parametric eq front panel

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ppa

Well-known member
Joined
Jan 18, 2009
Messages
1,172
Location
Italy
Is it better having a front panel of 2U, 3U or 4U in a full-parametric equalizer?
I'm not referring to the mastering equalizers.

Pier Paolo
 
Only hardware parametric I have is the Orban 622B, and it borders on cramped at 2RU, that's with dual concentric pots. 
 
pucho812 said:
you can fit bigger knobs in a 4 unit pannel

what is important to save space in a recording studio as given by an 2U eq vs. the ergonomic use of a 4U eq? considering that we are speaking of a no mastering eq.


 
How many bands?

3U works well on many popular mastering eqs, there's no difference ergonomically between how you want to use a mastering or mixing eq.
 
thanks to all,

I have designed it with 4 bands but I can easily adding another one.
These bands are: 
30 - 450 Hz 
150 - 2000 Hz
650 -10 KHz
2K - 25 KHz

the low band and the high band have the shelving option.
I could modify these bands.

I am oriented to 3U panel since many have this size.
Regarding the knobs any comment is very welcome.


 
If the EQ has pots than a 13mm knob is probably fine. In that case a 2RU panel would work. For rotary switches I think you need at least 3RU for larger knobs and more text.
 
Gold said:
If the EQ has pots than a 13mm knob is probably fine. In that case a 2RU panel would work. For rotary switches I think you need at least 3RU for larger knobs and more text.


since should be good having the mastering version I am going for the 3U panel.
 
It depends on how you plan to use it, this will also influence relative size of knobs and spacing. Boost/cut will be most used, so needs to be handy, center frequency next, and q last. There have been some nice mixed implementation with a slide pot for boost/cut and rotaries for the CF and Q.

If you plan to use this a lot, give it the panel real estate it deserves. If this is going to be a set it and forget it application, like for corrective room EQ, it's ok to cramp it up.

Parametric EQ has many applications so no single answer for all. Do you need to read accurate panel markings, or plan to tweak by ear, with no need to return to previous settings? This too will influence real estate dedicated to controls.

JR
 
JohnRoberts said:
It depends on how you plan to use it, this will also influence relative size of knobs and spacing. Boost/cut will be most used, so needs to be handy, center frequency next, and q last. There have been some nice mixed implementation with a slide pot for boost/cut and rotaries for the CF and Q.

If you plan to use this a lot, give it the panel real estate it deserves. If this is going to be a set it and forget it application, like for corrective room EQ, it's ok to cramp it up.

Parametric EQ has many applications so no single answer for all. Do you need to read accurate panel markings, or plan to tweak by ear, with no need to return to previous settings? This too will influence real estate dedicated to controls.

JR

thank you John,

2U is totally excluded at this point, I think that 3U with 22mm knobs for gain and CF and 16mm for Q should be good but I would prefer some comments on these knobs' sizes before design this front panel. I would want an eq to be used often, with precise label indications.
BTW my eq has its parameters really indipendent between them. 
 
I have intention to use the black as background color and also the white for the labels to having the best contrast to see. As second option the blue in place of the black color. Comments are welcome also here, please. 
 
You should take a look at the Maselec EQ. It is like what you describe. It's a very clean and functional layout. I've been using one for close to 15 years. Some don't like the sound of them but I've never heard anyone complain about the ergonomics.
 
Gold said:
You should take a look at the Maselec EQ. It is like what you describe. It's a very clean and functional layout. I've been using one for close to 15 years. Some don't like the sound of them but I've never heard anyone complain about the ergonomics.

done, I use alluminium black knobs.
Regarding the bands ,Maselec and Massemburg EQ have a very large range to set FC .
I think that is better having an 1:10 or 1:12  FC range just as does the amek 2500, to have better precision and recall, instead the 1:40 of Massemburg and Maselec, because, however, with 1:10 range and with 4 bands is possible to cover the audio band very good. Comments are very welcome.

 
 
ppa said:
Regarding the bands ,Maselec and Massemburg EQ have a very large range to set FC .
I think that is better having an 1:10 or 1:12  FC range just as does the amek 2500, to have better precision and recall, instead the 1:40 of Massemburg and Maselec, because, however, with 1:10 range and with 4 bands is possible to cover the audio band very good. Comments are very welcome.

