Has Anyone Ever Run TWO Identical Pairs of Speakers ?


I’m considering buying an extra pair of tower speakers identical to the ones I currently own. I would wire them as 4 ohm speakers powered by about 250wpc,

Each set of two speakers would be placed next to each other so there would be 2 identical left channel speakers and 2 identical right channel speakers, with each pair separated by about 1/2.” 
My listening chair chair can be as close as 8’ from the “center” of the speakers to as far back as 20’ from the “center” of the speakers.

And the actual distance between these two seperate pairs of speakers could range from 6’ from each pair to as much as 18’ for each pair. I would of course spend a great deal of time ‘dialing” them in for the best sound.

Has anyone ever tried this, and what were your results?

I’d appreciate your collective informed thoughts.




128x128vinyl_rules
#simonmoon 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.

https://www.axiomaudio.com/blog/comb-filtering-popular-misconceptions/
Wouldn't you rather have one pair of high quality speakers instead of two pairs of mediocre speakers?

Asking for a friend..................
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
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. 
@jasonbourne52  You are correct.  Stacked Advents were the bomb back in college.  Henry Kloss was a great guy as well.

Years later we found out that the speakers were pretty bad--there are MANY that are much worse, they they are pretty bad.  You have to actually LISTEN to them with good hardware to figure it out, but like most box speakers, they are pretty bad ("bad" meaning "inaccurate reproduction" of the music).

Still, back then they were considered quite a breakthrough, and if you could afford the better walnut cabs, they even looked nice.

Regarding stacked, yes, there were many discussions back then of how tweeters should be aligned, etc., how far away, etc., etc.  

As for various comments on "tall" speakers, gee, wonder where they got that idea?  Was not from Jim WIney, I am sure.

Finally, regarding stacked Quads in the HQD system, we made some of the stands for quads for Levinson (VERY slow payer) and some of the 24" Hartley woofer cabs. We listened to them next to Maggies.  Even back then we could easily identify listening fatigue from the Quads, which are shrill and have a number of other issues regarding delay, etc., that you can easily hear.  The Decca ribbon tweeter in the middle of the stacked Quads was interesting.  Running them with Levinson gear back then (when it actually worked) made the sound so bad we had to turn them off. 

REALLY bad!

Side by side with the Magges...NO contest.

Cheers!
I have a pair of Martin Logan’s ESL X’s and a pair of Vandersteen 2’s and running them with VTL mono blocks and I have to say when they are all on the dynamics are impressive and the bass response is awesome I haven’t played with placement for depth yet, it’s a work in progress and now I just repaired a pair of Thiels with repair work done by Rob at Coherent Sound (awesome service!) and look forward to listening to them as well just have space limitations.
Yes I have run two pairs of  klipsch KLF 30  and Two  pairs of klipsch  CF4 together side by side 2 for left and to right but with separate amplifiers the same preamp 
first pair run on balance XLR to preamp Parasound P6 XLR output second pair run on RCA To P6 RCA output 
the goal here is make-sure  all speakers tweeters are on the same ear 👂 level believe me it doesn’t have to be the same speakers 
I have try klipsch chorus ii and KLF30 combo klipsch KLF 30 and CF4 combo and forte and chorus ii combo…… if you set them right you will never go back to single speaker again 
the benefit outweigh the lost 
any 2 channel preamp with balance XLR and RCA output can do that not on AVR though 😂😂😂

I plan to double Polk RT-2000p’s. They’re  listed in my profile at www.tinyurl/mcintoshrules if you’re that interested.

The only speakers I’ve heard recently that REALLY IMPRESSED me were:

Revel F328Be’s for $16,000/pair, and
Tannoy Canterburys for $15,000/pair.

I could buy either of these right now, but I really like sound of my Polk’s. 
Anthony Cordesman gave them an exceptionally rave review in Audio magazine in 1999 and he specifically  commented on their remarkable imaging and sound staging as well as their exceptionally good midrange and highs (his words, not mine). He was lukewarm on their low bass but that’s not an issue for me. 
I use a Sunfire Tru Sub MKII AND a very large great sounding Cambridge Newton P300D sub that uses six 6.5” speakers for subs in a push/pull configuration and they are remarkably fast in an 90lb. hefty metal cabinet. Unlike the Sunfire, there is virtually no cabinet vibration when it’s running because of the push/pull configuration of its six bass drivers.

My center channel sub is an 18” Hartley custom made for Jon Dahlquist when he was developing and voicing his DQ-1 sub he made to go with his DQ-10 speaker. I happen to know Jon personally and the dealership I worked for in back in the 70’s was one of his first dealer.

I also have two passive M&K Goliath II subs I cross over at about 80Hz with 4 Polk LS/FX two way dipole/bipole speakers I use for Dolby side surround and Dolby rear surround speakers.

And I  use four Realistic Minimus 7 speakers for Dolby Atmos speaker that will be crossed over at about 100Hz  with some small Definitive Technology active subs with 8”woofers.

I really can’t restrain myself for saying this, but I do believe I have my bass’s covered.😂

 I’ve listened over the years to many products Anthony’s reviewed  and I generally agree with him.

