Speakers - 2 pair better than 1?

A

averageguy

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I have a couple pairs of small bookshelf speakers. I'm underwhelmed by either set. They are both similar in appearance and size - both are shielded. I hooked both pairs up to an amp and set them on top of each other, creating a set of mini towers. They seem to sound better this way than using either pair singly. Am I imagining things? I'm sure this breaks many rules of speaker design.
 
Perhaps you just prefer hearing music in mono rather than stereo. I've been told by a few different friends who consider themselves audiophiles that some music sounds better in mono rather than stereo. Whether or not they are right, I do know, but I do play some of my music mono. Mostly blues and jazz vocals CDs (i.e. Django Rheinhardt, Robert Johnson, Bessie Smith, Nina Simone etc.) which were analog recordings done on relatively primitive equipment (by todays standards) during the early days of the industry.

D13
 
[disclaimer]I'm no expert by any means regarding home stereos.[/disclaimer]

A large portion of it might have to do with positioning. If you're moving around a lot within a room, or you're not sitting in a centralized spot, listening to music in stereo can be erratic. If you listen to the radio while doing housework, or cooking, or anything where you're not stationary, the 2 channels will indeed sound goofy, and a mono setup might be better (or rather, your centralized stereo setup. Personally, I can find a difference between a centralized stereo and mono, and stereo still sounds better.

Lots of music is made with stereo in mind (or quadraphonic, but there's not much of that around these days). Lots of it isn't. Something like bigband (Glenn Miller, Duke Ellington) doesn't really matter if it's in stereo or not. A lot of pop music isn't recorded with nuances like stereo in mind (or a lot of other things, like quality, but that's a different discussion). The balance is pretty much neutral enough not to matter.

Then there's stuff like Pink Floyd or Frank Zappa that shouldn't be listened to with anything less than 2 channels. I mean, it wouldn't make sense to buy The Who's Quadraphenia(sp?) and listen to it in mono. Listening to this kind of music on a good stereo or with headphones adds another whole level of interesting stuff to enjoy, and these kinds of musicians realize(d) this.

So you've got 1 system to play 2 styles of recorded music. If you want your music to be more ambient (something to listen to while you do stuff), your arrangment is probably better for you. For TV/Movies/serious music listening, stick with the way it's intended to be heard.
 
I am using the speaker setting "A+B" - that's not mono, is it?

S .................. S
+ .................. +
S ..... amp ...... S

This is how the system appears if you're looking head on.
It definitely does sound better. Only tested at low volumes because I didn't want to wake up the house. It feels live. Tremendous detail and presence and good bass.

Further testing reveals this is a low volume solution at best. Boomy bass at middle and higher volumes.

Positioning the speakers a little further from the wall results in tighter bass and this is starting to look like a working solution again.
 
Planterz is correct. It's all about positioning.

Bookshelf speakers are known to sound best not on bookshelves, but on speaker stands! Essentially, what you're doing is using one pair of speakers as stands for the other. Generally, running dual speakers on each channel is bad for sound. There's really only supposed to be one tweeter per channel. Having more than one destroys imaging.

Try getting a pair of speaker stands so that when you do your normal listening (sitting), the tweeters are raised to ear level. You should notice an improvement in sound there. Moving the speakers away from the walls is often helpful.

Also, a setup approximately like this below is often a helpful starting point. (Sorry for the excess periods in my lousy ASCII picture, lol). The listener should sit 50% further away from the speakers than the distance between the speakers. Slightly toe in the speakers toward the listener.


Left Speaker=========2N=========Right Speaker
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.....................3N......................
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..................Listener...................


Try it out, and enjoy your listening!
 
Allright, It doesn't work - it's really just like some type of DSP effect. Although I am left wondering what would be the result if I used matching speakers. There are a number of systems that use multiple woofer and tweeter arrays. Why would this be different than stacking matching bookshelf speakers.
I'm just wondering aloud here as I play with stereo equipment. It was nice of you guys to play along. Thanks.
 
I have tower speakers (Paradigm Monitor 9) that have multiple woofers, but single tweeters. Most of the multiple cone speaker systems utilize multiple woofers or midranges, but only one tweeter. Can you tell us about any speakers with multiple tweeters?

As another example, the Dunlavy SC-IV, SC-V, and SC-VI speakers had many woofers and midranges of different sizes, but a single tweeter in the center.

Dunlavy SC-VI
scvi.jpg
 
I use a pair of DCM TF600's in my living room. They have three tweeters and two woofers each. I didn't realize this was a rare arrangement.

