ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2]  All   Go Down

Author Topic: Stamped baskets  (Read 13790 times)

Gordon Brinton

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 486
  • ID Verified
    • Raw Depth Sound, Harrisburg, PA
Re: Stamped baskets
« Reply #10 on: April 18, 2011, 12:32:45 pm »

For all the reasons mentioned aluminum, cast and then machined, is the best option. Stamped baskets can not be machined and tolorence can be held to no better than .010 in most cases. This may not seem like much, however, in the scheme of things tighter tolorences equal more precise alignment of all the motor assembly components.
 
If you'll notice the majority of all JBL speakers appear to have a chrome ring around the cone when looked at through the grill of a cabinet. This is the machined face of the basket from where all height and depth dimensions are referenced to a dimension of .005 or less. Additionally aluminum conducts heat much better allowing for greater heat dissipation and far less skew of the magnetic field. A case in point would be the 2242 in the photo below where better cooling has resulted in an additional 3db gain over extended periods of time due to power compression. Also, speakers may heat to almost 300 degrees when pushed hard. Kapton, invented in 1955, has been replaced by better materials for use with todays monster drivers. The latest, but more expensive material used in forming coils is Hisco P450, invented in 1992. All of this adds up to cost which you should be willing to except if performance and longevity is the goal. The speaker below will run $650 - $750, and it's worth every penny.
I don't mean to get off topic but, just a quickie FYI about your 2242...

I was once told by a JBL technician that the rubber magnet boot is to protect the magnet during shipping only. That the end-user should remove and discard it. If left in place it will hinder cooling of the magnet.

When the same components were installed in cabinets (in the factory) the rubber boot is not installed because it is not needed.
Logged
Member since 2005.

Randall Hyde

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 597
Re: Stamped baskets
« Reply #11 on: April 18, 2011, 04:38:37 pm »

my Dynaudio 30W100 12" home woofers have cast magnesium baskets. they handle 300 watts rms and have a 4" voice coil.
You forgot to mention the 8" Xmax :-)
Logged

Bob Leonard

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 6807
  • Boston, MA USA
Re: Stamped baskets
« Reply #12 on: April 18, 2011, 06:20:48 pm »

I don't mean to get off topic but, just a quickie FYI about your 2242...

I was once told by a JBL technician that the rubber magnet boot is to protect the magnet during shipping only. That the end-user should remove and discard it. If left in place it will hinder cooling of the magnet.

When the same components were installed in cabinets (in the factory) the rubber boot is not installed because it is not needed.

Although the rubber surround could be considered window dressing I've never seen or heard of it being removed either in the case of a replacement driver such as mine are, or when installed by JBL. Having seen hundreds of JBL drivers come out of the box I would have to say that if used for shipping purposes the boot would be extreme overkill. They pack them quite well boot or not.
Logged
BOSTON STRONG........
Proud Vietnam Veteran

I did a gig for Otis Elevator once. Like every job, it had it's ups and downs.

Jeff Bankston

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2269
Re: Stamped baskets
« Reply #13 on: April 18, 2011, 06:29:03 pm »

my Dynaudio 30W100 12" home woofers have cast magnesium baskets. they handle 300 watts rms and have a 4" voice coil.
You forgot to mention the 8" Xmax :-)
yeah but i have driven them to flicker light clipping with a qsc 3500 to many a time since i first bought them in 1986 and never had them bottom. i use a convergent audio technologies tube preamp without tone controls. the foam surround was replaced once by Meninscus. i have them in a sealed 3.5 cu.ft. cabnets with poly fiber fill foam, wool, & fiberglass mixture. there wernt designed for sound reinforcment but for reproducing the bass as it was recorded as accuratly as possible. yep besides being a musician i'm also an audiofile. VPI truntable with et2 airbearing arm. i use an eaton 7-380 hex for the mid and an accuton 1.125" ceramic dome tweeter. i paid a guy that use to build the infinite slope crossovers to design the passive x-over's. i use solen caps. i think if i had a bass level control and pumped the bass up the woofs slam apart. but the sound has great balance from low to high. fo about 2 years i tried different cabnet designs and driver spacing b 4 i got it right. i understand why a manufacture charges what they do for a high quality speaker. not only does it take the electronic design but also lots of listen with the same music and sorce. btw i'm not a golden ear and i really think its how you listen and what you listen for in a stereo system and compare it to the actual unamplified live instrument. why doesnt a manufacture copy my speaker if i think its so good ? i had suggested it to a couple manufactures at one time. is there somthing out there that i might like better then what i have ? possibly
Logged

David Parker

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1198
Re: Stamped baskets
« Reply #14 on: April 18, 2011, 08:39:54 pm »

I don't mean to get off topic but, just a quickie FYI about your 2242...

I was once told by a JBL technician that the rubber magnet boot is to protect the magnet during shipping only. That the end-user should remove and discard it. If left in place it will hinder cooling of the magnet.

When the same components were installed in cabinets (in the factory) the rubber boot is not installed because it is not needed.

Although the rubber surround could be considered window dressing I've never seen or heard of it being removed either in the case of a replacement driver such as mine are, or when installed by JBL. Having seen hundreds of JBL drivers come out of the box I would have to say that if used for shipping purposes the boot would be extreme overkill. They pack them quite well boot or not.

I've seen cabs, can't remember what they were, where the rubber surround on the compression driver fit in a hole in a frame inside the cab used to support the weight, take the strain off the horn. Without the rubber, the magnet wouldn't be supported by the inner frame. Never seen that on woofers, but just because I haven't seen something doesn't mean it doesn't exist.
Logged

Jeff Bankston

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2269
Re: Stamped baskets
« Reply #15 on: April 18, 2011, 08:41:45 pm »

top foto is a Ciare 12NDH-4 with cast frame and its heavy. bottom foto is from a second set of Dynaudio 30W100 woofers(not the XL version). the Dynaudio is way lighter then the Ciare. if i had a scale i would weigh them. i just got a web camera and these are the first 2 fotos with it. not bad fotos for a drummer !!!  :o
« Last Edit: April 18, 2011, 08:54:18 pm by Jeff Harrell »
Logged

ProSoundWeb Community

Re: Stamped baskets
« Reply #15 on: April 18, 2011, 08:41:45 pm »


Pages: 1 [2]  All   Go Up
 



Page created in 0.05 seconds with 22 queries.