Audio setup

[BIG clean GREEN]

Ayup all,

Please help

I've got a Kenwood head unit with all sorts of fandango settings, none of the usual bass and treble settings, I've replaced the OEM speakers with 4 Vibe Fli 210w 70w RMS triaxle speakers, the midrange and volume are good but it lacks bass, so I've just took ownership of a Ground zero (GZUB800ACT) active underseat sub with built in amp, I've plumbed it all in, but because I is as thick as sh*t it sounds crap, when I play Phil Collins "in the air tonight" the drum solo was far too deep bassy and had little to no clarity ! the sub has frequency settings on the rear and also the head unit has frequency settings, I don't where to set the, high mid low ? and should the head settings match the sub? I've used an RCA set up for the speakers and they run without an amp !

All suggestions are most welcome

Nick.

 

[fridayman]

If you can turn the sub volume down, start with that. You can also try to lower the sub's cut-off frequency (low pass filter). The lower this is, the smaller the range of music frequencies that get into (and are amplified by) the sub. You can do this on the sub and it sounds like you can do it on your head unit too. Maybe start with a cut-off of 50Hz and play with it from there. At the moment your sub might be trying to play some mids as well as the low frequencies.

 

[Jon Wildsmith]

If you've really wired the speakers to the RCA outputs instead of the speaker outputs and there's no OEM amp hiding away somewhere then you need to sort that out first as that would account for your main speakers not giving much low frequency output!

subs can be tricky things to get right. if the sound is a bit wooly or lacking definition it might help to reverse the phase which should be an option on either the head unit or the sub. If the sub describes its filter as low pass rather than band pass, I would set it as high as possible so it passes more or less anything the head unit sends it and then control the frequency from the head unit. If the sub describes its filter as band pass then you'll need the sub and head unit settings to match as much as possible.

 

[BIG clean GREEN]

Jon & Fridayman,
The description says it has a lowpass filter 50-100 Hz, so Jon do you suggest I set this at 100 Hz ? and if so what do set the head unit at ?there's a few dials on the rear first is for the X-over as mentioned, the 2nd is for gain ? where do I set this ? because I also have a gain remote which I can alter between min and max from the drivers seat( or doesn't that really matter as I'm bypassing the setting with the remote ?)it also has a phase button on the rear of the sub to set it to either 0 or 180 degrees, whats that all about ?
Also Jon when I fitted the speakers I used the OEM wiring, so if there is an hidden amp, then I'm still using it ! On the rear of the sub you can either use the RCA input (low level) or high level input which uses normal speaker wire, so I opted for RCA gold plated leads !

Thanks guys,

Nick.

 

[fridayman]

On the lowpass filter 50Hz is a deeper cut-off and 100Hz is a higher frequency cut-off i.e. which sounds are allowed to be amplified by the sub. If you have decent drivers in the doors you don't really need the sub to handle any of the mids. If you are unsure stick it in the middle (75Hz) have a listen and then turn it all the way up, have another listen, then turn it all the way down, have another listen, etc... To get the best from the system you would also want to filter all the low frequencies out of the signals going to the door speakers - this is where things get tricky.

Gain is basically a volume dial. Does the dial on the sub move when you change the gain on the remote? If not, turn it up on the sub and down on the remote to start with, then increase it on the remote until you are happy. Or you could turn it up on the remote too and control it from the head unit (turn it down on the head unit first). However you do it, you want to start low and work up to the level that works for you.

If identical sound from 2 different sources (2 different speakers or a speaker and a sub...) are "out of phase" the sound waves cancel each other out. You can create this effect in the bath tub full of water (in a bigger pool/pond it is easier to see). If you create a small ripple it will spread until it hits the side and then bounce and return. As the returning ripple passes through the original one you will see it calming the water as they pass through each other - the peaks of one wave pass through the troughs of the other cancelling each other out so that the water stays level where they have just met. You can't damage anything by playing with this so try both and you should notice which setting sounds better to you. It may not that be that noticeable though if you are using filters to channel frequencies to different drivers/speakers.

