Originally Posted by Handyman439
I have been doing some research, but am having a hard time wrapping my head around this and how it affects a line array.
Say 4 inch full range speaker separation in an array. That means your "comb line" would happen at 3390 hz, then again at 10170 hz, and 16950 hz. Am I correct that these are generally the places where heavy eq would be needed in such system?
If that's the case, other frequencies in that area are not as much of a problem because of more (uniform/uninform) interference due to multiple drivers. Where the 3 frequencies above are exactly 180 degrees out of phase, causing the comb line?
Is this the reason some designs use odd spacing or curved arrays to hide this effect?
If I'm thinking about this correct, with just two speakers, you could in theory have full cancellation at 3390, 10170, 16950, (180 degrees out of phase) and up to a +3dB peak inbetween?
You're new in here, so I will share some insights, as to the repute, of a couple of the men that have comments in your thread.
I'll start with Ivan, who comments first, then I'll move on to Arny who commented lastly.
Ivan is a well known and respected member of Danley Loudspeakers, of Tom Danley fame, the exceedingly well reputed NASA scientist and audiophile. He is a lead member of Toms team and next to Tom Danley is the biggest technical asset. All day long everyday, he has his hand and his mind upon all aspects of design, manufacturing, debugging and repair. This is his truly professional life. Danley has built several custom solutions, for almost a dozen stadiums, which later entered their main catalog, and became industry leading innovations (Genesis Horn). Ivan was apart of all of such events, making him the real thing. And he's a good guy to boot!
Arny, besides being the most vocal member of this community, has a legacy, of well noted contributions, to the home audio / consumer markets; which span several decades. All you have to do is Google his name and start reading (ABX Comparator - Foo Bar 2000, and countless writing publications in magazines and online forums, etc.). He also claims to have BS in Engineering, but hasn't claimed to be an EE or to ever have achieved his full designation, as a professional engineer; however, if he's telling us a fib, he has then become exceeding competent at masking it. Outside of moments/postings when Arny is clearly engaged for the purposes of gamesmanship, he has posted some of the most profound and actuate statements within this forum (which isn't to say that he's close to being alone in such regard).
In this thread, these two gentlemen have replied to you with the absence of gamesmanship and find themselves in tight accord (even though one slightly mis-read the others post). They are both clearly evidencing that comb-filtering not only takes places within true line arrays, but that such is requisite to produce the intendant application benefits.
Their comments mirror the central assertions of my own comments, but come with a known repute that you can trust and verify.
You have posted some great questions, and you deserve the most correct answers available from with AVS.
I hope this helps set your eyes on such.