How to cut off certain fequencys?

[bastec666]

How to cut off certain frequency?

I'm buying my own speakers, and making my own cabinet. Their will be 8 inch subs in each floor standing speaker (with a box @ the appropriate interior volume), 6 inch mids and 1 inch tweeters.

I have some old Fisher STV-649 studio speakers, and it has a 15" sub, 6" mid range, and a 4" tweeter, and its amazing. How do I get each speaker to only play the frequency range I want? I know its done with resistors or transistors or whatever, but what ones would I need to accomplish this.

The speakers are rated for 150 watts, so playing them in a 100watt house receiver at about 60-80watts wont harm the speakers, but I want to make sure each one gets the freq's they need without blowing them.

Thanks for you help in advance.

[chris661]

I know it's a big read, so here's the relevant part.

ESP - Frequency, Amplitude and dB

Chris

[planet10]

You are now into the wonderful world of crossovers. They are the hardest part of a multi-way speaker to get right. You have A LOT of reading and study ahead of you.

dave

[bastec666]

okay, I read it, and all it explained is about frequencies. It doesn't teach how to block them, or what to use to do so.

Any websites recommended for shopping? or do I need to get frequency blockers off crutchfield?

[Moondog55]

OK
Big subject and remember I am no expert.

Coils / Inductors block high frequency

Capacitors block low frequency

Simplest and hardest to get right is a first order XO using one component in each leg, so for a 3-way speaker 4 components

#3-way
low pass for bass (woofer ) / band pass for mid-range / high pass for treble ( tweeter )

Lots of reading for you to do, check the web and your local library.


Try and keep the band pass as wide as possible 300 -> 3000 Hz is good starting point, use big wire coils for low DCR

[godfrey]

Hi

Have you decided which speakers to buy yet?

When the characteristics of the speakers are known, then you can decide what frequencies to cross over at and begin to design the crossovers (or decide which to buy).

There's a nice explanation of crossovers here: Designing Passive Crossovers (the same principles apply for car speakers and home speakers)

Cheers - Godfrey

p.s. Welcome to the forum!

[chris661]

Passive Crossovers, Capacitor and Coil Calculator

Nice calculator here - it has diagrams somewhere aswell....

[Pano]

This is also a great calculator. Use it and you will learn a lot. The help pages are very good, too.
2-Way Crossover Designer / Calculator

[PeteMcK]

Passive Crossover Network Design

[head_unit]

To learn about theory, simple crossover calculators are fine. But for real world applications, you need to either:

1) Just use an existing design
or
2) Get equipment to measure the actual magnitude and phase of both the frequency response and the impedance of each driver. Then plug all that into software which simulates what will happen with the crossover connected. The play with it A LOT to get it all to work.

Crossover design is VERY HARD to do well, and it is a lot lot lot of work to learn. It can be rewarding, and interesting, and fun-but you're not going to get it figured out in an afternoon.

If you tell us exactly which drivers you are using, and ideally post data or links to data for each, we can be more helpful. Also specify what kind of cabinets you are thinking of putting all this in (dimensions, internal volume behind each driver, etc)