5 replies to this topic

[TEGBOY]

I have a pair of Alpine 2 channel amps. I have a T505, to run a set of Boston Pro splits, these will be passively ran.

I also have a pair of Rockford 8's in my front doors, that I want to run actively. How can I do this?? I don't have any passive x-overs for them. I only have the xovers in the amp, which is an MRV-1005, I also have an Alpine 9815 which does have in-built x-overs. The xovers in the amps are only HP/LP/OFF, although they are adjustable, infinately

The woofers are in the doors, which are heavily SD'd
What would be the best way to run them??

Ideally I would like to band-pass them about 80hz-300hz?? to where my Boston 4.5 take over... I am wanting a strong up-front midbass.

Thoughts?? Thanks any advise welcomed

[icacha]

you will have to then run the pro's from a little under 300hz to get some over lap to eliminate gaps around 300hz.

my question is how much power will you be running into the 8's as i don't recall what that amp outputs?

my answer would be you will have to highpass the 8's from where ever you want to highpass them from (like 50hz) then find coils that will cut high frequencies around 300hz and put them inline with the positive of the 8's or i can sell you my 3way crossovers

[Mr_Bob]

assuming you don't have raer fill,
whip the HU out and flip the switch underneath to 3 way.
this allow you to use the crossovers in the HU.

HOWEVER, the crossover values aren't fully flexible,
log into the alpnie site, and load up I-personalise, in there you'll see what crossover values are available and whether or not it's suitable for your setup.

personally i'd run the 8's a bit lower. maybe as low as 50Hz, depending upno how tough they are and how much pwoer your're feeding them.
if the doors rattle too much, bump it back up to 65Hz, there's no need to go as high as 80Hz, i use a 63Hz 12db/oct hp on my Focal 6.5's!

if you don't have all the crossover flexibility you need, remember you can use the amp for LP and the HU for HP, or viceversa, depending upon the available frequencies on each filter.

[TEGBOY]

ICACHA said:

you will have to then run the pro's from a little under 300hz to get some over lap to eliminate gaps around 300hz.

my question is how much power will you be running into the 8's as i don't recall what that amp outputs?

my answer would be you will have to highpass the 8's from where ever you want to highpass them from (like 50hz) then find coils that will cut high frequencies around 300hz and put them inline with the positive of the 8's or i can sell you my 3way crossovers

Thanks George-- The amp make 178.5 RMS at 4 ohm stereo per channel. So I think its enough to get the RF's moving. I was thinking about the coil idea... cheers.

Go on tempt me, how much you want of the 3 way x-over???

Mr_Bob said:

assuming you don't have raer fill,
whip the HU out and flip the switch underneath to 3 way.
this allow you to use the crossovers in the HU.

HOWEVER, the crossover values aren't fully flexible,  
log into the alpnie site, and load up I-personalise, in there you'll see what crossover values are available and whether or not it's suitable for your setup.

personally i'd run the 8's a bit lower. maybe as low as 50Hz, depending upno how tough they are and how much pwoer your're feeding them.
if the doors rattle too much, bump it back up to 65Hz, there's no need to go as high as 80Hz, i use a 63Hz 12db/oct hp on my Focal 6.5's!

if you don't have all the crossover flexibility you need, remember you can use the amp for LP and the HU for HP, or viceversa, depending upon the available frequencies on each filter.

Ben- i didn't even think of doing it that way, with the amp low-passed the headunit high-passed. Thanks

I think the little RF buggers are tough, the flog my 3way Utopia (yuk) that I had previously. 63Hz sounds like a nice starting point for them, these bloody doors better not rattle now, there is over 4 layers of deadener on the outer metal, and 3 layers on the inner with rear defusion pads Gotta love that SD..

Thanks will give that a go................

[mack202]

TEGBOY said:

these bloody doors better not rattle now, there is over 4 layers of deadener on the outer metal, and 3 layers on the inner with rear defusion pads  Gotta love that SD..

haha yeah that does seem like heaps!
Your doors must sound so good when you close them.
Hope it goes well for you

how much would it suck if after all that deadening, your window rails or something starts rattling lol. touch wood

[TEGBOY]

mack202 said:

haha yeah that does seem like heaps!
   Your doors must sound so good when you close them.
   Hope it goes well for you
   
  how much would it suck if after all that deadening, your window rails or something starts rattling lol. touch wood

They are the heaviest Honda door I have ever opened or closed. The now close with a very Merc like "THUD"