Speaker Ideas for 500 bucks - 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 25th October 2001, 11:21 PM   #21
jteef is offline jteef  United States
diyAudio Member
 
Join Date: Feb 2001
Location: Ogden, UT
Send a message via AIM to jteef
I have a couple questions about the phase alignment as I think it is pretty important, and I want to get it right.

imagine 2 speakers, a tweeter and a woofer crossed over at 1.5khz.

If I use a zobel on the woofer to counteract the high frequency impedance rise from the voice coil inductance and compensate the tweeters impedance peak at fs, so that both speakers have a resistive input impedance for a few octaves on both sides of the crossover frequency, will their cones move in phase, or do I have to worry about that as well?

If they are in phase, why are zobel nets hardly ever mentioned when using active crossovers. When using active xovers, is your only option in phase alignment the physical distance of each driver to your ear?

Is the only reason to use a zobel net obtaining a constant input impedance so a passive xover doesnt shift values depending on frequency.

my audio book is pretty thin on crossovers and covers compensation networks and the phase effects of the driver, but not both in the same example. Several articles i've read cover one or the other, but not both. i.e. the articles on ESP.

Thanks a lot

jt
  Reply With Quote
Old 26th October 2001, 12:14 AM   #22
diyAudio Member
 
Join Date: Feb 2001
Location: Columbia, SC
jteef,
The Zobel network is there purely for the benefit of the passive crossover. If you use an active crossover, you won't need one. That said, I believe I recall seeing someone on this site saying that they use a Zobel to even out the load presented to the amplifier. If that line of reasoning appeals to you, by all means put in a Zobel network. I don't use them, myself.
As far as time alignment goes, yes, you're going to be limited to the physical position of the drivers...until you start looking at the active crossover. Keep in mind that any filter, regardless of where it is in the system, will give you an arbitrary amount of phase shift at a given frequency. You should account for this with an active crossover just as you would with a passive crossover. You also have the option of adding a phase shifter to the active crossover if you'd like, something that is frequently done on subwoofers these days.

Grey
  Reply With Quote
Old 26th October 2001, 01:10 AM   #23
jteef is offline jteef  United States
diyAudio Member
 
Join Date: Feb 2001
Location: Ogden, UT
Send a message via AIM to jteef
ok, i can understand that

what is a "phase shifting circuit" then?

The example in my audio book uses the scenario of a closed box woofer, and closed box midrange with equal sensitivities with a 1st order crossover. It specs the midrange QTC at 1(higher than normal, but it makes the example easier). The speakers are to be crossed over in the midband of the woofer, and at the fs of the midrange.

It is easy to see how you can get phase coherence with a first order crossover in this scenario. But unfortunately, my setup will be nothing like this. to my understanding the only network that will allow the cones to move exactly in phase near the crossover frequency is the 1st order. The 2nd and 4th order filters while providing phase coherency as by themselves, fail when the transfer function of the driver itself is added to the system.

To get close to optimum results, am into a lot of trial and error with phasor diagrams, matlab, and spice simulations, and then compensating with small distance adjustments? Is this what the pros do?

I would like to use active xovers with this setup, so I am really interested in how this phase adjustment thing works.

Thanks

jt
  Reply With Quote
Old 26th October 2001, 01:43 AM   #24
Super is offline Super  United States
diyAudio Member
 
Join Date: May 2001
Location: Connecticut
Send a message via AIM to Super
I'm not too knowledgable on this subject, but I do know that several high end loudspeakers do compensate for phase alignment by the driver position when not using 1st order crossovers. Take a look at the majority of JM Lab's Utopia series, or to an even further extent, Wilson's line of speakers (pyramidal shaped WATTS, odd alignment of MAXX, SLAMM, WAMM, etc).
__________________
Bryan
  Reply With Quote
Old 28th October 2001, 05:17 AM   #25
 is offline
diyAudio Member
 
Join Date: Dec 2001
Talking Have you seen the Audax KLS9 DIY kit?

Go to
http://www.audax.com/doit/england_kls9.shtml
This should fit into your budget, and get good bass.
P.S. You are my first reply at this forum.
  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
PVC Pipe speaker ideas chipco3434 Multi-Way 5 29th May 2009 05:36 AM
speaker stand ideas Midnite Mick Everything Else 6 3rd May 2007 08:27 AM
Diy midrange speaker ideas -(daz84)- Planars & Exotics 0 10th April 2007 08:26 PM
help me wih ideas for a speaker.... Andy G Multi-Way 16 15th September 2006 12:47 AM
Speaker Ideas.. Need advice damonpip Multi-Way 2 22nd September 2003 04:41 AM


New To Site? Need Help?

All times are GMT. The time now is 03:26 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