RCA outputs from the head unit to RCA inputs on an active sub are fine. You are sending un-amplified signals to the amp in the sub which is what you want, so that the head unit only has to amplify the other speakers and the sub amplifies its own input.

 

[Jon Wildsmith]

I've used an RCA set up for the speakers and they run without an amp !

Do you mean just the sub is connected via RCA (which is good) and not the main speakers? Did the head unit just plug in to the OEM wiring, possible with an adapter, or did you have to cut and splice the wiring? If it's a plug and play job then you didn't use RCA's for the main speakers and we can forget about that.

On the sub, it may be that when the remote is plugged in the controls on the amp are bypassed. The low pass filter settings just set the highest frequency that is passed to the amp without attenuation, so a setting of 80Hz lets everything below 80Hz through unmolested but filters any higher frequencies out. I would set it high on either the sub or head unit and then use the other to control the frequency, whichever gives you the most / easiest control. On a small sub you'll find the lower end around 50Hz probably doesn't work too well and 125Hz will be a bit much.

As fridayman explained, the phase control is because you want the sound from the sub and main speakers to arrive at your ear in phase but how far the sound has to travel from each speaker affects that and means that e.g. if the sub bass arrives 180 degrees out of phase, cancels out any bass from the main speakers and leaves you with only the deeper bass from the sub. This often sounds like there is more bass but it's all low frequency. Using the 180 degree phase control in this situation may make it seem like there is less bass when it's just better balanced. Try the control both ways and see which sounds best while experimenting with the cut off frequency. Use a variety of music styles to test it to get a more balanced idea of how well it's working.

 

[BIG clean GREEN]

Wow, thanks guys
Some great explanations there, I'll give it a bash tomorrow !
Yes Jon it's just the sub I've connected with RCA leads !
I'll post you when I've played with it !

Many thanks,

Nick.

 

[Chris]

Don't tell me I've got to fix tha flamin stereo an all now. Did our lasse's bearings in't alternator today. Man that's better. All courtesy of Mr Rubie and International Imports

C

 

[BIG clean GREEN]

You'd never get your 18 fingers round my dials

was it a bitch of job to get to the alternator ?
Do you know anywhere locally I get some decent pads from, over the counter ? I could go the tinternet route, but delivery is always a pain in the ar5e !

Nick.

 

[Chris]

Couple of chin scratchers, but basically very straight forward job. Really smooth now. Bearing was banjaxed.

Pads? Mr Rooooobie. I'd avoid Milner ones. They are a bit soft and very dirty. There's always Lambies! Actually EBC pretty good. Oh, you're banned from that site. I could get them for you, because I can behave.

C

 

[BIG clean GREEN]

Audio setup done

Now I've got bass, through to tweeter, Big Jack by AC/DC sounds mint

Thanks all,

Nick.

 

[fridayman]

What size are the door drivers that you have fitted? I will probably change mine too at some point in the near future.

 

[BIG clean GREEN]

I've got 6.5" front and rear that are a straight swap, I used the OEM wiring and just soldered them up, I've got Vibe Fli intergrator 6, 210w max 75w RMS, they run without a amp and are now only £29 a pair at halfords, however I got mine off e-bay for the same price !

Nick.

 

[fridayman]

I'm going to try and wedge some Polk 6x9's in there.

Do you have instructions for removing the door cards?

 

[BIG clean GREEN]

It's quite an easy job to do ! But not sure 6x9s will fit !
:- remove 1 screw securing opening handle and 2 screws securing the arm rest.
:- twist and remove the 2 plastic body pins on the front door, near the hinge.
:- you need to push the opening handle frame backwards towards the door hinge, only about 5-10mm
:- then gently pull the door card away from the door frame, but dont pull right out.
:- You now need to twist the whole door card through 90 degrees to allow the opening handle to go through the opening in the door card !
:- Job done !
:- the OEM speakers are glued in as well as screwed in and need gently prising out.
:- which ever speakers you buy, ensure that they are not so deep that you can't open the window !

Nick.

 

[fridayman]

Thanks for that. I'm hoping that there is some room between the speaker and the door card. Then I can make a ring spacer to mount the speaker on.