Ok, what would you do here, i have a KAM KXR1500 amp, a Warrior IS600 amp, a pair of 300 watt AC Euro Mid Range 8ohm speakers and a pair of Behringer 300 watt 4ohm Subs. The KXR1500 runs at 750 watt per channel into 4 OHM and 450watt per channel into 8 ohms. The IS600 amp runs at 300 watts per channel at 4 ohms and 180 watts per channel at 8 ohms. I have always used the warrior amp with the AC Euros and at some gigs have been running the Warrior Amp into clip, so, no headroom left at all. The subs do not give a punchy bass they give a proper subwoofer rumble, i find that the punchy bass tends to come from the AC Euros. Should i use the KXR1500 for the AC Euros and the Warrior for the subs? I may be wrong but i think that may give a better sound and provide more power where its needed (i.e the mid range speakers) or have i got this all totally wrong as usual???!!!


Many thanks in advance for your comments.


Bob

Hi Bob

quick question. do you use an extrernal crossover or do you run a full signal to both the mid tops and subs.

cheers
Dave

Hi Dave,

Full signal to both. Am using subwoofer out xlr from mixer to KXR, then to Behringer Subs. Full signal from Usual mixer outputs to warrior amp then on to AC euros at moment.




Bob

best solution is to use an external crossover to remove the bottom end from the ac euro's. That way they dont have to deal with the full range of signals and therefore wont need as much power. Also you will eliminate any potential phasing issues.

If you feel the bottom end is lacking then sub placement may help, there are loads of hints and tips about sub placement which will help you get the best possible sound. Many say that having a sub directly under your tops either side of the rig is not a good idea but its down to the room that you are in, a complex affair but some very valid points.

use the kam amp for the subs as usually subs need a bit more power and the kam has pleanty of headroom, the warrior will happily do the tops.

try to borrow a crossover and try it, you could pick one up s/h on fleabay

regards
Dave

Thanks for that Dave, to be perfectly honest I was trying to compete with the performance of a bands pa system at a wedding gig in a marquee. Their main pa was through a pair of mackie srm450s combined with a pair of mackie subs. The band also had a bass amp and lead guitar amp. Never gonna compete with that one I suppose! If I ever come into money I would definetely buy some mackies I have heard and seen them in action many times and I must say they sound very good!

Right, now i have really confused myself.......Decided to have a read up about crossovers as suggested and came across a question in my head that i could not get an answer for whilst researching.

i will try and explain the best i can.....................

An active crossover does its magic before the sound signal gets to the amp. The magic it does is split the various frequencies up so the correct bit of sound goes to the amp/ speaker best suited to play it. A passive crossover is usually built in to a full range speaker cabinet and splits the various frequencies so that each speaker built in to the cabinet gets the best suited frequency. This is done just as the sound signal enters the speaker cabinet via the speaker cables. I understand this.(They both do a very similar job??)

My mixer has a subwoofer output and main outputs. The two subs are fed from the Subwoofer output on the mixer, the full range speakers are fed by the main mixer outputs. The full range speakers have passive crossovers fitted (i have checked!) . The subwoofer output on the mixer has an adjustable frequency control knob so the low frequencies being sent to the subwoofers can be adjusted.


So, the big question is, as the subwoofers are recieving the low frequency signals "only" anyway, will an active crossover be worth fitting, and what happens when an already "crossed over" frequency arrives at the passive crossovers fitted in the full range speakers? (There is no switch fitted to the speakers to turn the passive crossovers off by the way.)



I wish i had never started thinking about this now....................!!


Right, now i have really confused myself.......Decided to have a read up about crossovers as suggested and came across a question in my head that i could not get an answer for whilst researching.

i will try and explain the best i can.....................

An active crossover does its magic before the sound signal gets to the amp. The magic it does is split the various frequencies up so the correct bit of sound goes to the amp/ speaker best suited to play it. A passive crossover is usually built in to a full range speaker cabinet and splits the various frequencies so that each speaker built in to the cabinet gets the best suited frequency. This is done just as the sound signal enters the speaker cabinet via the speaker cabinet. I understand this.(They both do a very similar job??)

My mixer has a subwoofer output and main outputs. The two subs are fed from the Subwoofer output on the mixer, the full range speakers are fed by the main mixer outputs. The full range speakers have passive crossovers fitted (i have checked!) . The subwoofer output on the mixer has an adjustable frequency control knob so the low frequencies being sent to the subwoofers can be adjusted.


So, the big question is, as the subwoofers are recieving the low frequency signals "only" anyway, will an active crossover be worth fitting, and what happens when an already "crossed over" frequency arrives at the passive crossovers fitted in the full range speakers? (There is no switch fitted to the speakers to turn the passive crossovers off by the way.)



I wish i had never started thinking about this now....................!!

Passive crossovers in full range speakers divide the sound between its woofer and its tweeter. Most decent speakers will have some sort of protection circuitry on the crossover to protect the tweeter.


