2way vs 3way, same sound?

[leadcoma]

going to build a set of speakers but before I do, been thinking about this:

2 way speaker vs 3 way speaker

- 1" metal dome tweeter in both, no horn load of any sort
- 6.5" woofer in both
- 3way has a 3" mid ( or whatever size is "optimal" so the directivity is matched to the woofer and tweeter )
- same volume of enclosure for woofer
- same baffle size
- same THD
- identical in-room frequency response at the listening position in a typical size living room (if that's possible)

Do they sound the same? If not, how is the sound different?

[murphythecat8]

the main difference wll be the fact that your woofer, in the 2-way, will need to do, and the bass, and the midrange, resulting when listening in higher volume, less clarity, more distortion, ect.

but really, your question is too broad, we ca not tell you anything. If your real question is if a 3-way is really worth the effort., now that may result in more interesting answers...

[mdocod]

The 3 way will have "better" off axis response and less noticeable distortion when driven beyond linearity.

Typically, if you are going to go through the trouble of the 3-way, then there should be more "return on investment" than these slight advantages. The point of increasing the complexity of a system to a 3-way design is typically to get more bandwidth, or output, or both.

[cotdt]

A 3-way allows you to do a dedicated midrange driver which tends to sound superior, besides the fact that the midrange won't need to perform bass duties.

[a.wayne]

The 3way is the way to go , but it will require a lot of experience to get it right , best to do the 2way, if such ...

[cT equals piD]

If the "listening position" is on-axis, then I think that at the listening position both the two-way and the three-way would sound very much the same. This is assuming that you properly design and build the three-way system, which is more difficult than the two-way.

By limiting yourself to the same 6.5" woofer in both systems, you are defeating the purpose behind implementing a three-way, which is to get greater bandwidth and/or increased distortion-free SPL, as mdocod has said.

[Jay]

Originally Posted by mdocod

The 3 way will have "better" off axis response and less noticeable distortion when driven beyond linearity.

Typically, if you are going to go through the trouble of the 3-way, then there should be more "return on investment" than these slight advantages. The point of increasing the complexity of a system to a 3-way design is typically to get more bandwidth, or output, or both.

Right. With 6.5 inches I will mostly want a 2-way.

Some drivers can produce wide spectrum well, some can't. So there is option to limit the spectrum so each driver can perform better. But another issue arrives. You need those 3 drivers be in phase (which is the most critical issue imo).

If the woofer cannot produce high enough frequency and the tweeter cannot produce low enough frequency, 2 way is probably not a good option. But 3 way is not the only option left, because you can find more suitable drivers for the job.

[Old'n'Cranky]

my first speaker build was a 'sp95' by troels.
my second build was the 'ekta' by troels.

I used the exact same bass and tweeter drivers in both builds.
(Actually pulled them from the first system to reuse in the second)
just added the midrange, new crossover, new cabinets.

The 3 way slaughters the 2 way in so many ways.
driver integration, clarity, sound stage, smoothness.
the bass driver is a 6-7" driver for reference..

If your doing a full proper diy approach, go for a two way, much easier to do the crossover.

[leadcoma]

thanks for the interesting responses!

I should have been more specific with my question. It's not really about what I should build, which is easier, cost less, has more/less distortion.

I'm interest in hearing about the effect of the directivity on the sound given all other parameters between the two systems are equal.

There's all this talk about how the woofer directivity needs to match up to the tweeter so use a tweeter loaded horn with a big woofer or use a smaller woofer with an wide dispersion tweeter.

But if I can get the on-axis in-room frequency response at the listening position to be the same, is the sound any different?

I've measured several 2 way bookshelf speakers in rooms. With some of the better speakers, I do not see the off-axis dips in the my on-axis listening position measurement. Some of the 2 way speakers measure surprisingly well (almost no peaks/dips) above the Schroeder frequency.

So is it snake oil or can a 3 way sound better taking into account the assumptions I've listed?

[cotdt]

The directivity of a 3-way and 2-way is the same if the crossover point in the 2-way is low enough. The 3-way only sounds better because of its dedicated midrange and dedicated woofer. The 6.5" midbass required for the 2-way tends to lose definition in the upper midrange. I never realized this until I started using true midranges with very light cones. It is another level of clarity and dynamics, at the expense of bass.

In the case that the 2-way has a high 4kHz crossover, then even if on-axis response is flat, there would be less room gain at the 2kHz-4kHz region due to directivity. It would be fine in a large room, but not in a small room unless one prefers a laid back sound. You have to think about having the same total energy at all audio frequencies.