Sigberg Audio Manta (12" dual cardioid active speakers) prototype / build thread

[Digby]

@sigbergaudio

Can this be wall mounted with no ill effect to sound? Personally, if something is on the floor, i'd rather it was a floorstander. How heavy are they?

 

[sigbergaudio]

Seems very promising as it truly is the only speaker that attempts cardioid radiation pattern but at the same time doesn't force itself to be full range.

Every other such design basically houses a dedicated subwoofer in the same cabinet and that doesn't seem that good of an idea. Certainly my dedicated sub will work better below 80hz anyway so speakers like D&D 8C or as of yet unreleased GGNTKT M3 try to serve me something that I don't need. Manta also has lower distortion than competition.

That would make Manta the most logical choice, only few things that concern me is the early tweeter roll of and its potential compression. Horns as used by GGNTKT make me more confident since those I know can play really loud without problems.

As mentioned earlier, there is no tweeter roll-off, they're flat to 20khz. The measurements shared so far are of early prototypes.

With regards to compression, the coax acts as a waveguide so basically a light horn loading. I can ensure you we wouldn't have mated this coax with a 12" midbass driver if it couldn't keep up. Early tests indicate the tweeter will likely be <2% THD @110dB/1m from one speaker, so 116dB with two.

[email protected] will likely be <0,5% THD.

In other words, capacity won't be a problem.

 

[sigbergaudio]

@sigbergaudio

Can this be wall mounted with no ill effect to sound? Personally, if something is on the floor, i'd rather it was a floorstander. How heavy are they?

Yes, but wall mounts will not be included and likely not be available as an option, so you'd have to figure out a solution to that yourself.

Weight TBA, but rough guess somewhere between 25-30kg.

 

[mightycicadalord]

Any desire to go with black instead of silver screws for the drivers? They stand out to me and make the speaker look cheap IMO.

 

[sigbergaudio]

Any desire to go with black instead of silver screws for the drivers? They stand out to me and make the speaker look cheap IMO.

All pictures so far is of early prototypes made of untreated MDF. All screws on amps and drivers on the finished product will be black (as well as the speaker itself).

It will likely be low profile machine screws similar to what's used on our SBS.1 speaker:

 

[sigbergaudio]

I hope to show some pictures of new, great looking cabinets in about a week or so.

In the meantime I've been experimenting with the frequency response. Here's the final version of the day that sounds pretty good. Measurements done indoors at about 50cm. I've been working on the smoothness of the response and on/off-axis consistency. There was some excess energy around 1800hz as well as around 2400-3000hz that's smoothed out a bit now. The level of the tweeter is increased a bit as well.

This has to be redone when new cabinets arrive, so this is mostly to see how it sounds as well as how the speakers responds to fine tuning (haven't spend that much time on that so far). Because of the cardioid design, what happens off-axis can potentially be a bit unpredictable, but the experience so far seem to indicate that it should be possible to get a pretty decent response.


On-axis:

0-15-30-45:

 

[sigbergaudio]

Sigberg Audio on Instagram: " #prototype #cardioid #highendaudio"

Sigberg Audio shared a post on Instagram: " #prototype #cardioid #highendaudio". Follow their account to see 187 posts.

www.instagram.com

 

[HooStat]

That is really nice looking. I am surprised that the insulation in the speaker allows the sound to escape enough to get the cardioid effect. I know when I block my ports, it doesn't seem to allow any sound through. I would be more curious to understand. Or maybe I am just not seeing the photo correctly.

 

[sigbergaudio]

That is really nice looking. I am surprised that the insulation in the speaker allows the sound to escape enough to get the cardioid effect. I know when I block my ports, it doesn't seem to allow any sound through. I would be more curious to understand. Or maybe I am just not seeing the photo correctly.

The black fabric you see is a felt material that is only 2mm thick. The exact nature of the insulation inside of it will likely not be shared (until someone takes one apart at least).

 

[sigbergaudio]

A couple of more pictures of the new high quality prototype. Looks pretty menacing if you ask me.

