Active crossovers

Gentlemen,
thank you for the excellent responses.

The speakers in question are von Schweikert VR4's; I've learned they have an impedance low of 3.8 ohms at 25 Hz and a high 0f 19 ohms at kHz. Crossover between mids/highs and woofers is at 150Hz. High/mids and woofers are physically separate (stacking design).

I would be using Rogue Magnum's for the high/mids, bass amp(s) not yet determined. The Rogue amps have an input resistance of 200k ohms.

Hiram

KP, i would contact Albert and see what he thinks about active crossovers and see what he recommends in terms of necessary mods to the speakers. Most of the benefit of active multi-amping comes from going "direct drive" from amps to speaker drivers and bypassing the internal passive crossovers. Going active while still retaining the internal crossovers should offer some benefits but not all of going "direct". Sean
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PS.. Even if going to "direct drive" and bypassing the crossover or "dividing" network, it is still quite feasible and recommended to leave impedance compensation ) Zobel ) networks or notch filters in place. Doing so would require removal of the actual crossover network while still retaining some of the parts in the circuitry. That is why i suggest contacting the manufacturer before attempting to do anything. Putting their advive and knowledge to work for you could save you a LOT of time, money and headaches.

Hello, Sean, I'm not sure I understand (would not be a first!).

I thought, in a case such as the VR's, when the lows/mid are physically seperate (the speakers must be bi-wired or jumped to work) there was no crossover (between mids/woofers) to worry about.

I know there's other crossovers inside the speakers, but I don't know how practical it'd be to by-pass those (between the mid/tweeter). Or is there another croosover or filter involved right after the binding posts (ha, I hadn't thought of that!, maybe I'm begining to undestand?)

KP

Search your topic "active crossovers" on www.diyaudio.com and you'll get gobs and gobs of info. "biamping" is another search that'll pull up alot of related info too.

KP: There is a filter prior to the driver. It is effectively the cross-over. Essentially a high pass for the highs and a low pass for the lows. As Sean points out, you should bi-pass these. However, there is a word of warning here. While the cross-over is reducing the benefit of active bi-amping, these filter networks can be part of the voicing of the speaker. Eliminating them may change the characteristic of the speaker--sometimes for the better, but depending on it's design it can be for the worse. This is an area where I would contact the speaker manufacturer and ask them how (and even if) they recommend active bi-amping. For some speakers active bi-amping just won't work very well, but I'm not familiar enough with yours to know whether or not that is the case.