Hi All,

I'm planning to go semi-active on my install new. My current HU doesn't have any built in crossover functionality at all, it simply has a front and rear RCA output. My current amps and the one I will be getting don't have the crossover functionality that I need.

So my only option is to use an active crossover (I don't want to use passive's for the midbass bandpass needed).

My install is a little different in that the crossover I need will need to be able to split the following frequencies:

Sub-bass - Subsonic filter that is adjustable (that can go up to around 30hz) to a low-pass of between 60-100hz
Midbass - band-pass between 60-100hz (same as sub-bass) and 300-900hz
Midrange/tweeter - high-pass between 300-900hz (same as midbass) - the existing passive will be used between the midrange and tweeter.

The reason for the adjustability is that I don't know what will sound good until I try it.

Ideally the crossover will use 24dB slopes.

If I can't find one that does what I want (at a reasonable price, I don't want to spend a fortune on one), then I was thinking of building an active 3 way linkwitz-rielly 24dB crossover. I've got a bunch of some nice opamps sitting here waiting for such a project (Burr-Brown OPA2134's). Only problem is it won't be as easily adjustable as a commercial offering (I'd simply have different pluggable modules that will change the frequencies rather than simply twisting a dial).

Anyone know of any existing commercial crossovers that can do what I want at a reasonable price?

Thanks.

Have you looked at the Alpine PXA-H701 + controller?

You will however need an AI-Net headunit, or a headunit with optical out.


Audiocontrol make a number of units.
Behringer also makes one however you will need an inverter to run it in car.

Thanks for the reply Fury.

I did look at the PXA-H701, but unfortunately my HU is a Kenwood not an Alpine and it has no optical outputs.

Do you have any recommendations as to which Audiocontrol models would suit?

Actually, I had a look at the Audiocontrol 6XS and it seems to do exactly what I want. It's a bit expensive however.

im sure the PXA has rca inputs.. that can use an rca signal from a different model head unit.. altho you might lose some of the head units features that will be controlled by the PXA..

rockford 3sixty?

the behringer is the cheapest option, but does require an inverter to run.

the Alpine is very flexible, and has good EQ (2x31band+10band) as well as TA and crossover(8 channel). It will work, but not so good running off the RCA input.

Rockford 3sixty will do it quite well, and reasonable price, but you need a PDA or similar to program it.

unfortunately, there's not a lot around in terms of good adjustable crossover for cheap.

have you thought about using the crossover in the amps?.

mad89 has a precision power which does all that u requested. shoot him a PM see if hes willing to sell.

There is a beta version of the control software available for the 3Sixty.2 developed for bluetooth enabled laptops. You can download it from here:
http://www.rockfordfosgate.com/scripts/rig...2%3Afaqs.faq_id

I have just bought one of these (its still in the post) and am eagerly awaiting its arrival. It does lack full 6db/12db/18db/24db/oct crossovers instead allowing just the usual 12db/24db/oct crossovers. Apart from that it should do everything that you want it to do.

I've never seen an amp that runs a bandpass xover? I've been running active from my amps for a while now, and its really not ideal. Running your mids without a bandpass x-over is bad news (well it was for me) as you can quite easily overpower your mids by running low frequency through them. But if you use the High Pass on the amp and let the mids run out their natural roll-off then you can suffer from breakup, or the mids not integrating well with the tweeters.

My DD C2a has bandpass crossovers

Thanks for the replies guys.

The Rockford and the Alpine units are still too expensive for my needs though.

I did a search on Coustic crossovers and found the Coustic 3 way crossover XM6. This does nearly all the stuff I'm after (it only has 18db slopes though, the reason I wanted 24db was so that the phase didn't change, but the Coustic has a phase reversal switch in case I need it anyway). The price is certainly right though (I didn't want to spend a fortune since I will want to upgrade to a new Alpine HU sometime in the future).

Anyone dealt with this specific crossover or any other Coustic crossovers? I know they used to have a pretty good reputation back in the days, but not sure of their new stuff. I did have a Coustic amp back in 2000 in my first car and it performed nicely, but I believe that was the start of the "new school" Coustic (probably meant they started to be manufactured in Asia).

