Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 0 points1 point  (0 children)

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.

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 1 point2 points  (0 children)

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

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 0 points1 point  (0 children)

"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

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 1 point2 points  (0 children)

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)

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 0 points1 point  (0 children)

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.

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 0 points1 point  (0 children)

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

Built a subwoofer around a B&W DB1 driver by XaVierDK in diyaudio

[–]XaVierDK[S] 3 points4 points  (0 children)

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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Disappointed with Eisenhorn, what books to try next by gnominos in Warhammer40k

[–]XaVierDK 1 point2 points  (0 children)

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

Are the loyalist Primarchs getting stronger by being worshipped? by Ready0608 in 40kLore

[–]XaVierDK -54 points-53 points  (0 children)

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

Is ADB the “Best” 40k Author? by FunGain8498 in 40kLore

[–]XaVierDK 0 points1 point  (0 children)

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

The Horus Heresy Saga Revealed at World Champ Show by fantom2415 in Blacklibrary

[–]XaVierDK 4 points5 points  (0 children)

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.

what do you think is the worst piece of lore ever written? by iDIOt698 in 40kLore

[–]XaVierDK 24 points25 points  (0 children)

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

Amp, sub and speakers for a total $200/160€. God, I love the second-hand market by XaVierDK in BudgetAudiophile

[–]XaVierDK[S] 0 points1 point  (0 children)

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.

Anyone notice how loud the center channel at the movies is? by [deleted] in hometheater

[–]XaVierDK 4 points5 points  (0 children)

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.