Zaph Audio ZA5.2 DIY Kit Speaker Review

[Trdat]

So far, ASR has only tested one DIY speaker and it tested better than many other speakers. Despite some initial objection, it is in the database. Like the electronics, it has a DIY prefix (which is pointless IMO). Both the Overnight Sensations and the Samba are backordered into June and August respectively. The S2000 is out of stock too.
Would love to be building something else to test, but am in a holding pattern for now.

I don't live in the States so obviously shipping would amount to outrages costs but I have a range of DIY speakers that I would love to be tested. I have Amiga, Overnight Sensation, Classix 2, Troel 3WC and the Tritrix MT and the Bantam Micro's.

 

[RickS]

didn't you (or someone else, maybe) send in a C-Note? Is that still pending?

Yes and yes. Checking with Amir on his timing...

 

[QMuse]

Meh, I had PMC Twenty.22's and at very low frequency's they produced some weird port noise. I wasn't impressed by them at all.

Was that supposed to serve as an argument that TL design is bad?

Btw, unlike ported designs TL doesn't suffer from port noises nor from port resonance issues when implemented properly.

 

[thewas]

Btw, unlike ported designs TL doesn't suffer from port noises nor from port resonance issues when implemented properly.

A well designed BR also doesn't suffer from those, on the other hand a TL can have a resonance higher (around 200 Hz) which can be seen often at such loudspeakers. In the end all resonator designs have their advantages and disadvantages, if you have enough driver surface displacement the best option from sound quality point of view is to use a closed baffle bass, especially in times of active speakers or DSP/EQ.

 

[QMuse]

A well designed BR also doesn't suffer from those, on the other hand a TL can have a resonance higher (around 200 Hz) which can be seen often at such loudspeakers. In the end all resonator designs have their advantages and disadvantages, if you have enough driver surface displacement the best option from sound quality point of view is to use a closed baffle bass, especially in times of active speakers or DSP/EQ.

I don't think TL's pipe resonance is an issue. IMO with tapered lines that are properly damped with different materials TL is a superior design to BR.

 

[QMuse]

A well designed BR also doesn't suffer from those, on the other hand a TL can have a resonance higher (around 200 Hz) which can be seen often at such loudspeakers. In the end all resonator designs have their advantages and disadvantages, if you have enough driver surface displacement the best option from sound quality point of view is to use a closed baffle bass, especially in times of active speakers or DSP/EQ.

Btw, with sealed box you always have to deal with rear radiating sound. Sealed box will also have higher distortion as air is compressed and expanded adiabatically so the force needed to produce linear cone movement behaves in a non-linear fashion. And finally, there is only so much DSP can do to extend LF range.

 

[thewas]

Its not a pipe resonance but the phase shift at those frequencies compared to the frontal output of a bass driver, causing a partial cancellation:

(source: https://www.stereophile.com/content/pmc-db1iii-loudspeaker-measurements)

(source: Sound & Recording)

(source: https://www.connect.de/bildergalerie/transmissionlines-im-messlabor-1474537-343532.html)

If it was clearly superior solution to BR, measurement driven companies like Genelec, Neumann etc. would have chosen it.

 

[Koeitje]

Was that supposed to serve as an argument that TL design is bad?

Btw, unlike ported designs TL doesn't suffer from port noises nor from port resonance issues when implemented properly.

Well maybe PMC is just really bad at the thing they are known for. Could be.

But it was clearly noise coming from the port, so I don't know what your point is?

 

[QMuse]

Its not a pipe resonance but the phase shift at those frequencies compared to the frontal output of a bass driver, causing a partial cancellation:

View attachment 58312
(source: https://www.stereophile.com/content/pmc-db1iii-loudspeaker-measurements)

View attachment 58313
(source: Sound & Recording)

View attachment 58316

(source: https://www.connect.de/bildergalerie/transmissionlines-im-messlabor-1474537-343532.html)

If it was clearly superior solution to BR, measurement driven companies like Genelec, Neumann etc. would have chosen it.

IMO opinion phase cancellation you just showed is not a TL design flaw but of that particular PMC speakers. My speakers, nor other successful TL designs don't exibit such phase cancellation.

If it was clearly superior solution to BR, measurement driven companies like Genelec, Neumann etc. would have chosen it.

BR is chosen as a compromise between production costs and time to develop, not because it is a superior design. IMO TL has numerous advantages over BR and over sealed box, but it is a complex development and production costs are higher.

 

[thewas]

Btw, with sealed box you always have to deal with rear radiating sound. Sealed box will also have higher distortion as air is compressed and expanded adiabatically so the force needed to produce linear cone movement behaves in a non-linear fashion. And finally, there is only so much DSP can do to extend LF range.

