Hello most honorable diyAudio members!
We (see at the bottom if interested) are starting to outgrow our PA system. So, I'm hoping that somebody will be kind enough to offer some advice on what subs we could possibly get for our quite antique PA system, which is made up of:
So, my questions regarding adding subs to this systems are as follows:
About the band: We are a glamorous rock coverband called PLeaSureDomE and are based in Berlin. Check out or Youtube clip (link) or our Facebook page (link) if you like Bowie, the Jam, Sweet and The Rocky Horror Show shiee .
Thank you goodnight we love you!
We (see at the bottom if interested) are starting to outgrow our PA system. So, I'm hoping that somebody will be kind enough to offer some advice on what subs we could possibly get for our quite antique PA system, which is made up of:
- Wharfedale Pro BX1060SD – mixer/amp (link to instructions manual) (Maximum output power: BX1060/1360SD: 300W/4Ω 200W/8Ω @0.4% THD at 1KHz"),
- HK Audio Classic Compact 122 (link to pics) – a pair of passive tops (or monitors), (150 Watts RMS, 8 Ohms)
- Skytek 170.730 (link to pic) – a pair of passive monitors (or tops), (Power: 200 Watts Max, Impedance: 8 Ohm, Weight: 10 Kg)
So, my questions regarding adding subs to this systems are as follows:
- Active or Passive subs? My gut feeling is running subs and two pairs of tops would be too much for the amp/mixer to handle, but I don't know how these things work.
- If active subs: How connect? There are only two "main out" and two "monitor out" on the amp/mixer, so I presume I'd have to connect the subs to the "main out" and then continue from the subs to the tops. But then theres a powered signal coming into an active sub, does that work?
- If passive subs: How connect? Can the power like explained above, go into the subs and then continue to the tops?
- What other advice can you give that might be useful? As I said, I don't have a clue how stuff like this works, so I'm grateful for any advice!
About the band: We are a glamorous rock coverband called PLeaSureDomE and are based in Berlin. Check out or Youtube clip (link) or our Facebook page (link) if you like Bowie, the Jam, Sweet and The Rocky Horror Show shiee .
Thank you goodnight we love you!
What's your budget?
For your setup, I'd probably go for active subs. The mixer-amp is going to be running hard enough as it is, especially if you're trying to keep up with a drum kit.
Chances are there's a main output at line level for use with an external amplifier, so send that to the subwoofer. If possible, get a high-pass filter on the main speakers, too. This will clean up the midrange considerably.
Chris
For your setup, I'd probably go for active subs. The mixer-amp is going to be running hard enough as it is, especially if you're trying to keep up with a drum kit.
Chances are there's a main output at line level for use with an external amplifier, so send that to the subwoofer. If possible, get a high-pass filter on the main speakers, too. This will clean up the midrange considerably.
Chris
Thanks for your kind answer Chris! (follow-up questions)
Thanks a lot Chris! Our budget is just as low as possible, the PA is old and I think we should get a whole new one later on. I think I found an output that goes straight out of the mixer, before the amp like you said. It's on page 5 of the operating manual (link to pdf) and described as:
"32. MAIN/MONITOR Out: Can be used to drive an external power amplifier or sound system from the internal mixer bus, just after the MAIN MASTER control and MAIN EQUALIZER, allowing more speakers to be connected."
Do you agree this should be the one? Regarding the high-pass filter, could you recommend one? On page 11 of the above-linked pdf it says "Never plug amplifier outputs into anything except speakers.", could we still use a high-pass filter?
Do we need a "lo-pass" filter or something for the active subwoofers, or is that generally built into them?
Another related question: I have a feeling that one 18" subwoofer could possibly do the job better than two smaller ones, would you consider this an option? (If two, they would be about 3–6 meters apart in general.)
Again, thank you very much for taking your time to help us out!
Thanks a lot Chris! Our budget is just as low as possible, the PA is old and I think we should get a whole new one later on. I think I found an output that goes straight out of the mixer, before the amp like you said. It's on page 5 of the operating manual (link to pdf) and described as:
"32. MAIN/MONITOR Out: Can be used to drive an external power amplifier or sound system from the internal mixer bus, just after the MAIN MASTER control and MAIN EQUALIZER, allowing more speakers to be connected."
