In Reply to: RE: Pure Audio Project Open Baffles & 2 Questions posted by Mick Wolfe on April 18, 2017 at 15:53:39:
Thanks Mick! Also for mentioning the Audio Circle OB forum. I didn't know or forgot about it. I took a look and there appears to be lots of interesting and active threads.
Here are a few thoughts I didn't mention in my original post because it was already a bit long. The reason I originally bi-amped the system is because the PAP Neodymium woofers are less sensitive than my Altec/Jensen drivers. With the Crown woofer amp, I was able to dial up the woofer level to match the other drivers. However, two items made me think the new setup could work.
The first is a quote from the woofer product design manager: "(this model) can play with any tube amp starting at 3.5w. They are very responsive 95/96db drivers!" The second is that I believe having 2 woofers per side increases the output somewhere between 3 and 6db.
Even though those factors should get the woofers up to the level I need, in practice I did lose some bass below 40hz. Of course we are comparing 8 watts vs. 525w for the Crown amp into 4 ohms. However, running the speakers full range using just the Bottlehead Paramount 300B amps sounds better!
My only concern now is the speaker system impedance. My Paramounts are upgraded with Magnequest BH-5 output transformers and only have 8 and 16 ohm taps. If my OB impedance is much lower than 8 ohms, I wonder what impact that has power or distortion? I know impedance calculations can be complicated and that it varies with frequency so that's why I asked the impedance question.
Gerry
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Follow Ups
- RE: Pure Audio Project Open Baffles & 2 Questions - Gerry E. 14:34:06 04/19/17 (5)
- RE: Pure Audio Project Open Baffles & 2 Questions - Mick Wolfe 09:07:23 04/20/17 (0)
- RE: Pure Audio Project Open Baffles & 2 Questions - Tre' 15:03:03 04/19/17 (3)
- RE: Pure Audio Project Open Baffles & 2 Questions - Gerry E. 09:27:43 04/23/17 (1)
- RE: Pure Audio Project Open Baffles & 2 Questions - Tre' 10:14:21 04/23/17 (0)
- RE: Pure Audio Project Open Baffles & 2 Questions - Gerry E. 11:45:21 04/20/17 (0)