DIY Audio Projects Forum
 NEW  Matt presents bias and operation data for the 6V6 tube in SE operation - 6V6 Single-Ended (SE) Ultra Linear (UL) Bias Optimization.

DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

It is currently 17 Jul 2018, 20:08

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 4 posts ] 
Author Message
PostPosted: 20 May 2017, 23:09 
Offline

Joined: 20 May 2017, 22:49
Posts: 3
I'm wiring these ND91-4s in series-parallel to give me a 4 ohm total impedance. They have a nasty rise in impedance, up to 17 ohms at the 4500hz crossover. When designing a Zobel, can I treat the four drivers as one? The calculators recommend a 29 mF cap and a 5.4 ohm resistor, using Re of 4.3 ohms and Le of .83 mH. And will a 10 watt resistor be adequate?

I'm pairing these with the Dayton AMT2-4 and the Dayton 6.5" passive radiator in a .45 cu ft box I built. So far I'm looking at a 2nd order L/R at 4500hz, with some level of Baffle Step Compensation.

These aren't the first speakers I've built, but they are the first I've designed.

Rick


Top
 Profile  
 
PostPosted: 22 May 2017, 10:12 
Offline

Joined: 20 May 2017, 22:49
Posts: 3
Here's some more info on my design, for your review and comments:


This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.



Top
 Profile  
 
PostPosted: 22 May 2017, 15:21 
Offline
User avatar

Joined: 08 Aug 2009, 03:11
Posts: 2220
Location: Chilliwack, BC
Welcome!

Quote:
When designing a Zobel, can I treat the four drivers as one?


Yes.

Designing crossovers is part science and part art.

Usually math gets you in the area and sweeping the system and tweaking for flattest response in an anechoic chamber (don't have one? No problem! Do it outside) gets the system flat on papaer and watcing for any peaks-or-valleys (you may have to try several xover frequencies).

After, change components for best sound. Re-sweep to see the difference and if need be, add a switch on the back.

Cheers!

_________________
-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design


Top
 Profile  
 
PostPosted: 22 May 2017, 21:06 
Offline

Joined: 20 May 2017, 22:49
Posts: 3
The enclosure size is actually about .2 cu ft, not .45.

Thanks, Geek. You've validated the info I got from the PE Tech guys. I just needed to make sure.

I've been using REW for several years now, and just about have it figured out (except for the Phase stuff. I'm still not sure what to do with the information from the frequency sweeps.)

I'm playing with XSim to refine the xover. It says the BSC circuit does more harm than good, and that I need an L-Pad on the AMT. It also changed a few values in the other circuits.

Rick


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
DIY Tube Projects :: DIY Tube Amp Kits :: DIY Speaker Projects :: DIY Solid State Projects :: DIY IC / Op-amp Projects :: DIY Phono Projects :: DIY Cable Projects :: Hi-Fi Audio Schematics
© diyAudioProjects.com - Terms of Service - Privacy Policy