Changing the cross over frequency!

[Nanometer]

I am tring to alter an audio cross over frequency so that my speaker towers send more of the frequency spectrum to the larger speakers in the tower. It's a 3 way split and I was wondering how to raise the low pass frequency. Any tips?

it's changing one of the low pass circut values. either a resistor, capacitor or coil

[jason str]

Im no crossover expert but i know you will need to make a change to both drivers if you want to raise or lower the crossovers frequency so you dont have a big overlapping of frequencies.

Maybe you can use an active crossover for starters to see if your plan will work or not.

[STEvil]

take a few wraps off the coil.

I would suggest using some store-bought crossovers if you want to play with it though before unwinding the "good" ones.. or do that to the stock ones and buy new ones for backup ;)

[OldChap]

Can you draw out the circuit for the crossover that you have, give it values and post? If not then it will be tough to know where to start.

[Nanometer]

I'm still on the hunt, and the only thing I could really get was do my best to draw out the diagram, I would rather take it completely out of the system, but I really dont want to desolder anything... Personally I wish I had access to an eager electrical engineer in their third year... or a master haha

[STEvil]

You can use a jumper wire to bypass it if you dont want to solder on it much.

[Nanometer]

well I wanted to take it out in order to figure out the diagram, but it seems there are no traces on the board so that's not really going to work either... It would be nice to get an adjustable crossover setup, but I haven't really seen any for my application, I'll try to look around for it. An active crossover seems to be my best bet...

yea... I think im just going to give up.. I don't think it's worth it to go crazy with this. If I had been able to get a diagram of the circuit it would be a different story... but without it this is a lost cause in my opinion...

[Nanometer]

http://img.photobucket.com/albums/v718/NanoMeter/cross.jpg

Basically I need to make this, all I need to find is a circuit board that will fit easily inside, or preferably in the 4.5" by 3.5" input cup on the outside of the speaker...

[OldChap]

No need for a board just solder the ends of components together and add wire where needed. Insulate as required

an active crossover will need an amp for each speaker....the active goes between the pre and the power amps so a pair of the above speakers would need 6 amps

[Nanometer]

But I'd rather not have a bunch of components flopping around, it's... unprofessional :-\ ... Maybe I could just build my own, and drill holes where needed, I think I found my possibility =-).

[Donnie27]

But I'd rather not have a bunch of components flopping around, it's... unprofessional :-\ ... Maybe I could just build my own, and drill holes where needed, I think I found my possibility =-).

Why not go to some of the OEM resellers at EBay?

http://cgi.ebay.com/2-NEW-CERWIN-VEGA-CROSSOVERS-SPEAKER-3-WAY-400-WATTS-NR-/130384208468?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item1e5b812254

I've tried at least 4 and never got one I didn't like! I did try to match the speakers I already had.

[Nanometer]

it would fit, but it doesn't say what the crossover frequencies are. I emailed one of the sellers if they would customize it.. haven't heard back yet though.

[Nanometer]

Can't find any specs on Cerwin's site for their crossovers so I highly doubt I'll get an answer, or even a response at that. It would be a possibility but without knowing the circuit diagram or having the spec sheet it might as well be a paper weight.

[Donnie27]

Can't find any specs on Cerwin's site for their crossovers so I highly doubt I'll get an answer, or even a response at that. It would be a possibility but without knowing the circuit diagram or having the spec sheet it might as well be a paper weight.



310 model

# Deluxe 3 Way Adjustable Cross Over
# Rated to 150 watts, works with 4 to 8 ohm speakers
# Cross Over Points are 300 Hz (woofer / midrange), and 6,500Hz (midrange / tweeter)
# Has controls to brighten or soften the tweeter and midrange drivers.
# 2.5 by 5.625 inch opening, 3.5 by 6.625 inch frame
# Sold in Pairs or one set of (2) two for one bid...
# Great for Car Audio speaker boxes and Do It Yourself (DIY) home speaker projects....
# Woofer Cross-Over Points are good for a 10 to 15inch woofer.
# All leads are marked so no directions are needed to hook up. IN +/- , W +/- , M +/- , T +/-
IN = Input , W = Woofer , M = Midrange , T = Tweeter , + / - = That there is a Positive and Negative Lead



The 312 Model

Rated to 200 watts, works with 4 to 8 ohm speakers

* Crossover Points are 500 Hz (woofer / mid-range), and 5,000Hz (mid-range / tweeter)
* Has controls to brighten or soften the tweeter and mid-range drivers.

They're cheap and little info to be found because they're discontinued. They are talking a real 150 and 200 watts like Harmon Kardon and a few others who still tell the truth, not some PMO BS.

