Clean crossovers

anyone know of any really clean crossovers that will keep the original signal as clean as possible?

I just pulled the eq/xover hooked up to my RFX8140 and the sound blew me away when i hooked it up straight to the amp.

the best one ive had so far is an old rockford AF4/HD but its limping on 1 channel now, and needs new hybrid cards.

tried every soundstream xover, but lost fidelity.

tried an AC eqx before , but was really noisy.

any suggestions?
 
The problem is not the crossover electronics themselves (except in case of some real junk) but the alignment of the filters, which is a very complex topic.

If you want neutral sounding crossovers, get a DSP (either car-audio for several thousand $ or PA like Behringer DCX2496 for $250) and work out your own filter alignments with proper delays/polarities, and use your own EQ in a driver per driver basis.
 
Last week I had to set up a system using an alpine 9887. It was two way front speakers and rear sub (as usual).

The wost of all about 9887 is the control interface, it's really depressing and frustrating. The interface in previous series was messy too, but not that terrible. Menu layouts and key sequences to access functions such as delays, crossover and parametric EQ will make you wish to smash the 9887 with a big hammer.

On the other hand, it features the 6 usual delays (althouth the linked adjustment mode of the previous versions, called "bass focus", is missing!!! damn fools!!! this mode was very useful to find front to sub delay...) It also features 3 crossovers with adjustable frequencies and 6/12/18/24dB/oct slopes but it still doesn't allow to set the type of crossover (Butterworth, Bessel, Linkwitz-Riley, etc...) and the type employed is just undefined! The parametric EQ of the previous versions is also there, with the usual stupid limitations (you can't set two bands too close and there are only 3 Q choices).


A $250 behringer DCX2496 can be modified for car use and has like 5 times more functionality than the most complete DSP headunit. It has 3 inputs and 6 outputs. Outputs have independent adjustable phase-shifters and low-pass and high-pass filters (6/12/18/24/48 dB/oct, Butterworth, Bessel, Linkwitz-Riley). Up to 9 parametric EQs can be set on each input and output (CPU power allows up to 36 simultaneous with 3-way stereo LR24 filtering). Inputs and outputs have independent delays, routing and limiters!! (no more blown speakers) Control interface is nice to the point that this DSP is used by embedded non-adjustable DSP designers of other companies to find out optimum system parameters in a comfortable way. It has everything you would dream to have (but will never find) in a car DSP.

Some other pro-audio digital crossovers are even better (and some expensive ones are actually worse!!) but they cost $500 to $5000 rather than $250 (see Xilica, BSS, dbx, BBE, etc...)
 
i messed around with a 9887 in a customers car once, all i can remember was overshooting what i was looking for and having to figure out how i got there in the first place. :xeye:

i remember there was a big behringer hype at carsound about a year ago...maybe i can find a dc/dc convertor to hook it up.

you know what the voltage requirements are for that unit?

as for alpines, do the 9886/5/4/3 have both a low and hi xover?
i tried downloading the manuals but everytime i try they are corrupt....the general info says 'no' but i think that would be kinda stupid on alpines behalf.

maybe i'll try an AC 2xs...any experience?
 
Some of the 985x used to have a "3-way" or "4ch+sub" switch that could be toggled through a small opening on the bottom plate. It seems as if their DSP was not powerful enough for midrange bandpass filtering and they were doing extra stuff in the analog domain. I don't know if the 988x still have that switch. It may be included only in some versions.

I used both AudioControl 2xs and 4xs in the past and I wouldn't ever consider them again. While these filters do what they are supposed to do, they are very expensive and are plain analog with basic functionality and no real time adjustments. Once you discover what can be achieved with the functions found on pro-audio digital crossovers you start laughing at old-school stuff like that. Of course, not everybody knows how to use delays and parametric EQ on a driver per driver basis, but learning is possible.
 
how did the 2xs sound, was it close enough to the original headunit?

i just need something to cut my subs for right now, i have a bass cube that i use to eq the sub...but still no match for an octave eq.

im going fullrange on my mids/hi's and gonna try going passive this time around.

im going to try some really weird stuff to get the imaging up...but in theory should work, i came across these 3" midranges that image REALLY well, they go exactly where you point them.

going for manual time alignment this time around. :cool:
 
You can produce various image feelings by applying individual EQ and delay to each driver. It has more to do with the way the radiations from all drivers interact and sum up in the listening position than with the drivers themselves.

