speaker stacking

[Moh]

Can you stack 2 bookshelf speakers..one on top of other ..Thus 2 speakers on left side and 2 on right side to get a more filling sound. Each speaker Has tweeter on top of woofer.

I play speakers at low volume so hopefully the receiver won't go into protection mode.  How best to wire the speakers (in series or parrallel) if it is a good idea.

 

Thanks.

[Marvel]

You would want them in parallel, but they should be nominal 8 ohms for it to be safe for your amp (in parallel, two 8 ohm cabinets will appear as a 4 ohm load).  You will very likely get comb filtering from the different drivers close together and their wave fronts interacting, but it may also should fine to you. You certainly wouldn't be the first to try this.

[babadono]

You will get lobing errors(comb filtering as Marvel mentioned) where the frequencies played by say the tweeters interfere with each other because you are sending the same signal to both tweeters but they are in different positions. Will it be a sufficient amount to bother you? Only you can tell the answer to that question. I would definitely say go ahead and try it. Don't hesitate to put the top speaker upside down to get the tweeters closer together. The woofers being that much further apart will not matter much because of the bass frequency wavelengths involved. Your room probably has more deleterious effects on the low frequencies.

And as Marvel said if the speakers are 8 ohm make sure your amp/receiver can drive a 4 ohm load before wiring in parallel.

[KT88]

If the speakers are 4 ohms is it possible to connect them in series to reach a 8ohms load? Like it is done with guitar amps e.g. a Fender super reverb has two of four 10“ in series each pair and then together in parallel so that the resulting impedance is the same as with just one driver. 

Just a thought perhaps one could put two the same speakers together in a way that the tweeters both are close together or very up and very down to have a somewhat symmetrical over all baffle?

[MMurg]

I never understood the desire to run multiple speakers playing the same channel signals.  Yes, you can achieve higher SPL, but you are introducing other issues.  Correct stereo imaging depends on the amplitude, phase/timing, and directional information coming from each channel arriving at your ear without losing that information or adding anything to it.  This will allow your ear/brain system to properly process it and turn it into a stereo image in your head.  In turn, this allows you to locate sounds between the speakers that are a reasonable reproduction of what was captured by the microphone or created at the mixing console.  Ideally, this means there should only be one early arrival of the sound of each channel at each ear.  This is one reason why people treat their rooms to eliminate the early reflections.  However, when you add more speakers reproducing the same channel you are now intentionally adding multiple arrivals at each ear.  This causes confusion for the ear/brain system and can muddy or destroy the imaging.  Another downside to having multiple speakers per channel, as @Marvel and @babadono mentioned, is that there will be interference between them depending on the distance between them and the frequencies being reproduced (a.k.a. comb filtering).  Peaks and dips will be present at different locations.  If you want higher SPL, just get a more capable pair of speakers.

[wuzzzer]

No, it's not a good idea.

[Schu]

line array

 

[Peter P.]

That stacking concept was a trend years ago, a gimmick. I think it gets you 6dB of gain, and all of the other possibilities mentioned above.

[garyrc]

• You could try it
• Keep careful notes and many listening trials with many recordings.  It's conceivable that you may get the appearance of more bass with some recordings, and less bass with others.  For instance, if a big bass drumbeat occurs on one recording, centered at about 60Hz, but having vibes (of some level or another) throughout nearly the whole audio frequency spectrum* and there is no such drumbeat on another  recording, the latter recording may sound fine, but the first recording, with the drumbeat, may sound bass attenuated if 60 Hz is reduced in SPL.  If that won't give you audionervosa, few things will.
• Do turn the upper speaker upside down, so from top to bottom (or bottom to top) it's Woofer,Tweeter,Tweeter, Woofer.
• Try merely turning the bass control up (hope you have one) as an alternative, or try a loudness control - rather than using a volume control - or Dynamic EQ in Audyssey, or turn up the sub, or try pushing the speakers all the way into a corner, toed in toward the main listening position, with something absorptive of mid and high frequencies on the two walls where the first bounce off of each wall will occur, to lessen early mid/high reflections.  The corner option may give you as much as 6 dB more bass without costing you any watts.
• Although comb filtering is a possibility, some of the best truly big speakers used to have multiple woofers: Bozak Concert Grand,                  http://whttp://www.audioheritage.org/images/jbl/photos/pro-speakers/thumbs/c6000-crop_small.jpgww.audioheritage.org/images/jbl/photos/pro-speakers/thumbs/c6000-crop_small.jpg    http://www.audioheritage.org/images/jbl/photos/pro-speakers/thumbs/c6000-crop_small.jpg"Jim Lansing Theatre Sound System" of 1954n(Also Manufactured as Westrex T550 and Ampex 6000C) [Five of these behind a large curved screen for Todd-AO & other 70mm]

 

* Bass drums (and kick drums) are untuned

[geoff.]

...you will never know until you try it for yourself, have fun!

 

Besides, your room accounts for as much of what you hear as your speakers. And where you sit in relation to the room’s effect.

 

But as mentioned, just don’t fry your amp.

 

 

[MMurg]

3 hours ago, garyrc said:

• some of the best truly big speakers used to have multiple woofers

 

While that is true, those speakers were designed with that intended driver arrangement.  It's quite another thing to simply stack one speaker on top of another that were not designed to be in that arrangement.  It might work out fine and it might not.  It's also going to raise the acoustic center (may be good or bad depending on where it was with one speakers) and may muddy imaging.  It's not something I'd bother with, but try it if you are curious.  Just be careful.  If you put them in parallel and the impedance gets to low for your receiver to handle, it could be badness.

[Moh]

The speakers are PSB image 1B . the tweeters are fried and I was going to replace the tweeters. They are 6 ohm speakers. Perhaps if the tweeter sound can interact,

I should only replace tweeter on the top speakers and let only the woofer be active on the lower speaker? Would this also increase the Ohm of lower speaker (if I unplug it)

and thus less risk to the amplifier?

[Schu]

13 hours ago, garyrc said:

• "Jim Lansing Theatre Sound System" of 1954n(Also Manufactured as Westrex T550 and Ampex 6000C) [Five of these behind a large curved screen for Todd-AO & other 70mm]

 

 

 

 

I know where a pair of these are for sale... 😛

[carlthess40]

 
 
I know where a pair of these are for sale... [emoji14]

Where and how much

[tigerwoodKhorns]

21 hours ago, MMurg said:

 

  Correct stereo imaging depends on the amplitude, phase/timing, and directional information coming from each channel arriving at your ear without losing that information or adding anything to it.  This will allow your ear/brain system to properly process it and turn it into a stereo image in your head.  In turn, this allows you to locate sounds between the speakers that are a reasonable reproduction of what was captured by the microphone or created at the mixing console.  Ideally, this means there should only be one early arrival of the sound of each channel at each ear.  This is one reason why people treat their rooms to eliminate the early reflections.  However, when you add more speakers reproducing the same channel you are now intentionally adding multiple arrivals at each ear.  This causes confusion for the ear/brain system and can muddy or destroy the imaging.  Another downside to having multiple speakers per channel, as @Marvel and @babadono mentioned, is that there will be interference between them depending on the distance between them and the frequencies being reproduced (a.k.a. comb filtering).  Peaks and dips will be present at different locations.

 

This sounds like a great idea.  You know, at a concert, 89% of the sound is reflected and only 11% come in directly from the orchestra.  Let's do this.  We can call it 'direct / reflecting' sound. 

 

 

 

[MMurg]

17 minutes ago, tigerwoodKhorns said:

 

This sounds like a great idea.  You know, at a concert, 89% of the sound is reflected and only 11% come in directly from the orchestra.  Let's do this.  We can call it 'direct / reflecting' sound. 

 

 

That is true.  However, a recording of a concert captures those reflections.  Adding additional copies during stereo reproduction with extra speakers per channel is not a more accurate reproduction.  A more accurate reproduction would be actual multichannel recording and playback.

[MMurg]

1 hour ago, tigerwoodKhorns said:

 

This sounds like a great idea.  You know, at a concert, 89% of the sound is reflected and only 11% come in directly from the orchestra.  Let's do this.  We can call it 'direct / reflecting' sound. 

 

 

It just occurred to me that your comment might have been a dig at Bose.  If so, well played.  🙂 

[garyrc]

5 hours ago, tigerwoodKhorns said:

 

This sounds like a great idea.  You know, at a concert, 89% of the sound is reflected and only 11% come in directly from the orchestra.  Let's do this.  We can call it 'direct / reflecting' sound. 

 

 

 

                         

 

Despite Dr. Bose, most of us (myself included) like our sound without early reflections, but, quite by accident, I used to have a room that had great "direct/reflecting" sound--with corner horns.  It was this one (minus the Realtor's wide angle lens distortion): I know, it doesn't look great for sound, but it was.  There was a big Persian rug when we owned it.  I was very sad to sell it.

Here is a diffusor: 

 

I haven't been able to duplicate its beautiful, complex sound, even with a room almost exactly the same size, treated with different configurations ranging from very live to very dead.  (P.S. My parents originally designed the house, and my dad built it.  When he was almost done, every member of  the family drove one symbolic nail)

[tigerwoodKhorns]

1 hour ago, garyrc said:

                         

 

Despite Dr. Bose, most of us (myself included) like our sound without early reflections, but, quite by accident, I used to have a room that had great "direct/reflecting" sound--with corner horns.  It was this one (minus the Realtor's wide angle lens distortion): 

 

I grew up with 601s.  I never knew what imaging was until I bought a pair of JBls.

 

Nice house, sorry to see a good room gone. 

 

 

[Rolox]

On 5/11/2022 at 9:03 PM, MMurg said:

I never understood the desire to run multiple speakers playing the same channel signals.  Yes, you can achieve higher SPL, but you are introducing other issues.  Correct stereo imaging depends on the amplitude, phase/timing, and directional information coming from each channel arriving at your ear without losing that information or adding anything to it.  This will allow your ear/brain system to properly process it and turn it into a stereo image in your head.  In turn, this allows you to locate sounds between the speakers that are a reasonable reproduction of what was captured by the microphone or created at the mixing console.  Ideally, this means there should only be one early arrival of the sound of each channel at each ear.  This is one reason why people treat their rooms to eliminate the early reflections.  However, when you add more speakers reproducing the same channel you are now intentionally adding multiple arrivals at each ear.  This causes confusion for the ear/brain system and can muddy or destroy the imaging.  Another downside to having multiple speakers per channel, as @Marvel and @babadono mentioned, is that there will be interference between them depending on the distance between them and the frequencies being reproduced (a.k.a. comb filtering).  Peaks and dips will be present at different locations.  If you want higher SPL, just get a more capable pair of speakers.

This, exactly. You were able to explain it better than I ever could!

Stacking speakers makes no sense. Using more than one pair of speakers for stereo makes no sense and is detrimental.