Active or passive monitor controller?

[Marrone]

HI!!

I am a bit confused. I am about to buy a monitor controller and have been reading a lot about it. Some people claim passive is better and other claim active is better. Who is right?? What are the differences, advantages and disadvantages between active and passive monitor controllers?? Thanks

Marrone

[pieter]

I'm using a Cranesong Avocet which is about the best purchase I ever made.

A lot depends on the functionality you need (talkback, D/A conversion, gain offsets) and your budget of course. The more complex things you need, the harder it is to implement in a passive controller.

Before the Avocet, I used a custom built passive volume control (basicly a hardwired volume pot in a box), which is OK but not great as long as you are using short cable lengths etc.

[Marrone]

So let me get this straight.. You are saying that passive is better but when you need extra stuff on there like headphone preamps etc. active is better?

[pieter]

I would rather say that passive can be OK for simple solutions (e.g. coleman boxes) but not if you need all the extras.

Do note howver that there is a difference between active and ACTIVE. If you take Crane Song and Dangerous for example, they use remote controled relays for setting volume, which is far superior to some other designs. Basically good active circuitry is gonna cost.

[Koed]

Usualy the headphone amps and some other gadgets are the only active components in an monitor controller.
As long as the audio path is passive, you're set.

[Marrone]

Would the SPL Volume 2 monitor controller (active) affect the quality of my ua 2192 or Rosetta converters??

[flute player]

Koed,

I own this one from Coleman audio.
It is a passive controler and in combination with my active BM6a a very good one.
A nice device which has the opportunity to switch several speakers.
The most important thing in a level controler is that it has good pod meters.
Well, this one does.
And it has got no talk back function but it is manufactured with a headphone input.
It is not for sale in The Netherlands so therefor I have bought it in the US.
And that is off course cheaper too !!
I had to remove the US connector into a Euro connector.
There is a voltage switch on board form 110 to 240. ( the frequency is changing too )
But they can suply it with everything in European specs also.



Paul

[kt66]

Originally Posted by pieter

I'm using a Cranesong Avocet which is about the best purchase I ever made.

Ditto.


This is an absolutely wonderful box with a D/A that sounds incredible. I wouldn't even consider anything else.

[S-N-S]

Originally Posted by flute player

Koed,

I own this one from Coleman audio.
It is a passive controler and in combination with my active BM6a a very good one.
A nice device which has the opportunity to switch several speakers.
The most important thing in a level controler is that it has good pod meters.
Well, this one does.
And it has got no talk back function but it is manufactured with a headphone input.
It is not for sale in The Netherlands so therefor I have bought it in the US.
And that is off course cheaper too !!
I had to remove the US connector into a Euro connector.
There is a voltage switch on board form 110 to 240. ( the frequency is changing too )
But they can suply it with everything in European specs also.

Attachment 30535

Paul

what is the price off these?

[Bill@WelcomeHome]

remember that with a passive system you need to keep those cable runs very short.

Both have advantages. I picked a simple, high quality active unit (I built it from scratch using high quality parts) with VERY FEW components. More importantly, it has stepped attenuation for repeatable levels.

Wish i could afford an Avocet, which is much more than just an attenuator. Barring that, I am very happy with my choice.

[Firechild]

Originally Posted by Marrone

So let me get this straight.. You are saying that passive is better but when you need extra stuff on there like headphone preamps etc. active is better?

Correct, a passive is not affecting the sound, and I guess it is that you think is "better". An active controller will indeed affect the sound a bit but in return give you more features.

[Geoff Waddington]

Goldpoint SA1X, SA2x, etc.

Goldpoint Level Controls

[Big_Bang]

As long as the path is all analog to the mix monitoring, all rest is budget analysis.

If the path is active, I wouldn't go that way.

[Fezzle]

Yeh active controllers use amplifiers etc to get the signal to the speakers. Passives dont, I use the coleman unit aswell and its wicked. Basically Wire with Switches and an attenuator.. this has no electronics so just limits the amount of signal comin from your converters, So.. completely transparent
Im sure active systems can be excellent too, but have to be very high quality in order for the circuits not to colour the sound your gettin

[Bill@WelcomeHome]

Originally Posted by Fezzle

Y.. this has no electronics so just limits the amount of signal comin from your converters, So.. completely transparent...

Not true. If it was, we'd all be using passive systems except in special cases. It still comes down to which you prefer and which works best for you.... a matter of taste, not science.

