powering pa subwoofers

[g1]

One thing you didn't mention is budget. That would help.
I doubt you will find an amp that is min. 8 ohm per side. The lowest I have seen is min. 4 ohm per side.
I think the most common configuration that you will find for your purpose would be 500W RMS per side at 2 ohms, and run it bridged into your 4 ohm load.

[bwheat]

One thing you didn't mention is budget. That would help.
I doubt you will find an amp that is min. 8 ohm per side. The lowest I have seen is min. 4 ohm per side.
I think the most common configuration that you will find for your purpose would be 500W RMS per side at 2 ohms, and run it bridged into your 4 ohm load.

My budget is buying something used that will work for the application. The 2 ohm stable bridged to 4 ohms was another option i had found searching a little bit ago, as well as the class h power amps which produce the same power at 4 or 8 ohms, those are rather expensive though. My system isn't super high end, so buying a 600 dollar amp is not an option. The 2 ohm stable or, 2 smaller amp's bridged seem like probably what i will end up with. I am on a budget, so a lot of my stuff is used stuff that i happen to come across other than my mixer and rack case. So based on what i have bought and some of the prices on used stuff on guitarcenter, and other places probably 100-200 is where i would be at for a used one. Remember, i am a guy getting back into this after not gigging for 10 yrs, so i just need something to add some low end to my setup that i have, not a super high end setup. I can always upgrade down the road if you know what i mean. I am not looking to buy like berhinger or anything cheap like that, i'd love another alto if they were 2 ohm stable as those put out good clean power. Gc has a lot of used brand name's that aren't trash for real good prices, but have no specs on any of it, so that is why i made the post hoping someone had come across something like this in the past, or had something currently like that and could tell me the model number and i could wait until one popped up, instead of going thru all the stuff on their site and emailing different stores to get me specs on what they have.

[tedmich]

Most every modern amp will run at 4 ohms bridged, if I were you I'd think about getting something like the Behringer NX1000D, which will put out 1000W rms at 4 ohms in bridged mode into the two subs in parallel. I'd use the DSP to set a very steep low frequency highpass filter (24-48db/ocatve). Most PA "subs" are really just 18" woofers that can't do much below 40-50Hz. This is plenty for thump but expect to get a 1000w 20Hz Dubstep God fart only one time before Leo's silence... So set a brick wall filter at around 50Hz and then step it down slowly and see if it can be musical/sound good any lower. Once you set the low end high pass you can select the high end low pass so they blend best with your other mains speakers. This amp then has plenty of DSP if you'd like to fine tune group delay etc.

I'm assuming you do want these to simply add as much transparent bottom end to your mains as possible right? You don't want the god fart right?

[bwheat]

Most every modern amp will run at 4 ohms bridged, if I were you I'd think about getting something like the Behringer NX1000D, which will put out 1000W rms at 4 ohms in bridged mode into the two subs in parallel. I'd use the DSP to set a very steep low frequency highpass filter (24-48db/ocatve). Most PA "subs" are really just 18" woofers that can't do much below 40-50Hz. This is plenty for thump but expect to get a 1000w 20Hz Dubstep God fart only one time before Leo's silence... So set a brick wall filter at around 50Hz and then step it down slowly and see if it can be musical/sound good any lower. Once you set the low end high pass you can select the high end low pass so they blend best with your other mains speakers. This amp then has plenty of DSP if you'd like to fine tune group delay etc.

I'm assuming you do want these to simply add as much transparent bottom end to your mains as possible right? You don't want the god fart right?