Do you agree this should be the one? Regarding the high-pass filter, could you recommend one? On page 11 of the above-linked pdf it says "Never plug amplifier outputs into anything except speakers.", could we still use a high-pass filter?
Do we need a "lo-pass" filter or something for the active subwoofers, or is that generally built into them?
Another related question: I have a feeling that one 18" subwoofer could possibly do the job better than two smaller ones, would you consider this an option? (If two, they would be about 3–6 meters apart in general.)
Again, thank you very much for taking your time to help us out!
Unfortunately, the manual won't load past page 5, but I can take a guess at what's available.
The "Main/Monitor Out" is the one you want, yes. If you connect an active subwoofer to that, the mixer will be passing line-level signals out, perfect for an active sub. Active subs will only play the frequencies they're supposed to, they have their own crossovers built in.
If you wanted to add a highpass filter to the main speakers, things get more complicated. I'd say its worth doing. You'll stop the midrange drivers from flapping around trying to do bass, meaning less distortion.
So, you'll need to make sure the mixer-amp has a "power amp in" socket, possibly on the back. This disconnects the mixer from the built-in amplifier, allowing you to use the built-in amp for other things.
For this setup, you'd do this:
Main/Monitor out ----> active crossover (highpass)------> mixer amp in ------> speakers
....................................................... (lowpass)-------> active subwoofer
Since the active crossover (see Behringer CX2310 for an idea of what I'm talking about) will have a low-pass and high-pass output, you can use this to set the crossover points for the subwoofer and main speakers equal, probably around 100Hz.
A stereo crossover (like the Behringer) would mean that you can also do the same for the monitor speakers. Its common practice to stop the monitors from doing much bass since the extra low-frequency energy isn't always welcome on stage.
You'd run Monitor out ---> other channel of active crossover (highpass) ----> mixer amp in #2.
HTH
Chris
The "Main/Monitor Out" is the one you want, yes. If you connect an active subwoofer to that, the mixer will be passing line-level signals out, perfect for an active sub. Active subs will only play the frequencies they're supposed to, they have their own crossovers built in.
If you wanted to add a highpass filter to the main speakers, things get more complicated. I'd say its worth doing. You'll stop the midrange drivers from flapping around trying to do bass, meaning less distortion.
So, you'll need to make sure the mixer-amp has a "power amp in" socket, possibly on the back. This disconnects the mixer from the built-in amplifier, allowing you to use the built-in amp for other things.
For this setup, you'd do this:
Main/Monitor out ----> active crossover (highpass)------> mixer amp in ------> speakers
....................................................... (lowpass)-------> active subwoofer
Since the active crossover (see Behringer CX2310 for an idea of what I'm talking about) will have a low-pass and high-pass output, you can use this to set the crossover points for the subwoofer and main speakers equal, probably around 100Hz.
A stereo crossover (like the Behringer) would mean that you can also do the same for the monitor speakers. Its common practice to stop the monitors from doing much bass since the extra low-frequency energy isn't always welcome on stage.
You'd run Monitor out ---> other channel of active crossover (highpass) ----> mixer amp in #2.
HTH
Chris
Active subs usually have filters built in. A very simple high pass filter is to use power amplifier output controls if your mixer has them. There should be "bass/mid/treble" or "high/mid/low" Turn the "bass" or "low" all the way down. Just make sure that it only applies to the mixers amplifier output and not the line level output to the subs, otherwise it also kills bass going to your subs. Also check if the mixer's amp output has a "low-cut" or "subsonic filter" function. That helps also. Sub filter usually cuts off everything below 20-30Hz or so. "Bass" or "low" usually cuts everything between 20-100Hz or somewhere in that ballpark.
If your budget allows, you can get an active crossover to precisely set where the cut point between subs and tops is.
