Hi, I am new to this community. Recently the following P.A. system was purchased for my Church: (These are all Indian made, except the mixer, so kindly refer the link for specification).
1. AHUJA DXA-1802 (1800 Watts) (1 amp) Ahuja Sound Solutions
2. AHUJA SPX-400 (350 Watts) (two speakers) Ahuja Sound Solutions
3. AHUJA SWX-650 (600 Watts) (1 sub) Ahuja Sound Solutions
4. BEHRINGER X2222 Behringer: XENYX X2222USB
The stereo output of the mixer is fed straight into the amp. The amp is dual channel, so one channel runs two speakers and the other channel runs the sub.
My first question - Is it right to hook up this way or is there any other way round?
Second question - I want to add a passive crossover in between for my sub to roll off the high frequencies. Would this crossover work? Ahuja Sound Solutions
OR
should i go for an active crossover?
Waiting for a decent answer! 🙂
1. AHUJA DXA-1802 (1800 Watts) (1 amp) Ahuja Sound Solutions
2. AHUJA SPX-400 (350 Watts) (two speakers) Ahuja Sound Solutions
3. AHUJA SWX-650 (600 Watts) (1 sub) Ahuja Sound Solutions
4. BEHRINGER X2222 Behringer: XENYX X2222USB
The stereo output of the mixer is fed straight into the amp. The amp is dual channel, so one channel runs two speakers and the other channel runs the sub.
My first question - Is it right to hook up this way or is there any other way round?
Second question - I want to add a passive crossover in between for my sub to roll off the high frequencies. Would this crossover work? Ahuja Sound Solutions
OR
should i go for an active crossover?
Waiting for a decent answer! 🙂
First of all you will not be operating in stereo.
By having the 2 x SPX-400 on one channel, they will both be outputting the same half of the stereo image.
The sub will be trying to output the other half of the stereo image.
You really need three amplifiers. (Or 2 stereo amplifiers)
1 for LEFT hand SPX-400
1 for RIGHT hand SPX-400
1 for SWX-650
The sub is usually fed from a mono feed with the LF crossover before the amplifier.
By having the 2 x SPX-400 on one channel, they will both be outputting the same half of the stereo image.
The sub will be trying to output the other half of the stereo image.
You really need three amplifiers. (Or 2 stereo amplifiers)
1 for LEFT hand SPX-400
1 for RIGHT hand SPX-400
1 for SWX-650
The sub is usually fed from a mono feed with the LF crossover before the amplifier.
Last edited:
From your post it looks as though you are not trying to do this DIY fashion ?
You would probably be better with an active sub which would have its own crossover built into it.
You would probably be better with an active sub which would have its own crossover built into it.
Hi,
Its easy enough with a typical mixer to mix stereo
in to mono out on the left and right channels.
You can then EQ each channel to suit its purpose,
a from of crude active crossovers that will work.
With an extra amplifier you could remain in stereo
and use the monitor mix output for the subwoofer.
rgds, sreten.
Its easy enough with a typical mixer to mix stereo
in to mono out on the left and right channels.
You can then EQ each channel to suit its purpose,
a from of crude active crossovers that will work.
With an extra amplifier you could remain in stereo
and use the monitor mix output for the subwoofer.
rgds, sreten.
I know that the output isn't stereo. My question is not about stereo output.
I just wanted to know about the passive crossover (link given). Would it work with the sub?
yes it would work but at 250 hz at loud volumes your sub might wind up boxier sounding than you'd like!
the question of stereo is valid because it kind of determines allocation of equipment resources.
the question of stereo is valid because it kind of determines allocation of equipment resources.
Hi,
It would work but is not needed. It would would be needed
for running a sub and speaker off the same amp channel.
rgds, sreten.
It would work but is not needed. It would would be needed
for running a sub and speaker off the same amp channel.
rgds, sreten.
well there's no other x-over in the equipment list and running the subwoofer full range ain't gonna be pretty.
A fixed frequency active crossover is not difficult to build, cheap, and will increase your loudness considerably. For the time being you are feeding into each of the speakers frequencies they can't use, and are merely heating their voice coils. Before audio quality op-amps were available I built them round emitter followers, complementary times one amps, darlington pairs and once cathode followers on a double triode (I had the voltage available, so…). Just Googling 'active crossovers' will give a selection of workable circuits.
