Fast, fun, Inexpensive OB project

Well, I consider $300+ for a single coil, being that low R, big diameter, flat wound, whatever, a very bad price.
Double that for stereo, then drivers, then other bits and pieces and Manzanita is no longer a fast, fun, inexpensive OB project.

I am a farmer but still haven't found a way to grow money on trees, or vines in my case.
 
  • Like
Reactions: 1 users
I spent a few hours googling last night and I found these Mundorf MCoil BS140-22mH Wire Diameter 1,4mm and RDC 0,56 Ohm (https://www.mundorf.com/audio/en/shop//MCoil+BS140+iCore+StackCore/?card=1785).

It seems they are only available in Europe (several places stock them) and the prices range from around 55-60 Euro each plus shipping.

Still not cheap and cheerful, but at least they are available.

I also checked out the Jantzen Audio C-Coil 17AWG 20.0 mH (Toroidal), again readily available in Europe for similar prices, but I did see these following notes which concern me:

It is not recommended also to use C-Coils in crossovers with an XO-point above 1.20 kHz (due to the core’s distortion factor).
 
I built these 13 years ago and just now realized I never posted them here. They are Open Baffle, Line Array, EconoWaves.

The drivers are PE 69 cent NSB close outs.

The horns are JBL 6"x6" wave guides with Selenium D210T (JBL wave guide part 364914-001)

The cross overs are stock eWave - http://www.audiokarma.org/forums/attachment.php?attachmentid=151281&d=1242968714

They are 48" tall and 24" wide with the driver centers 6" from the edge and (top to bottom) centered on the baffle.

IMG_4544.jpeg
 

Attachments

  • IMG_4545.jpeg
    IMG_4545.jpeg
    244.8 KB · Views: 53
I also checked out the Jantzen Audio C-Coil 17AWG 20.0 mH (Toroidal), again readily available in Europe for similar prices, but I did see these following notes which concern me:

It is not recommended also to use C-Coils in crossovers with an XO-point above 1.20 kHz (due to the core’s distortion factor).
This is COVER YOUR ***🤭 This sentence also applies to ERSE, Jantzen and Mundorf coils. Do not worry about it.
 
Last edited:
Anyone ever try the Fountek FE85 for this project (I saw that Lingwendil asked about them in post #3424 but I didn't see a response after a quick check of later posts)? I have 2 on hand in a long-ago mediocre project but if they were able to work in this project, I might try them. They seem pretty similar except for the Qts and excursion, both of which are lower in the Fountek. The Qts is particularly worrisome for an OB, but I admittedly don't know much about this, particularly where higher frequencies are concerned (e.g. how important the Qts is for tweeters?). If so, any pointers on how to adjust the crossover? I will dig into that at some point if folks think it's worth pursuing, but any pointers are always welcome.
Hmmmm. No comments? Am I way off with these instead of the Vifas? I do know there are differences but they seem pretty similar in a lot of ways.
 
Another quick update re the 20mH inductors: I ended up biting the bullet and purchased 2x Mundorf MCoil BS140-22mH inductors from Banzai Music in Germany (https://www.banzaimusic.com/Mundorf-MCoil-BS140-22mH.html)

The total cost including shipping was 107.93 Euros, and this was by far the cheapest I could find anywhere with shipping Downunder.

I will have to remove a few windings to take them back to 20mH, but that should be relatively easy, at least I hope so!
 
These were made by a local audionut near me back in Michigan. Those are Fostex full range drivers completely open in the back. The woofs are A15s. When I got them, they sounded very good but in time I realized they lacked midrange, so I built boxes to enclose the back of the Fostexs. Then I stained and cleared them. They really came alive. Needles to say, it was a very large sound!!!

1703192858371.jpeg



1703192873831.jpeg



1703192908180.jpeg
1703193201505.jpeg


1703193227036.jpeg


1703193253265.jpeg
 
  • Like
Reactions: 1 users
Member
Joined 2014
Paid Member
I built these 13 years ago and just now realized I never posted them here. They are Open Baffle, Line Array, EconoWaves.

The drivers are PE 69 cent NSB close outs.

The horns are JBL 6"x6" wave guides with Selenium D210T (JBL wave guide part 364914-001)

The cross overs are stock eWave - http://www.audiokarma.org/forums/attachment.php?attachmentid=151281&d=1242968714

They are 48" tall and 24" wide with the driver centers 6" from the edge and (top to bottom) centered on the baffle.

View attachment 1248948
Do I see a pair of Advance AIIs? Those are a Stab From the Past!