Equalizers?

[similost]

Yes I am the systems engineer for the Cliff Richard and the Shadows tour in New Zealand which means I design the configuration of live sound reinforcement required to cover the venue effectivley, install and tune to provide the touring engineer a "blank Canvas" to be able to mix the show, Yes that is quite a lot of potential power there, on this show the system hardly ticks over, but there is 120,000WATTS of amplifiers in that picture..............That would give your lounge something to think about.
Someone said about using parametrics, I only ever use parametric eq to tune a PA system never a graphic, graphics tend to introduce more phase shift, and they are not flexible in terms of frequncey selection and Q shape, its always about compensating resonances in the room, never about eqing the speakers. At least not with the system we use.
In fact when we are outdoors, I use little if any eq at all........
Depending on the music, like for example in this show, I have the subs turned down quite a bit from where I ran them last week when we did Faith No More.
I could go into it more but I dont know if people are that interested given this is a hifi forum and not a live engineers forum.

Thanks for the reply. Very cool stuff, and it must be pretty interesting working with Cliff, and Faith No More sure would be a fantastic bonus.

I'm not an engineer myself, but I sure would love to play one. I've always been interested in large systems, how they are built, and how they are tuned, so on and so forth. I used to work local crew years ago in Texas, and would always bug the hell out of the sound guys to work with them. Turning a few vibrations into huge sound has always been intriguing to me..

I'm with Fred Sanford, we'd love a thread about what you do and how you do it. There are a lot of engineers in one sort or another involved with sound reinforcement around this place...

 

[kevzep]

Here's something I haven't seen mentioned in EQ discussions, & I'm thinking about getting one just to play with because of this concept.
If you go & get a good hearing test the results will most likely show that your "response" isn't even close to flat. If you're of a certain age you're almost certain to have a dip in the upper mid's. So I wonder what it would sound like if I used an equalizer to flatten out the graph I got from my Audiologist...
I know - this should probably be a whole different thread.

Well first you would use a parametric eq, because the response curve you get from your hearing test would require you to use many filters on a graphic, this causes phase shift, yes phase shift, doesnt ,matter how good it is or what anyone says but this is what happens.
When you use a parametric you would use one or two filters and be able to manipulate the q shape to the required curve. Minimising phase shift, Meyer make an excellent parametric called the CP10 http://www.meyersound.com/products/processor_drive_systems/cp-10/
Too many people start using tone controls whether its negative feedback active eq's or passive eq's without thinking about whats happening with your most important curve, which is phase.
Why cant you hear the "air" in a song or the reverb or whatever, the way another person claims, well its most likey to do with Phase.
What you need to is to have the correct match with your speakers amps and whatever else you are using.
I use nothing in the way of tone manipulation, when you have your system right there is no need. If you want a fatter sound, use speakers with bigger bass drivers, dont just turn the bass up for example.
Anyway, thats what I know, not what I think.

 

[kevzep]

:drool: :drool:

I have a JVC SEA-80 Eq I run with, which I have tuned to my room parametrics. It has a pink noise generator and a microphone input. It is a dam fine unit and can tune the room to "flat" as easy as pie The best EQ I have found sofar.

My point is that you have fixed filters on graphic equaliser, whatever resonant frequencies are in your room are most likely not specifically the exact frequency options you have, its most likely not 250hz but rather 235hz or whatever so you naturally take out the closest frequency, and remove a lot of something thats not the problem.............This is where a parametric comes into play. Also another way, and its what Ive done
is to treat your room for problem frequencies rather the exchange the problem you solve with some phase shift.
Unfortunately we do not have this luxury in Live sound because we play in sports arenas and the likes, even outdoors we encounter grandstands and the likes which make it very difficult sometimes, but we have extremely expensive measuring equipment to combat these situations.

 

[kevzep]

There are a number of live engineers here, feel free to start your own thread. I'd check it out, for sure.

je

Yes good idea, I will look into it for sure, Ive spent most of my adult life doing live audio, I have learned a lot in that time, and sometimes the hard way.

