# Just ordered my BP 1503, here's the plan! (comments)

Discussion in 'Archived Threads 2001-2004' started by Greg P, Jan 28, 2002.

1. ### Greg P Stunt Coordinator

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I just ordered the 1503 last night, and the loudspeaker cookbook should be here any day.

Box: sealed (mdf)

Qtc estimate: .62-.63

Vb calculations for .62 Qtc: 2466 in^3 (40.392 liters)

Box ext. vol.: 16.5 x 16.5 x 16.5in

Box int. vol.: 15 x 15 x 15in = 3,375in^3

Net Int. vol = (Int. vol.) - (Motor Struct.) - (bracing) - (flange)

Net Int. vol = (3,375) - (415) - (337.5) -(366)

= 2,256 in^3 (around .63)

I think I over compensated for the amount of bracing I will use, so I should be right around .62. I am going to get the bfd, just looking for a cheap one on ebay, and a QSC rmx 850 or 1400. I know I'll learn a little more when I read the loudspeaker cookbook. I just got a couple more questions.

1. Do you think I should make the baffle thicker than 1.5 in MDF

2. What do you guys think?

Thanks!

2. ### Greg P Stunt Coordinator

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3. I have one more question, how much bracing should I have? I have heard you can over brace a sub to the effect that it will sound very dry, I dont want to do this or of course under brace it, how much should I have?

Thanks

3. ### Greg P Stunt Coordinator

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Anyone there??????????????

4. ### Anthony_Gomez Guest

For the BFD, you can get one new for \$129 new + tax, so don't get stiffed.

as for your box, you have .75" thick walls, so they better be very heavily braced. That 1503 can create some very high/low pressures. I would highly suggest a double thick baffle.

I am actually considering putting my 1503's into some 1.5" thick(all around) boxes that are 17" cubed.

Make sure you moderately to heavily stuff the box.

Gor a q=0.62 and 1000watts, you will hit 102db @ 20hz. @ 30hz, you can hit 108db. This does not include room gain/ corner loading.

5. ### Greg P Stunt Coordinator

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Hi Anthony,

My walls will be 1.5 in thick not .75 (16.5 - 15) from unibox I got about 105db @ 20hz and about 111db at 30hz anechoic with 1500 watts. I think I may get the mx 1500.

Are you really pleased with your 1503's, dont you have 2? Im planning on using some vertical gloss black formica all around and round off the edges. It should be an HGS-Killer.

What are some good sites to see pictures of box sub construction (well done), I know Thomas W has the klone site which I will check on, can anyone recomend any others?

6. ### Anthony_Gomez Guest

Greg,
16.5 - 15 = 1.5", but that is split between the parallel walls. With a 16.5" cube with 1.5" walls all around, your internal dimensions are 13.5 x13.5 x 13.5.
1500watts is what I plan on using.
As for my sub, I really like it! If you go to www.htguide.com, Thomas is building a sub that is slighly scaled up from mine in size.
Are you looking for finished products, or inprocess pics?

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