Variable (or sweep) frequency is a touch more complex.
If you put the passive crossover onto one half of the amp, without loading the HF section, the amplifier is seeing a very odd impedance on its output. I'm not stating it will go unstable, mind, but you're not being nice to it at all, and it never does any harm to give your devices – any of them, not just power amps – the best conditions you can manage.
Really cheap: do a simple 6dB/octave RC network, passive, on the output of the mixer.
In the case of really wide stereo information (some records with two vocalists are mixed hard left/right, one vocalist in each speaker. Your system would make one much quieter than the other, and totally muffled) it would be much better to mix the two outputs to mono, then cross over after the mix. That's for the Behringer's stereo inputs, obviously. If you're running balanced XLRs between the mixer and the amp, I can cobble together balanced circuits, but we are now getting a bit complicated. Clear? Of course it isn't, it's me.
Variable (or sweep) frequency is a touch more complex.
If you put the passive crossover onto one half of the amp, without loading the HF section, the amplifier is seeing a very odd impedance on its output. I'm not stating it will go unstable, mind, but you're not being nice to it at all, and it never does any harm to give your devices – any of them, not just power amps – the best conditions you can manage.
Really cheap: do a simple 6dB/octave RC network, passive, on the output of the mixer.
In the case of really wide stereo information (some records with two vocalists are mixed hard left/right, one vocalist in each speaker. Your system would make one much quieter than the other, and totally muffled) it would be much better to mix the two outputs to mono, then cross over after the mix. That's for the Behringer's stereo inputs, obviously. If you're running balanced XLRs between the mixer and the amp, I can cobble together balanced circuits, but we are now getting a bit complicated. Clear? Of course it isn't, it's me.
I had a talk with the company guy. He told me that you'll need an active crossover. So I go ogled and found out this STUDIOMASTER PROFESSIONAL
Hi,
Well he's very wrong and you don't understand the equipment
you have and the very simple options that are available to you.
rgds, sreten.
Last edited:
Don't know if you solved this problem yet...
My advice is definitely ACTIVE Crossover !
You need one that is stereo 2 way, and has a provision for mono subs.
One example is the Rane Mojo MX22. Now discontinued, but low cost and good sounding. Better sounding than the AC series from Rane. Also Ashly makes great crossovers.
This will work correctly with the equipment you now own, and will be easy to expand in the future, or use in other ways.
There are several ways to hook this up... from super simple to more complex - depending on the skill of your mix engineer.
Simplest way is to wire one Main Output only (let's say R out) from your mixer to the active crossover; Let's say, R input. Pick a crossover point around 100hz to start. Lows from mono sub out go to amp channel 1 (low number) and Highs from R high out go to amp channel 2 (high number) . Make sure all channels on your mixer are set to mix to either 1) both L and R equally - 12 o'clock, or 2) All the way to the R side you wired as your one output. Also, remember stereo playback devices still require stereo inputs, even though the PA is mono.
If you add amps in the future, connect the L out of your mixer to the L in of the crossover, and connect the High outs of the crossover to your L and R amp channels. Sub remains in mono.
Trying to use passive crossover for subs is a waste of your effort. It can be done, but active crossover is so superior.
Another way of wiring puts the subs on a separate control, known as "aux subs" .
This way, only bass containing instruments can get to the subs. It is much more difficult to mix on, until you get used to it.
The difference in the wiring is that the main out goes to the R side of the crossover, and the last post fader aux send gets wired to the L side. Do not use the mono sub out.
Now, the Highs come out of High R, and the subs out of Low L.
No bass comes out unless you turn up the aux sub send on the given input channel of your mixer.
If you lower mixer main out with this setup, sound still comes out of the subs. Lowering the channel out lowers all sends including the post fader aux.
If you wanted aux subs AND stereo tops, you'd need a second crossover as well as more amps.
Questions?
My advice is definitely ACTIVE Crossover !
You need one that is stereo 2 way, and has a provision for mono subs.
One example is the Rane Mojo MX22. Now discontinued, but low cost and good sounding. Better sounding than the AC series from Rane. Also Ashly makes great crossovers.
This will work correctly with the equipment you now own, and will be easy to expand in the future, or use in other ways.
There are several ways to hook this up... from super simple to more complex - depending on the skill of your mix engineer.
