Ported Blueprint 1503

[Bent]

Thomas, it may be more convenient if I were to purchese all 5 sets, and sell the remaining 4 to you. would you have any objection to this?
I'll provide purchase cost proof and you can have them for the same price plus shipping to you. (you can choose method of shipping if you prefer)
(I don't know if any duties would be applied when shipping South of the 49th though)

Any objections?

[Bent]

Well, I've got all 5 sets on the way, I should have them by the middle of next week.

$65 bucks CDN,each/set. plus taxes and delivery each/set.

[ThomasW]

Oops, I was waiting for an email so missed your post.

That's great news. Let me know the total and I'll get the funds to you.

Canadian Post is fine by me there's no hurry. They're very llight weight so postage should be minimal, do insure them for the full amount.

I really appreciate you doing this .... :T

Thomas

[Bent]

No Problemo - it's the leats I could do since I wouldn't be doing this sub project if you weren't there to offer advice.

[Bent]

My Flares are in, My Flares are in!

I think....
I'll see for sure tomorrow.

[Andrew Pratt]

So you did find a source for them afterall?

[Bent]

Well, I leaned on my local dealer, and got nowhere...
Then I leaned on Brian Reimer's, and got nowhere...

Then I contacted Advance Electronics,
Nick got them in in about 4 days - now it just remains to be seen if they are the real deal, or a knock-off, or worse, just the 4 inch flares.

[Bent]

Ok, so I picked up all five sets today, they arrived in perfect shape, unblemished and wrapped in poly bags.

They are bigger than I could ever imagine...

The outside of the flares are 9-1/2" across, and the bore looks like a chubby child could easilly be born through it...

[ThomasW]

It's funny one can post the dimensions of these flares, but until you actually hold one in your hand, it doesn't hit home how BIG they are :wink:

[Bent]

Here it is!:



and here are all five sets:



Notice how the Ice Age DVD jacket can fit inside one of the flares...
8O

Thomas, I should have a total cost including shipping for you tommorow.

[Bent]

So yesterday afternoon, I went to the local hardwaere store, located some of the green sewer pipe and test fitted the flare on the pipe (which is only available in what looks like 10' lengths, for about 40 bucks) and I noticed that although th pipe will fit inside the aeroports' flange, there is what seems to be about 3/32" of an inch of exces "pipe" that leaves a ridge inside the throat of the flare.

I noticed it seems to exist on the AS-15 here:

Image not available

is this a sonic compromise, or would it be worthwhile to try to ream out the inner pipe?

[ThomasW]

I beveled it slightly with a file. But not enough to make it completely smooth.

For Pete's tube sub we just left it alone, there was no audible difference between the two.

[Bent]

Thomas, thanks for the reply.
I'll leave it be too, or just rely on the glue overflowing to give me a smoother transition.

It's almost time to wreck some wood.

[Andrew Pratt]

Ah there's nothing like the smell of MDF in the morning

[Bent]

'Smells like Victory.

[Bent]

More news!!!!!

My ADA 1200 has arrived.
I only checked it out for a second - 'cause I have to calm down... It's still at my office on the desk.

from what I saw so far, it's built very well, I think I could drive over it with my minivan and it wouldn't be damaged.
I noticed one slight difference between mine and the one on the Adire web photo, mine has no empty power supply cap outlines, it's jammed full of caps - I guess the web photo wasn't a '1200.

[JonMarsh]

So how close are you to getting this beast together? Gota rough estimate? (I know mine are never any good, but I figure most people are better at that than me... )

[Bent]

I'm going to err on the side of caution and say who really knows....

I'm hoping to have something causing "pressure variations" in my media room by the end of January... but we'll see.

I'm getting this one built for me, but I'm going to start buying wood working equipment really soon so I can do it all on my own next time.

[ThomasW]

Ben,

One thing we haven't talked about is the weird little 3/4" black spacer directly behind the front flare. That's designed to move the entire port assembly forward, so there's more 'breathing room' between the rear flare opening and the back wall inside the box. This is added insurance against 'chuffing'

Make sense?

[Bent]

Thomas, yup.

I have accomodated that spacer into the plans as well. I may even have to extend the box an other inch yet, so the guts of the ADA 200 will fit. (unless I make it live inside last driver/baffle cutout.).

[David R.]

Thats good news on the amp bent. Going by the info on the website it looks like adire just uses the same circuit board & chassis for all 3 amps.. Just upgrade the parts for the larger amps.

I assume you have gotten a local carpenter to build the sub for you? hope all turns out.

[Bent]

David, I meant you when I said getting it built for me, LOL.
I have some plans drawn up in MS paint, I'll send them to you in the new year, we can discuss details and cost.

[David R.]

Oh! well thats great news :T i will wait for your email.

hmmmm MDF dust.

[Bent]

Here's a couple pics of the amp,

Plus I had a couple more questions, my calculations say it should be 35-1/4 inches total length not including the front port arch thingy... am I right, or is it not that critical?

Also, about dimensions being critical - I intend to rear mount this big bugger of an amp to the back in the neighborhood of where the rear baffle brace will allow the amp to sit inside the driver cut-out. will the volume that the amp occupies make a significant difference in tuning, or should I add another inch or two to the length of the total box?

