-
Welcome to ASR. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
New Sigberg Audio development thread: The Sentinel - A music oriented reference subwoofer developed for the Manta system.
- Thread starter Sigberg Audio
- Start date
Paul7777x
Addicted to Fun and Learning
- Joined
- Feb 11, 2026
- Messages
- 646
- Likes
- 899
I really don’t have the patience for electronics building.
But in any case it the RP from Lyngdorf that I’m after.
OP
- Thread Starter
- #105
That picture is from the review at Stjernholm Reviews, and yes, Lyngdorf and ipad.
OP
- Thread Starter
- #106
Paul7777x
Addicted to Fun and Learning
- Joined
- Feb 11, 2026
- Messages
- 646
- Likes
- 899
Maybe they will.
I hope that’s a bit of insider knowledge…
OP
- Thread Starter
- #108
Mcintosh do a sort of preamp with room perfect. The MEN220.
McIntosh MEN220 Room Correction System
The MEN220 Room Correction System offers an all-in-one solution for sophisticated room correction, custom EQ, and two-way crossover functionality.
www.mcintoshlabs.com
Ohaaaa I always wondered, why there was no successor of the DPA-1. Now, you got me excited.Maybe they will.
Paul7777x
Addicted to Fun and Learning
- Joined
- Feb 11, 2026
- Messages
- 646
- Likes
- 899
Mcintosh do a sort of preamp with room perfect. The MEN220.
McIntosh MEN220 Room Correction System
The MEN220 Room Correction System offers an all-in-one solution for sophisticated room correction, custom EQ, and two-way crossover functionality.
Nine grand though. And naturally I don’t buy USAian stuff.
But something similar for a realistic price would be the thing.
I was a little bit surprised at the Uk price too
For that price you could buy a second hand 3400 and use it as a pre amp into a top of the line Power Amp and pocket £5-7k
OP
- Thread Starter
- #114
Doing a bit of measurements at higher volumes. These measurements are at the MLP (around 2.5 meters from the subwoofer). I always use soft/decoupling feet on all our subwoofers and speakers, and I know there is some debate to the audability of this.
On this prototype I only had hard feet to begin with, and the prototype also has thinner panels and less bracing than the production will have. I always start with "lesser" cabinet models to see how well they work, and then improve over time until it ends up what I'd call over engineered, but not going crazy. I find it interesting to see what is required, many speakers are extremely overbuilt compared to what is needed in reality for an inert cabinet. Anyways, I digress.
As mentioned, I used hard feet, and due to the somewhat underbuilt cabinet, there is significant vibration in the cbainet when you pass say 100dB at the MLP and down in the 10-30hz range. So I replaced them with slightly softer feet (still harder than what will be on the production model).
While the frequency response look the same, there is actually a significant change in the THD. The only change here is the feet.
Hard plastic feet:
Softer rubber feet (still not perfectly adjusted for the weight of the sub):
So relatively similar over most of the frequency range, but from 40-60 especially, it's apparently able to dampen some resonances so much that the THD is cut in half at around 50hz. What frequencies that are dampened and how much will depend on the composition of the feet, and of course what resonances are present. The difference will arguably be less with a better cabinet.
Either way, just a small anecdote implying that how you couple your speakers or subwoofers to the floor might make a small, potentially audible difference.
Anyway, this is with some room gain of course, but 1.9% THD @100dB/30hz (2.5m distance) with a single sub, so with a Manta system with two of these, you'd probably hoover around 1% THD@100dB for the entire frequency range in-room.
And frequency response still not really showing roll-off before 10hz, will test in a different an larger room soon.
On this prototype I only had hard feet to begin with, and the prototype also has thinner panels and less bracing than the production will have. I always start with "lesser" cabinet models to see how well they work, and then improve over time until it ends up what I'd call over engineered, but not going crazy. I find it interesting to see what is required, many speakers are extremely overbuilt compared to what is needed in reality for an inert cabinet. Anyways, I digress.
As mentioned, I used hard feet, and due to the somewhat underbuilt cabinet, there is significant vibration in the cbainet when you pass say 100dB at the MLP and down in the 10-30hz range. So I replaced them with slightly softer feet (still harder than what will be on the production model).
While the frequency response look the same, there is actually a significant change in the THD. The only change here is the feet.
Hard plastic feet:
Softer rubber feet (still not perfectly adjusted for the weight of the sub):
So relatively similar over most of the frequency range, but from 40-60 especially, it's apparently able to dampen some resonances so much that the THD is cut in half at around 50hz. What frequencies that are dampened and how much will depend on the composition of the feet, and of course what resonances are present. The difference will arguably be less with a better cabinet.
Either way, just a small anecdote implying that how you couple your speakers or subwoofers to the floor might make a small, potentially audible difference.
Anyway, this is with some room gain of course, but 1.9% THD @100dB/30hz (2.5m distance) with a single sub, so with a Manta system with two of these, you'd probably hoover around 1% THD@100dB for the entire frequency range in-room.
And frequency response still not really showing roll-off before 10hz, will test in a different an larger room soon.
You had earlier mentioned limiting the LF frequency response of the sub, but many of us, especially in the US, love subs that go down to single digits, based on the FR curves I've seen for this sub (page 4). Believe it or not, there is plenty of movie LFE at single-digit frequencies. At least, provide an option to defeat it.
OP
- Thread Starter
- #116
The goal is to have a multiband limiter, which means it can be configured to limit the lowest frequencies without limiting the rest of the frequency band, which means the subwoofer can be allowed to play into the single digits as long as you play within reason, and then at higher SPL, the lowest band will be
limited.
Beyond that, while single digit can be fun to shake the couch for movies, it can have the opposite effect for music. As all you achieve is making everything in your house rattle along with the music - which isn't necessarily desirable.
For that reason 'Shakers' are available all over the market ... just saying ...
OP
- Thread Starter
- #118
Testing in a larger room today, 50-60m^2 (500-600sqft).
Single sub and no room EQ applied, so the point isn't the overall response but just to test the extension.
-6dB in-room around 14hz.
Single sub and no room EQ applied, so the point isn't the overall response but just to test the extension.
-6dB in-room around 14hz.
Last edited:
OP
- Thread Starter
- #119
Some more outdoors testing today, but was unable to finish. Ironically because the weather was too good, both me and the sub overheated. Also windy+background noise which made it challenging to get good distortion measurements.
Now using a temporary 1000W Hypex amp (500W per driver), still feels like I'm running out of amplifier power, which I guess matches the simulations.
Low end CEA2010-tests (30hz and down) gives almost exactly double the capacity of a 10D subwoofer (+6dB) currently, which I guess was the goal.
Max levels hit today was at 50 and 60hz, 123dB@1m.
Now using a temporary 1000W Hypex amp (500W per driver), still feels like I'm running out of amplifier power, which I guess matches the simulations.
Low end CEA2010-tests (30hz and down) gives almost exactly double the capacity of a 10D subwoofer (+6dB) currently, which I guess was the goal.
Max levels hit today was at 50 and 60hz, 123dB@1m.
Last edited:
OP
- Thread Starter
- #120
In Norway we have a saying that goes "It's starting to taste like a bird". Now that I translate it, it sounds pretty weird, but anyways, what it means is that something is starting to go very well.
Since I was amp limited yesterday, I bridged the two amp channels today to get more power, and we've now achieved the goal of matching the Manta with 122db/40hz@1m without violating the distortion limits of the CEA2010 test. The actual measurement was taken at 2m, so 116dB@2m.
Highest measured results today was 126dB/50hz@1m and 129dB/60hz@1m, both well within the THD limits of the CEA2010-tests, and interestingly still amplifier limited. So these new drivers get a stamp of approval.
The Sentinel is now more than twice as loud as the 10D across the passband, with a whopping 8.5dB more at 20hz, and minimum 7dB more at all frequencies above that.
The goal of the Sentinel of course isn't just to play loud, and this capacity allows very clean playback at any moderate level.
Since I was amp limited yesterday, I bridged the two amp channels today to get more power, and we've now achieved the goal of matching the Manta with 122db/40hz@1m without violating the distortion limits of the CEA2010 test. The actual measurement was taken at 2m, so 116dB@2m.
Highest measured results today was 126dB/50hz@1m and 129dB/60hz@1m, both well within the THD limits of the CEA2010-tests, and interestingly still amplifier limited. So these new drivers get a stamp of approval.
The Sentinel is now more than twice as loud as the 10D across the passband, with a whopping 8.5dB more at 20hz, and minimum 7dB more at all frequencies above that.
The goal of the Sentinel of course isn't just to play loud, and this capacity allows very clean playback at any moderate level.
Last edited:
Similar threads
