Low pass filter?

[happyb]

I am looking to add a passive filter at about 600hz to a pair of 4ohm 4x6 dash speakers that I only use for fill and was wondering what I need. I know there are several consumer ones, but I thought if it was a simple cap perhaps I could use a better quality one myself. Any ideas? Thanks

[dfdye]

Well, I think you mean High-Pass filter (you don't want bass in 4X6 speakers), and yes it can be as simple as a cap inline with the speaker. Before we get into that, will you be driving these speakers from the head unit or an external amp? If the latter, I would just pick an amp with an on-board high-pass filter already in the unit.

If not, please give a little more info as to what you are trying to accomplish with regards to crossing these over and what you will be using for mid-bass drivers. Then you can talk about building an integrated 2-way crossover for these speakers, which is what I would recommend to make sure you don't have weird unforeseen issues down the road.

[happyb]

Thanks for the reply. The dash speakers are just being run from my head unit and yes (sorry) I need a high pass filter to block the bass.

Regarding what I have, it is in a regular cab pickup and I have a set of 6.5 separates in the front door driven from an amp which delivers most of my front sound, however the 4x6 speakers in the dash are a fairly decent pair of mb quart plates and I noticed with them faded in a little the front sound stage is improved.

So basically since these plates won't keep up in the low end with my sub and separates, I just want to block out the low frequencies so I can add some better staging for now. So to do this, what kind of filter or cap would I use? There is allready a small crossover to split the separate 4" woofer from the tweeter, so I think I just need to block the lows. Any ideas? Thanks again.

[dfdye]

Hmm. . . . . Well, I would guess that you will have an over-bright high end if you have full ranges in the doors + high on the dash, but if it sounds right . . . .

As for "blocking the lows," you can use a simple capacitor, which is what these are, and what I would start out with. They are cheap and will get the job done, plus they are about as simple as you can get. I seriously doubt if you will be able to tell the difference between those and higher quality caps, but if you really want to, you can look around Parts Express and use one of their higher end inline crossovers.

They will have a sharper cutoff, but since you are overlapping the door speakers with the dash speakers, that may not be a great thing.

Anyway, these are some prebuilt solutions that will get the job done well. If you are looking at using better components, I would save your money. Remember, the internal crossovers between the mid and tweeter on the 4X6 plate use about as cheap components as you can get. I would use the cheap components, save my money, and buy a better pair of speakers!

[happyb]

OK, I think I'll just use the cheap bass blockers then for now and look into better speakers and maybe a small amp....Thanks again.

[dfdye]

No problem. Like I said, I really think that is your best bet based on your situation. Plus, the bass blockers aren't that bad relative to what you already have in those plate speaker crossovers. Good Luck!