PS, Simon, the reason I can't use my amps crossovers is that they don't have the full range that I'm after. I'm using an MTX Thunder 4122 for my mids and tweeters, either an MTX Thunder 8302 or 302 for midbass and an MTX Thunder 6500D for my subs. The 4244 is very limited in it's built in crossover (its 85hz low pass or high pass only), the 302 has an adjustable one, but no bandpass and the 6500D has a low pass only with no subsonic filter (something that I will have to retrofit to the Coustic crossover also).

there are a few others as well i believe the JL slash series can do it. its not common but bandpassing can be done on some amps.

how much is that coustic x-over?

From *ahem*ebay*cough* it's around the $35 USD mark excluding shipping (so shipped to here would be around $65 AUD).

Technically the phase doesn't change, but the signal is delayed by one full cycle. At 50Hz this is 2msec, which you might give a crap about, but probably won't. Also the x-over slope value only affects the signal below or above depending the x-over point, depending on whether it is highpass or low pass respectively.

Thanks for clearing up my misunderstanding regarding the phase shift. I was getting confused regarding how the crossover order affected the signal.

So its really only when the signal is 180 degrees out of phase that I should really be worried (ie 2nd order) about, but that can be fixed by using the phase switch anyway (or by swapping the leads on one set of speakers).

The phase is only shifted below the crossover point (for a high pass) or above the crossover point for a Low pass. If you had a 12db/oct high pass for a tweeter at 8khz, then you might like to swap the phase due to the amount of music information below that frequency being more. It really comes down to what sounds best on your system and trying the different settings to see how it affects it.

My brother is running is only a two way + sub setup, but running completely active.

I know he had a lot of trouble finding an active crossover to do bandpass, but ended up finding one from crossfire ... may be worth checking out (although i'm not 100% certain if it has a subsonic filter or not).

I'm pretty sure it was fairly cheap (arond $250 or so).

If you wanted any more information, drop me a PM and i'll ask him for you

there is a pioneer dsp with full crossovers in the FS section

I hate people who say 'phase reversal' when they mean 'polarity reversal'

hahaha

the JL amps are HP or LP only, but the monoblock has subsonic.
Audison LRx6.9 has bandpass for the middle channels

The Alpine 9855R or 9855 headunits will do exactly what your asking and more,

it is capable of Sub lowpass from 25hz to 200hz /midrange bandpass from 50hz-20khz,/High 200hz upwards.
(You have to change the high output from Makers to Users to allow this.)

Throw your Kenwood out, (sell it if need be) these are hard headunits to find in stores as they are as good as discontinued, retail at $799, but can easily be still picked up on ebay brand new for around $600 or less.

Most, "BUT NOT ALL" Bass engine pro headunits will do what your asking. and give you the option to run a PXA-H701 at a later date if you so see fit.

the "but not all" refers to my 9965E which doesn't allow the High section be to adjusted below 1khz, strangely. This would be to do with it being made in Japan, and not china with slightly different programming of the software.

I am unsure at this time if the 9887 will do it either.

Juls

bassengine pro will do what a 9855r will do that is 7998r 9813 9815 9833 9836 9853r 9855r

bassengine not pro wont be of much use. u have PXA RUC h 701 and 700. as well from teh alpine stables.

dude.. stay off the turps when your on CAA!! LOL .

I think what you ment to say is.

Bass Engine pro is available on,
7998r 9813 9815 9833 9835 9853r 9855r

And that Bass engine pro is not of use if you use the PXA-H701/700.

Also only the AI Net headunits with processor control can control the H701/700 themselves without the RUX-C701.

Juls.

and 'normal' bass engine (not pro) is no good for what you want.

Thanks for all your replies guys.

I ended up getting a Coustic 2/3 way crossover (XM6). It seems to do nearly everything that I want except for the subsonic filter (but I'll just add my own to it instead). Got it for a cheap price too as I didn't want to spend a fortune since I will be upgrading my HU to probably an Alpine later down the track.

Simon, I was only using the terminology that most of the crossover makers seemed to be using regarding the reverse polarity switch. The Coustic XM6 manual contains the following:

Yeh, they're talking electrical phase.

Pulse-R was referring to acoustical phase.