 

[HandyHamlet]

Okay, this is what I don't get.

You have a system where everything is working correctly. The speakers, amp, media players all are perfectly matched.

Yet no matter what media you are playing the sound quality varies from recording to recording. One album may sound great yet another will not. A perfect system isn't going to fix an unpleasant recording. Room dynamics won't fix it.

So... instead of adjusting the tone controls or introducing an EQ into the system we are supposed to just suffer through?

This is what I don't understand. What am I missing please?

 

[Fred Sanford]

Okay, this is what I don't get.

You have a system where everything is working correctly. The speakers, amp, media players all are perfectly matched.

Yet no matter what media you are playing the sound quality varies from recording to recording. One album may sound great yet another will not. A perfect system isn't going to fix an unpleasant recording. Room dynamics won't fix it.

So... instead of adjusting the tone controls or introducing an EQ into the system we are supposed to just suffer through?

This is what I don't understand. What am I missing please?

If I like the album enough, I re-EQ it myself using parametric EQs within ProTools.

Actually, yeah, it's a personal decision. I think he's just pointing out that everything is a compromise. Sometimes you can get closer to what you want tonally, but you pay the price of adding distortion or noise, adjusting only approximate frequency ranges, or messing with phasing. It's your individual choice.

je

 

[HandyHamlet]

If I like the album enough, I re-EQ it myself using parametric EQs within ProTools.

Actually, yeah, it's a personal decision. I think he's just pointing out that everything is a compromise. Sometimes you can get closer to what you want tonally, but you pay the price of adding distortion or noise, adjusting only approximate frequency ranges, or messing with phasing. It's your individual choice.

je

Thanks for the reply. I want to make it clear I am not singling out any individual post. I really am trying to wrap my head around this.

Also there are actually two different conversations going on here? One is about professionally recording/presenting live music and one is about home systems? Parametric EQs are for sound studios?

Could someone please explain "phasing"?

Thanks!



I feel like I jumped in the shark tank without waterwings. I have reread kevzeps posts several times.

So there may be weaknesses in a system or the room is not conducive to optimal sound so people wrongly use tone controls or EQs to compensate? Instead of fixing the room or swapping out equipment?

What about playing crappy recordings? That's what I thought EQs were for? I use mine on individual recordings. I haven't noticed distortion. Not trying to be argumentative (for once). Just trying to figure out what I'm supposed to be listening for.

 

[kevzep]

If I like the album enough, I re-EQ it myself using parametric EQs within ProTools.

Actually, yeah, it's a personal decision. I think he's just pointing out that everything is a compromise. Sometimes you can get closer to what you want tonally, but you pay the price of adding distortion or noise, adjusting only approximate frequency ranges, or messing with phasing. It's your individual choice.

je

Fair enough, totally fair comment................

 

[kevzep]

Thanks for the reply. I want to make it clear I am not singling out any individual post. I really am trying to wrap my head around this.

Also there are actually two different conversations going on here? One is about professionally recording/presenting live music and one is about home systems? Parametric EQs are for sound studios?

Could someone please explain "phasing"?

Thanks!



I feel like I jumped in the shark tank without waterwings. I have reread kevzeps posts several times.

So there may be weaknesses in a system or the room is not conducive to optimal sound so people wrongly use tone controls or EQs to compensate? Instead of fixing the room or swapping out equipment?

What about playing crappy recordings? That's what I thought EQs were for? I use mine on individual recordings. I haven't noticed distortion. Not trying to be argumentative (for once). Just trying to figure out what I'm supposed to be listening for.

Im talking about extreme scales here, and I guess domestic audio gear verses proffessional gear, because I use both and can make informed comparisons.
Later on today when Ive got some more time I will put something about phasing into simple terms, theres no need to too silly techical about it.
I know this might sound snobish or whatever, I dont play crappy recordings, in any case a crappy recording on a nice sysytem wont actually sound as crappy as it would on a comprimised system.

