Development Thread: Sigberg Audio Saranna - active floorstander

[sigbergaudio]

Moved the Saranna to a new room, this one is around 18-20m^2. The avg level of this measurement is around 75dB, so this is basically flat to 20hz in-room.

This measurement is a stereo measurement at the listening position with zero smoothing and only one manual EQ point (reduced a peak at ~45hz with 4dB).

 

[sigbergaudio]

Developing speakers is pretty labour intensive, and even most larger speaker companies don't have their own anechoic chamber (we certainly don't). That said, I am lucky enough to live 20 minutes drive from the Seas factory, and they DO have an anechoic chamber. So we use that extensively during our development.

In addition to that, measurements outside is another useful approach:


Here is a groundplane measurement showing a pretty even bass response from the Saranna. The crossover to the coax is at 170hz, as one can see it's pretty seamless.



I've also built a certainly-not-anechoic-but-still-reasonably-accurate corner in our workshop with quite a bit damping. Comparing it to measurements from Seas, it is probably around +/-2dB down to 100hz. From around 4-500hz and down to 100hz, it shows a level that is probably 1-2dB too low.

Here is the Saranna measured in that corner. The on-axis response is somewhat untidy, while at 15 degrees it is pretty okay.

On-axis:



15 degrees:

 

[sigbergaudio]

This week we visited the Seas Anechoic chamber for some measurements.

Also; Quick video showing excursion at relatively loud levels (averaging around 105dB@listening position). Healthy movement on the bass drivers, but perhaps more of note is the relative lack of moment of the coax, for those worried about distortion / problems related to what is essentially the waveguide of the tweeter moving back and forth.

The speaker is now essentially running in a 2.5-way configuration. The coax is allowed to roll off naturally, which it starts to do at around 200hz due to the small enclosure. To control the excursion there's also a 4th order high pass filter at 60hz.

 

[sigbergaudio]

Distortion measurements. Well under 1% at 96dB@1m basically everywhere except beyond 10khz and slightly over at 1500hz. The graph says 90dB at the Y-axis because this measurement is done at 2 meters.

 

[sigbergaudio]

We're now moving on to third generation prototype, converting the speaker to a hybrid open baffle configuration. The coax (operating from around 200hz and up now has ported side walls and an enclosure that is fully open towards the rear. The hole will of course be covered in the final version, not open like in the bottom photo.