[ThomasW]

Yikes look at all those caps !!!

[JonMarsh]

Now, that's the way these things are supposed to be built! :B

~Jon

[Bent]

thanks
But how about those dimension variences?
should I (ok, David) add some extra length to the box to accomodate the volume displaced by the amp, or is it not critical?

[ThomasW]

When I designed the AS -15 I targeted 18Hz tuning point and got 18.56Hz.

So depending on how closely you're copying the design it can't hurt to increase the volume a little....

[David R.]

i think adding a 1/2" to the depth should account for the amp.. Only the transformer and caps are actually inside of the enclosure.

Also Thomas.. on another forum (I believe diyaudio) you posted the internal dimensions for the as-15.. The depth measurement you gave was different then the one on your website. Can you confirm that the enclosure is 35" O/O (not including port spacer).. which would make the internal depth 31 1/4".

[ThomasW]

The website information is correct.

The outside dimensions of the box are 18" wide, 29" tall, 35" deep. All the walls are doubled 3/4" MDF except the front baffle, it is 3 layers of 3/4" MD.

[Bent]

I can't see 1/4 inch difference in length making any noticeable change - there are still too many other variables coming into play here, espeacially in this case where a large internal volume is weighing on the equation - however the way I came up with the 35-1/4" length was.

front re-base = 3/4"
doubled up front baffle = 1.5"
4.5 inches of 1st spacer = 4-1/2"
first baffle = 3/4"
6" of second spacer = 6"
second baffle = 3/4"
6" of third spacer = 6"
third baffle = 3/4"
6" of fourth spacer = 6"
fourth baffle = 3/4"
6" of fifth spacer = 6"
doubled up rear baffle = 1.5"
--------------------------------
Total depth (my calc.) = 35.25" (not incl. arch-shaped front port spacer.)

But what's 1/4" between friends. :W

I imagine keeping the port length the same and gaining 1/4 inch in total length will affect my tuning frequency slightly by lowering it (hopefully approx 0.5 Hz).

Would I test tuning frequency by feeding the driver a constant voltage variable frequency (my variable frequency/voltage/current supply I'll use was more expensive than my first house) and monitoring the impedance curve with an acurate clip-on (calibrated to be as good as a clip-on type meter can get...) ammeter - the lowest indicated current will give the highest measured impedance?
Agreed?

[ThomasW]

Basically there's about a 10% fudge factor with subwoofer cabinets. Error on the 'too big' side and you can't go wrong

[Andrew Pratt]

Hmm I like Fudge :eating:

Don't worry to much about the tiny differences..you'll likely have more error in the other area's most people forget about like the driver hole cut out and holes in the braces etc. Even with those difference you'll likely never notice a difference...try running some "what if's" in Unibox with different port lengts or box volumes...a few liters or inch's here or there won't amount to any significant difference...and this assumes the T/S para's are identical to those of the driver you're using.

[Bent]

excactly - and I am not able to extract the T/S parameters of my driver without building a test box... Catch 22, huh?

I have the claimed T/S parameters, but that doesn't necessarily mean they are written in stone.

[david teltschik]

ADA1200 volume displaced

Bent.....I am using the same ADA1200 amp as you, and yes....I'll admit it....i'm extremely anal about getting the volumes just right. What can I say...it's the engineer in me. I have modeled everything in my system as closely as I can in AutoCAD and it's real easy to get volumes in there. From the back of the face plate back, the ADA1200 displaces ~130 cubic inches. Now keep in mind that the cabinet is large by the volume of the hole cut out in the back wall as well so that might cancel each other out, but it's easy to check on your end.

I hope this helps,
David

[Bent]

David, how do you like the ADA 1200?
I haven't even put power to mine yet...

[david teltschik]

mine is still on order. It should be here in a few weeks.

[Bent]

Two birds with one stone...
I used Irfanview to re-size a 1.3 Meg jpg of the foam seal on the ADA 1200.
this is what I was wondering about w.r.t. sealing the amp plate where the input terminals are.



the photo was shrunk to approx 42k - not to shabby of a photo program.

[Andrew Pratt]

That's not a bad resize at all...far better then MS PhotoShop:T

[ThomasW]

I'm a fan of building a subenclosure to isolate the amp from the vibrations coming from the back of the woofer. If you do that sealing the amp it isn't a big deal.

[Bent]

I can see your reasoning behind that too, Thomas.
I still may opt to keep the '1200 seperate from the sub entirely, then I keep more options open in the future for both of them.

[Andrew Pratt]

Ben if you can seperate the two that's what I'd recomend as well. I've seen leaks from plate amps when used in these high excusion subwoofers...plus you're right it offers greater flexibility

[Bent]

Well Pr@ has built an infinite more number of subs than I have, so I'll take heed of his advice.

[Andrew Pratt]

Perhapse...but I'm sure Thomas's built plenty more then the dozen or so I've built ;x(

[Bent]

Just thought I'd check in with my progress.
as it stands, I have the panels cut to size (thanks David)
I've purchased a router and need to make my DIY circle jig.

I was wondering what happens to box tuning when the box gets a "tad" larger and the port remains the same?