Pros and cons of tweeters in the middle, BTM, in a three-way speaker?

[fpitas]

When I bought my Castle Conway 3s in 2005 they were described as being a d'Appolito design. I think the two mid/woofers were supposed to act like one larger driver?

View attachment 240951

Sort of. There are big implications for vertical directivity when you do that. You're on your way to a line array.

 

[DanielT]

I know Ken, having talked with him on other forums about break-in. I have to disagree with him somewhat, especially if time-alignment is low-hanging fruit because of digital delay. Of course, the vast majority of speakers are passive, and pure delay over a wide band is difficult. Here's Rod Elliott's take:

Phase, Time and Distortion in Loudspeakers

sound-au.com

Phase Shift Delay Networks

ESP - Using phase shift networks to achieve time delay for time alignment

sound-au.com

I will read what Rod Elliott writes, thanks for the tip.

I read a few weeks ago a bit of that thread I referred to, i.e. this one:

Time aligned speakers - do they make sense?

I see some speaker brands claiming to be physically time-aligned, usually by titling the speaker back so the tweeter is farther from the listener. Is this truly effective? It seems if there’s a positive effect, it would be for only one narrow listening position (which may not be where you’re...

audiosciencereview.com

I don't know if I got that much wiser. Also, like you, I can put in a delay if I want, ...so in practice it's not something I care too much about.But it's always fun to read about the theoretical stuff.

 

[Deleted member 19122]

What model do you have?

I've got some Ergos and Karats rumbling away.

 

[dualazmak]

Interesting thread, indeed.

In my multichannel multi-driver multi-amplifier active stereo system, I could establish 0.1 msec precision time alignment over all the SP drivers including tweeters and super-tweeters; my very unique (eccentric?) physical alignment (positioning) of super-tweeters described here would be of your interest and reference, I assume.

Edit:
Our ears are located left and right of our head, and hence we are rather sensitive for left-right sound image/allocation. On the other hand, our ears and brain would be relatively gullible with up-and-down sound staging, I assume. I think that my unique physical alignment (positioning) of super-tweeters at under the main SPs, together with the upper tweeters, would give pseud-coaxial sound staging if complete time alignment has been achieved like in my setup, where tweeter and super-tweeter sing together higher than about 8 kHz.

In any way, I would like to suggest those who using super-tweeters to at least try/test the positioning so that super-tweeter and tweeter would sandwich the woofer and squawker from up and down.

 

[DanielT]

Here is a comment regarding the placement of tweeters:

I-or
Furthermore, placing the tweeter element below the midrange element gives an advantage in that the main lobe is directed upwards (instead of downwards) for a planar baffle.

faktiskt.io • Visa tråd - Dewpo planerar en aktiv mellanfältsmonitor, hjälp önskas!

Edit:
What should be added is that I don't know if it can be seen as a general tip or if it relates more to the DIY construction discussed in that thread. That is to say, the statement applies to its specific conditions.

 

[dualazmak]

Here is a comment regarding the placement of tweeters:

I-or
Furthermore, placing the tweeter element below the midrange element gives an advantage in that the main lobe is directed upwards (instead of downwards) for a planar baffle.

faktiskt.io • Visa tråd - Dewpo planerar en aktiv mellanfältsmonitor, hjälp önskas!

Edit:
What should be added is that I don't know if it can be seen as a general tip or if it relates more to the DIY construction discussed in that thread. That is to say, the statement applies to its specific conditions.

Above reference and/or my unique super-tweeter positioning would possibly make sense if flexible relative gain control and perfect time alignment could be implemented and achieved, I assume, even though it would be greatly dependent on each setup and room acoustic conditions. Somewhat relating to the topics, possibly my post here would be also of your interest.

 

[valerianf]

I got a 3 way tower speaker that is designed similar to a Canton.
The tweeter is at 32 inches height.
Advantage is direct radiation to the couch and proximity with the center speaker tweeter.
The center sound image is more homogeneous.

It would be nice if Amir could measure a Canton tower speaker.