Yes, just adding a little punch to the low end of the system that isn't overwhelming. Being that i only have 2 way mains they really don't have the balls of the 3 way carvin i had yrs ago. They are loud and produce real good mid bass but just don't really have that deep feel it in your chest type of low that even a good 3 way speaker with a built in crossover. I'd really prefer a more basic amp, and use an actual crossover so i can limit the signal to the mains as well, as my main power amp doesn't have anything but a low pass filter, but doesn't give the ability to set a cut off point to the mains. I want to be able to cut the signal to the mains that cause any muddiness and send those to the sub, and then limit the sub a to a little higher than where the mains muddy up have a little overlap in signal going to both. I honestly should of just bought some 3 way mains from the get go, bit i kind of figured a 2 way main with 15's would be a little punchier than what it is. It works amazing as a loud speaker, and is very clear and loud, just missing that bottom end. These 18's are supposidly good down to 20hz, but i am not sure how accurate that is. My mains claim they will go down to like 67hz, but that for sure doesn't happen. Is berringer actually any good these days? I know a lot of that stuff used to be pretty mediocre back in the day, but things do change sometimes. I am always kind of weary buying cheaper electronics, i will take a chance on a cheaper speaker as they can be upgraded if the cab is built well, but just was always turned off that stuff after having a Bugera. If it is not bad nowadays i might look into some of those though.

[glebert]

Watts are cheap these days, I would just get an amp that has the power rating you want at 8 ohm. Ignore the 4 ohm rating, this won't apply to you, and you will be running the amp at far less than its maximum, which is good for reliability.

[nevetslab]

I have one power amp, and that is powering the mains, the whole reason for my post is that i was looking for an amp that provides max power at 8 ohms vs 4

Bridged Mono with both of your subs in parallel will be the most efficient means with older as well as new technology Power Amps. What's available in the new generation amps with DSP signal processing and current regulation, you should be able to find one suitable to the task. QSC & Crown have such products. I haven't looked at the budget-oriented Behringer products mentioned elsewhere, but I'd tend to stay with a more service-oriented company like QSC or Crown.

[bwheat]

Bridged Mono with both of your subs in parallel will be the most efficient means with older as well as new technology Power Amps. What's available in the new generation amps with DSP signal processing and current regulation, you should be able to find one suitable to the task. QSC & Crown have such products. I haven't looked at the budget-oriented Behringer products mentioned elsewhere, but I'd tend to stay with a more service-oriented company like QSC or Crown.

Thank you, i appreciate it. I am looking at a few used Crown models right now that are able to be bridged at 4 ohms.

[bwheat]

It's funny that 2 people finally mention that after the few who didn't even know that option. I spoke with a rep from Crown earlier to verify , and they said the usual way to power subs is to run at 4 ohms bridged with subs in parallel. , so the correct answer is to buy an amp that is 2 ohm stable that can be bridged to 4 ohms. It is built to be ran like that so it isn't going to hurt it. I thank the few who actually knew what they were talking about. The people with the thoughtless answers that were not helpfull in anyway. You might want to think about doing a little more research into things before throwing in your 2 cents. That would be much more helpful to people. Just think if i were some young kid who knew nothing about nothing, and i have guys in here telling me to buy more speakers before i have even tried these out, guys telling me to buy an amp double the size i need, not realizing the price difference between the 2. Incorrect info is much worse than no replay at all. Not that anything i am saying will matter as people have ego's and hate to have those challenged, but honestly this forum would be a better place without all the "well i don't really know, but i am just gonna give you some random advise anyway" type of stuff.

[g1]

In defense of some folks here who are very knowledgeable with regard to PA systems, it was difficult to discern what you were really looking for in your original post. I didn't have a clue until post #16.
We get all kinds of questions here, and sometimes we have to ask a lot of questions to get to the meat of the matter.
No need to burn any bridges in case you should need further assistance in the future.

[bwheat]

In defense of some folks here who are very knowledgeable with regard to PA systems, it was difficult to discern what you were really looking for in your original post. I didn't have a clue until post #16.
We get all kinds of questions here, and sometimes we have to ask a lot of questions to get to the meat of the matter.
No need to burn any bridges in case you should need further assistance in the future.

