Crossover??? Where to put em

[JRKO]

Other than in the enclosure...Where do you unsually place crossovers?

Are there pro's/con's to having the crossovers near the amps with a longer cable run to the loudspeaker or...

having a long cable run from the amp to the crossover and a short run to the loudspeaker?

Last but not least does anyone split the signal before it even gets amplified (for each driver of course)? This seems to be a good way as then the amp can be designed specifically for the freq. range its powering.

[Stuart Easson]

Hi,

A speaker which has been designed with the 'guiding' principle of splitting the audio spectrum into individual speaker freq bands before power amplification and then delivering the result directly to the individual drive unit is commonly referred to as 'active'. Sonically there are many benefits, but of course a low/line level crossover/equalizer, plus additional channels of amplification are needed...so as in all things there are tradeoffs.

The orion and phoenix speakers, many pairs of which are described in threads here are a multi-way, state of the art active, equalised speaker system.

There are speakers that have 'outboard' crossovers, they are generally a generic looking box designed to sit close to, perhaps under or behind, the speaker they feed. The box will generally run 2 or more sets of cables to the main cabinet which represent the outputs of the crossover sections.

Stuart

[johnnyx]

Personally, I think that active crossovers are easier to design. I'm having problems with a passive crossover, just tweaking it, not even designing from scratch, and the interaction of all the parts is a real headache.

It might be easier if the drive units were better quality to begin with, but I'm renovating a given speaker. If you have an active filter to smooth the response then that is what it does. In a passive crossover, increasing capacitance to reduce a peak increases it It isn't so predictable, and you end up with an impedence curve like the Himalayas, does my head right in. Is it worth while building another 6 power amps? Maybe for the sake of my sanity

[JRKO]

Active or passive I have one problem.

My Tannoy Berkerleys are 4.5m ish as the crow flies from my pre.

The cabs are getting a rebuild at some point and I have a refoam kit. Whilst I'm in there I'll take the crossover out and make a small box for it so I can play with it later!

Does the disance from pre to my speakers preclude an active crossover? Its just that I think 2 runs of signal cable over 4.5m long could have problems.

[wintermute]

You are making the assumption that you have to place the amps (in an active design) near the speakers

You could just keep the amps with the preamp, and run multiple speaker cables to your speakers, hence avoiding the problem of long runs at line levels.

Tony.

[JRKO]

Didn't think of that!! 2 runs of cable per speaker I can cope with.

Now how do you go about splitting the signal BEFORE the amps, direct from the pre? Are these types of crossovers powered? Do they give the same effect as passive post amp crossovers?

[planet10]

Originally posted by JRKO
Now how do you go about splitting the signal BEFORE the amps, direct from the pre? Are these types of crossovers powered? Do they give the same effect as passive post amp crossovers?

They can be powered or they can be passive... if powered you have more flexibility -- in your case using one of the designs which delays the tweeter signal so it is in exact time alignment with the woofer.

There is at least 1 AES paper on the subject.

dave

PLLXO
http://www.t-linespeakers.org/tech/f...ssiveHLxo.html

Active XO reference
http://www.t-linespeakers.org/linx/xolinks.html

[JRKO]

Time allignment shouldn't be a problem. My speakers are Tannoy Berkerleys (385HPD) 15inchers.