Air compression and the connected non-linearity is also an issue on TML or BR (as they aren't open baffles), also distortion is of course reduced for the same SPL as you use also the rear energy, but on the other hand distortion gets higher again when you for example go lower than the tuning frequency.
Here is also an interesting paper showing the disadvantages of resonator designs when you go lower in frequency
https://www.grimmaudio.com/wp-content/uploads/RMS-white-paper-3-Bass-reflex.pdf
Everything in life is a compromise, also sound quality vs. max SPL and bass depth.

 

[QMuse]

Well maybe PMC is just really bad at the thing they are known for. Could be.

But it was clearly noise coming from the port, so I don't know what your point is?

Or maybe your specimen was bad.

My point is that you cannot possibly judge a TL technology nor PMC loudspeaker in geenral with your limited experience with a single pair of speakers that exibit non-specific artifacct.

 

[QMuse]

Air compression and the connected non-linearity is also an issue on TML or BR (as they aren't open baffles), also distortion is of course reduced for the same SPL as you use also the rear energy, but on the other hand distortion gets higher again when you for example go lower than the tuning frequency.

Not really. Non-linearity related to air compression is much less of a problem with TL then with sealed boxes. Also, TL rolls off with 12dB/ octave, same as sealed box and unlike BR.

 

[thewas]

IMO opinion phase cancellation you just showed is not a TL design flaw but of that particular PMC speakers. My speakers, nor other successful TL designs don't exibit such phase cancellation.

I am reading DIY magazines with high resolution measurements and there you can see it everytime, don't want to say it must be audible but as said everything is a compromise.

If you read the German wikipedia article about it, it also says it:
Charakteristisch ist eine durch destruktive Interferenz zwischen dem Direktschall des Lautsprecherchassis und dem durch die Rohröffnung abgestrahlten Schall verursachte Amplitudenfrequenzgang-Senke im oberen Baßbereich (80 bis 120 Hz). Abhängig von der Gehäuseausführung und Bedämpfung zeigen sich zu höheren Frequenzen weitere Interferenz- und Rohrresonanz-Effekte im Amplitudenfrequenzgang.
which can be translated to English:
Characteristic is an amplitude frequency response sink in the upper bass range (80 to 120 Hz) caused by destructive interference between the direct sound of the loudspeaker chassis and the sound radiated through the tube opening. Depending on the cabinet design and damping, further interference and tube resonance effects appear in the amplitude frequency response at higher frequencies.
from https://de.wikipedia.org/wiki/Transmissionline-Gehäuse

Am sure also your loudspeaker have it, only the only measurements I know about them are too smoothed and thus only show it partially (look at 70 Hz)

from https://stereo.ru/before/test.php?article_id=12.html

BR is chosen as a compromise between production costs and time to develop, not because it is a superior design.

Yes, as companies like Genelec or Neumann care about costs, time and are too stupid or low-tech to implement a TML if they wanted....

IMO TL has numerous advantages over BR and over sealed box, but it is a complex development and production costs are higher.

Its usually only a couple of internal MDF boards more, a good noise free 3D BR tube like of the above mentioned companies is something complex to design (with fluid dynamics simulations) and produce.

 

[Kustomize]

So I made an account just to discuss this.

I have the Zaph 5.3T, which is the Tower version containing 2 mids of the Zaph 5.2 Bookshelf variant. I did measurements 1 meter away, on axis, psychoacoustic smoothing applied.

Why is my tweeter's top end run hot, unlike the measurements included here? My crossover was assembled by madisound, so should be no mistake there...

This is the Right speaker.

This is the LEFT speaker, Red is RAW response.
Green is -6db at 16khz EQ'd using my Denon.

 

[Kustomize]

This is the response I get at my Listening position, Green is with -6db EQ at 16khz, Purple is no EQ.

 

[Kustomize]

Here is the distortion for the Left or the Right speaker, I don't remember which. Sorry.

 

[tuga]

Why is my tweeter's top end run hot, unlike the measurements included here?

Could be your mic.
Which mic are you using?

 

[Kustomize]

Could be your mic.
Which mic are you using?

My mic is UMIK-1. Calibrated file is used.

 

[Kustomize]

Adding on to my last post. My issue was my mic. You were right Tuga! I had the wrong calibration file set up! Stupid me!

This is how they measure now. In room. 1 Meter. On axis.

 

[tuga]

Adding on to my last post. My issue was my mic. You were right Tuga! I had the wrong calibration file set up! Stupid me!

This is how they measure now. In room. 1 Meter. On axis.

Pretty good!