Bass control for speakers?

[mufc]

Hi, I have currently got my sound system set up with alpine CDA-9847R headunit, legacy 1000w 4 channel amp powering a 10inch JBL sub and a set of 6x9's. Through the amp controlls I have managed to take all the bass signal out of the 6x9's so they don't distort, but the other day my friend had some I would say at a guess 100mm-120mm infinity speakers he was chucking out. I said I would have them for my car, they were to big for door replacements so I placed them inbetween my 6x9's on my parcel shelf and wired them directly to the stereo through the existing speaker cable for the stock speakers. The problem is when I set the bass to its lowest setting so that the infinity speakers don't distort, by doing this I don't get anywhere near enough bass as I would like off the sub even when I have the bass boost to full and the headunit sub output set to max, so to conclude I was wondering is there any possible way to remove the bass signal from going to the infinity speakers?

 

[volxstu]

You can use capacitor x-overs that will filter the unwanted frequencies i will try and post some more info today but we are waiting for the electric to be turned off so i am in a rush to get everything done. But there is a research point for you.

 

[mufc]

Anyone have more info on this?

 

[volxstu]

You need to add a High Pass filter inline with the speakers set to SAY 100hz ish. A variable one will be better but the chances are that by the time you fit them the Sub has fooked the speakers anyway as a sub will move a lot of air pushing the excursion of the smaller speakers, burning out the coils etc.
Again i will have to explain a little more later i need to leave work but will be back online in a bit.

 

[mufc]

Searched high pass filter into google? No links to audio equip. Wtf?? I have never heard of this before? jus the smaller speakers? Or the 6x9's aswell?, All sound systems I have seen have sub in boot and atleast 1 pair of speakers on the shelf? How do i stop this? Is it even possible?

 

[volxstu]

A lot of people seem to make them themselves, once you know the formula its a pretty easy thing to do.
The formula is
C = 1/(2xπxRxƒ)
C = net effective capacitance, in Farads
π = 3.14159
R = the load impedance seen by the filter
ƒ = the desired corner frequency
I stole this formula from the net so there is plenty of Info out there. If you want variable points on the x-over you just double the just double the capacitance for each point used.
Do you understand Ohms as this would be a good point to start.
All you are creating is something similar to the Dial that is on your amp Labeled HFP or LPF as you already have used on the other speakers.

You only need the HPF on the unamplified speakers. i know that this will seem very confusing but i will try to source some light reading for you during the day to help you understand a bit more.
Unfortunately it isnt something that i have ever had to do so although i have asimple understanding of it i dont as of yet know where to get them and how to exactly implement them so bear with me.

All of your friends who have had speakers in the shelf may have found that the speakers cease rather quickly and could have dismissed it as just blowing them or if they are really stupid may not have noticed that the cones no longer move and can eventually catch on fire.

 

[mufc]

I found a pair of bass blockers from auto leads, they block below 150hz, but they are only for 6x9's. My speakers are 5 1/4, by the cone do you mean the part that produces bass? The oval structure below tweeters? Where the hell am i supposed to put the speakers then if the sub is inevitably going to break them?

 

[mufc]

I purchased these at 800hz :

http://cgi.ebay.co.uk/Two-pair-4-New-Bass-Blocker-Crossovers-of-your-choice_W0QQitemZ290292039789QQcmdZViewItemQQptZCar_Speakers?hash=item290292039789&_trksid=p3911.c0.m14&_trkparms=72%3A1683%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

I dont need much midrange from the speakers so 800hz should be fine?

 

[volxstu]

I would much rather go for around 400Hz
That seems a bit steep for a simple capacitor even i can work that one out if i had a decent calculator
1/(2xπx4x400)
Have a read of this.
http://www.gearslutz.com/board/geekslutz-forum/142978-diy-hpf.html

You will need mid range and the speakers should be in the doors.