I found a second pair of mint RT-2000p’s for an exceptionally low piece so this will be an interesting low-cost experiment for me to hear what doubling them does . If two pair really suck, it’s been a vert low cost experiment for me.

But then there’s the possibility I could be incredibly surprised for significantly less money than a new pair of Revel’s or Tannoy’s.

I’ll know in about 6 to 8 weeks as I’m moving to a newer home with a much larger listening room. I’m on the wait list for my very busy electrician as I’m going to install a whole-house surge protection system and two 30 amp/120 volt circuits for my electronics.

as always, in all things audio , YMMV😎

OP still hasn't said what speakers he's using, but I think it's a bad idea no matter what they are.
Yes. I have run 2 pairs of Quad 2905's simultaneously, but not side by side. There are theoretical reasons why 2 pairs of the modern Quads won't work together (the delay lines in each speaker create the illusion of a point source 1' behind the speaker, and you can't have two of those on each side), but if you think about it, there are alternative alignments.

And some of those work for me.  
So I just got another pair of Focal Sopra 3 for another room but decided to try how it would sound to have 2 pairs running side by side in the same room with the same integrated amplifier (Anthem STR). Initially I placed them side by side and the sound was visceral and the dynamics were unbelievable. But the sound stage got muddy. Then I measured the tweeter distance from listening position on both pairs and got them aligned as good as I could so that the upper frequencies would reach my ear at the same time. The sound stage got much better and all the qualities of running both pairs at the same time were still intact. I must saw I am in complete awe. The sound is so much more enveloping, real, effortless. The bass is more even and full. I also got rid of some of the peaks from the standing waves, which could be a result of having both pairs in slightly different locations in the room. Absolutely Loving it. Now I’m not sure if want to take one of the pairs to the other room and just want to leave them both side by side. Will play with placement to get it aligned even better to get the sound stage to be as good as playing the single pair, if that is even possible.
Having a lot of fun with this!
Fiesta75 wrote: "Also series speaker connections are not recommended by anyone I know."

Well, you don’t know me, but I recommend (and use) series speaker connections in situations where it makes sense to do so, which of course depends on the specifics.

Many years ago JBL published a white paper with misinformation about series-wiring loudspeakers, stating that doing so degraded the electrical damping (Qes). Since JBL was the source, that misinformation has gone largely unchallenged and become audiophile folklore. Adding a resistor in series with a woofer WOULD degrade the effective electrical damping, but adding another driver in series DOES NOT because the BL of the first driver is ALSO added. Double the resistance AND double the BL, and Qes stays the same.

Duke
Knihttodd# thank you for putting into words what I was having a hard time saying. It really does have a wonderful way of filling the room is the best way to explain it. Some are you audio filers Out ther should live a little and give it a try
pedroeb - Sorry, you need to check Ohm's law. Parallel will halve the nominal 6 ohms to 3 ohms. Series will make the load 12 ohms. As for your comment on THD, maybe, but not necessarily. Also series speaker connections are not recommended by anyone I know. The best way to connect multiple speakers if your amp can't handle the lower parallel impedance is series/parallel, but you'll need 4 speakers per channel. Good luck.
I use two separate speaker pairs. ML Motion 60 XTI and GE Triton Reference. I also run them through two separate Amplifier's. PL EVO 400 and Parasound A21+. The music is fantastic no matter what you are listening to. Clear, detailed no crossing of frequency. Bass is tight and accurate. You can hear everything that is being played in the band, and vocals are perfect.  70- 80 DB is all you need. All of my friends say it's some of the best sounds they have heard. A couple are musicians and DJ's. Bottom line is your building your system for you. If you like it it's all good. Even at 90- 100db the sound is awesome. 
Depending on their height, you should really try three, much better results. The line array thing.
I did the same thing right side to sideTerri I divided the signal at the preamp And have two identical MacIntosh apps that run the sack. It’s just like the guy above me said it fills the room with sweat mellow music
Has Anyone Ever Run TWO Identical Pairs of Speakers ?

Don't listen to the negative comments, as it ain't necessarily so.

Sometime ago I tested mine by disconnecting the enclosure on one side and connecting it in parallel to the one on the other side. I then played a mono track. I was shocked as I didn't believe there would be any difference.

Caveat: just be certain you won't be damaging your amp by not having a load on the unused channel.

Warning: do not connect them in series as you will halve the impedance, so even 6 ohms will become 3 ohms.

You're not going to muddle the sound and it is likely to sound better as you'll be doubling to impedance, which will reduce your amplifier output but importantly it will also reduce THD+N. Each enclosure will be reproducing around half the volume which is a bonus. I heard people say you'll mess timing, but honestly does it really make any difference if the speakers are in one large enclosure or two?

Don't take anyone's word. Try it for yourself and trust your ears.

