useable sensitivity. Check the impedance at the terminals with an ohm meter and see what it really is. If they measure about 6 ohms you're in luck, if it comes out like 3 ohms your amp requirement just got a lot more difficult.

Similar speakers being sold here locally under the brand name " Q Power" have two 8 ohm 15's in them. They sell like hot cakes precisely because you can buy the exact replacement woofer for about $15. fs about 35, VAS about 10 cubic feet, Qts about 1.3. That's what you get in a $150 speaker.

Oh yeah, and X-max about 2mm.
 
Behringer NU3000DSP and a notepad mixer.

The NU3000 will drive down to 2ohm just fine, so even if the cabs are 4ohm, it'll be fine. It's an honest 300w/ch@8ohm, 600w/ch@4ohm, and around 1000w/ch@2ohm. That's enough to run these.

As to the sound of those boxes, the others have covered it.

Chris
 
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