Hello
We're a 80s band that have been playing together for some years. Back in the days we purchased a big PA (for us atleast) to be able to play in larger avenues after recommendations from different people that works with live sound.
 
Our PA:
2x Martin Audio W8
2x Martin Audio W8S
2x Tannoy TDX1 Digital System Controller
2x Crown CTs 3000
1x LAB.GRUPPEN LAB4000
1x LAB.GRUPPEN FP7000
 
Monitors:
1x LAB.GRUPPEN LAB2000c
4x Marin Audio LE-350A
 
Mixer:
Soundcraft Si Expression 3
 
We haven't been tinkering too much with the PA, the adjustments we've done to the sound has been to the indidual instruments using the 3-band EQ on the mixer.
 
After using the PA for some years, these are the issues we currently have:
1. Our synth sounds hard (especially the piano sounds). We have a Roland Jupiter 80, but just this month we bought two VSTs (Omnisphere and Hans Zimmer piano) and they have the same tendencies.
2. Some lack in the lows (If we want that punch from the bass-drum I feel we need to boost it a lot so we often opt to a middle way).
3. Lack of crispiness in the highs.
 
Our experience with live sound:
 
At home we have 2x Munro Acoustics sE Electronics The Medium EGG 150 System which we used when we decided to buy the VSTs. The VSTs sounded great with the EGGs compared to the sounds from our Jupiter-80 (even though the EGGs are lacking some lows), so we will with time build a computer and only use the synths as midi controllers for to use the VSTs from a computer. Also we've been to concerts where the bands sound amazing (playing for 500-30.000 people), but most of them are national or international artists (so I guess they have access to great gear and great sound engineers).
 
In the later years we've worked with 5-6 sound engineers, but we've always ended up doing the sounds ourselves as they have been below par.For instance we ended up giving our two guitarists each a Voodoo Lab Amp switcher. Usually the output from the guitar goes into the switcher and you have four selectors to send the guitar signal to one of four different connected amps. Instead, we connect the guitar to the amp, and take the DI-signal from the preamp of the amps and feed it into the Amp Switcher, and then run four jacks into four different tracks in the mixer where each track is panned (to the sides or center) and volumes adjusted differently. This is so that when one guitar switches from comp (panned to one side) to solo (center with higher volume), the other one switches from comp (panned to other side) to a stereo panned track with higher volume to compensate for the other guitar dissapering from the comp and keep the balance. Audiences and some semi-professionals have taken note of our well-balanced live sound.
 
Maybe we are a bit perfectionistic, but we know the sound we want is possible (as we've heard great bands with great sound live before), though we don't know if it's possible with our current PA. We are new to the idea of configuring a PA and that's why I come to you. Can our issues be solved? The problem here is that we don't know what we don't know so it's hard to look for information about our issues.
 
Please keep you answers simplistic enough so we understand, we haven't learned all the jargon/slang yet.

How are you judging what your current live PA actually sounds like?

Currently we think our PA sounds a bit hard so I'm guessing it might be somewhere in the mid area. People from other forums have pointed out that it could be wrong settings on our Tannoys creating a crossover. Our reference is that with our EGGs the VSTs sound big, clear and crispy, but on our PA they sound a bit hard making our ears tire quickly.

I bet the PA is good but you are not setting your FOH EQ very well.  And really you have to check your FOH EQ for every venue you play.  It is NOT a set and forget situation. Before any audience arrives for the gig e.g. in the afternoon.
 
You need a reference CD. I use Steely Dan's Two Against Nature or Everything Must go.  First thing you have to do is hear it on studio monitors in a nice room so you know what it sounds like.  It is perfect mix so it is not hard to hear when it is sounding perfect. 
 
So live, you run the CD player into a stereo channel or pair of channels and remove all EQ from the channel so the CD is going direct to your FOH Mix.  Start by setting the FOH EQ total flat e.g. no boost or cut on any of the sliders.  Listen to the music and you should hear what needs to be adjusted.  (If you have subs and they are too loud which they will most often be then turn them down!! This is also where any crossover issues will reveal themselves) If the PA is good you should only have to move 2 for 3 sliders (max) to get the music sounding sweet and perfect.  And not by much either. 
 
