Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Fostex FF125K  4.5"  speaker
Fostex FF125K  4.5"  speaker
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
Thread Tools Search this Thread
Old 24th April 2005, 07:21 AM   #11
barth2102 is offline barth2102  United States
diyAudio Member
Join Date: Apr 2005
Location: Washington state
Send a message via Yahoo to barth2102
Thanks for the help with the websites for driver measurements.
I have also been studing the TS parameter definitions and hope to gain some good knowledge that I can apply in the near future.
I have plenty of drivers that I bought in China that I have no specs for, so I have much work ahead of me.

Today I finished a new pair of bass reflex cabinets for my stereo.
The old speakers were, a pair of tweeters from Norway, the OLD
OLD style Jordan aluminum cone drivers from the 70's for the mid
range, and the Dayton 6 & 1/2" woofer that Partsexpress sells that seems to be so popular. The ancient crossovers were from a place called McGee Electronics.

I removed the woofer from the .98 cu. ft. box and went to work with the saber saw using the scroll to cut out a larger hole for a new 8" aluminum cone woofer from MCM. It has a FS of 45 HZ.
Using the port calculator at a few websites I came up with a decent figure for the tube length. The 8" woofer is far better suited for the .98 cu ft cabinet compared to the smaller woofer. It has much more output, sounds cleaner and goes lower. I used minimal stuffing at the base of the cabinet.

I built a separate box for the midrange, tweeter and crossover. The midrange unit has an aluminum-magnesium cone, is about 4.5 inches in diameter, and has a rubber suspension. By the looks of it I would guess the FS to be about 90 - 110 HZ. The tweeter is a soft dome unit. Both the mid and tweeter are made in Shanghai, China. The company name is T & T. They are both English designs. Crossover points are 375 HZ and 3,000 HZ and the crossover is the Partsexpress unit.

I would like to reduce the output of the mid and tweeter just a little. The woofer is rated at 86 db spl. The mid and tweeter are rated at 89 db spl. I need advice on the resistor value that I should use to reduce the mid and tweeter by about 1 or 2 db.
One ohm ? Two ohms? .5 ohm ? And where should I put the resistors? In series with the positive terminal of the drivers ? I am hoping not to do any mods to the crossovers, just to cut the output of the mid and tweet a bit .

I am hoping to build some classic TL lines in the future, and that is what part of this thread is about. I have a nice pair of 10" woofers that I purchased in Shenzhen in 2003. Big magnets, 2"
v.c. , ribbed cone with treated cloth suspension, large diameter spyder, aluminum basket. I am guessing maybe a high BL figure and low QMS figure. So maybe good for a TL cabinet . I will try to purchase a multimeter, signal generator, and the other things needed to obtain the TS parameters. I have heard about the q-wave website , but I have much to learn.

I have tried to attach a picture of the woofer, but it has too much info, so I will have to do this later on.

Thank you everyone for your thought and ideas .
  Reply With Quote


Fostex FF125K  4.5"  speakerHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
What Does Fostex "Rated Input" and "Music Power" mark02131 Full Range 5 13th October 2012 06:18 AM
Kofi Annan in: "225K: The Lonely Fostex" Kofi Annan Full Range 64 23rd April 2008 01:51 PM
Fostex FF125K Bass problom lscangus Full Range 5 6th October 2006 08:28 PM
Fostex "rated input" and "music power" hugz Full Range 12 16th March 2006 05:33 PM
Any designs with Fostex FF125K? Lil_JV Multi-Way 1 13th April 2004 04:24 AM

New To Site? Need Help?

All times are GMT. The time now is 12:30 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio