MIGHTY DUB PASS MK2 (FSP-MDP)

35hz to 75hz
as loud as possible

as small as possible

stay on topic...Edited by: Heathrow_B_Line

Well, for those requirements, the existing Bandpass Bertha is about right (andthe X1 too).

One factor when comparing bandpasses with horns is that bandpasses are typically designed to run as singles, and give their best sensitivity, frequency response, group delay etc when run as a single. Bass horns on the other hand tend to suck in singles because the airload discontinuity causes standing waves and a comb filter effect - most plots and specs for horns are for multiples of at least 4 (some people are honester than others about this).

When you stack up horns, you get efficiency boost from coupling, making the result pretty sensitive and more so than a single bandpass. On the other hand, when you stack up bandpasses, the additional inertience component of the airload lowers the tuning, with the result of subjectively slow and disconnected bass as well as a much reduced efficiency gain.

The answer, I think, is to raise the tuning for bandpasses that are to be stacked up, so as to compensate. Going further, a system with an adjustable output port could fit both scenarios.

But before typing all that, I should have asked the question: do you want to run this bin in singles or stacks, and if stacks, how big?

PS
Just for fun, here's a YouTube of a demo I wrote back in 92:

Heathrow_B_Line wrote:

stay on topic...

posh Spice has just qouted that she is camera shy

Some food for though maybe?

www.speakerstore.nl/constructions/18s_kit21/18s_kit21.pdf

mykey wrote:

Heathrow_B_Line wrote:

stay on topic...

posh Spice has just qouted that she is camera shy

mykey wrote: posh Spice has just qouted that she is camera shy

Hi Mykey

Here's some bed-time reading for you: en.wikipedia.org/wiki/The_Unreasonable_E...the_Natural_Sciences

Quote from the article:
Hamming alleges that Einstein was so confident that his relativity theories were correct that the outcomes of observations designed to test them did not much interest him. If the observations were inconsistent with his theories, it would be the observations that were at fault.

Heathrow_B_Line wrote:

35hz to 75hz
as loud as possible

as small as possible

stay on topic...

X1... enjoy

Don't miss it!

3 years so far and no takers yet - that I know of. I still recommend getting in touch with me and working on the port tuning together.

MIGHTY DUB PASS is really a very straightforward SP8, there's just nothing odd/unusual in there to go wrong, so I still have faith in the designs, though I won't submit it to the plans repository until one has been built (or preferably four).

One thing to watch out for with MDP is that it really will do what it says on the tin. Many scoops I suspect are peaking at around 40-60, rolling off above and below. Scoop output in that band is prodigious, giving them their reputation as king of sub. MDP may sound quiet in comparison. But it will effortlessly deliver the same SPL at 30Hz that it does at 60. And with very low distortion, which will play tricks with your ears. So although the intention is to make a scoop substitute, it will probably be a different beast sound wise. Some may like it more, some may like it less.

Personally, I want to hear the Prodigy's "Death of the Prodigy Dancers" through a stack of 24.

However...here's the sim, just taking the port lenght from drawing...because...I don't know how to calculate them from the frequency tune . B&c18tbx100 loaded. BTW if someone knows how to do that please teach me.