Has Anyone Ever Run TWO Identical Pairs of Speakers ?

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!

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!

I'd appreciate you telling us what loudspeakers you are talking about.

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.  

@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!

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.

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.

+1 Stacked Advents. Would be better if ALL drivers are vertically aligned.

I do and I absolutely love them.

When you stack speakers vertically, shouldn't the upper speaker be inverted?  Like this.
https://www.stereophile.com/content/toronto-audiofest-day-1

#2 stacked Large Advents!

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

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. 

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. 

 

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.

@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

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. 

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.



  

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.

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.

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

Depending on their height, you should really try three, much better results. The line array thing.

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. 

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.

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

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

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!

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.  

OP still hasn't said what speakers he's using, but I think it's a bad idea no matter what they are.

It'll be a bit like Tektons.

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😎

@vynil_rules

I have a couple of subs for sale if you’re interested 😂

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 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.

@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!

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

Wouldn't you rather have one pair of high quality speakers instead of two pairs of mediocre speakers?

Asking for a friend..................

@ozzy62  

+1 !

#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/

i still have my 4 bose 901 series 2  set up as the old 'super bose' system powered by my mcintosh mc602 power amp!

Wouldn't you rather have one pair of high quality speakers instead of two pairs of mediocre speakers?

What I been saying... about Home Theater.

Wouldn't you rather have one pair of high quality speakers instead of two pairs of mediocre speakers?

Consider having two pairs of High Quality Speakers that perform mediocrely.

"...Wouldn't you rather have one pair of high quality speakers instead of two pairs of mediocre speakers?..."

Yes for the same money you can have one pair of way better speakers. 

Hello  vinyl_rules.  If your speakers are smaller, non floor standers its certainly worth a try. I used to run two or four pair of the smaller Advent speakers. If you have serious $3k or more floorstanders, it may not be much of an improvement. Have you tried one or two subwoofrs?
It is remarkable what they can do for you. Use an electronic crossover (miniDSP?) to send 80 Hz or so to the subs and everything else our current speakers. It's really quite impressive with quality subs, 12" or bigger. It doesn't have to break the bank, try Emotiva's larger units. I experiment a lot with various speaker setups and I'm sold on subs. Keep experimenting!

Kingsley, russ69, and millercarbon, If your questions are directed at me, I would politely counsel you to actually seek out and listen to a pair of Polk RT-2000p’s or RT-2000i’s before you so causally dismiss Polk’s RT-2000p’s as “mediocre.”

For example, it would be ludicrous for me to offer an opinion on how millercarbon’s new Teckton Moabs sound: I’ve never heard any so how could I possibly offer an opinion on how they sound? Doing so would make a poser and an audio store cowboy.

I would wager none of you never have actually listened to Polk RT-2000p speakers and are simply trashing them like many people who pile on and trash Bose speakers without having ever actually listened to any.

I managed a very high-end store back in the 70’s and early 80’s. Our store actually took in a pair of the early 901’s Series 1 (A rather inefficient acoustic suspension version supposedly better than their latter bass reflex models) in mint condition with undamaged surrounds to the small individual drivers as a favour to a customers spending a very large sum with us. He was moving from a Sansui receiver powering his 901’s to Mark Levinson electronics, a Sequerra tuner, a Linn LP-12, and full size Magnaplanar speakers. We waived the hefty sales tax as his 901’s trade in value. It was a sweet deal for all as he was amazed at the magical sound of his new speakers driven by his new electronics.

We only had one problem: I can truthfully say these 901’s were the worst sounding $1,000+ speakers any of us in the store had ever heard. But as my brother-in-law who owns some car dealership says in the car business they say there’s an ass for every seat.🤪 And sure enough, we sold them for a slight profit a week after we finally opened in our new location to a student who always wanted a pair but could not afford new ones. He (and we) were ecstatic when he took them off our hands.

Now, a bit of backstory explaining why we thought they sounded terrible. Our store was built from scratch inside a former A&P grocery store our owner purchased. We completely gutted the store even down to removing SIX layers of tile that had been put down over the 50 year+ life of the store. 
And the owner spared no expense making it a incredibility good sounding store. He hired acoustical engineers to design three fantastic listening rooms we had surge protection at the three breaker boxes necessary to power the store, and we ran multiple individual 30 amp/120V circuits to each of our showrooms, even including the service shop. The electrical contractor told us it his first ever job where he never installed any 15 amp or 20 amp 120V circuits.

We even put up a big-ass multi-element yagi FM antenna on a ten foot tower with a rotator running multiple powered FM feeds to each show room as we sold a shitload of FM tuners because we were in a central physical location from the student FM stations at Duke, UNC-Chapel Hill, NC State University, and Shaw University in Raleigh. And I remember we had at least 3 complete commercial album rock FM stations , two classical music FM stations, and we even had an album-oriented Modern Jazz station in our area. It was the absolute best FM environment I’ve ever lived in.

l’m going into all this detail because we actually listened to the 901’s under the best possible conditions and we tried numerous placements in our new location after we finally opened in October. We played them on high powered SS and tube electronics and nothing we did could make these things sound good. You just cannot puts lipstick on a pig. 🐷

So when people trash brands like Bose or Polk or JBL or Klipsch or Sony, etc. the first thing I want to know is did they actually listen to what they’re trashing or are they just an audio store cowboy who’s just another poser.

If you’ve actually listened to what you’re trashing then I can at least respect your opinion even I may have a different one. But if you’re a poser trying to fit in and/or be accepted by other audiophiles, you’re just spewing verbal diarrhea, your opinions are vapid and meaningless.

As always, YMMV 😎

boomerbillone,

Please read my 5/19/21 post made at 5:38 am.

It will answer your questions.

@vinyl_rules OP

Thanks for posting again what I have posted many times.  As a former dealer myself, we had FOREVER to listen to various pieces when the door was locked and BOY, did I get a fast education.

Yes, the 901's were amazingly bad--beyond anything we imagined, actually.  Also, many other speakers we "loved" (Advent's, Klipsch, etc.) were so horrible it was painful for me personally to learn how "uneducated" I was, and I have been playing music in bands since I was 10!!  I sure thought I knew what was what, but one listen to the Audio Research/Magneplaner system brought me to my senses quickly.

As for boxes, Mr. Robert (Bob) Fulton had a couple of boxes that were not bad--80's and 100's, I think.  Today, boxes are probably better, but you will never improve upon Maggies, IMO.

Cheers!

I wonder what the inspiration was behind these.
https://www.gershmanacoustics.com/grand_studio_ll.html

 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.