Keith Kidder's 4eleven - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th September 2004, 02:18 AM   #21
Zaph is offline Zaph  United States
diyAudio Member
 
Zaph's Avatar
 
Join Date: Sep 2003
Location: Wisconsin
Quote:
Originally posted by studiotech
Zaph, you refered to the issue of the cupped spider rather than a flat spider in terms of inducing distortion.....could explain that a little further? How can you have a flat spider, when it needs to movwe up and down a certain amount? Thanks. Greg
Well, lets start out by saying a spider needs to be spaced away from the top plate of the magnet to avoid damage during maximum inward Xmax. There are several ways it can get that spacing. The first is with a plastic spacer ring, popular on subwoofers. The second is with a specially designed frame that supports it the right distance. The better designs like this (Scan Speak, Seas Excel, etc) allow venting under the spider. And the final method is with a cupped spider, which is just like a normal spider, but it's got sides to it, formed right from the same material as the rest of the spider. Including the sides, the spider has a cup shape.

See the attachment below. Flat spiders have no dimension C because they are designed to mount to the frame or to a spacer piece. Cupped spiders do have a dimension C, and the bigger the dimension, the worse the distortion.

Cupped spiders cause distortion because they become non-linear as excursion increases. The sides flex in and out while the spider flexes up and down. The problem is that the outward flex rate is not the same as the inward flex rate. This "Tension variance" directly affects voice coil movement, and then you have distortion. So, I say there is no such thing as a good cupped spider. They are a workaround for a poorly designed voice coil length and frame combination.

Flat spiders generally have a symetrical up and down movement, resulting in lower distortion.

And while we're on the subject, progressive spiders lower distortion even more with a linear increase in tension as the voice coil gets close to the design Xmax.
Attached Images
File Type: jpg spiderdims.jpg (3.1 KB, 165 views)
__________________
-Zaph|Audio-
  Reply With Quote
Old 16th September 2004, 05:20 AM   #22
27ph is offline 27ph  Denmark
diyAudio Member
 
Join Date: Sep 2004
Location: Cph
Check ut the Audax midranges. I was recommended the HM130C0.

vH pH
  Reply With Quote
Old 16th September 2004, 08:51 AM   #23
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
though the HCM130C0 is a bit pricey I've heard this and its good..

http://www.partsexpress.com/pdf/296-063.pdf

cheaper alternatives to consider that have similarly slightly def. output and less than flat on-axis curves:

Focal Access 5A:

http://www.zalytron.com

and the GR Research M-130:

http://www.gr-research.com/drivers.htm#grt1

with budget constraints I'd prob. pick the Access 5A, especially considering the current sale price.
__________________
perspective is everything
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Keith Monks Uni pivot, Mercury contact Jonathan Bright Parts 4 14th September 2008 09:08 AM
calling Keith Pritt AndrewT Everything Else 1 15th November 2007 07:30 PM


New To Site? Need Help?

All times are GMT. The time now is 11:21 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2