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 17th February 2003, 02:29 PM   #1
diyAudio Member
 
Nappylady's Avatar
 
Join Date: Feb 2003
Location: Salt Lake City
Send a message via ICQ to Nappylady Send a message via AIM to Nappylady Send a message via MSN to Nappylady Send a message via Yahoo to Nappylady
Default Attenuation

I'm currently building a pair of very big 3-way speakers with the goal of good sound and high SPL. (If the sound is superb that's a plus, but I'm only going for good.) Oh, and cost. The cost is a huge factor; all the drivers, horns, and crossovers (I've already bought them) cost me less than $200.

The problem I'm having is that while the woofer and horn tweeter are efficient to about 93 dB, the mid-horn (hehe) is efficient to 110 db. (!!!!!)

The mid-horn itself is 6.1 ohms DC resistance, and by my calculations, I need something like 5.97 ohms in series with that, in order to reduce the output to the level of the other drivers. Question 1: did I do that calculation right?

Next question: how's the best way to attenuate this? Ideally I'd build my own active crossover and then triamp the thing (*droool*) but alas, I have not got the money to do such a thing... I'm thinking that if I go to my local art store and buy some BIG pieces of graphite, I can use them as series resistors next to the driver to cool off the sound some.... I mean really, it sounds terrible with the midrange so loud and the treble so wimpy....

Last question: anyone interested if I dig up a digital camera and take some pictures?
  Reply With Quote
Old 17th February 2003, 04:11 PM   #2
diyAudio Member
 
FrankDIY's Avatar
 
Join Date: Mar 2001
Location: Quebec City
Normally you use an L-PAD. One resistor in serie and one in parallel. 10W resistor a normally enough. From my experience, it is hard to calculate the good value because of many factors. Simply buy a variable L-PAD and adjust to taste. When the sound is fine, read the resistor value on the LPAD and then build a fixed LPAD with standard resistor.
__________________
Imagination is more important than knowledge. knowledge is limited, imagination encircles the world. Albert Einstein
FrankDIY's Audio Corner
  Reply With Quote
Old 18th February 2003, 04:10 AM   #3
diyAudio Member
 
Nappylady's Avatar
 
Join Date: Feb 2003
Location: Salt Lake City
Send a message via ICQ to Nappylady Send a message via AIM to Nappylady Send a message via MSN to Nappylady Send a message via Yahoo to Nappylady
Thanks...

I actually discovered that if I take a piece of foam left over from the project, and shape it to fit the throat of the horn, and then jam it in there, it gives about the attenuation I want. :-)

I'm afraid I have neither the money nor the time to spend getting L-pads, and I suspect they wouldn't give the range I wanted anyway; it doesn't matter though, my problem is basically solved.

I spent less than $130 on all the drivers for these boxes, and when you wrap it up to high SPLs, it really shows, especially to people who are spoiled like me. :-) The higs and mids sound like someone is going "WSHHHSHSHSHSH" out of the horns. It's very yucky. These are $5 ABS horns and I can tell by looking for 5 seconds, they are NOT shaped right.

Oh well. It's for dance parties and I don't think they'll care a whole lot.

Pictures? Pictures coming.

Thanks again!
  Reply With Quote
Old 18th February 2003, 12:07 PM   #4
diyAudio Member
 
FrankDIY's Avatar
 
Join Date: Mar 2001
Location: Quebec City
LPad are not so expensive. The 15W one are around 3-5$ and you need only one to "debug" you crossover
__________________
Imagination is more important than knowledge. knowledge is limited, imagination encircles the world. Albert Einstein
FrankDIY's Audio Corner
  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
attenuation using I/V ailouros6 Digital Source 14 15th October 2008 06:20 PM
XLR to RCA with attenuation pad. KOL69 Everything Else 1 24th April 2008 11:10 PM
hum attenuation AndrewT Power Supplies 3 2nd July 2006 09:12 PM
Attenuation argonrepublic Analog Line Level 5 23rd August 2005 07:22 AM
10 dB attenuation box june Parts 2 20th July 2004 04:07 AM


New To Site? Need Help?

All times are GMT. The time now is 08:40 AM.


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