Benefits of large speakers?

[HMenke]

I may show my ignorance here, but I am getting curious. On this forum I have seen some pretty large main speaker designs, either with very big boxes, or huge multi-driver arrays as tall as the ceiling. Much larger than anything I would consider purchasing commercially, but not larger than I would consider building myself. As a DIY noob, I am wondering about the benefits and trade-offs of these large speaker designs.

For years I have always used 6" 2-way monitor speakers for music, augmented with a subwoofer for movies. My logic was that the smaller speakers give the best bang for the buck commercially and the 2-way crossover presented the least amount of alteration of the signal for better fidelity, even though the woofer and tweeter might be called upon to cover more frequency range than they ideally should.

I am guessing that the large boxes in many of these DIY designs are there for bass reproduction, so I assume these are intended for use without a subwoofer? And I am guessing that the huge speaker arrays also effectively reproduce bass and are also intended for high SPL playback? Is there any sacrifice of clarity with all those drivers competing with each other, or conversely, is SQ improved at a given SPL because the drivers aren't working as hard?

Henry

[Dennis H]

is SQ improved at a given SPL because the drivers aren't working as hard?

Yes.

[Hdale85]

Well what i do know is that the bigger speakers do go into the lower frequencys a lot better thent he smaller enclosure's but they are usually still used with a sub people just cross the sub over lower to handle the frequency's that the towers dont handle. Thats kind of the same idea for all the speakers though like the ones im going to build which are the RS 3 Way towers on the forums here they split the signal up to each speaker to reproduce the sound better and more acurately. So when you have a full range driver its trying to reproduce all the sounds at once and the music or whatever your listening to gets muddy because of it and when you have a 2-3 way system each speaker is designated to a certain area of the frequency so that its not over worked trying to reproduce too much of the spectrum and messing up the sound. im sure none of what i said makes any sence but thats what i gather oh! also i believe when you have mains that produce more bass it lessens the bass localization you get when useing a sub and 2 small speakers so you cant tell where its comming from as easy because its comming from all your speakers rather then just the sub.

[Brian Bunge]

I went with the big 3-ways in a sealed enclosure for one reason. Dynamics.

[David G]

Usually, size means:
1. efficiency
2. more extended bass
3. greater power handling/ maximum output

Nothing beats a 2-way for bang for buck IMHO.
However if you are trying to go really high-end with extended frequency response & realistic SPL, then I think a 3 way (or more) ,or line array is mandatory (plus a sub). Benefits include the abilility to use drivers that were designed for a specific frequency range (rather than a compromised mid-bass driver for eg), & less thermal & dynamic compression as the load is shared. It also means your power amp may not need to be as powerful. Many 2-ways have sensitivity around 84dB!

Negatives are size, weight, cost, complexity (more things to stuff up), WAF, potential for enclosure resonance.

[HMenke]

These are great responses - I appreciate the feedback. I did not expect the efficiency benefit.

Now that I have built a pretty awesome sub, I am looking at my main L-C-R speakers and wondering if an upgrade is in order. They have nice SQ but they do not have the dynamics to keep pace with the sub, and they do sound strained when pushed hard.

[Hdale85]

Well the Nat P's and Modula MTM's are probably the most popular and from what i hear sound great. Both are 2 way MTM designs. For a couple hundred more you could probably build the RS 3 Ways or the TMWW 3 ways, it all depends on how much space you have and what not as the RS 3 Ways are like 50 inches tall so not sure you want somthing that big? If I were to build the Nat P's or Modula's id build the tower designs for the lower bass extension....and i like towers no need for stands :B

[poneal]

These are great responses - I appreciate the feedback. I did not expect the efficiency benefit.

Now that I have built a pretty awesome sub, I am looking at my main L-C-R speakers and wondering if an upgrade is in order. They have nice SQ but they do not have the dynamics to keep pace with the sub, and they do sound strained when pushed hard.

Sounds to me like the bug bit you again :-). Three ways and greater are hard to get right. I've built two and they are ok but not up to my liking. I'm starting my third one and if this one doesn't work out then it's back to 2 or 2.5 ways. My main reason for doing another 3 way is efficiency. My current 3 way is around 84-85db efficient. I want at least 90db. For me that means two woofers in parallel. I want it full range. I want a wide soundstage and all those good things that everyone wants :-). Just be careful, the 3 way road is much more difficult to get correct and much more expensive.

[Brian Bunge]

There are only 2 things I don't like about my speakers:

1) They are a royal BITCH to move!
2) They are calling to me buy/build a bigger amp for them!

[JonMarsh]

There are only 2 things I don't like about my speakers:

1) They are a royal BITCH to move!
2) They are calling to me buy/build a bigger amp for them!

1). Hard to move.... been there, done that in spades!!!!! Learned MY lesson







What you DON'T need with something like this is a big amp- sensitivity was ~93 dB, and they played LOUD with a 100 watt/channel amp, and LOUDER with a 200W/ch Aragon.

So why do I have these Aragon Palladiums? Oh yeah, for my passive crossover diople systems. Learned my lesson- Neodymium magnets, even on woofers, no enclosure, just a front panel; no MDF, just BB ply and HDF. Might even be possible to move them around or take them to a DIY meet when the new ones are finished.

[poneal]

Holy Cow Jon...

Those things are HUGH! It appears in the picture that they almost touch the ceiling. How tall are they? Just amazing....

[JonMarsh]

They're six feet tall. About 300 lb per side. The bass bins are currently scrapped, the upper modules are being upgraded from Eton 370 with Peerless 830883 and re-designed crossover. Will probably use dual NS12-513 or RS315HF for a new bass module, that will be smaller and built with BB ply. The original bass modules used Pro Audax 15" and 13" drivers.

[Jed]

They're six feet tall. About 300 lb per side. The bass bins are currently scrapped, the upper modules are being upgraded from Eton 370 with Peerless 830883 and re-designed crossover. Will probably use dual NS12-513 or RS315HF for a new bass module, that will be smaller and built with BB ply. The original bass modules used Pro Audax 15" and 13" drivers.

Jon,

Have you ruled out SEAS W18EXs for midrange duty for this design? I guess it makes sense to use the 883 because you have them, they tested well and from what I understand, you are going to adapt the Modula design with them. Just wonder how the W18s compare.
Jed

[JonMarsh]

Jed,

The W18EX's are great drivers, but when possible I try to find lower cost alternatives to drivers that are pushing the cubic unobtanium price category. Sort of to make up for my past sins. Also, sometimes I like to root for the underdog, particularly if it's an overachiever or plays out of it's league.

That said, there's SO MANY people using the Seas W18EX (BESL, Ellis, Selah, etc) on the DIY side, that it seems sort of redundant to have one more guy doing it. So, why not try something different, particulary since I'm pretty wedded to crossover frequencies no higher than 2 kHz for midwoofers anyway. At an almost 3:1 price difference, it's not hard to rationalize, and then there's that spike in the 3rd order HD in the W18EX between 1 and 2 kHz. Isn't really THAT big, but it's something else to rationalize.

So far, I haven't been intrigued enough with the W18EX to shell out $324 for a pair to test. That's almost what two NS12-513A set me back....

Yeah, there's going to be a "Super Modula MT" or "Elaine Marie to the Max" fairly soon; though I'd like to try a waveguide, I'm not sure if I will because I'd like to keep it in the 3/4 cu ft PE cabinet, and the waveguide will just take up too much space for the LF extension and cabinet face. So, maybe I'll "brute force" crushing the tweeter distortion.... can you spell, "C23-6"? :E

In other breaking news, the first front baffle for the prototype Isiris were laminated up this AM before starting my work day.... :B

[HMenke]

Sounds to me like the bug bit you again ... Just be careful, the 3 way road is much more difficult to get correct and much more expensive.

Yep, bitten! Your caution about 3-way projects is well-taken...that's one of my favorite things about this board - people do their best to steer you right.

[ThomasW]

We do create 3-ways...........they tend to be a bit more elaborate than those one normally sees.... :T

[JonMarsh]

Disgusting- just look at Thomas and I dredging up our '90's projects as prime examples of wretched excess.... of course, we got the Eton 370's in a special buyout purchase from Madisound, and I don't even want to tell you where the 4 15" woofers per system used in a compound dipole configuration came from... Of course, in our defense, that is a Tc120dx2 focal tweeter, which is NOT what Legacy used, 'cause we wouldn't stoop that low.

BTW, I've visited the Legacy factory in Missouri, and I've heard several of their systems first hand, inlcuding hearing them go into some awful core saturation clipping when driven too hard with "Down in Mississipi" - shouldn't use those cheap ferrite core inductors or electrolytic caps, guys.... :naughty:

~Jon

[HMenke]

Next thing one of you guys will be showing us how you turned a pair of Frigidaires into a speaker system because the enclosures are so well damped, yet it's easy to open the door to tweak the crossovers.