Thomann/Swissonic A306 - Review & Measurements by Erin

[Yanec]

Hey everyone. I suspect I have snatched up the last of the "current" stock of the A306, however that does mean that the ones that were available were some B-stock examples. According to Thomann, the equipment should be 100% working and might show traces of use, however I have noticed some buzzing from the woofer of the one unit (especially at lower volumes). I suspect this is voice coil rub, as it all but disappears when pressing on the surround at about 6 o'clock. From this I have 2 questions:

1. Are there any "soft" meathods of addressing the VC rub, such as test tones, burning-in, manipulating the cone etc. which do not involve opening the speaker (or dust cap)?
2. What would be the best way to test whether there are no other severely detrimental effects on the frequency responce of the units? I have a USB mic (but no SPL-meter), could I perform a measurement which would confirm that the speakers are within acceptable limits other that the abovementioned?
3. Given the issue, should I rather exchange these units for A305's or A308's (or otherwise)?

Thanks for any input!

Edit: I have tested by swapping the inputs and the issue remains on the same woofer, and with different sources/amps. I have also rotated the unit 180 degrees to no avail.

I would send the unit back to Thomann to fix the issue. And would negotiate the shipping on them as it was misleadingly sold as 100% working.

 

[Yanec]

A little bit of vinyl goes a long way in terms of integrating the A306 design into a living room instead of a studio.

 

[staticV3]

A little bit of vinyl goes a long way in terms of integrating the A306 design into a living room instead of a studio.
View attachment 341612

This stuff might work well for blacking out the logo:
https://youtube.com/watch/kzLh06fzMN0

 

[Yanec]

This stuff might work well for blacking out the logo:
https://youtube.com/watch/kzLh06fzMN0

I don't mind the logo, but consider covering the led as it is distracting, especially when watching in the dark.

This stuff would probably be noticeable as it has different color, reflectivity and surface smoothness compared to the polymer used for the front of the speaker. I often used similar methods when restoring old photo lenses and had a plethora of issues until figuring out how to do such patches or better how to avoid doing them.

 

[ZolaIII]

Below the tuning frequency of the port, cone and port are out of phase. It's like putting two subwoofers next to each other and inverting the phase on one: the main tone gets cancelled and all you hear is a lovely cacophony of port noise and other distortion - which is kind of neat to test different port designs, but people already figured out how to design ports decades ago.
View attachment 340327

You could delete the port entirely and extend the lower frequency response with a lowshelf filter, but honestly, just get a woofer.

What's the phase/impedance cross and what is woofer Fs? Asking as you are probably one of cuple of people who know this (as a designer of those) and in the purpose of cutting the port cuff out when crossing with more serious subwoofer to see how much they really can give no sweat and improving distortion.
If A308 can pass 80 Hz limit (woofer response alone and close to a peek so that it can hold it and be stressed out) as ideal crossover with similar FR that would make them a great choice for budget 2.1 systems which would gladly pass reference white noise calibration point on to mid field and probably even up to a far field (al do not really ment for that).