 

[Fred Sanford]

Thanks for the reply. I want to make it clear I am not singling out any individual post. I really am trying to wrap my head around this.

Also there are actually two different conversations going on here? One is about professionally recording/presenting live music and one is about home systems? Parametric EQs are for sound studios?

Could someone please explain "phasing"?

Thanks!



I feel like I jumped in the shark tank without waterwings. I have reread kevzeps posts several times.

So there may be weaknesses in a system or the room is not conducive to optimal sound so people wrongly use tone controls or EQs to compensate? Instead of fixing the room or swapping out equipment?

What about playing crappy recordings? That's what I thought EQs were for? I use mine on individual recordings. I haven't noticed distortion. Not trying to be argumentative (for once). Just trying to figure out what I'm supposed to be listening for.

EQs can absolutely be used to make crappy recordings more palatable. I have many, many recordings that are one-of-a-kind (either of that certain song or of that certain performance) and they sound like ass. If I love something about the recording enough, I used to EQ it on the fly (I had a TEAC/Tascam dual 10 band graphic in my system for that purpose). These days, if I love it enough I'll make a new recording of it with some EQ treatment, especially if it's on a format that the media (or my player) is deteriorating & I want to archive it on to another format anyway.

EQs are a hot spot here on AK for a number of reasons. First off, graphic EQs were in fashion for a while, so lots of manufacturers made them, and many of them sucked. Think about turntables- for a while, there were millions of them around, but lots of them were cheezy & sounded bad even with a good record. That doesn't make all turntables suck, but it does mean that when somebody sees a turntable in your system, they remember lots of suckage from their past. EQs can be the same for me- I've used lots of great ones, both in residential and commercial/pro systems, but I've seen LOTS of cheezy ones in home hi-fi systems, with either a big-boost smiley-face curve, or every single slider at or near max. In those situations, they're adding distortion & noise. A well-designed EQ in educated hands is a tool, and can do certain jobs just fine.

Parametric vs. graphic isn't really a home vs. pro thing, although I'd figure that many of the best parametrics are not made for home-use unbalanced line level signals. I think graphics are more intuitive for general users (they can see the spectrum laid out for them), where parametrics take a little more experience (it helps if you can "see" the spectrum in your head, with an ability to correlate the numbers to the corresponding frequencies, bandwidths & gain changes you're hearing). Parametrics are just more versatile & precise in their control, and less damaging to the original signal- that's why pros will reach for them & recommend them.

Yes, EQs are used to un-do problems with a room, but again- it's a compromise. You do the best with what you have. A graphic EQ (or any poorly-designed EQ) can introduce bad changes to the music along with the good changes you're looking for. It also can only really change the balance of the sound your system is producing...it doesn't stop the reflections you're getting from the room, it can only change the balance of direct & reflected sound at that adjusted frequency. Not sure if I've explained that very well...

je

 

[parcs]

I have an Audio Control 10 that I used for a couple of years. I was reasonably happy with its performance but then decided to go back to my MQ-102 on ML-1C speakers.

 

[HandyHamlet]

Thanks for the responses. This is what I have gathered.

Ooooo-kay.

When a sound guy says phase he is talking waves.

Every room has anomalies that an EQ can compensate for if the EQ is precise enough to correct the room's exact opposing phase shift?

Which a Parametric EQ is way better at than a Graphic EQ because center frequency and bandwidth are fixed on a Graphic EQ.

A Graphic EQ can be used for tonal control but it's a matter of personal choice.

Hope I got that right.



And not to derail the OP's thread anymore I use EQs when playing all digital files, with my computer, and for some CDs.




:drool:

 

[kevzep]

EQs can absolutely be used to make crappy recordings more palatable. I have many, many recordings that are one-of-a-kind (either of that certain song or of that certain performance) and they sound like ass. If I love something about the recording enough, I used to EQ it on the fly (I had a TEAC/Tascam dual 10 band graphic in my system for that purpose). These days, if I love it enough I'll make a new recording of it with some EQ treatment, especially if it's on a format that the media (or my player) is deteriorating & I want to archive it on to another format anyway.

