Would you rather build a 3 way with the listening axis on-midrange or on-tweeter? Why

[fjhuerta]

Here's what got me thinking.

I once built a three way (http://www.htguide.com/forum/showthread.php4?p=530342) with the Neo8 and Neo3. When deciding on a listening axis, I picked the midrange.

The reason I did it was because the vertical off-axis response of a Neo8 looks pretty ragged, and the Neo3 is a lot better. So I merely assumed I'd be better off this way.

Now, 5 years later, I'm still wondering whether I was right - mostly because pretty much every 3-way I know has its listening axis on-tweeter.

Opinions are welcome!

[billfitzmaurice]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

I'm still wondering whether I was right

Probably. But planars are the exception to the rule where most midranges tend to have wider dispersion than most tweeters, usually because the midrange is crossed to the tweeter below where dispersion becomes too narrow, while tweeters run all the way to their frequency limit. And of course planars have tighter vertical directivity than most other driver types.

[jonasz]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

I think a speaker sounds more natural with the tweeter above ear level, no idea why but to my ears it just sounds better.

[Pete Schumacher]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

I think a speaker sounds more natural with the tweeter above ear level, no idea why but to my ears it just sounds better.

Lately, we've been designing on the axis between the mid and tweeter, and positioning the speakers so that the tweeter is just above the ear level.

Just remember that you're likely to be listening at quite a bit more than 1m from the speakers. So vertical off axis of a planar mid shouldn't be an issue, which ever design axis you choose.

[mzisserson]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

Lately, we've been designing on the axis between the mid and tweeter, and positioning the speakers so that the tweeter is just above the ear level.

Just remember that you're likely to be listening at quite a bit more than 1m from the speakers. So vertical off axis of a planar mid shouldn't be an issue, which ever design axis you choose.

I agree with Pete. Unless it is nearfield, a 8"-10" difference in tweeter height matters little. Tweeter at listening height you are going to get more information once it becomes directional vs. reflected. For a 1" dome that si about 13K, 3/4" some 19K... Not sure about planar though... The only concideration is where you are crossing the mid. If it is corssed in the range it becomes direction, you may end up with a "hot spot" on axis where it beams a little. Likely fix-able with a little toe in, but again it will show up on the "ever-so-critical" measurement regardless...Even if it sounds fine. DO not forget that room interaction, as well as power responce has to be considered when at listening distance. It is amazing what a room can ultimately avarage.

[GranteedEV]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

Tweeter Axis. The midwoofer is normally the driver most likely to be pushed high in its passband, close to its breakups. Since it will be beaming near its breakups, it's nice to be off-axis from it, even if they are already 25-30+ db down.

The advantage of midwoofer axis, though, is that it pushes the tweeter "further away" from a phase rotation perspective, and thus may make crossover design easier.

[benchtester]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

Lately, we've been designing on the axis between the mid and tweeter, .....

+1

The big attaction for me is that the tweeter and mid phase relation stays the same regardless of distance. Or put another way, the distance to the tweeter and mid is equal at all listening distances (an isosceles triangle).

If you center on the tweeter, the distance to the tweeter is less than the distance to the mid; and the ratio of these distances changes at different listening distances.

[mzisserson]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

+1

The big attaction for me is that the tweeter and mid phase relation stays the same regardless of distance. Or put another way, the distance to the tweeter and mid is equal at all listening distances (an isosceles triangle).

If you center on the tweeter, the distance to the tweeter is less than the distance to the mid; and the ratio of these distances changes at different listening distances.

Lately, we've been designing on the axis between the mid and tweeter, and positioning the speakers so that the tweeter is just above the ear level.

Just remember that you're likely to be listening at quite a bit more than 1m from the speakers. So vertical off axis of a planar mid shouldn't be an issue, which ever design axis you choose.

Yeah, this whole mid way between thing is great if you listen with your head in a vice and the room is not involved and the air pressure is a certain way, etc etc. Pete keeps it in perspective nicely when he said, and I paraphrase, distance is a great equalizer. The whole angular distance with the tweeter and mid sounds smart, but this is the real world and unfortunately it is very, very small beans in-room. There are many great speakers designed both ways, and in between. If you think you can hear a drastic difference, good for you but really when it comes to listening center, I am unsure there is a "BEST" way.

I am not fully on board with breakup modes effecting the listening axis either, why would you use a tweeter with breakup modes so bad they would be in the pass-band AND you have to worry about them? That seems like poor driver choice...Don't pay any mind to me though, my latest speakers listening center is 3/4 way above the woofer and 1/4 down from the tweeter with the mid on top. :applause:

[DoubleTap]

Re: Would you rather build a 3 way with the listening axis on-midrange or on-tweeter?

This thread is a perfect example of how at times, the DIY crowd often focuses on the wrong thing.

When you're talking about degrees off axis at a typical listening position, it's negligible. But that's what people are focusing on. Things like beaming, phase summing, etc ... things that are related to off axis performance, just don't matter when you're talking 2-3 degrees at most.

What does matter however in this case is sense of scale, the picture your brain paints of image size - how high off the floor are vocals for instance. If you put your tweeter on listening axis, and you're sitting with your ears 36-38" off the ground, your speaker is going to have trouble creating an image any more than 4' high. And vocals 4' off the ground just doesn't sound right.

So a couple things I've found that do greatly increase sense of scale are putting the tweeter above your ear and design axis at the top of the midrange, and tilting the speaker back slightly. As little as a 2 degree tilt can from my experience raise the perceived image height 1-2 feet.

Try it with whatever speakers you have now. Raise the stands up a few inches, and/or put a 1/2" block under the front edge to tilt them back a bit and see what it does for you.