The Boominator - another stab at the ultimate party machine

[Nahaz]

I changed my primary shipping address to my friends and could make the order. So its been solved.

[Saturnus]

Originally Posted by Phaedras

Yea, thats what I thought.. They feel very sturdy and when mounted on the top i'm not gonna be worried at all if someone sits on them..

Btw, they do scratch pretty easy though but all you do is heat them with a hot air gun and the scratch. No matter how deep. Will disappear.

[Phaedras]

Originally Posted by Saturnus

Btw, they do scratch pretty easy though but all you do is heat them with a hot air gun and the scratch. No matter how deep. Will disappear.

Nice, thats an awesome tip! Thanks

[rubennn]

When using WinISD Pro for calculating the boominator I do the following:

1. I create the P. Audio HP-10W and put in the speaker specs according to this tutorial page.
2. I create a new project with the HP-10W and choose 2 drivers in one vented cabinet.
3. WinISD automatically spits out a box volume of 114.47 litres and a tuning of 47.25 hz.
4. I click on "Advanced" below the tuning, and change the Ql for Rear Chamber from 10 to 1 (Am I going to change anything else than this? There is Qa and Qp)
5. There's no automatic calculation after this action in the tuning or volume areas, so I change the tuning to 82 hz and the volume to 24.4 litres.
6. I click the "Vents" tab and see that the went is a tube/round. I change the vent diameter to 6.8 cm as recommended and vent length is then calculated to 1.65 cm with a vent cross area of 36.3 cm2 (I don't understand what "End Correction" is for).
7. I go back to the "Box" tab and the tuning has changed slightly to 81.97 hz and when I look at the frequency model, it looks like this:



So - Is this correctly done? Sorry if this is a stupid question. It just seems like there's a rise of almost 1 dB around 250 hz. Thanks in advance!!!

[Saturnus]

You almost right. You must have plotted in some parameter incorrectly but with the new drivers the tuning is 69.8Hz in the same cabinet with the same port. End result is pretty much identical to the original though so it doesn't matter.

Please note that vent is in m, not cm so you have to plot in 0.0658m which results in 0.036m

Oh, and I too forgot something. Change Ql=7 to Ql=10 because the cabinet is more rigid and tight than a normal cabinet. Doesn't change that much but it should be done.

[Phaedras]

Originally Posted by Saturnus

You almost right. You must have plotted in some parameter incorrectly but with the new drivers the tuning is 69.8Hz in the same cabinet with the same port. End result is pretty much identical to the original though so it doesn't matter.

Please note that vent is in m, not cm so you have to plot in 0.0658m which results in 0.036m

Thats some Xmax you put in; 3m

How come you changed the tuning? I dont recollect you mentioning that before in any post

@Rubenn, if you click the small cm, m, in or similar next to the number you can change the input form.. Its easier than recalculating e.g 34mm to meters..

[Saturnus]

Originally Posted by Phaedras

Thats some Xmax you put in; 3m

How come you changed the tuning? I dont recollect you mentioning that before in any post

I just noticed that with the Xmax. It's not a big deal though.

Actually I didn't recalculate it with the new parameters before now. Turns out it's pretty much identical with the same cabinet and the same port. Only the tuning frequency have move down to 69.8Hz, the peak and drop off frequency have moved up a bit (by 3 Hz each), and Q has increased slightly to 1.22.

[Phaedras]

Originally Posted by Saturnus

I just noticed that with the Xmax. It's not a big deal though.

Actually I didn't recalculate it with the new parameters before now. Turns out it's pretty much identical with the same cabinet and the same port. Only the tuning frequency have move down to 69.8Hz, the peak and drop off frequency have moved up a bit (by 3 Hz each), and Q has increased slightly to 1.22.

Hmm, but with the changed tuning freq wouldn't the port have to be longer? I calculate it to be 7.1cm with a square port of 10,4x4,8cm.. Maybe im wrong?

[Wilcken]

@Saturnus, har sendt dig PM - vil du se på det når du får tid

[ThokN]

Just want to say for those thinking about buying the tweeters from eBay, that I got a mail saying they have sold out and will get some more in a couple of weeks :s