how many run an active front stage?

Jonathan · Post by **Jonathan** » Tue Jan 17, 2006 1:37 pm

There's also the argument that passive offers FAR more flexibility than active. Not as easily since you have to change out all caps and inductors to get the result, but with an active processor you're usually limited to 4th order Linkwitz Riley, sometimes you'll get a few different orders, but it doesn't give you a clue what topology the processor offers you. Usually Butterworth and Linkwitz Riley are it, and that is just dipping your foot in the water as there are hundreds of different possibilities for a crossover. You could make 10 3rd order passive crossovers that cross at 3khz, and have each one of them sound drastically different. It usually takes months to design a proper crossover for a component system. With passives, there are other options that may (or may not) work better in your installation.

There are also drivers that demand a passive network moreso than active. The SEAS Lotus Reference midbass driver is an example, as it has a rising response that has to be compensated for with an inductor in line, and also requires a notch filter to control the resonant peak around 5khz. You could run it active and equalize the difference, but it will still not have quite as good a result. There are many other drivers that demand the same attention.

Typically with active crossovers you're tailoring your speakers to the install. With passives, you're tailoring the install to your speakers. Pick your poison. Active is usually easier in the confines of a vehicle since you have few options, but that doesn't mean better results 100% of the time. If you go the passive route, the key is to make an intelligent decision on the components you intend to use by studying the engineering of the drivers and crossover and how well they can work with the install you intend to give them. This is often overlooked, and decisions such as this are rarely made.

geolemon · Post by **geolemon** » Tue Jan 17, 2006 1:54 pm

Those are great points... the only advantage with going active IMO is "instant tweakability".

Of course, if you are talking about building multiple sets of 3rd and 4th order crossovers... and potentially redoing them - there would also be cost savings as an advantage... where with milder setups (say, just keeping the factory 2nd order Xovers that came with your speakers

), going all passive would be the cheaper option.

Once upon a bygone day... I had imagined a "what if?" scenario...
What if [at a shop] you kept on hand a 6 channel amp, or pair of 4 channel amps, power distribution, the whole works - including a good active crossover system - in a portable amp rack, that you could drop into a customer's trunk, and perform tweaking with to determine ideal (given the customer's speakers, speaker locations, vehicle prep, seat position, and other acoustics) crossover settings, to determine up front what all these ideal crossover points, and crossover slopes were.
Work like that could probably be done within a day, with pretty accurate results.

Then, take those settings (which you recorded) and offer a passive crossover building service - to duplicate those active crossover settings in the form of a very high-end passive crossover network... letting the customer spend the budget they would have spent on three or four amplifiers and a high-end crossover network, and instead spending that budget on the custom passive network and likely a higher grade of two channel amplifier (maybe with a separate remote-gain adjustable sub amp, depending on customer and tastes)?

Honestly, my love of car audio does not extend to the degree where I extract pleasure from custom building passive crossovers (I enjoy fabrication more)... but I always wondered if anyone out there - sharing the views of Jonathan - ever did offer a service like this?

Jonathan · Post by **Jonathan** » Tue Jan 17, 2006 2:05 pm

Hell no I don't.

Too much time required, I'd charge hella labor for designing passives for somebody. I'll only do it for myself, and only few times then.

mikechec9 · Post by **mikechec9** » Tue Jan 17, 2006 2:28 pm

yop. the 360's sweet. here is another tune-from-the-front option: http://altomobile.com/html/ucs_pro.html
also, i like the pioneer p9 combo a lot as well.
*Edit* here is more info regarding the ilk:
http://www.passivecrossovers.com/index.htm
http://www.termpro.com/articles/xover2.html
http://www.frazierspeakers.com/download/cross.pdf
comparable distortion in the different orders: http://www.geocities.com/kreskovs/Stored-energy.html
also, here is a site that will help design your own passive in the event you aren't successful in Jonathan's persuasion :) http://www.speakerbuilder.net/web_files ... oconst.htm

geolemon · Post by **geolemon** » Tue Jan 17, 2006 2:34 pm

I think the best option I've seen so far, bang for the buck and all, is the RF new 360.2 system...
It's controllable through a PDA, does 6 channels per unit, and in addition to offering adjustable Xover slopes and points, also offers 32 bands of EQ and some parametric on each output channel.

Only downside is I'll need two of them.

Pioneer is also an option, but the P9 wasn't capable of 8 channels (possibly 10, if I tie in the extra SPL stuff as well), or something... there was something that made me rule it out... that was a while ago though, I honestly forgot what the issue was...

mikechec9 · Post by **mikechec9** » Tue Jan 17, 2006 2:53 pm

rf 360 info link/thread: http://www.carsound.com/UBB/ultimatebb. ... 010916;p=1

geolemon · Post by **geolemon** » Tue Jan 17, 2006 3:54 pm

Cool, much appreciated!
The software that runs on the Palm is very cool too, easy to use.

mikechec9 · Post by **mikechec9** » Tue Jan 17, 2006 4:15 pm

geolemon wrote:Cool, much appreciated!
The software that runs on the Palm is very cool too, easy to use.

sweet. i'm just getting into the world of "palm". i had the symetry though, and i loved it. just hated the ugly rdat and shallow (12db max) slopes. good to see them FINALLY come back with a solid hitter. especially, as you said, with the convenience of a mere palm as the controller.

Jonathan · Post by **Jonathan** » Tue Jan 17, 2006 6:33 pm

Yeah, that palm controller is really sweet. I could see myself tuning w/ that thing :)

6Spdcoupe · Post by **6Spdcoupe** » Tue Jan 17, 2006 9:14 pm

Running active with my DXE.

Arc 2500XXK> Dyn MD170s
Arc 4150XXK> Dyn MD140s,MD130s
Arc 2500XXK> Flatlines