16 replies to this topic

[Mattay]

So at the moment i've got a crescendo MB-6 running off 200w RMS 4ohm clean.

I'd like to add a Crescendo mb-3n midrange however i dont have any additional amplifier or processesing channels, so id like to possibly make a custom passive crossover and have the midbass and midrange running off it on the single 200w channel.

Unfortunately the crossover made for this midrange is for the tweeter/midrange

Is this feasable or would my best bet be to buy the tweeter and replace my current tweeter with the crescendo so i can use the tweeter/midrange with crossover on one channel and my existing midbass?

Thanks

[muzzy66]

Depends on whether you want a crosover that works well, or just one that works. Given the type of gear you are using I'm assuming you'd want oen that works well, in which case I wouildn't recommend a custom passive unless you really know what you're doing, or you know someone (such as a local installer or audio engineer) who really knows what they're doing. Somebody who can actually measure the TS specs at the very least (since I don't think Crescendo provides all the ones you need) and who can then use those to design a proper crossover.

You can always slap together a very simple one, but the chance if it working well is minimal. If it sounds good enough for you thought, then it's fine.

[Mattay]

Thanks for that, i think i might wait a while and possibly get a 3-way set later down the track

[268669♫]

The crescendo tweet and mid are very nice combo and if your going to mount them close together this would be the better option. Unless you mount your mid next to your midbass the passive for the mid/midbass wont work as well due to having the same T/A as each other.

Where did you want to mount the mid and what is your current setup positions?

Ant

[Mattay]

Heres my current setup

I should be able to mount the midrange either just above the midbass, or near the top of the door

Edited by Mattay, 18 November 2011 - 06:26 PM.

[muzzy66]

Sexy A-Pillar

[Mattay]

Thats an old pic, its not trimmed Looks real good, i'll take some pics of my entire car when its all done soon, mega props will be going out to you muzzy, certainly the most help.

[muzzy66]

Don't look at me, I don't even have a system! lol

[Tiger]

Damo95 had a 2 way passive crossover setup made... looked like 2 x amplifiers though! Mssive footprints!!!

If you know what frequencies/slopes you want for each driver, then it's a matter of knowing somebody with a desktop CNC machine that can work on your circuit boards to create a design; which will allow you to use whatever coils, capacitors etc that you require to achieve your 3 way crossover points. Depends how fiddly you are with electronics...

BUT... another option.. active 3 way. ALOT more control of your drivers, alot more power put into EACH driver but the downside... extra amps required and an external 3 way crossover unit or sound processor (like H800 or a BIt.One) is required.

My 2 cents.....

[~Spyne~]

Tiger, on 19 November 2011 - 06:55 PM, said:

If you know what frequencies/slopes you want for each driver, then it's a matter of knowing somebody with a desktop CNC machine that can work on your circuit boards to create a design; which will allow you to use whatever coils, capacitors etc that you require to achieve your 3 way crossover points. Depends how fiddly you are with electronics...

You need to know a lot more than frequency and slope to design a worthwhile passive crossover.
As suggested previously, it's A LOT of work to make a good passive, which also requires quite a bit of money. You (in my opinion) would be better off going active.
Amps are cheap, and processors really aren't that much either.

[~thematt~]

I used to have a custom passive for my mid and tweet in a 3-way config. Set me back more then $1.5k.....

Dont use it anymore. I'll leave passive to home audio.

[ubernoob]

I made a set of passive crossovers a few years ago, it cost a bit and I never used them, they were for 6Ohm spekers crossed at 550Hz, from memory.

Edited by ubernoob, 01 January 2012 - 11:41 AM.

[TMM]

Why not run the mids/tweets with the existing crossovers, and run the midbasses on their own? Or am i misreading that and you want all 3 to run off a single channel?

You really need to measure the frequency response of the drivers - or at least have a reliable datasheet - to properly design crossovers. Other than the basic crossover network you might need notch filters to flatten out breakup nodes, and attenuation pads to adjust levels. $50-100 should cover components for a 2-way, twice that for 3 way. Building it is the easy part, the design (and re-design if it doesn't work out as expected) and working out how you are going to mount it in the car is what takes effort.

Edited by TMM, 31 December 2011 - 03:22 PM.

[Pulse-R]

The main things that affect the results of a passive design are the crossover slopes and phase - but not on their own.
Best results are obtained when you design it to work in the car, not in your lounge room. This is what a lot of passives do not take into account.

also, being the midbass to midrange crossover, the chokes will have to be quite large.

[muzzy66]

Not to mention gain / level and possibly notch filters to tame and harsh peaks or cone breakup