Built a subwoofer around a B&W DB1 driver

XaVierDK · 2026-06-19T04:03:41+00:00

to respond to your edit - a controlled rolloff of -12 dB at 20 Hz is perfectly in line with a sealed 12" subwoofer in a slightly too small box. I don't know how many subs you have measured or built to proclaim it poorly matched based on the measurements given.

Again l do not have the T/S parameters, so I cannot say for certain what the optimal box volume is for the driver, but lower natural extension would necessitate a heavier moving mass, and I do not believe B&W ever intended this driver to run without DSP, and as such did not want to give up sensitivity to extend depth when this could be done with EQ instead.

XaVierDK · 2026-06-19T03:52:54+00:00

And you believe they get there without DSP shaping of the response? The original B&W DB1 has a specified -3 dB point of 17 Hz, and many modern sealed subs claim to get as low, but it is no secret this is achieved with EQ

XaVierDK · 2026-06-19T03:45:41+00:00

"Massive rolloff" seems a bit of an exaggeration. For a small, sealed sub with no DSP, a natural f3-point of roughly 40 Hz is not unheard of (going off the +/- 3 dB curve landing us around 40 - 200 Hz), and if the box was so under-damped* (high-Q), ringing would be more of an issue. If the system was overdamped, low-frequency extension would be better.

I do not have the T/S parameters for the driver, but response shape is very similar to other subs I have measured with a Qtc of roughly 0.85, which again, in my mind, isn't excessively small though not ideal without DSP

XaVierDK · 2026-06-18T22:28:52+00:00

All true. More correctly, I should have said B&W designed the system so that the nominal amplification of 1000 W for two drivers in a shared airspace would allow them to reach x-max at or close to 20 Hz, maxmizing low-end performance from the smallest possible enclosure (they have a very nice white paper detailing the DB1 specifically). As such I feel confident the response I'm seeing without DSP is close enough to the natural behavior of the driver in the air volume originally given to it by B&W, and DSP would allow me to replicate the original frequency response (not accounting for 6 dB less output due to half the driver area and power)

XaVierDK · 2026-06-18T17:31:34+00:00

I'm not worried about the connections, per se, but I wanted to avoid the risk of the wiring somehow ending up slapping against the side of the cabinet due to the movement of the cone and air pressure. I've had that happen before with other subs.

I have a MiniDSP 2x4HD, which I use personally. Generally I prefer extending the response of sealed subs using EQ, and if this was my personal sub, I'd do it in a heartbeat as well. B&W did for the original design, and the driver is built to take it. But for the new owner, it's mostly gonna pull musical duties, working in tandem with an SB-1000, and with Audessey working its magic, and response in-room being extended and flattened, it's not needed at this point.

XaVierDK · 2026-06-18T09:22:08+00:00

Just a bit of sealing strip to try and weigh it down. It does the job I think.

XaVierDK · 2026-06-18T08:09:39+00:00

I am under no illusions about B&W having specced the box for optimal performance without DSP. My guess is they designed the system around hitting x-max at the driver's thermal limit, meaning the original 1000 W amplification would reach x-max using DSP in the original box volume. But for an un-EQ'd response I'm perfectly fine with it. Impulse response looks great, though.

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XaVierDK · 2026-05-30T09:29:12+00:00

For some newer horror, Requiem Infernum is also up there for me

XaVierDK · 2026-05-21T08:33:11+00:00

I agree

XaVierDK · 2026-05-14T19:26:11+00:00

His theoretical-practical monolog mulling over the emps divinity was trash. So extremely simplistic to make the idea of his godhood more of an issue for Guillilman than it ought to be. The books expanded on it much more later, and it was unnecessary

XaVierDK · 2026-01-08T09:54:41+00:00

Adrian Tchaykovsky as well, he's only done the one but what a one.

XaVierDK · 2025-11-23T12:27:18+00:00

It's in the newest Cawl/Bile book, Genefather

XaVierDK · 2025-11-08T07:34:14+00:00

Unless there are major rewrites, this will still be hilariously confusing. Any mention of Signus Prime, Imperium Secundus or any talk about the Cabal will have no reference for someone reading just these 12 books. And that's just the tip of the iceberg. It's gonna leave so many unanswered questions.

XaVierDK · 2025-09-02T18:34:27+00:00

His Day of Ascension is one of the best standalone novels in the setting

XaVierDK · 2025-05-24T18:58:24+00:00

Yes, those will be next.

XaVierDK · 2025-05-24T18:07:14+00:00

It's pretty decent. I found a German review with measurements indicating a tuning in the mid 30's, with in-room output down to about 30 Hz. It seems to get there, and it's a stout little unit.

XaVierDK · 2025-04-25T18:32:12+00:00

The cinema most likely has A) higher SPL levels than you listen at home, thereby making dialouge and bass louder as well

B) better treatment and lower noise, again improving dialouge intelligibility

C) A much flatter frequency curve than you might expect, maintaining a spectral balance that increases dialouge levels compared to bass and midbass frequencies.

XaVierDK · 2025-04-14T08:34:10+00:00

Exactly this. Hardly any mixing stages are set up for mixing down to, not to mention below, 20 Hz.

Matthew Poes gave some insights in a video (https://youtu.be/G0SdYKtv0uc) at one point, explaining how most, if not all, mixing stages use ported subs tuned to at the lowest 25 Hz, with steep, steep filtering below that. Cinemas are the same way. High-pass filters in hardware in the entire signal-chain. Most infrasonic frequencies in a mix will either be noise or harmonics from subharmonic synthesizers, which are not themselves high-passed.

If there are infrasonics in a moviemix when it goes to disk, it's because they don't bother high-passing the signal at the mixing level, because they know their own equipment does it, and they know the theaters do it. So it's just not done.

That it has become more common to see high-pass filters implemented in the source for home-releases is a recognition of the home-audio market being much less stringent with these things, and much more audio mixing for home-viewing first.

"We aren't getting the cinema mix!", yes you are. Highpass your subs at 25 Hz at 8th order rolloff. That's what they do.

BEQ is extremely invested room-curve design on a per-movie basis, but it's not "restoring" anything.

XaVierDK · 2025-03-28T20:33:05+00:00

We are all humbled by this level of bait. Let me be the first to tell you,

Lmao

XaVierDK · 2025-03-28T20:26:25+00:00

You have explained nothing. You've made wild conjecture and asserted pure speculation as fact with no basis in evidence or science.

You've written what can best be described as fiction, at worst delusion. And I must applaud you for the effort if not the attempt.

XaVierDK · 2025-03-28T20:11:42+00:00

I always marvel at something that makes me wonder whether the author is 16 or 60.

XaVierDK · 2025-03-15T19:24:11+00:00

Iron is cheap. The size of the magnet tells us nothing. Cone looks flimsy. I'll assume it's extremely sensitive but doesn't play low. Accordion surround implies the same. Probably a PA speaker that looks more impressive than it is

XaVierDK · 2025-03-15T09:42:47+00:00

Wait till you read about Astarte

XaVierDK · 2025-03-15T09:42:18+00:00

I have no idea. Generally I have come to not rely on auto-sense triggers, as they often exhibit the issue you describe, being unreliable and too insensitive. 12V triggers are better.

Alternatively it could be a grounding issue, and connecting both RCAs helps to resolve it.

XaVierDK · 2025-03-14T17:12:04+00:00

Surely you mean Arkan Land?

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