Some passive subwoofers will have a passive crossover built in. Sometimes they're wired just to filter off any signals above a certain frequency (called low-pass filter). Some subwoofers will have a 2-way crossover fitter (such as Peavey Messenger Pro series), which has a "hi-pass output" on it...


Your mixer has a subwoofer output which has an adjustable low-pass filter (tuneable by the knob on the back). Think of this as a 1-way crossover but this goes before the amplifier (and is an active low-pass crossover).

A proper active crossover will take your MAIN outputs and filter any low frequencies to the subwoofer/low outputs, and the rest of the signal will be sent to the high-outputs..

The advantage of the separate active crossover means that lower frequencies will be filtered off from going to the top speakers, leaving the subs to do the main "thumping", while your tops will have an easier time as they won't need to work as hard pumping out bottom end bass frequencies.

I hope I've explained that ok, as I'm on a train coming back from Leeds, and I've been drinking..

David (hic!)

Thanks for that! Hope the head is ok this morning! Leeds eh? My home turf!


Now i have got my head round it from everyones helpful comments i feel i can explain my problem a bit better.

What i am actually trying to do is make the subwoofers louder and punchier if possible. At the moment they seem to be only playing the really really low frequencies, and the noise coming out of them is just a very very low "wumf wumf" with no kick to it at all. I am going to adjust the low pass knob on the mixer and see if i can let some higher low end frequencies through.

In your post you say that an active external crossover will filter out some of the low frequencies from the mid range speakers. I do not really want that if i cannot get the subs to work as i want. (I will end up with hardly any bass at all!!) If the subs are designed just to give a "Wumf Wumf" i suppose i will just have to live with that.

I know i am making it out that the sound is really bad, it isnt, but i feel that i am not getting the full potential from the subs.

Could it be that the speakers are only designed to give out very low frequencies?

Or could it be they are faulty? (I bought them secondhand.)

Or might it be that they are crap speakers?

Behringer B1500x subs.

Got a gig tonight at my usual venue so will have a mess around.


Bob

The frequencies that your subs are designed to handle are 42 Hz - 250 Hz frequency response (-6 dB)

So the knob on your mixer needs to be adjusted for or towards the upper frequency of 250 (Depending on taste etc).

You might find this useful as it shows how different frequencies affect different parts of the music spectrum if you will.
Click

A cross over and maybe a graphic EQ will help your system sound no end. But don't forget sometimes it is better to cut a frequency than boost another.

Hope this helps

Nik

Nik you are absolutely spot on there! 30hz to 200hz it says on the mixer knob!

The last few gigs i have done the knob has been up at 200hz and there is another knob that says min-max. This knob was at max.

I am going to try the hz knob at halfway tonight and see what difference that makes.


I think a crossover is going to be the way to go.

Thanks to all for fantastic input. (if you forgive the pun...)




Bob


I am doing a gig tonight

Hi,
Even though you have a subwoofer output on your mixer, your tops are still receiving full signal. With an external crossover, you will be able to set the crossover point, so you wont actually loose any frequencies, or double up any frequencies. The average crossover point for these type of cabinets is usually around 120 - 150 Hz. If you use a graphic on your subs, putting a slight boost on at 100, 125, 250 Hz should give you a little more 'kick'.

Hope that helps

Ok everyone, had a fiddle with all eq's etc etc. Sounds a lot better now. Am definetely going to invest in an active crossover though. Am I right in thinking that no proper volume as such comes from the subs? With the volume at 3/4 on the mixer I could put my ear very very close to each sub without any discomfort at all. Is this right?

the thing with Bass is that it is non directional so if you can not see the speakers people perceive the bass coming from your mids and tops.

Also our ears are tuned to higher frequency's more than lower ones and we tend to feel the lower frequencies more than hear them I am talking very low sub bass here mind.

The ting to try is turning your bass amp down then notice the difference, if you notice the bass level drop they are doing there job. However if you have a phase issue you might hear the bass increase as you turn down your bass amp.

Nik

Thanks Nik,

I was hoping someone would come back with an answer like that. They are doing their job. Brilliant! Ok, roll on the x over and i will report back!


Bob

Ok, crossover fitted...........









UNBELIEVABLE.............







Anybody out there running subs and full range speakers and using seperate amps for the full range and subs,(which i believe is called Bi amping...) buy an active crossover. Do not think about it, just buy one. (I bought a cheap one just to try, £69.00 including 2 XLR cables, best £69.00 i have spent in ages.)


The difference is quite frankly stunning. It sounds exactly as i wanted it to sound like now. Very crisp highs, proper chest thumping bass and the vocals are spot on, you can almost hear the singers taking breaths!!


If anybody has been reading this topic with interest and was waiting for the outcome, well, the outcome is not just a bit of an improvement, i now have a new PA. Well that's what it sounds like to me....


If anybody wants to know any more info, do not hesitate to contact me.





Thanks to all on this one. I owe a few people a beer or two.........





Bob

Good news Bob. Glad you are sorted and are a happy chappy.

Thanks for reporting back too

Best wishes

Dave