What are the advantages of tower speakers over bookshelf speakers? I am considering buying the new Arx A5 3 way speaker sold by The Audio Insider. I currently have Nola Mini's for both 2 channel (and 372) and HT (Denon avr 3311).
Generally speaking floor/tower speakers play louder and boomier than book shelf speakers. Book shelf on the other hand, tend to have better overall sound than floor speakers. Personally, I prefer shelf speakers with a subwoofer.
With any technology in audio you will have to accept trade offs. Select one component and you will have "this" set of trades. Select a different component and you will have "those" trades. Speakers are no different in this respect.
The advantages of a floorstanding speaker depend, obviously, on the speaker. Your question is so broad as to be nearly impossible to answer. I can't predict the performance you would hear from the Arx and so it is difficult to speak in anything more than generalities.
First, a floorstanding speaker requires no stand. This might seem at first to be no real difference, or a difference so common sense it should go without mention, but any small speaker relies heavily (no pun intended) on its supporting structure for its final performance. And that structure can easily influence the sound of the final product. The final product being a combination of speaker system and support structure. Add in the cost of high quality supports and you oftentimes have less of a price differential between the two types of speaker systems.
Beyond that, there are no particular benefits to a floorstanding speaker IMO. We have one forum member who was concerned about his small child pulling his standmounted speakers over and injuring herself. You know better than do I whether this applies to your situation. And, in any case, multiple work arounds were offered to solve that possibility.
In terms of the laws of physics which rule speaker design, a competent designer will have to deal first with three basic values when intially sitting down to think about a new speaker system. Those values are; bass extension, system sensitivity (how loud the speaker can play given "X" amount of wattage) and enclosure volume. When one value is changed, the other two are sympathetically affected. So trading enclosure volume downwards would typically give up some degree of volume potential and bass extension - that is should all other things be equal between the two speakers under comparison.
First, all things are never equal between two speakers. Second, certainly when you move from a simple two way system to a multi-driver (5 drivers in the Arx) system it makes for an impossible generic comparison.
In the first case, equality of two systems, there are numerous floorstanding systems which are really no more than the same two way system placed in a larger volume enclosure. Given the same driver and crossover, the basic laws of physics mentioned above would easily apply. In theory, you would be unlikely to hear significant differences between the two speaker systems other than a slight increase in both sensitivity and low bass extension. Ideally, this is how most of us would want to experience a line of speakers, as an expression of how an individual, or a group of designers, perceive music with a consistency throughout the entire line. Place the smallest, least expensive system up against the largest and most expensive and you should hear only those differences which relate to size. Unfortunately, that is seldom what you would experience in the real world today.
Larger enclosures make for more resonant cabinet panels. It is another law of physics which suggests larger panels will be less stiff overall than will smaller panels made of the same material(s). Additionally, the larger panel will have a resonant frequency which is more typically intrusive to the music by way of being placed closer to the range of human sensitivity to sound. In other words, larger floorstanding speaker panels are more likely to resonate within the frequency range where voices and primary instruments exist. Additionally, a larger, more massive panel structure would tend to hold onto its resonance for a longer period of time than would a smaller panel which might resonate at a much higher and, therefore, less intrusive frequency plus having the capacity to disipate the vibration sooner.
This one rule is typically why small bookshelf systems more easily disappear from the soundscape and tend not to draw attention to themself in a high quality consumer audio system. On the other hand, the larger panels on floorstanding systems have a more problematic tendency to have certain sounds "stick" to the cabinet. There are more reasons for this peculiar behavior of floorstanders than just panel resoannce but the florstander will often have to be designed with the physically larger diameter and/or multiple drivers used in such towers. The physical dimensions of the baffle on which the drivers will be mounted will ultimately contribute more to the system's final sound qualities than just panel resonance.
A wider front baffel would provide more support to the upper frequencies but it would also result in what is commonly termed "baffle step response" which involves the launching into free space of any signal travelling along the baffle's width and height. This typically makes for a less even in room response from the floorstander unless further electronics are added to the crossover to make a "step filter". While this baffle step can also occur with a smaller baffle, the problem can become one of expotential difficulty to deal with or use successfully as dimensions grow ever larger. For example, the simple difference between the distance mid and high frequencies must travel across the baffle of a standmount are shorter than those of a typical floorstander when you consider the distance between the tweeter's position relative to the top and the bottom of the baffle. A thinking designer will make use of dimensions to enhance the final product's quality but the basic issues of a driver requiring a baffle becomes more difficult for many designers to sucessfully manage as dimensions enlarge. This aditional circuitry meant to provide baffle step compensation then has the potential to make the foorstander a bit more of an energy hog as those additional components are turning the electrical energy of the amp into lost acoustic energy in the form of heat. There goes the higher sensitivity advantage of the larger enclosure volume. Of course, other values selected by the designer can regain this difference in system efficiency but they too are generally going to come with their own set of trade offs.