EQs are a hot spot here on AK for a number of reasons. First off, graphic EQs were in fashion for a while, so lots of manufacturers made them, and many of them sucked. Think about turntables- for a while, there were millions of them around, but lots of them were cheezy & sounded bad even with a good record. That doesn't make all turntables suck, but it does mean that when somebody sees a turntable in your system, they remember lots of suckage from their past. EQs can be the same for me- I've used lots of great ones, both in residential and commercial/pro systems, but I've seen LOTS of cheezy ones in home hi-fi systems, with either a big-boost smiley-face curve, or every single slider at or near max. In those situations, they're adding distortion & noise. A well-designed EQ in educated hands is a tool, and can do certain jobs just fine.

Parametric vs. graphic isn't really a home vs. pro thing, although I'd figure that many of the best parametrics are not made for home-use unbalanced line level signals. I think graphics are more intuitive for general users (they can see the spectrum laid out for them), where parametrics take a little more experience (it helps if you can "see" the spectrum in your head, with an ability to correlate the numbers to the corresponding frequencies, bandwidths & gain changes you're hearing). Parametrics are just more versatile & precise in their control, and less damaging to the original signal- that's why pros will reach for them & recommend them.

Yes, EQs are used to un-do problems with a room, but again- it's a compromise. You do the best with what you have. A graphic EQ (or any poorly-designed EQ) can introduce bad changes to the music along with the good changes you're looking for. It also can only really change the balance of the sound your system is producing...it doesn't stop the reflections you're getting from the room, it can only change the balance of direct & reflected sound at that adjusted frequency. Not sure if I've explained that very well...

je

Nicely put there, for me personally I like to use the very best equipment I can get my hands on, because thats what I am used to using. I can hear the shortfalls of cheaper gear immediately. Which sometimes is a curse........
I wasnt saying you cant EQ things, because you can, and thats why they make them, but I think its good to be aware of whats happening when you do. Yes after I wrote my reply I thought about it and I do apply a bit of eq to the odd crapy bootleg I have many of, so Im eating my own words now. But seriously Im careful with the amount I do use because if youre not you go past the point of improving it and then creating another problem.
You do actually want to have the best combination of gear to get the sound you like before you feel the need to turn on the eq and start fiddling. For example, maybe you like a bit more bass tan the average person so you might go for something with double 12" bass driver as opposed to a single or whatever.
Its all about what youre personal preference is at the end of the day............

 

[kevzep]

Thanks for the responses. This is what I have gathered.

Ooooo-kay.

When a sound guy says phase he is talking waves.

Every room has anomalies that an EQ can compensate for if the EQ is precise enough to correct the room's exact opposing phase shift?

Which a Parametric EQ is way better at than a Graphic EQ because center frequency and bandwidth are fixed on a Graphic EQ.

A Graphic EQ can be used for tonal control but it's a matter of personal choice.

Hope I got that right.



And not to derail the OP's thread anymore I use EQs when playing all digital files, with my computer, and for some CDs.




:drool:

Phase is everything to do with soundwaves. When the soundwave from one source hits a surface and is reflected, it arrives at the listening position later than the direct soundwaves from the speaker, what happens is the ones arriving later are out of time/phase (phase is also related to time, and polarity) so in some instances there may be "adding" of some frequencies or cancelling of some frequencies. So if you are in a very reflective room with windows and polished wooden floors you get lots of relflections, even the relections work against eachother as well, and because its very reflective, the reflections are almost as loud as the direct sound source and you have some serious problems. Lots of carpet soft surfaces, large curtains and things like that help a lot.
This is where your eq can help, but you need to know what these frequencies are in order to deal with them. There are measuring instruments which can help with this. but its getting a bit over the top for your home stereo.
With your parametric comment that is correct, also to add, some graphics have constant Q (bandwidth) like the White 4650's, some have variable q like the Klark Teknik DN360 the more you take out the narrower the q goes.
Also you would use more filters on a graphic doing the same thing as would on a Parametric, so therefore minimising phase shift from the filters because you are using less on the parametric, as this is what they do to varying degrees, the more developed the design the less phase shift you experience.
It is a matter of personal choice, but as I said before its good to understand a little aboutwhat is going on...........