[ofajen]

Bearing in mind that I work strictly analog in a fairly straightforward way, I'd say passive can work great in that setting, and can be high spec at low cost. The Avocet costs about 20 times more than my custom built system, for example.

I use a custom-made Shallco stepped attenuator that is basically a product line they acquired from Daven in the 1960s that has been in production in similar form and regular use for over 75 years. It uses precision resistors to provide excellent L/R matching and a high resolution audio path. I run the attenuated signal to my power amp and use a DIY bank of switches to select among the speakers. I made the switch bank using a box of standard AC light switches that cost less than $5.

Cheers,

Otto

[Fezzle]

Originally Posted by Bill@WelcomeHome

Not true. If it was, we'd all be using passive systems except in special cases. It still comes down to which you prefer and which works best for you.... a matter of taste, not science.

Isnt it, sorry i guess i mean active electronics. I dont think passive systems interfere with the sound like actives do, . Everybody isnt using passive designs because stepped attenuators are very expensive and I believe they are the only way to reach true transparency without shifting phase etc. VCA's in active systems introduce distortion and that is science. However they are cheaper to implement in a design so thats why active systems are often more accessible. I had a lengthy discussion with a tech before buying mine.. and whilst your not wrong about taste being a factor in what works for you. Passive circuitry (in theory)wins in retaining sonic purity despite other options available unit to unit.. and when monitoring that is of course important. Yet like you say there are exceptions. The Avocet is supposed to be transparent as hell, and is active.. so is a little more versatile, yet that design is pretty much high end when you look into it, using class A buffer amps etc.

[Granny Gremlin]

@ ofajen, Geoff Waddington or anyone else using a passive stepped attenuator (DIY or otherwise).

I am making myself a passive routing patch panel sort of thing and wanted to incorporate some passive attenuation. Assuming balanced +4 line level (the source device may vary between transformer coupled true 600 Ohm to active balanced to ground-sense/pseudo-balanced), what value of total resistance is required for the attenuators? Most readymades come in 10, 25, 50, 100 and 250K, but I've seen Davens spec'd at 500/600 but I'm not clear if they mean that they're for use with 600 Ohm line or if that's the actual DCR of the attenuator.

Also, any opionions out there as to the pros/cons of various resistive stepped attenuators (ladder, shunt, series) vs transformer based volume controls? Do they even make TVC trafos that could handle balanced +4 line level?

[Bill@WelcomeHome]

Originally Posted by Fezzle

... stepped attenuators are very expensive ........ Passive circuitry (in theory)wins in retaining sonic purity ....

Stepped attenuation has nothing to do with passive or active. My active unit uses a TKD stepped attenuator and op amps from Fred Forssell.

" Passive circuitry (in theory)wins in retaining sonic purity"

in theory, but not in practical application. Your opinion is yours to keep, but anything you put in between the signal source and the amp changes the sound. Which you like is what matters. Neither is inherently 'best', but either could be best for a given need.

[fredouli]

Have the Coleman M3A, which is actually currently for sale on the GS Classifieds...

Is the active version, however we can't hear this thing work, Coleman is a great company that makes top notch gear.

[Geoff Waddington]

Originally Posted by Granny Gremlin

Also, any opionions out there as to the pros/cons of various resistive stepped attenuators (ladder, shunt, series)

Stepped Attenuator Types

[u b k]

Originally Posted by Fezzle

I dont think passive systems interfere with the sound like actives do.

This is a commonly held belief, but it is mistaken. Passive 'systems' have the elegance of simplicity, but they present impedance issues both to the device feeding them and the device they feed, with the latter being much more susceptible to shifts in tone and transient response as a result. And for better or worse, a great many expensive pieces of hardware have design flaws which make them even more prone to impedance issues, including the built-to-a-budget amps that live inside everyone's powered studio monitors.

Originally Posted by Fezzle

IVCA's in active systems introduce distortion and that is science. However they are cheaper to implement in a design so thats why active systems are often more accessible.

It's true, vca's are prone to distortion, but I'm not aware of a single active monitoring system that uses vca's to adjust the gain. An input and output line amp buffering a simple gain change circuit are all that's needed, and some of the amps available for this use are orders of magnitude cleaner and more accurate than those used in 99% of the gear they'll be connected to.

I've got a clear bias here, as I make and sell an active monitoring system that's not too much more $ than the all passive, relays-and-switches-and-a-pot Central Station, and our monitor controller wipes the floor with that device. This is born out not just in listening tests but also objectively measured signal tests measuring distortions, crosstalk, frequency response, and transient fidelity.

There's a reason every high end, highly regarded monitor controller is active, and it's not because we fancy over-designed circuits loaded with unnecessary parts; it's because well-designed active circuits overcome the limitations and issues passive designs inherently suffer from. If they didn't, I'd simply source a $5 24-position switch from china, stick it on a $3 pcb with a handful of $.01 resistors, and sell boatloads of them for $50 because that'd be the no-brainer move from an ease and profitability standpoint.

I tried that, it didn't hold a candle to the sonic purity of the active design, so in the dumpster it went.


Gregory Scott - ubk

[Big_Bang]

With a grain of salt there Greg!

I've been a proper slut in regards to monitoring (as in buying, selling, an testing every god damn offer I could get my hands on).

While I absolutely do agree with everything you said, ergo, hi-end active gear kicks butt... it was in the 50 buck region I found my god sent budget attenuator. The TC Pilot. I love that thing so much I rave about it every chance I get, zero affiliation!!

It is by far cleanest and most transparent thing I've heard. Does not suck up tone at all, no noise at all (as in time prone scratching, 3 yrs now running), transients are clean, etc...

It only does the one thing, but it does it well.

[ckett]

Big Bang,

Is your TC Level Pilot getting scratchy at all? Just wondering if this thing holds up over years of use. Many have complained about it getting scratchy even after a few months use.

[Fezzle]

Originally Posted by u b k

This is a commonly held belief, but it is mistaken. Passive 'systems' have the elegance of simplicity, but they present impedance issues both to the device feeding them and the device they feed, with the latter being much more susceptible to shifts in tone and transient response as a result. And for better or worse, a great many expensive pieces of hardware have design flaws which make them even more prone to impedance issues, including the built-to-a-budget amps that live inside everyone's powered studio monitors.





It's true, vca's are prone to distortion, but I'm not aware of a single active monitoring system that uses vca's to adjust the gain. An input and output line amp buffering a simple gain change circuit are all that's needed, and some of the amps available for this use are orders of magnitude cleaner and more accurate than those used in 99% of the gear they'll be connected to.

I've got a clear bias here, as I make and sell an active monitoring system that's not too much more $ than the all passive, relays-and-switches-and-a-pot Central Station, and our monitor controller wipes the floor with that device. This is born out not just in listening tests but also objectively measured signal tests measuring distortions, crosstalk, frequency response, and transient fidelity.

There's a reason every high end, highly regarded monitor controller is active, and it's not because we fancy over-designed circuits loaded with unnecessary parts; it's because well-designed active circuits overcome the limitations and issues passive designs inherently suffer from. If they didn't, I'd simply source a $5 24-position switch from china, stick it on a $3 pcb with a handful of $.01 resistors, and sell boatloads of them for $50 because that'd be the no-brainer move from an ease and profitability standpoint.

I tried that, it didn't hold a candle to the sonic purity of the active design, so in the dumpster it went.


Gregory Scott - ubk

Hey Greg, well Im more clued up now so thanks, But Im pretty sure comparing a $50 dollar passive unit with one of your well thought out and highly accurate Active designs is a pretty inaccurate comparison. However I do not understand electronic principles much, so I do hear you!

[Big_Bang]

I have heard about this, but so far no issues with mine... as I said, 3 years in usage.

The only issue is the design flaw where when you set it really REALLY low, the image shifts left completely. It doesnt bother me at all though, as it is in a such a low volume region, below what I would set it to check vocal relative volume sit-in-the-mix.

[Matt Syson]

Hi
A properly designed and made passive unit stuck literally on the front of each monitor amp (within say a foot or so) COULD be 'best' as long as the 'source' comes from only one output stage (mixer, D/A or whatever) or from sources that are electrically similar. The main 'downer' is that the physical location puts it on the front of a powered monitor or you have a 'seperate' power amp driving passive speakers sat on your knee. The important thing with a 'passive' control is that there must be an absolute minimum of capacitive loading (length of cable) attached the the OUTPUT of the control. The input is not (or should not) be so much of an issue. You are probably not aware of how much the fequency response of your monitors change with the level control at 'max' compared to 6dB down. In many cases this will be rather more than any supposed change between one opamp or another.
Once you get beyond a simple level control (attenuator) and maybe a couple of source select switches you either have to go into serious mental gymnastics to work out constant loading of all parts (input and output impedances) or much simpler, add a 'buffer' amplifier.
Replacing the input level control on your active monitors with a 'relay' controlled attenuator so that the same control signals can be fed to your speakers several feet apart would be ideal.
Matt S