crossover ideas?

[mandude]

Hi people.

Here is my system at a glance:

Alpine deck, 3 RCA out's

pair of components up front, JL Audio 6" VR series

mid-bass behind the driver seat

sub in the trunk.

As far as crossovers go, I am using the deck and amps to get everything correct, but I am short in one area.

I need a high-pass for my components (prob somewhere in the range of 160-200Hz, the steeper the curve the better). I either want something relatively cheap, or something I can build my self (I am handy with a soldering iron, I can bread board if needed, etc).

I suppose I could either do the filter on the deck output, or on the amp output.

What would be recommended? Thanks!

[I Am An Idiot]

What model is the Alpine Deck?

[mandude]

7873

[jol50]

IMO cheap crossovers suck, they put noise into the system in my experience. I have asked about cheapest and was told to get a coustic 6 or a soundstream. I need to pull my doors apart to see what drivers will fit so have not got one yet. Or find an amp with one that works for you.

[I Am An Idiot]

There is a built in crossover in your deck Page 9

Page 9 according to the page numbers at the bottom of the pages. Page 11 According to Adobe

[Nanook]

Harrison Labs crossovers

a passive line level for particular frequencies, $25 the pair. And line level is the way to go if possible.

[mandude]

I am an idiot - I already know about that and use that, thanks. The problem is, that there are only two crossover controls, but three rca outs. one of the crossovers controls two RCA outs.

Nanook, that may be the ticket! So, I would want to put those in between my deck and amps, right?

[jol50]

You mean you need to HP your front comps higher than the rear midbass because the HU is HP front/rear the same?

[mandude]

yep!

[Nanook]

the Harrison pieces are PLLXOs or "passive line level crossovers", something I recently "rediscovered" due to a friendly reminder from this board's top poster "planet10". Dave has probably forgotten more than I may ever know. The article is not written by him but posted on one of his sites, www.t-linespeakers.org

Here is an explanation and a couple of example calculations to help you out. Basically you need to know the input impedance of your amp(s)--something that I think is fairly standard in car audio. Only 6dB and 12dB slopes are represented. You could use more by cascading them, but then insertion losses can occur. If your deck has an output buffer and a 4 V out, then probably no problem (or your amp has an adjustable input sensitivity). The great thing with this is the quality can be so much improved compared to typical car audio pieces. If I understand the Harrison pieces correctly, 2 Xs 6dB crossovers and an attenuator can be set up to do a 24 dB/octave slope.

I am a little out of my "scope" regarding car audio, but saw this thread and thought of a similar issue I needed solved for a project I am working on. Take this from a guy who (now 44) ten years ago bought some Soundstream Reference components, 2 Soundstream SPL 10s and quite a nice Eclipse deck , and a Planet Audio 704 amp with built in crossovers, and have never installed them in any car (cause I don't think anything I have warrants them).

I tried this (the high pass section only) on my pair of home speakers (mains, but I am currently using them as satellites in a 3 piece sat/sub combo), and they are very transparent (in my case I only needed a .01 microFarad cap in the signal path). You will have to adjust for the "balance" Also do yourself a favor and kill off as much equalization as possible, because this can counteract any possible benefit using a PLLXO can bring. Also use the best possible caps and resistors (to the highest spec possible) as these are very transparent and will definitely alter the sound if typical "industrial" types are used.

stew


stew