xovers, impedence compensation, notch filters, baffle step, confusion?

[speekergeek]

I have been doing tons of searching on the net and am trying to come up with one concise FAQ or maybe a how-to of xovers, including impedence compensation, notch filters, baffle step and when and how to incorporate them. I am baffled.... how do i know when to put what in? i know that i need a xover. but how bad do i need the other stuff? should i use it all just to be safe or what? I read in my radio shack speaker book that you should do a impedence compensation on the woofer to help the xover function properly because it is looking for a steady impedence. in that case then shouldn't i add a notch filter too? I am looking to build a MTM dayton with the 6 1/2" woof and the 1 1/8" tweet. and i want to make the list of stuff to order now so i don't have to order more and wait weeks for more components. also, is baffle step a major needed thing? I confused. I need a manual for this stuff. I want the speakers to soud like a million bucks, like i payed top dollar for them, can that be done with a simple 1st order and no compensation? how can know this!?! pleeze help me, i have only used 1st orders before due to simplicity.

 

[sreten]

Sorry but it sounds like you don't have a clue.

Find a reputable design and build it or
go into a good retailer and use your ears.

There is no such thing as 'sounds like a million bucks'
on the cheap, just unscrupulous copywriters.

/sreten.

 

[speekergeek]

I know somewhat about electronics, i took a year long military course on basic and advanced electronics, so i do have a little clue. I just don't know when i would need to incorporate these filters and notches. I can do all the calculations myself with a pad and pencil (mostly). how would i know when to add a notch filter. I do appreciate the criticism. when i said "a million bucks" i didn't mean to sound like an idiot, which i may have. I just want them to sound good compared to what i have now. If i could be pointed in the right direction to understanding all aspects of the crossover and filters and notches, that would be great. is it a trial and error process adding notch filters and impedence comp networks? How common is it in your average DIY projects to add baffle step comp and impedence comp, is it just as common in store bought speakers? I have found a reputable design and am going to build it, it has impedence compensation in it and i think a notch filter, but maybe i don't need it, i am not sure. Maybe i should just copy it exactly, not ask any questions or try to learn anything new and be happy with what i have.

 

[Mikett]

for that combination of drivers there is already a fine tuned design. visit speakerbuilder.net
at least that gives you a start and the design process is actually explained

 

[rabbitz]

Get the "Loudspeaker Design Cookbook" by Vance Dickason which would give you a good start in crossovers and has the required formulae.

Not an easy read, but gets easier as you start doing projects.

 

[sreten]

sorry SG,

but electrical engineers (and I'm one) can be just about the
worst people I've come across for understanding speaker
design simply because they think they should be able to, and
to a far greater degree than the less electrically enlightened.

Mikett is showing you the way to go. If it is a finely tuned design
it will incorporate design features appropriate to the cost of the
drivers, of the things you mention baffle step compensation is
incorporated I believe as are are a few things you don't mention.

/sreten.

 

[av_phile]

There are other design considerations like time and phase coherence, although some manufacturers consider these two irrelevant for audibility. Personally,I think the simpler the design, the better. Like uisng 1st or 2nd order crossovers. There are many sites on the net that allow for computation of some of these design parameters. If you google search the topic on "speaker design compuations" you will get some intersting sites. Happy speaker building.

Here's one

http://www.mhsoft.nl/spk_calc.asp#crossover