Woofer goes up to 500Hz and 300Hz on the 312 & 310 respectively. A robust Mid and Tweeter is needed since 500 and 300 Hertz is too low for many of them. A soft dome and Planar tweeter than can clearly reach down to 5kHz and 6.4kHz isn't a must but helps a lot! I like to build my own speakers but don't like messing with Crossovers.

To get the best out of Full range speakers you need to use a system without Bass Redirection. You have to make sure you Woofer/Sub Woofer can handle the lows. A Robust wide range Sub that does something like 18hz to about 1000Hz is sweet, 20 to 23hz is more realistic. You never want to just barely reach a spec. I like Parts Express, Electro Mavin and 101world on eBay, there are a few other good ones as well.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-460
23 to 1000Hz Sub Woofer

http://www.mavin.com/index.php/products/cerwin-vega-enclosed-back-mid-range-drivers-pair
Response is from 100 to 8,000 Hz


http://www.parts-express.com/pe/showdetl.cfm?Partnumber=275-085
2000 to 26KHz Tweeter

The full range and no Gaps.

For Music I use 60Hz for bass redirection and 80hz for Movies. Both the Receiver and Computer match crossover points for Bass Redirection. My mains can comfortably be set to 30Hz but that takes too much from the Sub!
The 80hz for movies seem to have the best Sound Effects & positioning.

I personally don't like 5.1 speakers systems since the MTM (Midrange Tweeter Midrange) satellites on many of these can't reproduce sounds lower than 100Hz. Even THX calls for only 80Hz. Hope that helps.

[Nanometer]

I looked into those active crossovers. Though the issue with them is that the higher crossover frequency is set so high, I'm pretty sure it will change the sound more then I am intending it too. I can see raising the higher frequency from 1800Hz up to the 3500Hz range, but I feel going higher is going to start to make the upper mid range suffer. I'm not so sure forcing a 5.25 driver to play 3500Hz in my setup would sound to good. I think those are half tunable, you can't change the crossover frequencies, but you can change the frequency balance, not exactly what I'm trying to do though.

[Donnie27]

I looked into those active crossovers. Though the issue with them is that the higher crossover frequency is set so high, I'm pretty sure it will change the sound more then I am intending it too. I can see raising the higher frequency from 1800Hz up to the 3500Hz range, but I feel going higher is going to start to make the upper mid range suffer. I'm not so sure forcing a 5.25 driver to play 3500Hz in my setup would sound to good. I think those are half tunable, you can't change the crossover frequencies, but you can change the frequency balance, not exactly what I'm trying to do though.

1800Hz is the lower end of the Frequency range for a Mid Range Speaker. Now if you mean up to 18 thousand and not 18 hundred then yes, that's too high. 1800Hz isn't out of the reach of many woofers and is a cross-over point some speaker makers use. I'd generally like 800Hz as the crossover point between the woofer and mid-range driver. Then have the highest frequency the mid range can reach being 6500Hz, most tweeters can hand the rest! Some reasons why.
High Freq sounds require less wattage.

Driver/Speaker Speed is important just like they are for Headphones. Speakers have the advantage of you multi drivers and not depending on one to make many simultaneous sounds. Awe but Headphones aren't affected by the environment or acoustics like speakers that are influenced by reflections and etc...

If you look at a 3 way speaker it be something like
Tweeter playing between a low of 6500 to 13000 and a higher from 18 to 26000hz, much more than that is a waste since instruments don't produce sounds any higher LOL!. Movies aren't mastered with sounds higher than 20Khz.

The Low number on the tweeter will be the High Number or crossover point for the Mid-Range or 6500 to 13000, the low number for the Mid Range is the cross-over point for the Woofer that might range between 800hz and 3500hz.

Without making this 10 page long, 3 way speakers with Sub Woofers are GENERALLY crossedover at lower points than those with straight woofers. Many Sub woofers don't like playing above 1000hz, in fact, many never reach about a 800hz. Since many systems are set to 80hz, ever that becomes moot.

Of speed and lows, slow moving low freq are harder to reproduce but not impossible. Many folks like 10's because they tend to be more accurate but not as loud as larger speakers.

[Nanometer]

The tower supports Bi amp so it kind of doesn't even matter. As soon as I get cable I'll test that out haha. I'm glad I don't have to modify anything!

[Donnie27]

The tower supports Bi amp so it kind of doesn't even matter. As soon as I get cable I'll test that out haha. I'm glad I don't have to modify anything!

That only means knowing the cross-over points are even more important.

[Nanometer]

I do know them, but all the same it also means that I can drive them up to 200 watts per tower. :)

[Donnie27]

I do know them, but all the same it also means that I can drive them up to 200 watts per tower. :)

OK!:up: