Alpine 7894 HPF/LPF queries

[backtothefuture]

I've been tinkering with the HPF and LPF on my Alpine H/U and noticed that a HPF (high pass frequency) on 80HZ gives more bass than on 120Hz etc

is it the 6x9s producing this extra bass? I basically use the HPF settings in place of bass blocker cables to prevent my 6x9s giving bass...

just to confirm..these settings don't affect the sub output do they ?

Also what good do the LPF(low pass frequency) settings do ?.. I've been told they only affect SUB output settings... is 80Hz suitable so as the bass seems to come from the front?


finally , any of you chaps know what phase alignment is good for ?
I got a range of 0 to 180 to fiddle with on my Viper monoblock ...

[kryten]

OK, a high pass filter, lets signals ABOVE the frequency through and rolls off at the defined frequency a certain numner of dB per octave.

So, when using 120Hz, you are in effect reducing the volume of all frequencies BELOW that point, so you're lower midbass of 80-120 Hz will be quieter.

Your 6x9s should be fine down to 80Hz.

You need to match the HP/LP filters so your speakers play the range of frequencies they can manage.

Phase is a nightmare in a car, hence my choice of an Alpine processor that set itself up with a microphone!! (For sale, incidentally).

If its for the sub, set it after your crossovers, from the driver's seat and 'twiddle' until it sounds best (when listening to music).

I'd suggest you get along to a decent car hi-fi shop and get them to set your system up. It should take them less than an hour and will almost certainly give you a massive improvement in sound!

[backtothefuture]

can you recommend any decent car hi-fi shop around London where I can get this tuned?

the place i had it all installed is complete rubbish, its been over 2 months and they still have to sort out their bungled wiring


right now I don't have much faith in these car audio places

[kryten]

Well, London is a pretty big area! I only know two that I'd personally recommend, but they are both top class. I'm sure there are more, but I'm from further West:

Prestige Car Audio (Rayners Lane)
Wentworth Car Audio (Virginia Water nr Egham)

I doubt either will be the cheapest, but I'm a firm believer that you get what you pay for....

For those looking further west, I can also highly recommend the Car HiFi centre in Cheltenham.

None of these are 'box shifters' - as long as you don't go in when they're massively busy (ie saturday) then they'll have a chat with you about your system, probably have a listen, find out what music you like and then make some suggestions.

Just packaging up my Continuum amp and having second thoughts about getting rid of all my gear.....

[backtothefuture]

i gave prestige a call once, for a quote...very expensive .. i have a feeling they wouldn't charge less that £100 just to tune up my system..also i think they have moved to Rickmansworth.....

but thanks for the suggestion , you are not the only one who recommends prestige...may well try them !