impedance mismatch

ddoyle · 16th January 2008, 03:52 AM

Want to finish an old speaker project. Turns out my speaker/crossover combo will be down to around 4 ohms. 2 identical 8 metal cone woofers ans a 1 tweeter.(see old zetag posts) My HT pioneer is only good for 6-8 ohms. Any easy way out?

Dan

ddoyle · 16th January 2008, 01:29 PM

not a valid question? I have all these drivers and parts....why did I choose this as my first large scale DIY project?
The way I see it I could, bag it all and just use my AR3s or
start over and make 4 2-way speakers or
buy the new crossover parts, put it together, run it and see if the receiver lives or use an active crossover/amps setup and fill up my space with more units or spend a pile of money on impedance limiting transformers. I do know that I have gone about the project the wrong way, I will do better next time. Current design: 2 identical 8" metal cone woofers(6.2ohm), 1 custom vifa tweeter(7.1ohms). Crossover, lower bass, 1st order 6db with zobel, 105hz, upper bass 12db at 3000 with notch and zobel, and tweeter 12db at 2500hz. Can I make this work, my concern is the low impedance when using my HT receiver which is not 4 ohm stable. Of course any advice, suggestions or even admonishments appreciated!

Cal Weldon · 16th January 2008, 02:06 PM

Hi Dan,

Wire your woofers in series and adjust your XO to suit?

Caferacer · 16th January 2008, 03:28 PM

Ditto. Reciever amp will be much happier.

ddoyle · 17th January 2008, 01:42 AM

Thank You! Now would this require a complete redesign of the crossover network?

Caferacer · 17th January 2008, 03:04 PM

Not a complete redesign. The topology can stay the same. But the values on the woofer half of the crossover will change because of the impedance change.

Caferacer · 17th January 2008, 03:06 PM

Keep in mind that as long as you don't crank your volume, your reciever probably can handle the 4 ohm load. It's just not ideal.

16th January 2008, 03:52 AM	#1
ddoyle diyAudio Member Join Date: Feb 2006 Location: oregon	impedance mismatch Want to finish an old speaker project. Turns out my speaker/crossover combo will be down to around 4 ohms. 2 identical 8 metal cone woofers ans a 1 tweeter.(see old zetag posts) My HT pioneer is only good for 6-8 ohms. Any easy way out? Dan

16th January 2008, 02:06 PM	#3
Cal Weldon Speakerholic diyAudio Moderator Join Date: Jan 2004 Location: British Columbia	Hi Dan, Wire your woofers in series and adjust your XO to suit? __________________ Next stop: Margaritaville Some of Cal's stuff \| Cal Weldon Consulting

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16th January 2008, 01:29 PM	#2
ddoyle diyAudio Member Join Date: Feb 2006 Location: oregon	not a valid question? I have all these drivers and parts....why did I choose this as my first large scale DIY project? The way I see it I could, bag it all and just use my AR3s or start over and make 4 2-way speakers or buy the new crossover parts, put it together, run it and see if the receiver lives or use an active crossover/amps setup and fill up my space with more units or spend a pile of money on impedance limiting transformers. I do know that I have gone about the project the wrong way, I will do better next time. Current design: 2 identical 8" metal cone woofers(6.2ohm), 1 custom vifa tweeter(7.1ohms). Crossover, lower bass, 1st order 6db with zobel, 105hz, upper bass 12db at 3000 with notch and zobel, and tweeter 12db at 2500hz. Can I make this work, my concern is the low impedance when using my HT receiver which is not 4 ohm stable. Of course any advice, suggestions or even admonishments appreciated!

16th January 2008, 03:28 PM	#4
Caferacer diyAudio Member Join Date: Apr 2007	Ditto. Reciever amp will be much happier.

17th January 2008, 01:42 AM	#5
ddoyle diyAudio Member Join Date: Feb 2006 Location: oregon	Thank You! Now would this require a complete redesign of the crossover network?

17th January 2008, 03:04 PM	#6
Caferacer diyAudio Member Join Date: Apr 2007	Not a complete redesign. The topology can stay the same. But the values on the woofer half of the crossover will change because of the impedance change.

17th January 2008, 03:06 PM	#7
Caferacer diyAudio Member Join Date: Apr 2007	Keep in mind that as long as you don't crank your volume, your reciever probably can handle the 4 ohm load. It's just not ideal.