It is very typical for a floorstanding system with multiple drivers to exhibit the characteristics of a "line source" while most small standmounted systems can approach the theoretical ideal of projecting music (soundwaves) into the room as a "point source". In theory, only a single driver providing full range material can truly approach that point source ideal. But two drivers mounted closer to each other on a smaller baffle and with fewer electrical components inserted between their inputs make for a different sound quality than will five drivers divided by more complex circuitry spanning the same musical spectrum. The difference between the two objectives is more than slight and you should, IMO, do some research into both types of speaker design to determine which type of final product you might most enjoy.
Moving from a very simple and well engineered two way such as the NOLA to the multiple driver Arx would, in all likelyhood, also mean you are adding a more complex overall load on your amplifier. (Without seeing more definitive specs on both speakers I am just guessing here from my experience with both types of speaker systems.) It is "relatively" easy to design a two way filter in the crossover which does little to add a load to the amplifier and, therefore, the more complex multi-way system can result in the amp being less capable of succesfully driving the speaker rather than the speaker driving the amp. There are certainly work arounds to this but the more divisions of frequency you add to a speaker system, the more likely the design will suffer from various ills. A crossover must affect both the frequency response plus the time and phase response of the two drivers it is meant to control. This can easily result in a three or four way system which suffers from a lack of coherencey in the more important issues of tonality, soundstaging and simply "realism" and transparency.
Finally, I would think it important to mention any floorstanding system is typically placed within a room to (mostly) accomodate the lower frequency response of the system and not the midrange tonality, soundstaging and overall transparency of the system. By adjusting the speaker's position relative to the reflective surfaces of the room, your aim with any floortstanding speaker is typically to make the bass as clean and tuneful as possible. You therefore trade off those values which are of relevance to most listeners familiar with live music. in this case a standmount system can more easily be positioned to enhance the mids and upper harmonics of the music while a separate, integrated subwoofer system can be placed and adjusted according to its needs. This further adds to the ability of the standmount to disappear from notice. Should domestic bliss be an objective, a small standmounted speaker can be moved in and out of position as needed. The same cannot be said for many large floorstanding systems.
Those are a few of the generic trade offs of the two types of speakers. There are more and there are certainly comparisons to be made between specific speakers. However, in general, the more complex the system becomes, the more difficult it becomes for the designer to accomplish most "audiophile" goals without significiant trade offs in either performance or cost or both.
As you have alluded, things aren't always equal. I believe my floorstanders are superior in most facets than the two bookshelf models I owned prior, and are thus ultimately more satisfying to listen to. But it's hard to quantify what part of that is floorstander vs. bookshelf, as I'm comparing completely different designs. I'm not comparing a bookself and floorstander from the same line, so it's not just size of the cabinet that differs, but also the drivers and crossovers and other parts of the design.
Furthermore, how the speakers work with your electronics is another part of the puzzle. Synergy as it's known, and maybe my floorstanders just have more of it. Then comes personal preference, and maybe I just like their presentation more. It would be interesting to compare the floorstanders to the same speaker in bookshelf format...that might reduce some of the variables (but not all of them).
As you say, reducing the complexity is generally desirable, so I prefer floorstanders with only two drivers (one woofer, one tweeter). And as my room is small, the speaker shouldn't be overly large. On that note, the OP hasn't mentioned the size of his room. I would think a five driver floorstander would be more suited to relatively large rooms, and is certainly a big jump from a Nola Mini.
Finally, a thought about matching a subwoofer to a set of monitors. Integration may be difficult. I have read some opinions online recently, and many suggest using two subwoofers to help with this. The extra sub is to fill in null points in certain parts of the room, and to cancel bass in others. This achieves more even bass overall. The goal is not to add more bass as one may think. Some people even run four subwoofers! And then one might want to consider the use of a high pass filter, so that low frequencies can be directed to the subwoofer and away from your main amp. This enables your amp to work less and direct it's efforts to the upper lows, mids, and high frequencies. All of this should hopefully lead to a more effortless sound. One can also use an external crossover and/or other technologies to achieve better bass integration. Subwoofer setup can be extremely complex, and I think goes much further than the simple setup steps provided in the typical subwoofer manual. This simplified setup is likely to lead to disappointing results (though not always, if one is lucky). But I think it's one reason why audiophiles often tend to have a negative view to running a sub. If the subwoofer isn't integrated properly it is very apparent when listening to music.
Thanks for the responses.My post maybe misleading. I'm not comparing the Nola's to the Arx. I was just wanting know the advantages of one over the other. The room is 10x12. I've nit had problem integrating the Rel sub with the Nola's to my liking. I thought the towers might have bigger sound for movies. Has anyone checked into the Arx? It is a 3 way speaker with 3 XBL2/splitgap motor 5.25" midwoofers. 1 dedicated midrange with non-moving phase plug and multiple copper shorting rings. 1 ARX planar tweeter.