cpsmusic

Hi-Fi Graphic EQ as Tracking EQ?
« on: March 04, 2018, 06:17:32 AM »
Hi Folks,

I have a small home studio that I use for demos and songwriting. I've been on the lookout for a while for an EQ to use while tracking (I like the idea of getting things how I like them and then committing to a sound). I remembered that I had a Technics SH-8020 graphic EQ in storage - see here https://www.hifiengine.com/manual_library/technics/sh-8020.shtml.

Any reason why this won't work for tracking?

Cheers,

Chris



MagnetoSound

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #1 on: March 04, 2018, 06:49:37 AM »
Not great for repeatability. You might need to be taking a lot of photos if you want to get back sounds from earlier sessions. Also, there is considerably more phase shift going on beween frequency bands. There's a reason we favour parametrics or switched EQs for this. Other than that, I guess if it sounds good it is good.
Dan

I don't think people realize what an embarrassment of riches this place is   -  Paul Gold

JohnRoberts

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #2 on: March 04, 2018, 02:24:37 PM »
A friend of mine who built his own recording console (back in the 80s) put something like a 5 or 7 band graphic EQ in each channel. 

He operated a working studio and did a lot of commercial work. He likes the WYSIWYG aspect of GEQ for fast tracking sessions, that his advertising clients appreciated the speed too.

Different GEQ topologies will exhibit different Q/bandwidth vs boost/cut... opinions vary about which is best (but we know parametric is best).  8)  GEQ wins on speed.

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

ruairioflaherty

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #3 on: March 04, 2018, 03:07:13 PM »
Not great for repeatability.

Neither are musicians :-)  I need absolute recall in mastering but it never mattered much to me in my tracking days.  A lot of records were made on consoles with no repeatability.

Quote
Also, there is considerably more phase shift going on beween frequency bands.

No more or less phase shift than any other eq with the same curves, right?   

In my experience for tracking you want broad gentle tone shapers, and graphics will be necessarily a little more selective or focussed than that.

You may face challenges with headroom, older hifi gear often runs on +/- 12V rails and runs out of steam earlier than typical pro gear, that could leave you prone to clipping in tracking.

But all that said, you should just try it.  It might be great, or great on certain things.


Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #4 on: March 04, 2018, 04:34:13 PM »
I used do live sound in a local venue here for a while ,as is customary you find graphics on front of house and monitor sends.
Very often an engineer has his idea of whats right ,and puts puts a big sweeping curve across all the faders .First thing I did when I got in there was zero out the graphic then bypass it on front of house,and just work with the individual desk channel eq to get it sounding right  ,only on monitors where you need to notch out certain frequencies did I use it  and very sparingly at that.Graphics arent the most transparent of devices ,even the very good ones ,each fader has its own discrete op amp path and there all summed back together later ,noisey ould things at the best of times and some engineers cant resist putting a big smiley face on them .Not really what Id use for creative eq'ing ,the real plus of them is you can notch out problem frequencies very fast ,and not interfere with adjacent bands .

squarewave

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #5 on: March 04, 2018, 04:49:10 PM »
I have two UREI 527A that I really like. They use inductor capacitor filters, they're very quiet, they use only  4 op amps for all 27 bands, they're +-18V and the band frequency locations are accurate which is visually very useful.

Although the 527A slide assemblies are almost always horribly gummed up. I actually created a totally new slide assemblies for mine.

squarewave

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #6 on: March 04, 2018, 04:55:16 PM »
Graphics arent the most transparent of devices ,even the very good ones ,each fader has its own discrete op amp path and there all summed back together later ,noisey ould things at the best of times
Some graphic EQs are pretty horrible. But I think it depends greatly on the implementation. My UREI 527A are pretty quiet and transparent. Here's an SNR measurement plot of one of my 527A:



So 95.2 dB SNR and 0.006% THD. That's pretty transparent AFAIC.

And most of the op amps you're referencing are just the Gyrator circuits which I don't think generate a lot noise. There are usually only a handful of op amps in series with the signal (4 in the case of the UREI 527A). Maybe in the passband they do generate noise. The 527A is LRC so it doesn't use Gyrator's. Maybe that's why it's quiet. Not sure.
« Last Edit: March 04, 2018, 05:00:07 PM by squarewave »

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #7 on: March 04, 2018, 05:28:15 PM »
I remember having a look at some DBX graphics a while back ,defo no inductors in there ,fairly low end ones too .
One thing that struck me was as I cut frequencies the backround noise levels seemed to increase.

cpsmusic

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #8 on: March 04, 2018, 05:42:09 PM »
Thanks for the replies!

Repeatability isn't such a great concern for me however noise and headroon/clipping might be more of an issue.

I'll give the unit a test run and see how it goes.

Cheers!

JohnRoberts

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #9 on: March 04, 2018, 07:35:35 PM »
I remember having a look at some DBX graphics a while back ,defo no inductors in there ,fairly low end ones too .
One thing that struck me was as I cut frequencies the backround noise levels seemed to increase.
Depending on the topology both high boost and high cut can increase noise gain, but generally that should not dominate noise floor in decent designs.

There is nothing inherently good or bad about GEQ, just another flavor of tone shaping.

