Adding Midrange Speaker/Crossover to 2x15 Cab

[waterdog]

OR-
How about a pair of lower sensitivity mid drivers, two crossovers at a nominal 8 ohms then wire the sets together. Just like stacking without the stack. Reduces the power handling requirement of the crossover.

 

[theshadow2001]

It most definitely cannot. Even if a speaker WERE just a simple inductor (which it's not, see my post above), the impedance of an inductor IS frequency-dependent -- i*omega*L. Period. No argument.

Take the simplest possible circuit you can think of: a resistor and inductor in series. The impedance is Z = R + i*w*L. How do you reduce that to a frequency independent number? Unless you know some math that I don't (and, statistically speaking, that's unlikely), you can't.

Asad

my mistake

 

[greenboy]

bluebledthesea,

I PM'd you crossover information which can get you there, and into playing.

 

[bluebledthesea]

bluebledthesea,

I PM'd you crossover information which can get you there, and into playing.

Thanks man, I replied with a random monologue that included my thoughts on the cab situation, life in general, and Indian curry...

 

[billfitzmaurice]

Is it the speaker pushing air in and out changing current draw?

Yes. Air has impedance, the amount is determined by the cabinet configuration. That impedance is a component in the equation.

 

[greenboy]

Thanks man, I replied with a random monologue that included my thoughts on the cab situation, life in general, and Indian curry...

Gotcha. I disagree on the aging of the curry powder though.

 

[bluebledthesea]

Well, this is my plan for a simple 2nd order Linkwitz Riley crossover. Please let me know if I screwed something up or if I need to add anything else.

I may have asked this before, but I don't think I quite understood. When the crossover calculator ( http://www.lalena.com/Audio/Calculator/XOver/ ) asks for Tweeter and Woofer impedance, is it simply 8 ohms and 4 ohms, or is it driver impedance?

Thaaaaanks

 

[billfitzmaurice]

asks for Tweeter and Woofer impedance, is it simply 8 ohms and 4 ohms, or is it driver impedance?

Thaaaaanks

To be precise it is the driver impedance at the crossover frequency, as shown on the driver data sheet. In the case of two drivers in parallel divide by two.

 

[bluebledthesea]

Well, I finally got everything built, crossover and speakers installed, and one of my 3015LFs sounded terrible. I checked over all the connections, then I ran the single 3015LF direct to the amp at 8 ohms to rule out the crossover and it still sounded ugly. There is a staticy distortion at any volume, and even if I just tap on a bass string I can hear the sound. When I press on the speaker cone I think I can hear a slight grating on the voice coil. I swapped in the other 3015LF and none of this is present.

UGH! What is your experience with loudspeakersplus.com and replacements? I'm pretty much convinced I received a damaged speaker. I was all set to get this baby finished and ready for practice on Sunday.

 

[greenboy]

I was just about to PM you after your last PM last night, to tell you to test the speakers directly connected - to isolate whether it was actually your crossover. Troubleshooting 101.

So it seems time to get an RA# and replacement 3015LF, eh? Use phone : }

 

[bluebledthesea]

I was just about to PM you after your last PM last night, to tell you to test the speakers directly connected - to isolate whether it was actually your crossover. Troubleshooting 101.

So it seems time to get an RA# and replacement 3015LF, eh? Use phone : }

I guess I'm not as stupid as I look!

 

[greenboy]

Actually you seem to be on the move pretty good - unlike many you've seen that audio performance could be enhanced, and actually tackled a crossover, speaker retrofitting, etc.

 

[bluebledthesea]

Actually you seem to be on the move pretty good - unlike many you've seen that audio performance could be enhanced, and actually tackled a crossover, speaker retrofitting, etc.

Unfortunately, I never made it to the port tuning stage. No use in tuning a busted speaker.

You'll like this. When I knocked out the triangles filling the ports it was just layers of cardboard glued together.

Another thing I thought I'd add. One of the wires going to the speaker cone was very poorly welded on, but I didn't want to mess with it if I was going to return it. I don't know if this is enough to cause the problem as there was still contact and the voice coil still grates slightly.

 

[billfitzmaurice]

A bad driver out of the box usually indicates you've been UPS'd. That's one bad thing about neos, the box is so light that it's a lot more likely to be thrown at least once between the factory and you.

 

[bluebledthesea]

A bad driver out of the box usually indicates you've been UPS'd. That's one bad thing about neos, the box is so light that it's a lot more likely to be thrown at least once between the factory and you.

Unfortunately this means I'm cab-less until I get that speaker in.

Maybe I can slap that old Peavey back in and temporarily seal the port... blah.