Fitted my sub in the car finally yesterday after meaning to do it since I bought the thing (got it last October!) Anyways, was driving round thinking this doesn't soudn quite right. Can't seem to turn it up as loud as before and it sounded just strange. Then it hit me that I'd forgot to apply the LPF on amp on the channel powering the sub!! The input is taken from the sub-w output on my headunit so not sure how much it filters if any at all but applying the LPF on the amp did affect the sound from it. Question is, with driving round for an hour at reasonable sound volumes would it have damaged the sub at all?
If your HU has a sub out then chances are it can be adjusted from the HU, this is excellent. I would put the amp on full range mode and then use the HU to adjust the lowpass, this gives you much more flexability from the driving seat. If you appy a lowpass from the HU and then from the amp as well it can affect the phase and sound of the sub.
Cheers Onnie, yeah the headunit has a HPF and LPF but I haven't really had the time to sit and play around with them. Got the Alpine CDA-9812rb if you've any other tips??
Hi. Stick the HU's HPF on and set it to about 80hz, this will allow you to play your mids harder without fear of bottoming them out and damaging them. Then stick the LPF on and set that to about 60ish hz if you can. This is a rough guide and every car and system is different so dont be afraid to play about with the frequencies. hope this helps?
I tried playing with the HPF and LPF yesterday to see what difference they made and tbh I can't really tell! If I leave the 4 channels on the amp to all pass and set the LPF on the HU to 80Hz (lowest it'll allow) I can still hear some of the singers voice etc thru the sub. Is this normal? Now going to check what frequency the filters are set to on the amp as they're fixed so it'll be a case of finding the manual online. As for the HPF on the HU, can't hear a great deal of difference with that. Got the Media Expander set to the suitable one for subs which sounds best. Tried the stronger settings and I can hear the door speakers 'farting' at me cuz they can't handle all the bass. Was considering getting a second amp so that the front components could be run actively and ditching the passive crossovers in the door. Would this make a great deal of difference to the sound? Obviously the speakers would be receiving more power than they currently are as each channel is going to a single speaker instead of the crossover, tweeter and mid but when I bridged the 4 channels previously so each set of comps was receiving around 125Wrms I couldn't hear any differnce in quality of sound only they went louder. Presume ditching the passive comps and using the HU's crossovers would be a better alternative?
hmmm, i'm just thinking, maybe you have wired the speakers up wrong? mids going to sub and sub to mid? swap the rca's over on the amp and see if it now sounds better? Running active definately is a great step in the right direction but, and i dont mean to sound condescending, you may struggle to set it all up if you dont have a good understanding of it all.... swap the rca's over on the amp inputs and see if that makes a difference. And i say stick the highpass onto 80 and lowpass onto 60, you should deffo be able to tell when the settings are on.
Right I sat down last night and had a proper play around. Looked in the manual for my amp and the LPF is set to 80Hz and the HPF is fixed at 120Hz. Set them both to AP and then enabled the LPF on the headunit. Set this to 80Hz which is the lowest it'll go, even tho it is supposedly the same frequency the sub has a few more 'high's altho you can hear a hell of a difference between LPF being on and off. Think it was a case of me expecting to get it all set up in a short space of time, sat playing with all the settings for 30 minutes or so and I've got it all set up now. Don't think I'll be bothering with going active for now as I can hear sybillis thru the tweeters (think thats the correct word) so will be saving up for a new set of speakers I think. The current ones were a cheap stop gap for the time being, was warned that Alpine comps sound harsh before I got them so I should have expected it really. You couldn't recommend a decent set of 16.5cm comps for a budget of between 100 - 200 could you?