The only way i have ever heard of two sets played together is as stacked units lke the original stacked advents and the original stacked jbl l100.
I run two pairs of 3 way sealed enclosure speakers from the late 80's.  The brand name is "Kirksaeter".  The sensitivity is rated at 93db .   The two pairs are stacked on top of each other.  I use an old speaker stand that angles the speakers up at a slight angle.  The two pairs are running two PS Audio Sprout100s.  I bought both pairs used.  When I listen to FM radio, which isn't high fidelity, I listen to both speakers.  I keep the volume low, but yet both pairs fills the downstairs of my home with comfortable level of music.   This is not critical audiophile listening but rather back ground music for everyone to enjoy.   In conclusion you need to decide what you want.  A greater dispersion of back ground music for everyone in the house or critical listening for a few staying with in the sweet spot.



  
I have done so, and it's a waste. It's how you move away from SOTA. You'll get a TON of mediocrity - if that's what you're after. 

Save your money and get a better single pair of speakers, if you want quality sound. 
@onhwy61 wrote: "If you must go this route I suggest you try placing the loudspeakers front to back. One loudspeaker pointed towards the listening area and the other pointing in the opposite direction. Something of a bipole radiation pattern."

Agreed!

You could also place them side-by-side but with one facing forwards and the other facing backwards. This should theoretically improve how the wrap-around wavelengths combine, relative to a back-to-back configuration.

Note that a bipolar configuration will theoretically result in a roughly 3 dB boost in the bass region relative to elsewhere in the spectrum. This is because the woofers will be close enough to add in-phase at long wavelengths, while at shorter wavelengths the rear drivers’ contribution adds in semi-random phase. If the net effect is indeed too much low end, you might try plugging some or all of the ports.

Duke
bipolar loudspeaker designer
Place the loudspeakers side by side is a very bad idea.  If you must go this route I suggest you try placing the loudspeakers front to back.  One loudspeaker pointed towards the listening area and the other pointing in the opposite direction.  Something of a bipole radiation pattern.
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. 

 
I had two pair of Magnepan MG-1s back in the late 70's. This was before I understood about imaging. The two pair could play a bit louder with a bit more bass energy, but otherwise I think a single pair sounded better. 
#2 stacked Large Advents!

I had one speaker upside down so the tweeters of both speakers were in the middle.


Every time I have friends over that go gaga over time alignment in speakers, I hook up two identical sets of speakers.


Okay, I don't, but you get the idea.
Yes, vertical is much better, but you should know how complicated room acoustics get with additional drivers not built to coordinate with one another. You’re introducing a lot of extra energy into the room.

Imagine for a moment that you are trying to spray a garden hose set on "conical" onto a specific spot on your garden. Then, you put another hose just like it next to it -- or atop it. Just think about the kind of water sprays that would result at the intended target. You’d get a lot more water, for sure, but consider the many ways the water sprays would miss the target -- or, more important collide with itself along the way. On a hot day, on a human body or set of plants, none of this would matter very much, but for human ears which are trying to create precise sonic images -- in stereo, no less -- this will create quite a mess.
@onhwy61 

This what the OP has listed in Audio Asylum ... 

Den: Polk RT-2000p's for front, Polk CS-400 with a Dahlquist DQ-LP1 active crossover paired w/18" Hartley subwoofer custom built for Jon Dahlquist for Centre, & two pair of Polk LS f/x speakers - one pair for Dolby side surround and one pair for Dolby rear surround run through two M&K Goliath II subwoofers. And there's more - Effects & Dolby Atmos speakers are two pair of Realistic Minimus 7 speakers - one pair for front effects/Dolby Atmos and one pair for rear effects/ Dolby Atmos. Also use a Cambridge SoundWorks Newton P300HD subwoofer and a Sunfire True Sub MkII - Can you say "SHAKE THE HOUSE?" Alternative front speakers are B&W DM3000's for front, B&W HTM for centre, and B&W Solid Monitors for surrounds; Living Room: Hartley Holton 'A' and Hartley Zodiac speakers (Dynaco Quad adapter). MBR: EPI-100 speakers. Guestroom #1: Wharfdale Diamond speakers (second version) and a pair of AR 7 speakers. Guestroom #2: AR-2a's. Guestroom #3: KLH 22's. Basement: Coral BX-1200 and Coral BX-1000 "Kabuki" grill speakers. Also have two additional pairs of Realistic Minimus 7's (early models) that get used for various projects. Most recent addition: A pair of Polk Monitor 4.6's from the GW for $12 - These are great sounding speakers! My wife's sewing/quilting room has Pioneer SP-FS51-LR front speakers, SP-BS21-LR rear speakers, SP-C21 centre, and TWO SW-8 powered subs - KUDOS to Andrew Jones for champagne quality at a "Night Train Express" price!


I recall when I had my Opera monitors, the brochure suggested running two pairs, one on the floor and one on stands.  They showed how to wire them up, but I forgot how.  Interesting thought, but I never considered trying it.  
Double KLH Nine ESLs were a popular SOTA system back in the Sixties. They were placed side-by-side. Often driven by a pair of Marantz Model 9 tube amps!
This was tried back in the Seventies! The Double Stacked Advents. It was discussed in TAS. Your idea of side-by-side placement can only produce a smearing of the soundstage and a loss of image focus. Vertical is much better! Stacked Quads (which I have) still are one of the finest systems ever - witness the Mark Levinson HQD!