As I said, the 2xs and 4xs were doing their job, PSU was regulated and isolated, noise floor was reasonably low and it seems that they were producing nice phase matched outputs unlike other filters (as it should be expected from any state variable circuit). But later I learnt that I was not getting good summing because I was not considering the phase shift from the drivers themselves (and from the delays due to different distances to the listener). Then I started to do my own active filters with driver and distance phase shift compensation. Then I discovered DSP. They call it the learning curve...
 

jol50

Member
2007-11-08 2:14 am
Only clean old school ones I ever used were old nakamichi and LP. I have a G190 alpine now that seems ok, but this system is not up to snuff yet so hard to say if it is great. I think I'll move to digital somehow, but what I will miss most is having x-over and gains in hand. I hate trunk mount stuff with a passion, or HUs you can't do anything with while driving. Should at least be able to fiddle with basic stuff on the road.
 
my favourite x-over i've used to date and still use is the trusty ppi frx-456, very simple in operation and nothing to go wrong and mess with the sound, just cross over frequencies to adjust...that's it. SQ is to die for, can't fault it at all :)

have used ac 4xs, pg 406 (still have one and love them) and also the marvelous kef unit made by coustic which is just too complicated for it's own good and i found myself tweekeing it every day of my life to keep it in tune :rolleyes:

as for all these digital units with time allignment and stuff, they just don't appeal to me and are a band aid for poorly matched/installed/located drivers... just my opinion of course :D
 

jol50

Member
2007-11-08 2:14 am
I have not used DSP yet in a car, but now I hear people saying if you don't get the expensive units they do not have the quality...and even then you really need to go outside auto audio to get anything good and capable. I'm not sure what to do, I know if I hook up a PA2 LP it will sound clean and I can lay my hand on it while driving. It would be nice to take out some problems with DSP sure, but then a good system can sound quite nice in a car of all places so it just has not been worth it for me yet. I guess I really don't care if it sounds perfect in a car, in a few minutes I jump out of the car and forget about it.
 
Clipped said:
i messed around with a 9887 in a customers car once, all i can remember was overshooting what i was looking for and having to figure out how i got there in the first place. :xeye:

i remember there was a big behringer hype at carsound about a year ago...maybe i can find a dc/dc convertor to hook it up.


Since you asked:

Drop in replacement for the DCX2496. :nod:

12V DCX2496 Convertor
 

tomtomjr

Member
2008-02-15 7:18 pm
I prefer the Nakamichi EC-200 crossover. I have had one in all my systems for the past 20+ yrs. Easy to set, and you can dashmount, or underdash mount it. Never had a problem with them, and always sounded smooth. Plus you can add it to a EC-200H, and it runs the tweeters too.
There is another one that I picked up recently made by Harrison Labs. It is an eq/crossover unit, but has more functions than any other crossover I have seen. The eq function is a definate sq type, and only has 3dB of boost. Do a search on the Harrison Labs site. If you like to tweak your crossover and eq, this might be what you are looking for........
 
hmmmm i can get the nak ec-200....only problem is theres alot of fake ones rolling around here...

although i hear the real ones have black metal knobs and the fake ones have black plastic knobs...

yours?

know anything about the ec-204?

i picked up a phoenix gold mx-2...but the sound isnt the same as the source unit, not as full...and i seem to lose bass if i dont press the boost button... i hate that... im stuck in a loop of either pressing it or disengaging it...
 

jol50

Member
2007-11-08 2:14 am
Fake nak 200s? Really? I bought mine at least 20yr ago and if it is fake then it works really well. I think knobs are plastic but I'd have to get it out and look. I've never seen another, it is different in that it switches to different frequencies and is not variable. I'd also look at LP x02s but are not dash mount. They made a dash unit that I read can be upgraded to be pretty good, and is 3way. One went last year I think <200 I bid on it for a friend.
 

jol50

Member
2007-11-08 2:14 am
You are correct, it has aluminum knobs with a plastic insert that grips the splined shafts. Also the gains have tiny steps in them you can feel and hear. I should check out the guts in it, I never have. I actually bought it from a tech who said he had repaired it back then but I've never touched it. He did extend the wires on it. Also some people have used them for home crossovers with a PS, thats why I would never get rid of it I could use any amp for subs in HT. Have not used it much lately and if I get a DSP HU I likely wont. Using a g190 alpine right now it seems ok and the parametric works awesome on my IB subs. It does not have a gain for the high side though, but can work around that. It is a dashmount though, and not sure how I will feel about not having that at hand with a HU doing it. Every CD is different.