Xover design help
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 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
 30th December 2002, 12:57 AM #31 kelticwizard   Wizard of Kelts diyAudio Moderator Emeritus   Join Date: Sep 2001 Location: Connecticut, The Nutmeg State Have not found the site yet. Looking for one. I could say, "Find a nice textbook on AC circuits" but I would bet the info is on the internet, and it only takes a few paragraphs to explain. How does theta degrees fit in? Well, A) if 0 degree or 360 degrees is exactly right-add two values that are either 0 degrees or 360 degrees apart and you get twice the amplitude and B) if 180 degrees is exactly wrong-add two values together 180 degrees apart and you get zero then if two values are added together that are not 0, 360 degrees or 180 degrees apart, then they must come out being something between twice the amplitude or zero amplitude. That value theta tells us what. PS: It is not linear. It goes according to a sine wave. __________________ "A friend will help you move. A really good friend will help you move a body." -Anonymous
 30th December 2002, 01:04 AM #32 kelticwizard   Wizard of Kelts diyAudio Moderator Emeritus   Join Date: Sep 2001 Location: Connecticut, The Nutmeg State Pinkmouse: Thank you so much for the formula for the notch filter. Man, you are one precise guy-you take the value for 2 pi out to four decimal places! One thing, though. Looking over the equation, I see that the formula includes F or Frequency and C for Capacitor value. But the notch filter also includes an inductor, which is normally labelled L. Yet the formula for the notch filter contains no mention of L for inductance. Since the inductor has just as much to do with the phase angle as the capacitor, are you sure there is no value for "L" in that equation? Or has the value of L already been converted into terms of F and C in the equation as written? Just asking before I start figuring, (my math skills are limited enough as it is, LOL). __________________ "A friend will help you move. A really good friend will help you move a body." -Anonymous
 30th December 2002, 01:26 AM #33 kelticwizard   Wizard of Kelts diyAudio Moderator Emeritus   Join Date: Sep 2001 Location: Connecticut, The Nutmeg State Bose: Haven't found the webpage for you yet but here is nice web page about crossovers that I think you might like. Explains a lot. It tells you at what level crossovers the drivers should be compared to the midpoint at various configurations: each driver should be 3 dB under the midpoint for first order crossovers, 6 dB under for second order, etc. http://www.traymann.free-online.co.uk/xover_2.PDF __________________ "A friend will help you move. A really good friend will help you move a body." -Anonymous
 30th December 2002, 01:31 AM #34 pinkmouse   diyAudio Moderator     Join Date: Apr 2002 Location: Rotherham, England oops... The bracketed bit should be: (1/6.2832FL -......FC) Talk about sad, when I was about 10 years old, I could recite pi to 100 decimal places p.s. Anyone know of an equation editor on the Mac OSX? (don't say M\$ office!) __________________ Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
kelticwizard
Wizard of Kelts
diyAudio Moderator Emeritus

Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Quote:
 Originally posted by pinkmouse Talk about sad, when I was about 10 years old, I could recite pi to 100 decimal places
Don't tell me, let me guess. Your parents sent you away to one of those famous British boarding schools? Is that what they make those kids do there? (In America, the parents would sue the school for "Neuron Overload Abuse" or something).

Now, one more thing. I take the value of this equation for any frequency that is whithin the notch filter's range, correct?

I can get the phase angle of any woofer at any frequency just by plugging the Thiele small parameters into Subwoofer Simulator, a freeware program written by F4ier, a member of this forum.

Once I establish the phase angle for the frequency selected before the notch filter is added, do I just add that value to that value from this formula? So if the reactance is -20 degrees at the selected frequency before I add the notch filter, and the equation yields a value of +15 degrees with the notch filter, do I have a total phase angle with the notch filter of -5 degrees?

Anyhow, is the equation written correctly below?

Quote:
 p.s. Anyone know of an equation editor on the Mac OSX? (don't say M\$ office!)
I would think that your fellow moderator, Planet 10, would be the man to ask for that one.
Attached Images
 formula for notch filter .gif (2.5 KB, 147 views)
__________________
-Anonymous

Bose(o)
diyAudio Member

Join Date: Dec 2001
Quote:
 Originally posted by kelticwizard Bose: Haven't found the webpage for you yet but here is nice web page about crossovers that I think you might like. Explains a lot. It tells you at what level crossovers the drivers should be compared to the midpoint at various configurations: each driver should be 3 dB under the midpoint for first order crossovers, 6 dB under for second order, etc. http://www.traymann.free-online.co.uk/xover_2.PDF

Thanks a lot Wiz, hopefully I can help you out on a project of your own some day.

 30th December 2002, 06:13 PM #37 prash diyAudio Member   Join Date: Mar 2002 Location: boston area. Sorry to butt in, but are you guys going to build the xover with the manuf. specs? How about actual measurements which will be quite diff from the "marketing" dept figures of the mfrs. unless, I dont know, Audax has more precise numbers or something. Just curious.
pinkmouse
diyAudio Moderator

Join Date: Apr 2002
Location: Rotherham, England
Yup, Wiz, that's the one!

After thinking on this for a while, I'm not sure if we need to worry about phase angle too much, or even sorting out that peak. It might be worth while for a first cut just going for a 3k crossover with a standard second order Xover, or at least waiting on the in box measurements of the mid/bass driver, just to seee how bad it is in reality.

The reason I thought this was that I was going through a load of old back issues of Hi-Fi mags, and many commercial speakers have much worse dips and lumps than this, so although it may look nasty, it may not work out in reality to be so bad.

Hmmm, I don't know...
Quote:
 Now, one more thing. I take the value of this equation for any frequency that is whithin the notch filter's range, correct?
AFAIK- the phase change is maximal at the centre frequency of the filter, and alters in proportion to the slope of the filter. As for the rest, yes!

Regarding Pi, no i was just a sad kid!
__________________
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?

 5th January 2003, 08:33 PM #39 Kram   diyAudio Member   Join Date: Jun 2002 Location: Durham UK Wow, I was surprised to see so many replies after my absence from the Internet over xmas, Thank you to you all. kelticwizard I will try that cap value that you suggested for the time being, then I will try whatever more complex xover you guys come up with later on. and we will see if i can hear the difference. Thank you Kram

 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 Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         Dx Classic Amplifiers         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post mclsound Multi-Way 12 29th July 2009 12:56 AM auriches Multi-Way 4 12th January 2009 09:10 PM AudioGeek Multi-Way 4 2nd April 2007 01:28 PM ronjg Multi-Way 26 4th September 2002 07:25 AM

 New To Site? Need Help?

All times are GMT. The time now is 12:35 PM.