TC3000 Box Design Help

[only126db]

Hey a guy wants me to build him a box for his TC3000 QVC 15" and I was wondering a few things.

First the specs I found for the sub on their site(archive) seem a little odd since it's a quad coil at 1.2ohm each.

1) RES... 4.63 ????
2) No Xmax

Then box size specified as 4.2cu ft with 25sq in x 30" long port ???
That seems very impractical doesnt it???

Any help is greatly appreciated.


TC-3000
58 Fixed QVC 15"
59 Qms 6.10
60 Res Ω 4.63
61 BL (Tm) 27.10
62 Mms (grams) 373.00
63 Cms µN/M 136.00
64 Sd (m^2) 0.0820
65 Lp (mH)
66 Ls (mH)
67 Rp Ω
68
69 Constants
70 c (m/s) 341.00
71 d (kg/m³ 1.20
72 K 0.00E-01
73
74 Calculated
75 Vas (liters) 127.60
76 Fs (Hz) 22.35
77 Qes . 0.330
78 Qts . 0.313
79 n0 0.04E-01
80 SPL (dB) 1watt 84.55 88.19

[Geoff St. Germain]

The TC-3K is largely a sealed box driver. For your queries:

1) RES (series resistance of VCs) = 4 x 1.2 = 4.6 (I guess they actually measured 4.63)
2) Xmax = 30mm on the TC-3K

If I were porting this driver 25 sq in would be the minimum I would consider. A 25 sq in x 30" port on a 4.2 cu ft box gives a tuning frequency of around 22 Hz.

How much power are you going to have available for the driver? I believe it can handle around 2 kW thermally (and with a high pass filter in the box you're considering it will easily take that mechanically). When you start getting up into the 2 kW range with that enclosure with that port the port velocity starts getting up to around 20% of the speed of sound which is going to be easily audible. Of course in order to get the port velocity down to around 10% you need to go with a port that has twice the area and twice the length. I think that is the biggest problem with using a ported enclosure with this driver. It is more suited for either a sealed or passive radiator enclosure.

[only126db]

Geoff St. Germain wrote:

The TC-3K is largely a sealed box driver. For your queries:

1) RES (series resistance of VCs) = 4 x 1.2 = 4.6 (I guess they actually measured 4.63)
2) Xmax = 30mm on the TC-3K

If I were porting this driver 25 sq in would be the minimum I would consider.

not a whole lot of room for a port in a box of the specified size (18x18x22.5) internal with that large a motor is there....

[Geoff St. Germain]

Well, you could alter the dimensions of the box to get one of the sides to be long enough for the port, but I still think it isn't a good idea (see the edit in my post above).

[only126db]

Geoff St. Germain wrote:

Well, you could alter the dimensions of the box to get one of the sides to be long enough for the port, but I still think it isn't a good idea (see the edit in my post above).

What I did was emailed dude and told him my cocerns about port area, length and positioning and explained about going sealed and he agreed so we will see.

As for a material for a home sub box, I was thinking of going 1 1/4" mdf with possibly a veneer or paint...who makes a good easy to apply veneer?

[only126db]

Well for anyone who cares...I built the guy the box...3.66 cu ft sealed made of
1" MDF...came out great...he flaked on me.....now I have a huge box and nothing to go int it....I am now out the $$$ it cost for materials and my labor....

Basically I was doing it for $120....

[Geoff St. Germain]

That's unfortunate. Maybe you can find someone else looking for a box that size for a 15" driver.

[only126db]

Geoff St. Germain wrote:

That's unfortunate. Maybe you can find someone else looking for a box that size for a 15" driver.

Yeah got it up for sale....has to be local cause of size and weight shipping is around $120!!!