You could do a pink noise RTA and that might help, but music is still a great final check.
 
Not all CD's are good reference CD's either. It is not about genre it is about a very well balanced mix and the CD I have mentioned has that in spades. 
 
Dont try and fiddle individual channels on your mixer to get the sound until you get the whole FOH sounding nice. Once you get FOH sounding nice then you can start with every channel flat e.g. no EQ and they will all be almost perfect. A Jupiter 80 for example sounds fantastic with no EQ applied. 
 
You can use the ref CD in your monitors too and get them also sounding nice. (using the monitor EQ's) I then roll off stuff below about 150 Hz and above 7-8 kHz to stop and squealing feedback in the foldback. 
 
Hope this is not too technical.  Some PA experts here will hopefully chime in. 

Nheme`
Currently we think our PA sounds a bit hard

How do you know? Is someone going out front and listening to the rest of the band, are you relying on what other people say, are you basing your opinion on what the foldback sounds like?

I'm wondering how you hear what's coming out of your PA at all.....

Nheme
so I'm guessing it might be somewhere in the mid area. People from other forums have pointed out that it could be wrong settings on our Tannoys creating a crossover. Our reference is that with our EGGs the VSTs sound big, clear and crispy, but on our PA they sound a bit hard making our ears tire quickly.

As Jeff says, it might well be an eq issue. Even inexpensive PA gear can sound pretty good these days but every room is different - and it's different empty to when it's full of people - and while there are settings that can be the ones that are always "pretty close" they'll still need adjusting some. Putting a graphic or parametric eq after the mixer and before the PA amps can help quite a lot because you can change the eq of the whole FOH system very quickly and accurately without touching the mixer channel eqs at all.

A test setup using a white noise CD, a measurement microphone and an meter and equaliser that can be used to flatten the PA eq response based on that can be useful.

Chasing perfection in mobile PA use rather than working in just one venue (or outdoors where there's no room reverb or rooms acoustics to get in the way) can be an endless task doomed never to succeed though. It's one of those things where "good enough" is often the best that can be achieved and throwing money at the problem may or may not help depending on what the problem is and how it's best addressed, if it needs addressing at all.

A band once asked me to check out their PA.  When I arrived I saw it was big Bose system with lots of 802's and subs etc so I thought it should be pretty decent.  They were about to sell it to buy a new one.  When I got there I put my ref CD through it and it sounded pretty horrible.  The FOH EQ had been set by some idiot and the band was told never to touch it!  It was a terrible setting.  When I flattened it out and fine tuned it so Steely Dan sounded perfect their jaws dropped.  It was like a totally different PA.  They ended up keeping it and getting great results out of it from that point on.  And saved a heck of a lot of money in the process.
 
The room I did this in was nice and not reverberant.  (lucky!) I taught them how to fine tune the FOH for each venue.  It is surprising how little one has to actually adjust the FOH EQ to get the ref CD sounding great.  Of course each venue is different and as tlw correctly says it is a sort of compromise each time but with care you can usually get it pretty decent every time.  What tends to change I have found is the low end and the high end and these are usually easily adjusted to suit the venue. 
 
I did a pink noise setup too with a measurement microphone and a live RTA display.  And this got it close but I still find the music is best for the last fine tuning step.
 
I have also walked in and done live mixes in many venues in Melbourne with built in PA's.  It never seems to amaze me what the ref CD sounds like. Terrible 9 times out of 10. When I look at the FOH EQ I am usually seeing a curve that looks like a dogs hind leg. Terrible.  Set my some stupid person the night before.  When I flatten this out to a straight line the ref CD most often sounds superlative.  Which tells me that the PA installers did a wonderful job.  Often there is another FOH EQ that is not accessible but they have set it beautifully! Then the owners come up to me and say they have never heard the PA sounding so good!  All I did was straighten out the FOH EQ!