 

[ojojunkie]

Even modern HT system still using EQ to compensate the roomacoutics... :scratch2:

so, I believe the best ever made are those made us smile while listening to our music!...

 

[kevzep]

Even modern HT system still using EQ to compensate the roomacoutics... :scratch2:

so, I believe the best ever made are those made us smile while listening to our music!...

Well try this, take your speakers into the bathroom or a room where there are lots reflections and resonances, then eq the the system until you "think" it sounds good. Right now take the speakers to a bedroom or a room that has carpet and curtains, not so much glass. Play the same song, leave the eq the way you had it in the bathroom and tell yourself you havent murdered the sound of your system.
Eq'ing a room does not get rid of resonances, they are always there, you end up removing those resonant frequencies from you system which may help to some degree, but it unbalances you systems sound introduces phase shift (doesnt matter how good the eq is, they all do it, some worse than others) and you have a whole new set of problems.
Reflections are something you have to physically fix, by re focusing where the speakers are pointing and go for carpets and big long heavy drapes and net curtains to keep the reflections to a minimum, in otherwords sort the problems out in the room phyically rather than doing it electronically.
FLAT FLAT FLAT!!!!! leave it the way it was intened to be heard, put a little bit of bass into it at low volumes and it will all be good.
Have good speakers which you like the sound of, I said ealier in the thread if you like turning up the bass, get speakers which are bass heavy speakers for example.
If you have an excellent phase coherent system, which had a flat repsonse you will be surprised at what you dont need to eq.......................

Rock on.........:guitar::guitar::guitar:

 

[Artie]

Sometimes I wonder if "phase coherence" is all its cracked up to be. Consider this: If I'm at a symphony, I don't hold my head perfectly still, while staring at the center of the stage. I move my head around looking around at the performers and such. So, the "live" phase is constantly changing. It doesn't detract from the performance.

Now consider a recording: The mics won't be placed where my ears would be, and my speakers won't be placed where the mics were. The chances of my stereo reproducing an original phase coherence is slim-to-none. Yet, it will still sound good, with a good sound stage. (Assuming a reasonably good system.)

I don't think that placing a quality EQ is going to do any more damage than is already done by the recording/playback process to begin with.

IMHO. :scratch2:

 

[Cheezman]

Sometimes I wonder if "phase coherence" is all its cracked up to be. Consider this: If I'm at a symphony, I don't hold my head perfectly still, while staring at the center of the stage. I move my head around looking around at the performers and such. So, the "live" phase is constantly changing. It doesn't detract from the performance.

Now consider a recording: The mics won't be placed where my ears would be, and my speakers won't be placed where the mics were. The chances of my stereo reproducing an original phase coherence is slim-to-none. Yet, it will still sound good, with a good sound stage. (Assuming a reasonably good system.)

I don't think that placing a quality EQ is going to do any more damage than is already done by the recording/playback process to begin with.

IMHO. :scratch2:

The mics may not be placed where your speakers would ideally be during recording; but that's where the mixer comes in.

All the sounds recorded are then mixed and played back through a stereo or surround sound set up that is much closer to what you would have in your home. Therefore, "correct" placement is still important for playback.

At least, that's how I have come to understand it.

 

[whoaru99]

Every room has anomalies that an EQ can compensate for if the EQ is precise enough to correct the room's exact opposing phase shift?

Hope I got that right.

:drool:

I disagree a bit with this part. If there is a dip caused by cancellation, trying to "boost" your way out if it is like trying to fill a bottomless pit.

 

[kevzep]

I disagree a bit with this part. If there is a dip caused by cancellation, trying to "boost" your way out if it is like trying to fill a bottomless pit.

Absolutely correct!! Fix the room............