"Now my question is, are there any power amps out there that aren't really high end that run at 8 ohms in stereo, and 16 bridged, or that will run 4 ohms bridged. " That was pretty clear what i was looking for. From post number 1. I don't think you understand, this is pretty standard behavior from people on forums nowadays. There used to be this thing called if you don't have an answer than don't say anything. But today's forums are all usually full of people who want to give their opinion, but aren't don't actually answer anything, just a bunch of rambling, and people repeating the same thing after you have told them that isn't your question. If i ruffle some feathers calling those people out than so be it. I am not going to lose any sleep tonight. I do greatly appreciate anyone who offers helpful information, but just coming in and giving information that doesn't pertain to the subject is not helpfull in any way. It also makes the search function on your site useless if people have to read thru pages of rambling to actually find what they are looking for. By the way don't just assume people with a low post count are people new to this stuff. Just because someone hasn't been on this forum for yrs doesn't mean that they havn't been messing with the stuff for many yrs. There is that attitude here, you can't disagree with that. The moral of the story, if you don't know, than don't open the mouth, very simple. And if anyone is angry that i said that than you are probably one of the ones i am talking about, i would prefer those people not answer any question i have, they will probably just ignore the original question any way and give me exactly what i am not looking for just like half the other threads i have started on here. There have been a few very helpful people, and more than a few who type just to type.

[glebert]

I think you should go buy the cheapest amp that says it can do 2 ohms at just barely the total power you want to run the subs,that way you won't be paying for any extra watts. Then when it fails you can post again in the repair section how we aren't listening that you really don't want to spend a lot to fix this amp.

[bwheat]

I think you should go buy the cheapest amp that says it can do 2 ohms at just barely the total power you want to run the subs,that way you won't be paying for any extra watts. Then when it fails you can post again in the repair section how we aren't listening that you really don't want to spend a lot to fix this amp.

I didn't say anything about buying cheap brands, only buying used. Are you dense? Why would i trust anyone here that can't even try to answer the question over a rep from Crown amplifiers? It was actually you guys that suggested the cheap amp. I will pay 100 bucks for a used crown amp, and if it blows i will buy another one, it's pretty simple really. As i said, 90 percent just want to run their mouth's and offer no usefull information. You got one guy over here saying oh don't go too high wattage, one guy over here saying oh you want more wattage, one guy saying to just buy more speakers, than one guy who actually gets it who is like hey there are 2 ohm stable amps out there. Do you know what that means, it means that it isn't going to die from running it at 2 ohms. Than half of you are disagreeing with the helpful information that is in line with the manufacturer of the amps i am looking at also says. By the way, being on a budget doesn't always mean buying cheap gear. You can get some good deals on nice used equipment, or are you too snobby to want to use that. And you know what, i actually won't post anything else at all in this forum, as i have much better luck just using google.

[nevetslab]

Thank you, i appreciate it. I am looking at a few used Crown models right now that are able to be bridged at 4 ohms.

Right......since in Bridged 4 ohm mono, each channels is driving a 2 ohm load. There are plenty of amps out there that will do this. Not sure what you'll find on the used market with DSP processing built in.....as that will save you having to come up with a stand-alone Subwoofer crossover. Crown's XTi-2 series have that capability as do their XLR-2 series. Or QSC's GXD series. I haven't stayed abreast with the later releases in the DSP-implimented amps.

[bwheat]

Right......since in Bridged 4 ohm mono, each channels is driving a 2 ohm load. There are plenty of amps out there that will do this. Not sure what you'll find on the used market with DSP processing built in.....as that will save you having to come up with a stand-alone Subwoofer crossover. Crown's XTi-2 series have that capability as do their XLR-2 series. Or QSC's GXD series. I haven't stayed abreast with the later releases in the DSP-implimented amps.

Not having the dsp is no problem for me, i am getting an eq with a built in crossover, so adjusting cutoff frequencies is no issue. I am looking at a used crown ce1000 right now, which makes 1200w bridged at 4 ohms. It is under the program rating on the speakers, but above the rms, as are my mains, so something like that should keep up alright. https://c1.zzounds.com/media/product...e63f48e4d0.jpg

[nevetslab]

Not having the dsp is no problem for me, i am getting an eq with a built in crossover, so adjusting cutoff frequencies is no issue. I am looking at a used crown ce1000 right now, which makes 1200w bridged at 4 ohms. It is under the program rating on the speakers, but above the rms, as are my mains, so something like that should keep up alright. https://c1.zzounds.com/media/product...e63f48e4d0.jpg

Is there a HP Filter (subsonic filter) with that built-in crossover? 30Hz HPF is pretty typical of what you'd want to prevent over-excursion below box tuning, 12dB/Oct or greater.