Something else that is worth doing too.  I have got three sets of speakers at home. Two of them are average and the third is very good.  I have a Behringer Mastering processor. DEQ2496.  It has got this feature where it pumps out pink noise into your PA and you set up a measurement microphone out front and while the noise is playing it actually adjusts all the sliders of a FOH EQ automatically (digitally) for a flat response.  It is actually quite remarkable to watch. Then you can store these settings.  The longer you leave it as well doing this the flatter it gets the sound. 
 
The best place to do this it outside and not near any walls or reflective surfaces.  It needs to be done at high volume and the mic needs to be set up about two meters away.  I did this for all three speaker systems I have and it generated a slightly different FOH curve for each one.  (the high quality speakers had the flattest corrective EQ curve of course) I must say this actually makes each speaker sound almost perfect and almost identical too.  It is quite something.  It makes a major difference to the sound of each speaker literally transforming each set into a beautiful flat sounding sound.   I also use another FOH EQ as well in series with this.  So the Behringer is flattening out the speakers and then the second FOH EQ allows me to fine tune for a perfect Steely Dan sound each time.  Sounds like a bit of a fiddle and it is but well worth it. 

I see from your OP in the list of gear that there is no mention of any form of graphic FOH EQ. I always thought that such a thing was just mandatory. Might be good to invest in one perhaps. It is the only way you are going to get any real control over your FOH sound.

The more accurate your FOH sound is the less and less the channel EQ's will be needed to correct for individual channels. In fact the channel EQ's will get closer to flat response as the FOH sound gets closer to a flat response.

Thank you for your inputs, much appretiated.
 
When we do sound checks, most of us are in front of the PA (at the area with our FOH) as we are most concerned with our audience giving them the best sound we can.
 
Jeff
Thank you for explaining thoroughly what the FOH engineer does. This week we tried sending our VST (Omnisphere) directly from the computer through an Audio Interface and into the EGGs (avoiding the mixer), and then switched out the EGGs, sending it to our Tannoys (leading through the W8/W8S). We experienced the sound from our PA to be hard, and suggestions from other forums, I accessed the EQ settings on our Tannoys and can see that there are absolutely nothing done with the EQ settings. I understand that Martin Audio has some general advices on the EQ settings on the DSPs which might correct some of our issues, but I'm struggling where to find exactly which frequencies and crossover settings they are recommending.

I did not realise the digital system controller would offer the EQ options.  Not ideal though, only a 4 band parametric EQ which might get you out of trouble.  Still not as versatile as a graphic EQ.  There is also no information about it anywhere on the Tannoy website which is also a bit weird. 
 
Stop using Omnisphere as the reference test signal.  It is not good enough for that purpose.  That is the reason you are having a hard time finding what frequencies to fiddle.
 
You need a full super well balanced mix or full range program material.  Such as a ref CD.  (Steely Dan, and you have to hear it on a high end speaker studio system to know what it sounds like as well. Only the last two albums I mentioned too, they sound the best) No harm in going through the mixer either, just set the CD playback channels for no EQ being applied anywhere.
 
A graphic EQ is going to get you the sound way faster too.
 
Check your crossover frequencies.  With the Martin subs the first crossover point is 120 Hz. The other two crossover points are 750 Hz and 3.5 kHz.  (according to the Martin W8 manual) Has the Tannoy crossover been set correctly.
 
I had another idea too. You could try using your digital processor crossover to only cross over from the subs to the W8's. Then use the internal passive crossovers in the W8's to handle the other drivers in there i.e. feed from 120Hz to 20 kHz to the W8's. That way if the sound suddenly became right you have found the culprit as the active crossover not being set correctly. If the slopes of the crossover points are adjustable in the processor I would start with 12 dB/oct first and see how that sounds as well.
 
Regarding the test CD, if you can get these ref tracks ripped into wave files then it is also fine to use the computer and the audio interface as the source instead of the CD player.