It's funny those Dunlavy speakers kind of look like two bookshelf speakers stacked head to head. I'm sure there's a lot of special engineering that goes into making a unit like that sound correct. But it just gets me thinking about doubling up a matching set of smaller speakers.

Really nice small speakers are just so expensive. I'm just toying in my mind with the idea of creating a set of mini towers from four less expensive speakers and winding up with better sound than a more expensive single set.
It's stupid.
 
OK, I've been trying not to chime in as threads like this are sort of like work for me, but you seem like a nice guy so I'll comment. I don't know if stereo expert applies, but I'm pretty close. For work I represent a dozen high end hifi manufacturer's in the southwest US and do sales and product training for a living. I get paid to drive to stereo stores and teach them how the stuff works. I often get my product training directly from some of the most respected engineers in the industry.

There's a variety of reasons why you like the sound better with both sets of speakers stacked on top of each other. Most likely it's because you're getting more bass because of the doubled up woofers. You are probably getting a litttle extra bass also due to one speaker being on the floor and an effect known as boundary reinforcement which happens when you place the bass driver nearer to a boundry in the room. If you want to demonstrate this to yourself, stick one speaker all the way in a corner and listen to how the tonal balance of the sound changes becoming more bass heavy. Unfortunately there's no such thing as a free lunch and when using multiple drivers in an array like that can cause as many problems as it fixes. There are issues like comb filtering that happen when you have more than one driver covering the same frequency range in close proximity to each other. What happens is that certain sounds who's wavelength is similar to the distance between the two drivers get cancelled out, thereby changing the sound from what the designer intended. Rarely will you get better sound from two sets of cheap speakers as opposed to spending the same cash on one better pair unless you're going for sheer output volume. In a better speaker, the designer has the parts budget to use better drivers in a more heavily braced cabinet (very important) and can integrate them together properly, where stacking two cheap pairs together has none of those benefits. A sharp designer can take the comb filtering problems, as well as a lot of others, into consideration during the design phase of the product. There are phase relationships, crossover slopes and crap that I could go on for hours about that all need to be taken into consideration for the design to work out well.

FYI: The Dunlavy speakers pictured are no longer produced as Dunlavy has gone out of business, but if I remember correctly they were around 20K per pair and large enough to use as a coffin for a full sized man. John Dunlavy was one of the engineers I mentioned above who has shared his knowledge and theories with during a product training many years ago when he was with Duntech, a company that preceeded Dunlavy Audio.

As noted by someone above, small speakers are generally designed to sound their best on stands at about ear level. If it's the improved bass that you're enjoying, the addition of a small powered subwoofer will do a better job filling your system in and if used with a single pair of mini monitors can provide much more coherent and focused sound than your current arrangement. You might also find that your amplifier is happier driving a single set of speakers and a self powered subwoofer than your current arrangement which I suspect is just putting both pairs in a parrallel circuit and showing a tougher load to your amplifier.

Of course Gollnick will probably come along and shoot holes in all of my post, but such is life. Just don't start talking about better speaker wires, please...

If you're really into tinkering on your own, there used to be a newsletter called Speaker Builder that was a good resource for the garage speaker engineer you might look for.

John
 
John, that's some good insight. Thank you. Yes, it's better bass I'm looking for. Could you please enlighten me as to the difference between a passive and active subwoofer - is there anything that would prevent me using either design? And, generally where would you recommend placing a subwoofer relative to the system and the listener.
Get to work my friend. ;)
 
Skipping the technical issues, don't bother with a passive. Active is the ONLY way to go. Your speakers (one pair only) may make fine satellites with the addition of a good subwoofer. Placement of the sub will be less critical but still requires some experimentation to find the best spot. Use your ears. A highly recommended addition to any stereo if you're looking for more bass than bookshelf speakers can offer.
 
PSDrew pretty much covered the answer regarding placement. A passive sub has no amp of it's own and therefore puts a greater load on your receiver where an active sub has it's own amplifier built in.

John
 
Depending how your amplifier/reciever is wired, A+B could be running in parallel and not series. In simplified terms, for the same volume setting you could be getting 3 db more volume from the paired speakers. Real world effects are certainly more complex and varied as others have explained.

Research has shown that people accept the louder sounding sample to be of better quality than the quieter sample. The actual loudness differnce can be very small, as low as .1 db is what sticks in my memory. This is one of the big perils of side by side speaker comparison.

In sound, quality is generally defined in ways other than loudness or speaker efficiency.

Phil
 
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