Development thread: High-end dual opposing 10" subwoofer: Sigberg Audio 10D

[azzy_mazzy]

we're at 1.4% THD at 20hz@81dB

is this measured in room?

 

[sigbergaudio]

is this measured in room?

Hi, that was a long time ago, I'm not 100% sure, it may have been in-room.


Here's an outdoor measurement with distortion at 96dB@1m from an earlier post. The final product is tuned a bit differently so it may not look exactly like this, but not too far off:

Here are CEA2010 measurements if that's helpful (the column marked "10D"), but that again says something about maximum level, while the point I was probably trying to make back then, is that this subwoofer has lower distortion at moderate listening levels (before you hit maximum) than many others.

 

[sigbergaudio]

Our 10D subwoofer has now been reviewed by Audioholics!

Sigberg Audio 10D Subwoofer Review: Best Performing Small Sub?

Our review of the Sigberg Audio 10D subwoofer shows what happens when a designer puts some of the world’s best audio components into a small package that hits above its size class. Pricey but potent.

www.audioholics.com

 

[sigbergaudio]

For those interested in expected low-end extension, here's a measurement from a setup with 2x10D at a Hifi show we visited this weekend. The room is about 30m^2 (323 square feet). The measurements are taken at row 1 and row 2 in the audience seats, approximately 2.5 and 3.5 meters from the system.

 

[sigbergaudio]

An update on pricing: For a while now we've had all included pricing, which meant that the price on the website included shipping and any import taxes and duties. This means we've basically had fixed, world wide pricing. In practice, import taxes and duties are obviously not the same in all countries, and especially the USA often have relatively low import duties and these types of products (6-10% depending on the state as far as I've understood). This means our products have been more expensive than they could have been in the US and other countries with low import taxes.

As a result I've decided to go back to our more traditional pricing model, where foreign customers (anyone not from Norway) will pay an ex VAT/duties price. It will still include door to door shipping.

Note that prices are still fixed to NOK currency so will vary somewhat depending on currency rates, so the pricing below is based on USD currency rate as of today October 2nd 2022.

What does this mean in practice for international pricing?

• Inkognito 10 subwoofer is now 1983USD (was 2479USD)
• Inkognito 12 subwoofer is now 2351USD (was 2939USD)
• 10D subwoofer is now 2645USD (was 3300USD)
• Set of dual 10D subwoofers is now 4761USD (was 5950USD)
• The SBS.1 active speaker is now 4629USD per pair (was 5786USD)

This includes shipping, but does not include local import taxes and duties.


Feel free to follow up (here or in a direct message) if you have any questions.

 

[emilkoz]

Why is internal volume necessary with dual opposed drivers? Don’t they cancel each other? Couldn’t this subwoofer have been made even smaller I mean?

 

[ryanosaur]

Why is internal volume necessary with dual opposed drivers? Don’t they cancel each other? Couldn’t this subwoofer have been made even smaller I mean?

Excepting a true Isobaric design, any dual Driver design will require 2x the internal cabinet volume (same as a 3 Driver design will require 3x Vas if sharing the same cabinet space)... Each Driver's Vas is additive. Dual Opposed and Push-Pull (like the Perlisten designs) are included in this.
The only thing that cancels in a Dual-Opposed design is the motor force which can cause the infamous Subwoofer Walk (not the same as the Subwoofer Crawl ).

In the Isobaric design where a second driver is added with a very small sealed space between both Drivers, and the second is contained inside the cabinet, then, Vas is halved. However, with that, you gain nothing but a decrease in cabinet volume for the addition of that second driver (no additional output, for example).

 

[sigbergaudio]

Why is internal volume necessary with dual opposed drivers? Don’t they cancel each other? Couldn’t this subwoofer have been made even smaller I mean?

As @ryanosaur said, the drivers don't cancel out each other (that would be bad. ) - the only thing that is cancelled is enclosure vibrations. Two drivers in a sealed enclosure typically require twice the enclosure volume. A reduction in volume can (within reason) be compensated by added power and DSP, which has already been done here.

 

[emilkoz]

Ok gotcha!

But cancelling inside a sealed box how is that bad? There’s no output there?

Probably a long answer so feel free to point to what basic physics I need to read up on. But how come the dual opposed drivers don’t cancel each other (other than mechanical force)?

 

[sigbergaudio]

Ok gotcha!

But cancelling inside a sealed box how is that bad? There’s no output there?

Probably a long answer so feel free to point to what basic physics I need to read up on. But how come the dual opposed drivers don’t cancel each other (other than mechanical force)?

Not sure what you mean by there being no output inside the box.

To be able to answer I think I need to understand how you are thinking first. Why would you assume that the drivers cancel each other out?

And by cancel each other out, what do you mean by that? Typically when we say this, we mean that the sound emitted from one of the drivers, are canceled by the sound from the other. The result would be no sound. Not a very effective subwoofer.

 

[ryanosaur]

But how come the dual opposed drivers don’t cancel each other

I can only say that what is inside the sealed box... the backwave of the Drivers, are immaterial to the output on the outside of the box. The key is that the Drivers be in phase, whether on a single baffle, or dual opposed... or even push-pull. (In this latter example, one driver will have the motor outside the cabinet and thus needs to be wired opposite the conventionally faced driver... but the cone of each driver is still in phase with each other; they excurse outwards together.) There is no cancellation to worry about inside the cabinet.
You can look at many reviews of dual opposed and push-pull systems to see the efficacy of this in practice.

 

[emilkoz]

Sorry to bother I just realized where my brain farted. ‍

 

[quattro98]

Any updates on the 11Q design?

 

[sigbergaudio]

Any updates on the 11Q design?

Thank you for your interest! That idea has been put to rest for now.