Soundcraft EQ improves QSC K10

[dazzjazz]

At my gig on Thursday I had a vocalist plug their Soundcraft mixer into my QSC K10. I also connected my Nord Stage 2 into a single channel of the mixer.

 

All I can say is - WOW. The NS2 sounded a lot warmer and detailed, even when the EQ was flat.

 

So, what exactly is going on? Can I replicate this easily by perhaps inserting one of those little 'lunch' box type studio EQs in the chain.

 

Darren

[MoodyBluesKeys]

Dazz,

I can't explain it by theory, but I have found that having a mixer OR the in and out of my DAW between the keyboards (PC3X, PC3) and my speakers (EON15G2, or EV SXA100+, or K10's) does have an effect on the sound - hard to describe, but seems smoother, less edgy.

 

I have a 5-channel & a 12-channel Tapco low cost mixer, and eMu 1820M Audio/Midi PCI based computer interface. EQ settings are left flat. Both Kurzweils are balanced out, all the speakers are balanced in, I use TRS (or TRS to XLR) cabling all the way through. There does not seem to be a major level shift - it just sounds cleaner and warmer.

 

I've been an electronic tech for 50 years, have installed lots of sound gear - I still don't have a logical explanation - but it is very little trouble to pack the little mixer and a couple of extra cables, gives me volume controls right beside me, and makes it all sound better - so it does get used. I've been considering getting a better mix board, one of the Allen & Heath models.

 

[ewall08530]

You may find that it has something to do with the mic/line preamps in the Soundcraft.

 

I have a Soundcraft Notepad mixer that really warms up the piano sounds on my Roland RD and Nord Electro HP. Our band uses a high end Yamaha digital mixer and I've tried just using the monitor feed from that into my K-10 and despite efforts to improve the tone with eq'ing, gain staging, the Soundcraft just sounds better to my ears and I always take a monitor feed from that directly into my K-10.

 

[frogmonkey]

I'd bet it's the mic preamps, more than the EQ. Even not-so-good preamps (Mackie, Behringer) make my keys sound more present. I can really notice it when I have a big mulit-board rig and I don't have enough preamp channels in the mixer, so some boards go without preamps. Night and day.

[Lord_Nord]

I'd bet it's the mic preamps, more than the EQ. Even not-so-good preamps (Mackie, Behringer) make my keys sound more present. I can really notice it when I have a big mulit-board rig and I don't have enough preamp channels in the mixer, so some boards go without preamps. Night and day.

 

I think you are onto something there. I have a little 8 channel behringer mixer with 4 mic channel inputs and 4 stereo channel inputs. When I put my boards through the mic channels, it's a warm clear signal. Through the stereo channels, not so much.

 

[JeffLearman]

I don't buy it (the mic preamp hypothesis). Since the NS has line outputs, the mic preamp shouldn't be an issue: the signal doesn't need to be amplified by 25-60dB like a mic does.

 

Furthermore, if the line inputs on the QSC aren't transparent, that failure will happen regardless of whether you put a mixer in front of it.

 

However, louder sounds better, and if the output of the mixer is hotter than the NS2 when comparing them, the louder one will sound warmer, more present, etc.

 

Since the line input of the speaker is involved in either case, if there was a difference, it would be due to the keyboard's outputs working better when plugged into the mixer rather than the speaker. This could be true if the mixer's inputs are higher impedance than the speaker's. Otherwise, I don't see how it could possibly improve the sound, assuming the mixer is transparent (as it should be, with no EQ applied).

 

This isn't the case of tube preamps, which are not necessary transparent, and change the signal in some beneficial way.

 

But if the mixer is changing the signal without any EQ involved, that would be a flaw, regardless of whether it sounds better in a specific case.

 

BTW, it's extraordinarily difficult to be objective in these audition tests, even when you're trying your best, and even when the results contradict your expectations. Listening is not an objective act. No two listening experiences are different, thanks to the way our brains work: they focus on, and hear, different things on each listen.

 

Regardless, if you like how it sounds, that's all that really matters.

 

[Dave Ferris]

At my gig on Thursday I had a vocalist plug their Soundcraft mixer into my QSC K10. I also connected my Nord Stage 2 into a single channel of the mixer.

 

All I can say is - WOW. The NS2 sounded a lot warmer and detailed, even when the EQ was flat.

 

Those have been my findings as well with a higher end preamp/mixer..

[ewall08530]

Imma just going to say it sounds "better" I know how and I don't care why!

[Jim Alfredson]

Impedence.

[MikeT156]

Some time ago, I got into a heated discussion on "The other site" with a professional soundman about the utility of an Equalizer. His opinion was that an EQ was just about useless. However, as a KB player that has played many small rooms where there is nothing to absorb the sound, my EARS tell me that the piano sound on my ES8 sounds much better when using a stereo 31 band EQ. Its not so much what it ADDS to the sound, its the crappy sounds and boomyness it REMOVES from the sound of a room that has nothing to absorb the sound.

 

 

Cheers!

 

 

Mike T.

 

[frogmonkey]

I don't buy it (the mic preamp hypothesis). Since the NS has line outputs, the mic preamp shouldn't be an issue: the signal doesn't need to be amplified by 25-60dB like a mic does.

 

That sounds reasonable in theory, but my experience tells me otherwise. It isn't just a matter of volume. I can dial in the volume on a non-preamp channel to match the preamp channel. I can even dial it in to the point of being apparently louder. But when the band kicks in, the non-preamp keyboard is more likely to get buried.

 

But now that you mention it, it is entirely possible that I have drawn the wrong conclusions. Now I want to do an objective comparison. (It'll have to wait-- I'm about to leave on vacation!).

[dazzjazz]

Thanks for the discussion everyone.

Still not sure if I should bother getting a mixer just for one channel of keyboard, but it was quite a different sound.

 

Darren

[J. Dan]

At home, running my Kronos directly into the K10, I noticed some master EQ adjustment REALLY helped. It's EQ, pure and simple. The k10 is great, but it needs some slight EQ adjustment IMHO. Just Saying!

[Tusker]

Based on my experience preamp circuits can improve sound as much as eq. I associate good preamps with a forward sound which does not wash out and a rounded sound without losing the highs. It's as though a lens has been focused.

 

True in most cases, I haven't had an spl meter to keep me honest....

[KeyMoe]

I also almost always use some type of decent mixer in line with the K10s. It really makes a difference in over all responsiveness and performance of the speaker.

[JeffLearman]

Based on my experience preamp circuits can improve sound as much as eq. I associate good preamps with a forward sound which does not wash out and a rounded sound without losing the highs. It's as though a lens has been focused.

 

True in most cases, I haven't had an spl meter to keep me honest....

If so, it's changing the signal, when it's supposed to be transparent. If it's a tube preamp, fine -- lots of folks like the way tubes sound and they're not necessarily intended to be transparent.

 

But if a unit that's not supposed to be changing the signal changes the signal, then it's not doing what it's supposed to do.

 

Note that I'm talking about line-level inputs, where the signal doesn't need to be amplified much at all. For mic level inputs, there are huge differences, because the job of amplifying a very weak signal to line level is not a simple one, and cheap preamps involve lots of tradeoffs. None are really transparent, even the expensive ones.

 

I doubt impedance is the issue since I doubt the impedance is much different between the two cases. I can't find a spec for the speaker, but someone mentioned 15K Ohms. The mixer is likely to be in the 10K to 20K Ohm range -- 10K is typical, but some mixers have lower input impedance (as low as 4500 Ohms) on 1/4" jacks for reasons I never understood.

 

But it's true that I'm speaking from theory. I'm skeptical, but there's always the possibility that there's something else at play.

[dazzjazz]

So, how could I get a better sound? buy a preamp? A good DI?

A mixer seems like overkill....

 

Darren

[Griffinator]

Based on my experience preamp circuits can improve sound as much as eq. I associate good preamps with a forward sound which does not wash out and a rounded sound without losing the highs. It's as though a lens has been focused.

 

True in most cases, I haven't had an spl meter to keep me honest....

If so, it's changing the signal, when it's supposed to be transparent. If it's a tube preamp, fine -- lots of folks like the way tubes sound and they're not necessarily intended to be transparent.

 

But if a unit that's not supposed to be changing the signal changes the signal, then it's not doing what it's supposed to do.

 

Come now, Jeff. The legendary Neve mixers didn't become legendary because of their transparency, they became legendary because of the distinctively musical fingerprint they applied to the sources.

 

There is no way for an electrical circuit that is anything more complex than a pair of wires (+ and -) attached to two sets of poles to not alter the signal traveling between them. The question then becomes is the effect of the intermediate circuitry a good one or a bad one?

[Dave Ferris]

.

[JeffLearman]

Based on my experience preamp circuits can improve sound as much as eq. I associate good preamps with a forward sound which does not wash out and a rounded sound without losing the highs. It's as though a lens has been focused.

 

True in most cases, I haven't had an spl meter to keep me honest....

If so, it's changing the signal, when it's supposed to be transparent. If it's a tube preamp, fine -- lots of folks like the way tubes sound and they're not necessarily intended to be transparent.

 

But if a unit that's not supposed to be changing the signal changes the signal, then it's not doing what it's supposed to do.

 

Come now, Jeff. The legendary Neve mixers didn't become legendary because of their transparency, they became legendary because of the distinctively musical fingerprint they applied to the sources.

 

There is no way for an electrical circuit that is anything more complex than a pair of wires (+ and -) attached to two sets of poles to not alter the signal traveling between them. The question then becomes is the effect of the intermediate circuitry a good one or a bad one?

But what we're comparing here is ADDING a circuit versus leaving it out. We're not comparing one preamp with another. We're talking about adding another preamp in line. Now just tell me, what is that thing going to do to make the signal BETTER?

 

Transparency is the goal, and for line level devices, we're pretty damn close. This is provable, too, by recording signals and doing sum cancellation tests in a DAW, among other things. The discrepancies that decent line level devices incur is ridiculously small -- or they're not half-decent!

 

No, I don't believe that adding a supposedly transparent device between two op-amps is going to make anything sound better. BTW, the Neve is an example of a nontransparent device that's coveted for its sound, and NOT for its transparency. A transparent device wouldn't need a "silk" knob.

[mate stubb]

Transparency is the goal

 

"Better sound" is the goal for some, whatever that means.

[Tusker]

Transparency is the goal

 

"Better sound" is the goal for some, whatever that means.

 

Agreed. Thanks for putting in the "for some" part. This is true for both tube and solid state higher end products from time to time.

[Griffinator]

If so, it's changing the signal, when it's supposed to be transparent. If it's a tube preamp, fine -- lots of folks like the way tubes sound and they're not necessarily intended to be transparent.

 

But if a unit that's not supposed to be changing the signal changes the signal, then it's not doing what it's supposed to do.

 

Come now, Jeff. The legendary Neve mixers didn't become legendary because of their transparency, they became legendary because of the distinctively musical fingerprint they applied to the sources.

 

There is no way for an electrical circuit that is anything more complex than a pair of wires (+ and -) attached to two sets of poles to not alter the signal traveling between them. The question then becomes is the effect of the intermediate circuitry a good one or a bad one?

But what we're comparing here is ADDING a circuit versus leaving it out. We're not comparing one preamp with another. We're talking about adding another preamp in line. Now just tell me, what is that thing going to do to make the signal BETTER?

 

Transparency is the goal, and for line level devices, we're pretty damn close. This is provable, too, by recording signals and doing sum cancellation tests in a DAW, among other things. The discrepancies that decent line level devices incur is ridiculously small -- or they're not half-decent!

 

No, I don't believe that adding a supposedly transparent device between two op-amps is going to make anything sound better. BTW, the Neve is an example of a nontransparent device that's coveted for its sound, and NOT for its transparency. A transparent device wouldn't need a "silk" knob.

 

Point being, if the circuit placed makes the system sound better, in a live situation this is a good thing. Transparency is something you worry about in the studio. Improving your FOH sound to the best degree you are capable is what you do live.

[Dave Ferris]

.

[Phil Aiken]

Impedence.

 

They have pills for that.

[dazzjazz]

So maybe I'll invest in one of these - pro engineer I know highly recommneded to me.

 

http://www.zenproaudio.com/goldenagepre-73.aspx

 

Pretty cheap - well, in relative terms.

 

Darren

[JeffLearman]

Impedence.

They have pills for that.

 

I overlooked a significant possibility. If the speaker's preamp is on the noisy side at higher gains, and you add a better preamp in front of it so you can turn the speaker's level down, you get a benefit.

 

Does the S/N ratio increase as you increase the gain on preamps? I'll certainly admit that as a possibility, especially in a "cost-saving" design (to put it nicely).

 

I certainly have no argument with folks who want to add devices that color the sound. I just doubt that that's what the Soundcraft is doing in the OP's case.

 

"Better sound" is the goal for some, whatever that means.

Right -- I should have said "WHEN transparency is the goal ...."

[ITGITC]

 

Gain staging.

 

I agree with my friend, Jeff.

 

(Hey LearJeff - I finally heard from our buddy, BluesKeys! I guess he had to come up for air (if ya knows what I meanz). Let me know when you're thirsty. He's buyin'!)

 

Tom

 

[JeffLearman]

woot! I'm always thirsty.

 

Question, though ... I'm now doubting whether the S/N ratio decreases when you turn the K10's volume up. If it was a gain control, sure. But isn't it just a fader in front of a constant-gain opamp? And if so, wouldn't the S/N ratio stay the same?

[Tusker]

I don't understand how observations about warmth and detail can be understood through the single metric of 'signal to noise ratio'. We seem to talking at cross purposes.

 

Dave Ferris your clips made your point, and I love how you play.

 

Good luck DazzJazz. Just find a way to audition the devices, because every pre has a different sonic signature, unless it's transparent in which case you probably don't need it.