 

[sigbergaudio]

Update on expected delivery:

For those considering the Manta: Original plan was to start delivery late 2022. This is a time consuming project, and at the moment a more realistic timeline is probably start of delivery around summer 2023.

 

[sigbergaudio]

Obviously early days and lots of work left, but here's preliminary on-axis + 30 degrees off-axis with the new enclosures.

(0,5m in door measurement)

 

[Rednaxela]

Beautiful!

Out of interest, will they come with grilles?

 

[sigbergaudio]

Beautiful!

Out of interest, will they come with grilles?

Thanks!

Yes, that's the plan. Haven't decided exactly how they will look, but possibly just plain black grilles covering the whole front. That will give it a significantly more sober look, but still look pretty cool and somewhat special with the ports on each side of the enclosure.

 

[sigbergaudio]

In other news, the new prototype has got revised side ports, especially the lower chamber has significant adjustments. Measurements have only been done indoors so far, so this won't tell us energy loss in absolute numbers due to reflections. What we can do is see the difference between the previous and the new prototype. Something is clearly going on from 150hz and below that looks very interesting.

Green is on-axis, red is 180 degrees on the old prototype, and blue is 180 degrees on the new / current prototype.

--

 

[dc655321]

In other news, the new prototype has got revised side ports, especially the lower chamber has significant adjustments. Measurements have only been done indoors so far, so this won't tell us energy loss in absolute numbers due to reflections. What we can do is see the difference between the previous and the new prototype. Something is clearly going on from 150hz and below that looks very interesting.

Green is on-axis, red is 180 degrees on the old prototype, and blue is 180 degrees on the new / current prototype.

--

Have a look at this post ( near the end) for hints.

 

[sigbergaudio]

Have a look at this post ( near the end) for hints.

Yes, I've seen that one, interesting patent paper!

 

[D!sco]

Obviously early days and lots of work left, but here's preliminary on-axis + 30 degrees off-axis with the new enclosures.

(0,5m in door measurement)

That's really impressive, is that in-room or open-air? When does the cardioid dispersion start cancelling off-axis? Are you going for a wide angle, like most coax (70+ degrees) or more narrow like the Kii series' (60 degrees) studio oriented design?

 

[sigbergaudio]

That's really impressive, is that in-room or open-air? When does the cardioid dispersion start cancelling off-axis? Are you going for a wide angle, like most coax (70+ degrees) or more narrow like the Kii series' (60 degrees) studio oriented design?

That's in-room at 0,5m, so largely unaffected by the room, but would look even smoother in an anechoic environment. Note that it's only from 400hz and up (the lower frequencies are disturbed by the room)

The cancelling start around 90 degrees.

The dispersion will be extremely even out to +/- 50 degrees or so (covering any conceivable listening position), but the overall tonality / balance is maintained basically anywhere in front of the speaker, so for casual listening it will sound good / the same anywhere in the room.

For a third party reference, here is a graph of +/-90 of our SBS.1 speakers from a recent review at Audioholics. So not this speaker, but it uses the same coax. As you can see it's pretty even all the way out.

 

[sigbergaudio]

The voicing of the new enclosures are moving along as well, it's starting to sound really good! These are all still in-door measurements at ~0,5m. We'll probably do some new Klippel measurements before summer to get more precise measurements.

The "BBC like" dip is almost gone, and so is the lift above 4khz. Overally pretty flat. It sounds open, balanced and big. Voices are beautiful, and there's plenty of punch in the mid bass as well as zing in the higher frequencies without anything sounding harsh.

Finally the precision and soundstage is ..well, I'd like to say nothing short of breathtaking! In a track like "Hold up, wait a minute" by Zhu, it's awesome to just close your eyes and excitedly wait to hear where in 3D space the next instrument or sound will pop up.

15 degrees / listening axis:

The dispersion is also very even within a realistic listening window (0-45 degrees), and this speaker will sound tonally balanced just about anywhere in front of the speakers. The responses tightens somewhat at 1300hz and 1500hz, but this hasn't been noticable in the listening sessions so far.

0-15-30-45:

Average of 0-15-30-45-60-75-90: