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View Full Version : Tweeter Crossovers are they needed?



Morts
07-08-2009, 11:35 AM
OK I am a little confused here. I have always used tweeter crossovers even after an active crossover. I just got a new set of tweeters and they are 6.4 ohm and have no crossovers with them. I have an old HiFonics amp with 2 crossovers built in the amp, one for low/mid and the other for mid/high 75-5 kHz adjustable. Do I need tweeter crossovers? What would be a good crossover point to set at so I dont fry the tweeters? Sorry for the question but I always used the crossovers. The tweeters frequency response is 1500 to 25000. So would 2K be safe? Thanks

Image Dynamics
07-08-2009, 11:52 AM
OK I am a little confused here. I have always used tweeter crossovers even after an active crossover. I just got a new set of tweeters and they are 6.4 ohm and have no crossovers with them. I have an old HiFonics amp with 2 crossovers built in the amp, one for low/mid and the other for mid/high 75-5 kHz adjustable. Do I need tweeter crossovers? What would be a good crossover point to set at so I dont fry the tweeters? Sorry for the question but I always used the crossovers. The tweeters frequency response is 1500 to 25000. So would 2K be safe? Thanks

The active crossover on the amplifier will be 12db/octave (more than likely). I'm guessing (obviously only guessing) you were using a 6db cap only for the tweeter as a passive unit too?

Are you going to be running the tweeter in conjunction with a mid-driver on the same channel? If not, then just run with the active crossover on the amp. At 6.4 ohms, you will have a lower output than a 4 ohms unit. Depending on the efficiency of the tweeter it may not be a big deal.
The crossover will keep the coil on the tweeter from moving too much and "jumping the gap" or tearing it apart thus destroying it. I would keep the tweeter crossover around 3.5K - 4.5K.

Morts
07-08-2009, 12:32 PM
It is indeed a 12dB/octave x-over. The tweeters are run separate on 2 of thier own channels 1 and 2, my mids are on channels 3-4 and the sub is bridged on channels 5-6. So I will not need any passive crossovers and if I set the crossover at 3.5K I am safe? I never ran a tweeter without a crossover and wanted to make sure I didnt fry them without a passive crossover or blocker. Do you think 2K would be too much with them on separate channels? I appreciate your reply and your time much is appreciated.

KOL
07-08-2009, 01:04 PM
without knowing what tweet you have we can't say for sure but 2khz @ 12db/oct is too low for most tweets

Morts
07-08-2009, 01:39 PM
They are Morels

Here is the spec sheet.

Appreciate the input.

http://www.renaudio.com/sale/MDT-105s.pdf

nismos14
07-08-2009, 02:02 PM
You're still running it with a crossover, even though the passive is removed. Right now you're basically doubling up on the crossover.

Morts
07-08-2009, 02:07 PM
I have not got these tweeters yet they are in the process of being shipped to me. I am not going to run a passive crossover at all with them. Just need a safe crossover point for them I guess and want to play them as low as I can and be safe. Hope I cleared it up now and I appreciate the input guys.