Active v. Passive rigs

josh

marathon solo-sessionahoy
Julz said:
Frankly, if you MUST have active...


So this is something that's interested me for a while. I have an old Mackie brochure and obviously they expound the benefits of their active system. But there seem to be many advantages to it, with better eq and phasing ability and i think there were many more advantages pointed out.

So why that statement above? (in the Psydmt classified ad section).

I know the Mackie brochure was obviously biased, so whats the score for the passive side?
 

turkeyphant

http://turkeyphant.org/
I always thought that active systems tend to be less customisable and allow less scope in fine-tuning. Also, they are usually more expensive and make upgrades far more difficult. To my stupid ears, Mackie Active rigs sound fine though.
 

Ishwara

Freedom
oh - I saw active vs passive and thought this was a gay thread - top vs bottom - swings an stuff - oops - bye
 

evilwill

definitely
dunno myself, but a mate of mine who works in the PA dept. of sound control bristol and runs his own business, highpressure sound systems, bought a mackie active rig and fairly quickly afterwards sold it to buy a passive rig. they both sounded pretty phat to me, but he went from being very pro active rigs to not at all pro active. not happy with some of the internal components i think, whereas with the new passive rig he could buy exactly the amps he wanted...
 

Plank!

The Sound Faery
josh said:
So this is something that's interested me for a while. I have an old Mackie brochure and obviously they expound the benefits of their active system. But there seem to be many advantages to it, with better eq and phasing ability and i think there were many more advantages pointed out.

There are NO technical advantages to Mackies "active" system. How can an internal amp have better EQ or phasing than a properly set up external amp on the same speaker?

Also the name "active" is just that, a trade name - Mackies active system is really "self powered"

Self powered speakers can also be active or passive, depends on the crossover type, and number of driver frequency ranges per amp.

Mackies product range is heavily biased towards live bands, as such they have a non linear EQ, with a large peak in the upper mid band - I find the sound of these systems very fatigueing, My ears hurt after a few hours exposure, even at moderate SPL's.

basically the mackie range - as with most self powered speakers - is designed for those who just want to plug in the PA and forget about it.
For the rest of us, who actually want to tailor the sound to a venue, or music genre, they are bloody hard work!
 

josh

marathon solo-sessionahoy
Plank! said:
There are NO technical advantages to Mackies "active" system. How can an internal amp have better EQ or phasing than a properly set up external amp on the same speaker?


I think they argued that it means the amp can be tailored specifically for that speaker.

However I see what you're saying with everything though, ta :Smile3:


Re. the horn-loaded speakers being better for psy/tekno, are the opus cabs horn-loaded? Like the smaller ones used at psyforum fundraiser party? And is horn-loading for the treble-only, not the bass right?
 

Plank!

The Sound Faery
josh said:
Re. the horn-loaded speakers being better for psy/tekno, are the opus cabs horn-loaded? Like the smaller ones used at psyforum fundraiser party? And is horn-loading for the treble-only, not the bass right?

The Opus CS750 system used at the forum party only uses horns on the HF section, Mids are direct radiating, and LF is reflex loaded.
Make of that what you will :Wink3:
 

josh

marathon solo-sessionahoy
While we're on this soundsystem FAQ freeforall... what does a phase-node do?

KSS have two speakers in their rig that have them:

http://www.kss-uk.co.uk/index.php?option=com_zoom&Itemid=28&page=view&catid=13&PageNo=2&key=23&hit=1

a guy is dusting one of them :Wink3:
They look like big air-raid sirens and phat as fook.

i want them in my room :Wink3:

And as for the two sets of two drivers in the cabs on either side - are they reflex loaded? where does the sound come out of them, it looks like they're facing backwards..
 

turkeyphant

http://turkeyphant.org/
josh said:
And is horn-loading for the treble-only, not the bass right?

I thought horn-loading was useful for lower frequencies because of the longer wavelengths? :iconfused
 

Plank!

The Sound Faery
turkeyphant said:
I thought horn-loading was useful for lower frequencies because of the longer wavelengths? :iconfused

Horn loading is useful in all frequency ranges, but requires a much bigger horn for lower frequencies.

Horn loading is great but not really needed in a small venue, gives too much throw, better to have reflex loading and get the sound you want rather than knock the back wall out :Wink3:
 

turkeyphant

http://turkeyphant.org/
Plank! said:
Horn loading is useful in all frequency ranges, but requires a much bigger horn for lower frequencies.

Sorry, I was being dumb. For some reason I read it all as "folded horn loading" rather than just plain linear horns. :iconfused
 

Plank!

The Sound Faery
josh said:
While we're on this soundsystem FAQ freeforall... what does a phase-node do?
a guy is dusting one of them :Wink3:
They look like big air-raid sirens and phat as fook.

i want them in my room :Wink3:

And as for the two sets of two drivers in the cabs on either side - are they reflex loaded? where does the sound come out of them, it looks like they're facing backwards..


they look like standard "phase correction plugs" to me - its a way of focusing the sound before it enters the horn, and helps control dispersion patterns.

No point having something like that in your room, they need to be 100M or so away to work properly :Wink3:

Nope those bass/low mid boxes are bandpass loaded, no reflex port there, as much sound comes from the back of the cone as from the front, all the designer did by putting them that way round, was increase the volume of air in the sealed side of the bandpass chamber.
 

josh

marathon solo-sessionahoy
how do they focus the sound? are the drivers in the bulging bits to the side of the cab? or are they in the node?



how does bandpass loaded differ from reflex or forward firing? what advantages does it have?

ta :Smile3:
 

josh

marathon solo-sessionahoy
already read :Wink3:

but just thought id take advantage of your presence hear for a more rough overview/laymans terms explanation.

Shall go and google some more though :Smile3:
 

josh

marathon solo-sessionahoy
i know ive nagged on at julz about these - but The End used to have them, i think they look absolutely wkd, thing theyre Thunder Ridge - although i cant find out anything about them on the web.
Would love to buy a pair though, anyone know how much theyd be? (obviously i wont but indulge my hypothetical wankery for a minute). There is literally nothing on them on the web.
I was gonna email the End when they threw their old system out and refit - to see if i could get a pair off them but didnt. Should have done.
http://www.speakerplans.com/index.php?id=mywork_011
 

norty303

Member (Todger)
Basically, reflex loading has a tuned chamber on one side of the driver (irrelevenat which way driver is, other than for box volume taken up/not taken up by driver - as Steve said) which is usually tuned for the lowest frequency the cab can play before the driver becomes unloaded (the air stops giving the driver mechanical cushioning leading to over excursion or 'bottoming out' where the voice coil former hits the magnet).

A bandpass cab has 2 chambers, front and rear which are tuned for different frequencies (6th order bandpass), one lower, one higher (or one a sealed chamber - 4th order bandpass). This allows slightly higher output but generally over a narrower bandwidth, and needs a fairly robust driver as there is less mechanical suspension in this type of cab and it's easier to break drivers as you can't hear them bottoming out because they're hidden away in the box.

Here's a plot of one of my BP6 cabs and you can clearly see how it only performs between 2 very distinct tuning frequencies:



In the KSS pics i'd say (imo) it's debatable whether the angle actually offers any sort of front chamber loading due to the narrow angle, it's very hard to measure these things - often it's done to reduce the frontal size of the cab (like Noise Control Audio).

Here's the aforementioned BP6 cab, which is more of what is known as a manifold design, where the whole open area in the centre acts as a port. you can really feel the effect of the port when you're in front of it.






Horn loading doesn't neccessarily give better throw, it's more to do with the fact that they have higher sensitivity to begin with so can achieve higher SPL's which means the sound travels further. There's also a funny thing to do with how the inverse square rule changes or something but you're better googling for that......

And i haven't said it yet, but will say it here, the Opus rig at the forum party was very nice sounding indeed, those 15" bass bins are proof that you don't need to go for large format drivers to go low and loud.
 

norty303

Member (Todger)
Oh, and Thunder Ridge are now defunct i believe.

And passive rigs all the way! Why bother running 2 sets of cable to every cab? And no redundancy whatsoever.
 

josh

marathon solo-sessionahoy
Are they? The End only refurbished their soundsystem with a new Thunder Ridge setup a few months ago?
 
Top