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I have a pair of Model 19 enclosures and a choice to make about the lf driver. I own a pair of 416z from Valencia's. I have a pair of 16 ohm GPA drivers for the hf horn. I also have a pair of 8 ohm GPA hf drivers. So, I can build a passive x-o scaled to 16 ohms, or I could sell the 416z's and buy a pair of GPA 416-8C.
Any guess as to the best choice?
thanks
Les
Build the crossover 8ohm, you can use a parallel non inductive resistor to bring the 16 down if needed, that way you can try either.Quote:
Originally Posted by les winter
Dayton Audio DNR-16 16 Ohm 10W Precision Audio Grade Resisto 004-16
16 divide by 2 in parallel = 8 ohms
Thanks OG. If I hang a 16 ohm resistor across the woofer terminals, I think the Qts gets cut in half. The simulation show a really nasty curve after that.
There would be a voltage drop across the resistor. That leaves less output voltage to drive the woofer. It would suck the life out of the sound.
How so Alan? The paralleled resistor would reduce the resistance and so the voltage drop.
Oh duh...series resistor would cause the voltage drop. A parallel resistor would result in a current drop.Quote:
Originally Posted by zelgall
It still sucks the sound out of the speaker. I just had to do this with my 300Bs. There was a woofer pumping going on at high levels and we were trying to figure out why. So I strapped a 5W across the terminals, which stopped the pumping, but it sounded like crap. We ended up making some value changes to the output capacitor as well as removing it from the feedback loop. Problem solved. But I'm not getting any design cred.
My bad here.I read 16 ohm HF- those are more common. Resistive matching on woofs not so good.Quote:
Originally Posted by alancohen
OTOH if the xover was 8, the HF could be resistive matched and the LF allowed to work into an upward mismatch. There may be minor issues, but an upward mismatch is much more forgiving.
One good solution- get another pair of 416z and run the extra pair in boxes below the Valencias. WAF may suffer.
Maybe I should have asked this question instead: All things being equal, which will sound better: a nw pair of GPA 416-8C or a vintage mint pair of 416Z?
thanks for all the replies.
Since you're asking what will sound better and you're considering buying a new pair of GPA 416-8C, I'd recommend buying a new pair of GPA 416-8B. The alnico 416-8B is what's in both pair of Model 19's that I own and was the original driver in most Model 19's (until Altec switched from alnico to ferrite). Of course keep in mind that your question (which will sound better?) is subjective in nature and there may be a few out there that prefer the ferrite 416-8C over the 416-8B.....
Quote:
Originally Posted by les winter
Will Z's mount to a 19 cab?
Quote:
Originally Posted by badtoby
Depends- z can have old or new frames. Old frames need rear mount or some manipulation to front mount.
I built the enclosures and made the front baffle removable, so it can be modified or replaced as needed. I have decided to build 16-ohm versions of the model 19 x/o and use the 416z woofers. I appreciate all the input.
thanks.
I owned 416z woofers in my 846a Valencias. They are great sounding woofers--please keep us posted on your progress!Quote:
Originally Posted by les winter
Good move! I think you can make a decent set of speakers with your components. You might have to be a little creative mounting the 511b's as well. The HF drivers might want to protrude out the back of the cabs a bit. Also you might want the crossover point a little lower than the 811b's on mod. 19's. You'll have fun getting there! Keep us posted on your progress.Quote:
Originally Posted by les winter