Speaker crossover graph questions

[ZR9B]

I was wondering what this graph trying to tell me. Is this a desirable curve? Also is a pic of the crossover that it goes with. I did post this in the jbl section but I also figured someone here would know what it says. Thanks.

 

[rothwellaudio]

The graph is describing a high pass filter, ie the high frequencies are passed through the filter and the low frequencies are blocked. You use such a filter to connect tweeters, blocking low frequencies to prevent damage and to integrate the tweeter with the rest of the speaker.
Filters can be 1st order, 2nd order, 3rd order etc., and roll off the low frequencies at 6dB/octave, 12dB/octave, 18dB/octave etc. That filter looks to be 2nd order. It appears to contain resistors which suggests it has been designed for a specific application (maybe a JBL L88?).

 

[Guest159]

It's describing the slope of the high pass filter for the tweeter for the different resistors, it look like. I'm not sure if "desirable" is an applicable term. It is what it is. It might be good for the JBL. It would be terrible in some speakers.

As a sidebar: nobody should cover resistors with hot-snot. It insulated them and effectively de-rates their power rating. Maybe they're big enough that's not an issue, but then again, oversized resistors add unnecessary capacitance and inductance.

 

[roxoncontac]

That's like asking if a 22 oz rip hammer is a good tool. We don't know what the summed output of the driver and crossover is or the transfer function of the LP section.

 

[ZR9B]

rox...care to elaborate? What you said makes no seance to dumb people like me! and I like the rip hammer better than a claw.

 

[toxcrusadr]

What he means is, if I may: If you hold up a random auto part and ask whether it's a good one, it's impossible to say unless one knows what car it was meant for and what car you're actually proposing to use it on.

 

[ZR9B]

Got it......they are for a older pair of jbl l88 . I'm trying to find some more mid range in a speaker that doesn't seem to give too much of it.

 

[toxcrusadr]

Ah, so you're wanting to increase the midrange output of the speaker. That's a different question from 'is this crossover curve desirable.'

Would decreasing the treble do it, or would that result in too much bass? This can be a complicated modification because the midrange probably comes out of both the drivers since it's a two-way.

 

[ZR9B]

You are correct....I worded it all wrong. At this point when I installed it in 1 speaker it blew out the channel of my 881 sansusi. (fuse I hope) No wires were touching and it was installed correct. I may just cut my losses and move on.