Has Anyone Ever Run TWO Identical Pairs of Speakers ?

I will have to reiterate some of the things I have said on another thread about playing multiple speakers stacked, or side by side.

I do not recommend it, at all.

When multiple drivers, that aren’t specifically designed to play at the same frequencies, there are quite a few (mostly negative) results that occur.

For example, the distance between the center of the tweeters and the mids, along with the crossover, are very important. If they are too far apart, vertical dispersion goes to hell. Get just a few inches off (higher or lower) of the axis of the tweeter, and highs will roll off.

If the baffle of the cabinet is too wide, horizontal dispersion goes to hell. You get things like baffle step loss, and poor horizontal dispersion in general.

Now, put 2 of the same speaker side by side, and you’ve just doubled the baffle width. The extra tweeters will not correct this problem. In fact, the extra tweeters will cause other problems, i.e., unpredictable lobing, with unpredictable cancelations.

And this is only some of the problems with the tweeters. The mids are likely to have similar problems, with interference patterns causing cancelations, or boosting in frequency response.

There will also be phase problems at the crossover points. I'm sure some of the many speaker design gurus in this site will be able to list other problems.

And who knows what the effects will be with speaker boundary interference response? This is how the speaker interacts with the room they are in. This is already problem enough with one pair of speakers, add to that problem, all the other problems, and I can’t imagine getting a reasonably flat frequency response, correct dispersion, etc.

I’ll bet money, that whatever imaging and soundstage one pair of your speakers are capable of, will pretty much be vastly worse with 2 pairs, stacked or side by side.

Of course, bass will increase, but this may not be an entirely good thing. 

 

It'll be a bit like Tektons.

No it won't.

Just because Tektons have quite a few drivers in them, does not mean they are in any way similar to have multiple speakers stacked or side by side. 

Please watch the vids by the designer, Eric Anderson on YT on the theory behind the design. 

Bottom line, Tektons are not just a bunch of drivers stuffed into a box.

I'm not even a big Tekton fan, but lets not compare them to stacking speakers. 

Here is an informative video by GR Research on why 2 tweeters don't work. This is describing why they won't work in the same enclosure, but the same concepts translate to 2 pair of speakers, stacked. 

In fact, most of the problems he talks about, get worse the further the tweeters are separated in distance. 

https://www.youtube.com/watch?v=MGSfaKWcetQ

https://www.youtube.com/watch?v=0GXEine4jpg

 i’m not a big fan of that GR research guy. Some of his techniques like the one where he used hey antenna meter from an old receiver to show you how radio frequencies affect speaker wires was a little goofy. Here’s a Website that I think the author has more chops the good old boy Danny.

But the videos I linked, are very simple, well used methods of measuring speakers. 

There is not much subjective opinion in them. Anyone, testing 2 tweeters mounted on the same baffle, will get the same results as Danny did. 

Anyone can repeat his test, and measure the comb filtering, the loss of high frequencies when 2 pairs of tweets are connected, and the improved frequency response when 1 pair of tweeters are disconnected. 

And as far as the other site you mentioned, you are correct, there is a lot more info there. But Danny's vids are not meant to replace much more technical sources, only to explain to the lay person what the problems are with running multiple drivers.

I am not a super fan boy of Danny's, but I can guarantee, he has probably forgotten more about speaker design, than many respected designers know. Have you heard his NX Otica's? If he is lacking knowledge as you say, he sure did get lucky (by random?), in designing a kit for $3000, that will stomp pretty much any $10,000 speaker.