Agreed, but you can also add 10x range expander by switching in different caps. That way you can have both decent resolution and wide adjustment range.

If you are using SVF with grounded inverters, I like to use the frequency pot approach where pot wiper goes full off (to ground) and you shunt the whole thing with a fixed resistor to set LF end, that way you have good fixed resistor tolerance frequency precision at both frequency extremes, and pot is used purely ratio-metrically.

JR
 
JohnRoberts said:
Agreed, but you can also add 10x range expander by switching in different caps. That way you can have both decent resolution and wide adjustment range.

If you are using SVF with grounded inverters, I like to use the frequency pot approach where pot wiper goes full off (to ground) and you shunt the whole thing with a fixed resistor to set LF end, that way you have good fixed resistor tolerance frequency precision at both frequency extremes, and pot is used purely ratio-metrically.

JR

yes, I use SVF with grounded inverters, I use a dual linear pot with two fixed 1% resistors to have a semi-reverse log curve, so the high frequencies of the same band can be set better than like a reverse log pot can do. 


 
JohnRoberts said:
Agreed, but you can also add 10x range expander by switching in different caps. That way you can have both decent resolution and wide adjustment range.

1x10 swich and a relay for the inverter caps is a good idea, the only thing is that I have just designed the cells' PCB so insert a relay inside these board is a bit complicated.
However, I will add it at the next version. At this point I am thinking to add a band more.

But do the amek 2500 eq's bands run good?

 

 
ppa said:
Regarding the bands ,Maselec and Massemburg EQ have a very large range to set FC .
I think that is better having an 1:10 or 1:12  FC range just as does the amek 2500, to have better precision and recall, instead the 1:40 of Massemburg and Maselec, because, however, with 1:10 range and with 4 bands is possible to cover the audio band very good. Comments are very welcome.

The Maselec is all switched so there is no issue with precision or recall.  The Massenburg comes with pots on the 8200 and switches on the 9500. 

The big advantage of he 1:40 approach is that you can work on two nearby frequencies using 2 separate bands.  For example I might want to cut 1K and boost 2K, the 1:40 approach allows this using 2 bands where a 1:10 might restrict access to certain close frequency bands if each band has a dedicated range.

Are you making your eq with pots?


 
ppa said:
JohnRoberts said:
Agreed, but you can also add 10x range expander by switching in different caps. That way you can have both decent resolution and wide adjustment range.

If you are using SVF with grounded inverters, I like to use the frequency pot approach where pot wiper goes full off (to ground) and you shunt the whole thing with a fixed resistor to set LF end, that way you have good fixed resistor tolerance frequency precision at both frequency extremes, and pot is used purely ratio-metrically.

JR

yes, I use SVF with grounded inverters, I use a dual linear pot with two fixed 1% resistors to have a semi-reverse log curve, so the high frequencies of the same band can be set better than like a reverse log pot can do.

I am always apprehensive about relying on the bulk resistance of pots in production, even ratio-metrically where they are much better can be challenging some times, but for low volume design you can probably manage. The tricks to change the taper of linear pots with a load, often look better on paper than real life.

Good luck.

JR
 
ruairioflaherty said:
ppa said:
Regarding the bands ,Maselec and Massemburg EQ have a very large range to set FC .
I think that is better having an 1:10 or 1:12  FC range just as does the amek 2500, to have better precision and recall, instead the 1:40 of Massemburg and Maselec, because, however, with 1:10 range and with 4 bands is possible to cover the audio band very good. Comments are very welcome.

The Maselec is all switched so there is no issue with precision or recall.  The Massenburg comes with pots on the 8200 and switches on the 9500. 

The big advantage of he 1:40 approach is that you can work on two nearby frequencies using 2 separate bands.  For example I might want to cut 1K and boost 2K, the 1:40 approach allows this using 2 bands where a 1:10 might restrict access to certain close frequency bands if each band has a dedicated range.

Are you making your eq with pots?

yes, I am making an eq with pots and its mastering version with rotary switches.

Ok, I agree with you regarding the large bandwith. At this point I am thinking for 1:40 ratio
or, as JR suggested, a 10X switch for 1:100 ratio.




 

Latest posts

Back
Top