OTOH for live sound reinforcement GEQ are commonly used for FOH (front of house) and  MON (monitors). FOH generally use the more gentle (wider) 2/3 octave for FOH room EQ and narrow 1/3 octave for notching out feedback modes on stage. 

Neither of these are concerns for tracking while recording.

JR


Visit https://circularscience.com to hear what properly "cleared" drums sound like.


Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #10 on: March 04, 2018, 08:19:58 PM »
If you’re dead set on graphic EQ, White Intruments 4400’s are legendary, and are quite cheap too nowadays.
« Last Edit: March 04, 2018, 08:27:10 PM by AusTex64 »

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #11 on: March 04, 2018, 09:07:58 PM »
With modern PA setups where you have dedicated system controllers or speaker management systems, graphic eq isnt nessesary ,all the functions you need are in the menu's and DSP based .
In the particular system I refered to earlier, which was EV, one of the main issues was some bright spark had dialed in attenuation on the controller as a means of preventing the amps and speakers being driven to hard ,downside was this ended up with the desk outputs being driven way higher than they needed to be and available headroom was diminished.
Once I had switched out the behringer graphics ,got a feel for the room and got to know the desk eq's  my job was a pleasure.
In the end management fell to pieces ,there was a tendency to have lock-in drinking sessions after the bands had finished and the guy who ran the place would invariably end up off his chops, shouting and roaring at the staff ,packed my trunk and said goodbye to the circus.The venue pulled the shutters down not too long after ,never to see the light of day again.

squarewave

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #12 on: March 05, 2018, 12:23:03 AM »
If you’re dead set on graphic EQ, White Intruments 4400’s are legendary, and are quite cheap too nowadays.
According the White Instruments documentation [1] the 4500 is active tuned RC whereas the 4400 is LC resonator (like the UREI 527) and the noise is stated as "4500 80dB, Others 90dB below 0dBu referenced to the input regardless of the equalization settings". So this would suggest there is a significant advantage to the LC resonator design.

[1] http://www.whiteinstruments.com/um4244.pdf

Michael Tibes

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #13 on: March 05, 2018, 01:35:03 PM »
In case it wasn't mentioned before: being a hifi device the eq might (most likely will) have a lower maximal level, which might lead to unwanted distortion in a high level recording chain. I'm not sure about the phase shift. I guess that if you want a broader Q and move several sliders to achieve that it might cause more phase shift than a parametric eq.
But anyway, it is not so hard to try it out - I'd just give it a go. maybe it turns out to become your secret weapon ;-)

Also remember that the input will be unbalanced and connect your source accordingly - or add an input transformer.

Michael

ruairioflaherty

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #14 on: March 05, 2018, 04:20:30 PM »
I'm not sure about the phase shift. I guess that if you want a broader Q and move several sliders to achieve that it might cause more phase shift than a parametric eq.

The phase shift is not an issue, the shape of the curves may or may not be depending on how many bands the EQ has (likely 10).

"Any two equalizers producing the same curve do so with exactly the same phase shift. Same universe, same physics, same results -- much to marketing's chagrin"

Taken from here, a great read - http://www.rane.com/note115.html


living sounds

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #15 on: March 05, 2018, 05:48:39 PM »
I've got a Court Acoustics EQ (same thing as the White if I remember correctly). Stereo, 31 bands per channel, an inductor for every band, hybrid make-up-gain stage. These come either fully transformer-balanced or unbalenced. Sounds very nice and clean, will work for tracking, as set-once-and-forget EQ on the mixbus or for single sources during a mix.

I've thought more than once about taking out the inducutors and building an uber-Pultec, but destroying this really well-built unit would be a crime.

abbey road d enfer

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #16 on: March 05, 2018, 06:48:27 PM »
Any reason why this won't work for tracking?
A graphic EQ, particularly a 10-band, is a tone-shaper, where the curves are broad. Definitely not suited for surgical EQ, but perfectly fine for tone control.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

abbey road d enfer

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #17 on: March 05, 2018, 06:55:20 PM »
No more or less phase shift than any other eq with the same curves, right?   
+1. There's so much misunderstanding about phase-shift in EQ's...

Quote
You may face challenges with headroom, older hifi gear often runs on +/- 12V rails and runs out of steam earlier than typical pro gear, that could leave you prone to clipping in tracking.
Not this one! Runs on +/-15. I've always been appreciative of Technics GEQ's; apart from their unbalanced connections, they are every bit of a pro audio product.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

abbey road d enfer

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #18 on: March 05, 2018, 07:00:15 PM »
I guess that if you want a broader Q and move several sliders to achieve that it might cause more phase shift than a parametric eq.
Your guess would be wrong. Broad Q, whatever the way it is achieved, means less phase-shift.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

ruairioflaherty

Re: Hi-Fi Graphic EQ as Tracking EQ?
« Reply #19 on: March 05, 2018, 07:12:40 PM »
+1. There's so much misunderstanding about phase-shift in EQ's...
 Not this one! Runs on +/-15. I've always been appreciative of Technics GEQ's; apart from their unbalanced connections, they are every bit of a pro audio product.

Very cool!