Phase Tech PC 3.1 Speaker Measurements

[amirm]

The issue here is the midrange, not the tweeter. Unless it is also fluid filled, it is hard to blame it on that. But it is possible and hence the reason this write up was NOT called a review. Just measurements.

 

[milosz]

The midrange in a center speaker should be flawless as it is often part of a home theater setup, and Dolby 5.1 directs most of the dialogue to the center speaker. A very bad choice for improving intelligibility of actors’ voices.

This is what I was thinking about, too. The response is nowhere near flat and dips from ~200 Hz to over 1 kHz, but then starts to increase some in a peaky way. Even so, I wonder how this peaky lower treble impacts intelligibility of voices? Isn't this the range where we use overtones of the voice to understand what is being said? I don't know the answer here, but I wonder if this was a deliberate effort to color the speaker to improve intelligibility? The graph is crappy, but how does movie dialogue sound through this thing? This fosters a question - do we WANT a flat response in a dialogue speaker? Of course, if it was a flat response, a neutral wide-range transducer, one could apply what ever EQ one wanted to the center channel to tailor the "intelligibility" for the listener.

But, with a surround system used for MUSIC such colorations just won't do. But use case for surround music seems less likely than for movies and TV.

Some things to ponder about center-channel speakers....

 

[Jimster480]

Phase tech... I think this was around when I was a kid. I don't think I have seen anything from them in a long time. I guess this "exploration" shows that speakers definitely can degrade with time depending on their designs? I doubt the product was this broken on release so long ago

 

[Penelinfi]

Likely not at its best; distortion right where there is a big dip.
Might not be worth money time for most people, but could be made better.
Making cheap/broken stuff better can be a fun hobby

 

[puffreis]

Back in the days there was endless amount of German 3-way speakers like these

Canton GLX 100 (Gear & Review) - Explorations in Audio

In 2013, not long before our daughter was born, my wife Sabina and I went out to search for a pair of loudspeakers for us to restart our journey in the appreciation of music. When it came to audiophile pleasures, we were both out of practice and felt unsure of what to aim for. Visiting some...

eiaudio.de

Canton, Heco, maybe Saba, Braun and some other.

I only heard one Canton model and it was plain awful, nothing like hi-fi at all. I mean, even Mission 760i were on the next level.

I don't know the speaker mentioned and the GLX series was the lowest series from Canton at the time anyway.





You shouldn't generalise.

I have tested many such old constructs.

There are also some very good ones.



Examples:

Grundig Box 860: midrange 1.5 inch, tweeter 0.75 inch crossover: 1000/3150 Hz

Grundig Box 8000: midrange 1.5 inch, tweeter 0.75 inch crossover: 1000/4000 Hz

Canton GLE 60: midrange 1.2 inch, tweeter 0.75 inch crossover: 800/2200 Hz



Here are the frequency responses at the listening position in my test room compared to the average of good LS/monitors such as Neumann, LSRxxx, Linton etc. (in red):



Grundig Box 860

Grundig Box 8000

Canton GLE 60

Apart from the weak low bass, which should come as no surprise with such small closed speakers, there is not much to criticise.

The slightly too high distortion could possibly be a problem, but this is due to the woofer, not the supposedly too small mid/high driver.

K3 @ 90dB/1m



Grundig Box 860

Grundig Box 8000

Canton GLE 60

With one or even two inexpensive and good subwoofers like the Yamaha YST-SW series from the nineties, you can listen to music very well



The 1.5-inch Grundig 19055-025 midrange driver in particular, which is used in the Box 860 and has even been installed in cheaper models, is an exceptional dome midrange driver anyway. The purity is clearly audible even when sweeping.

The disadvantage of these drivers is that the resonance is 750Hz, so they can or should only be used passively from around 1000Hz.





I once made quick & dirty measurements. Here is the k3 distortion with a bandpass between 500 and 3000 Hz (via an external active crossover).

Sound level 90dB/1m



19055-025

I had always wondered why the puny 1.5 inch midrange driver of the active Grundig Aktiv-Box 20,30,40 and 50 already plays from 500Hz. The answer is quite simple: it can do it.



Here is a 3 inch Seas H304 under the same conditions:


Seas H304