Simplest way is to wire one Main Output only (let's say R out) from your mixer to the active crossover; Let's say, R input. Pick a crossover point around 100hz to start. Lows from mono sub out go to amp channel 1 (low number) and Highs from R high out go to amp channel 2 (high number) . Make sure all channels on your mixer are set to mix to either 1) both L and R equally - 12 o'clock, or 2) All the way to the R side you wired as your one output. Also, remember stereo playback devices still require stereo inputs, even though the PA is mono.
If you add amps in the future, connect the L out of your mixer to the L in of the crossover, and connect the High outs of the crossover to your L and R amp channels. Sub remains in mono.
Trying to use passive crossover for subs is a waste of your effort. It can be done, but active crossover is so superior.
Another way of wiring puts the subs on a separate control, known as "aux subs" .
This way, only bass containing instruments can get to the subs. It is much more difficult to mix on, until you get used to it.
The difference in the wiring is that the main out goes to the R side of the crossover, and the last post fader aux send gets wired to the L side. Do not use the mono sub out.
Now, the Highs come out of High R, and the subs out of Low L.
No bass comes out unless you turn up the aux sub send on the given input channel of your mixer.
If you lower mixer main out with this setup, sound still comes out of the subs. Lowering the channel out lowers all sends including the post fader aux.
If you wanted aux subs AND stereo tops, you'd need a second crossover as well as more amps.
Questions?
NO.
Passive crossovers do not work properly with subwoofers because of the impedance peaks of the subwoofer and the rising impedance of the subwoofer at high frequencies. I once had to redesign a passive sub crossover for work, and measuring it, it did…very little. Terrible.
Now, you could insert a passive crossover BEFORE the power amp if you don't want to get an active crossover. Harrison Labs F-Mods are one brand:
FMODS
there are two reasons to use a crossover:
1) to stop your sub-woofer trying to reproduce higher frequencies than it usually operates at and interacting with your Mid-High speakers or causing interesting imaging problems.
2) to stop low frequency signals going to your mid-High speakers, driving them beyond their excursion limits and damaging them (particularly as there will be a temptation to push your bottom end hard, since you have a Sub-woofer).
At best the passive crossover will solve problem 1 (albeit poorly - 250Hz is a bit high for Sub-woofer crossover and a passive is not usually steep enough).
as for your setup, conceptually running say left into your Mid-high send and right into your subwoofer send (via an active crossover etc) can be useful because it lets you send things that need the extra bottom end to the Subwoofer by panning to the middle (or even to the right), and anything that does not need bottom end, or that may be adversely affected by having too much bottom end (for example vocals which could suffer plosives, or wind noise when out doors) you then pan left (i.e. the side without the sub-woofer)
Of course you still need an active cross over to do this, although you can do it with a standard two way stereo cross over.
now a brief word on active cross overs - you usually want a Linkwitz riley type as these result in both the high and low pass being in phase at the cross over point which hopefully (depending on any time alignment type issues) will reduce any comb filter type problems between your Mid-high and sub-woofer....
1) to stop your sub-woofer trying to reproduce higher frequencies than it usually operates at and interacting with your Mid-High speakers or causing interesting imaging problems.
2) to stop low frequency signals going to your mid-High speakers, driving them beyond their excursion limits and damaging them (particularly as there will be a temptation to push your bottom end hard, since you have a Sub-woofer).
At best the passive crossover will solve problem 1 (albeit poorly - 250Hz is a bit high for Sub-woofer crossover and a passive is not usually steep enough).
as for your setup, conceptually running say left into your Mid-high send and right into your subwoofer send (via an active crossover etc) can be useful because it lets you send things that need the extra bottom end to the Subwoofer by panning to the middle (or even to the right), and anything that does not need bottom end, or that may be adversely affected by having too much bottom end (for example vocals which could suffer plosives, or wind noise when out doors) you then pan left (i.e. the side without the sub-woofer)
Of course you still need an active cross over to do this, although you can do it with a standard two way stereo cross over.
now a brief word on active cross overs - you usually want a Linkwitz riley type as these result in both the high and low pass being in phase at the cross over point which hopefully (depending on any time alignment type issues) will reduce any comb filter type problems between your Mid-high and sub-woofer....
- Status
- Not open for further replies.