If you want to upgrade your whole PA, I'd recommend going all active. Get a new mixing console, on without an amp. I'd recommend Behringer. It's cheap, sure, but not exactly a bad brand and definitely better than any generic mixer. Then run the mixer's output through XLR to your tops. Get something with a built in EQ/filter/crossover. Also make sure your tops have a "link out" option. Then run the link out to the subs, ehre you can set their cuts.
One pair of decent tops is much better than a mixed pile of random speakers. I used to have HQ Power speakers, very similar to your Skytecs and a pair of old disco speakers or whatever. Now I got a pair of Phonic PA450 actives and ditched the pile of junk along with the ancient rack amplifier I had them hooked up to. Huge improvement.
A pair of active speakers is also very convenient if you're doing a smaller gig. Then you only need to take two speakers and a smaller console.
You could also use poles to mount your tops straight onto the subs and run them in stereo, one sub and one top on each side of the stage.
Many actives, like my PA450, and the famous Mackie SRM450 also double as stage monitors, so you can get two pairs and use one pair as monitors.
A decent pair of active speakers usually costs less than a pair of speakers and an external amplifier and cables.
If your budget allows, you can get an active crossover to precisely set where the cut point between subs and tops is.
If you want to upgrade your whole PA, I'd recommend going all active. Get a new mixing console, on without an amp. I'd recommend Behringer. It's cheap, sure, but not exactly a bad brand and definitely better than any generic mixer. Then run the mixer's output through XLR to your tops. Get something with a built in EQ/filter/crossover. Also make sure your tops have a "link out" option. Then run the link out to the subs, ehre you can set their cuts.
One pair of decent tops is much better than a mixed pile of random speakers. I used to have HQ Power speakers, very similar to your Skytecs and a pair of old disco speakers or whatever. Now I got a pair of Phonic PA450 actives and ditched the pile of junk along with the ancient rack amplifier I had them hooked up to. Huge improvement.
A pair of active speakers is also very convenient if you're doing a smaller gig. Then you only need to take two speakers and a smaller console.
You could also use poles to mount your tops straight onto the subs and run them in stereo, one sub and one top on each side of the stage.
Many actives, like my PA450, and the famous Mackie SRM450 also double as stage monitors, so you can get two pairs and use one pair as monitors.
A decent pair of active speakers usually costs less than a pair of speakers and an external amplifier and cables.
I'm going for the separate amp, too, be it built into the sub or separate. Reasons:-
1) A passive crossover at ultra low frequencies is big, inconvenient and probably as expensive as an active
2) You can adjust the levels of speakers at line level, practically impossible at speaker level.
3) You are adding to the power level, not redistributing it
4) Reduces the intermodulation distortion on the main outputs, improving clarity.
5) If there are 'power limiters' on the main amps it seriously reduces 'pumping' on them.
6) You can mix the outputs to mono without losing the stereo on the highs
7) Low frequency amps are a lot less critical about
Whatever you do you're going to need a high pass filter inserted between the desk outputs and the power amp inputs. Have you considered building the filters yourself? Even with transistors it's not difficult for a fixed frequency, and with op amps it's a doddle. The most complicated thing is building a box that fits behind the console and looks OK. And you can customise it to exactly what you need, even a couple of equaliser circuits or peak limiters, though those are harder to build.
1) A passive crossover at ultra low frequencies is big, inconvenient and probably as expensive as an active
2) You can adjust the levels of speakers at line level, practically impossible at speaker level.
3) You are adding to the power level, not redistributing it
4) Reduces the intermodulation distortion on the main outputs, improving clarity.
5) If there are 'power limiters' on the main amps it seriously reduces 'pumping' on them.
6) You can mix the outputs to mono without losing the stereo on the highs
7) Low frequency amps are a lot less critical about
Whatever you do you're going to need a high pass filter inserted between the desk outputs and the power amp inputs. Have you considered building the filters yourself? Even with transistors it's not difficult for a fixed frequency, and with op amps it's a doddle. The most complicated thing is building a box that fits behind the console and looks OK. And you can customise it to exactly what you need, even a couple of equaliser circuits or peak limiters, though those are harder to build.
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