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Discussion Starter · #1 · (Edited)
Ok I have been back and forth with all design considerations, and have made up my mind on final design. Thanks already to everyone who has gotten me this far....
Especially with some of the most rediculus questions I have had... :)

I'll be going with Dual subs, - Downfiring Ported Box's.... Aprox 9.5 cu ft. 270 liters each

This is going to be a set of over the top beautiful large endtables...
I am going to be using 3/4" hardwood for all vertical exposed surfaces, so I can finish nicely, 3/4 birch Ply for top and 1.5" Ply (doubled up 3/4) for bottom driver mounting. The Top of the box will then be covered with Granite. These suckers will be heavy. Bracing will be multiple window braces routed, 3/4 ply
This will take me some time to build, and I will do my best to document with pics.

My dimensions for the box with be something like this... Check my math....
Outside - 26H x 22W x 34L giving me Inside Dimensions of 24.5H x 21.25W x 33.25DL Im getting an Internal Volume of 10.01
Im not sure but guessed the displacement of my 15" TC-2K driver at between .1 and .15 cu. ft. and my window bracing at roughly 0.2 cu ft + or - a bit here...

Can someone run some numbers for me on the port size and length - as well as displacement for the port....
I have roughly come up with 6" port tuned to 16hz at a length of 27" (is this feasible?)
Correct me if Im wrong here....

Also I need to figure out how high I should be making the legs or spacers above the floor.
Still waiting to find out about what Im powering these with, I do have some time...

Posting pics of drivers next to my soon to be crushed SVS Plus/2 and Plus

 

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If the external measurements are 26H x 22W x 34L, then the internal measurements would be 24.5H x 20.5W x 32.5L, assuming you are building with 3/4 inch material. This will give you an internal volume of 9.4 cubic feet. The displacement of the 15" TC-2K would probably be around .3 or .4 cu. ft. You can check their website to find out for sure. I'm not sure how you are going to brace the cabinet, but allow for at least .5 cu. ft. for bracing, probably more. A 6 ich port 32 inches long displaces .5 cu. ft. After subtractions the net volume is 8. cu. ft. To tune it to 16hz would require a 6 inch flared port to be 32 inches long. Since you want a net volume of 9.5 cu. ft. you need to increase the size of the box to get a net volume you're looking for.
 

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Discussion Starter · #3 ·
[email protected] I was just thinking about this in the shower... and realized I messed up on the calculations....and I will increase my box dimensions.... doh...

External Box will be 29H x 23.5W x 33.5L , which should leave me with internal of 26.75 x 32.0 x 22.0 giving me a internal of 10.9 cu ft.
Subtracting .4 for driver, and .5 for bracing, and .5 for port.... getting me to a 9.5 Cu Ft. after subtractions... yes...?

Maybe give me a rework on the port length... Maybe better to tune to 16.5hz... ?

Thanks Mike for the quick corrections.... How does that look now... ?
 

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Looking better. The internal volume is right. One 6 inch flared port tuned to 16.5 hz would be 24 1/4 inches long. The difference between your external and internal hieght is 2 1/4 inches. What are you using to build this sub?

Edit. Duh. I figured it out. Double bottom plate and single top.:doh:
 

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[email protected] I was just thinking about this in the shower... and realized I messed up on the calculations....and I will increase my box dimensions.... doh...

External Box will be 29H x 23.5W x 33.5L , which should leave me with internal of 26.75 x 32.0 x 22.0 giving me a internal of 10.9 cu ft.
Subtracting .4 for driver, and .5 for bracing, and .5 for port.... getting me to a 9.5 Cu Ft. after subtractions... yes...?

Maybe give me a rework on the port length... Maybe better to tune to 16.5hz... ?

Thanks Mike for the quick corrections.... How does that look now... ?
The Driver won't take up more than .15ft^3.
 

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Discussion Starter · #7 · (Edited)
Then I can drop the size down a touch... I got the .1 to .15 .Ft3 reading on this site http://www.bcae1.com/spboxnew2.htm pretty good and informative on sub design. Gives rough calculations on displacement of different size drivers and was thinking the TC-2K might need a touch more room givin to it...
8 inch .03 ft3
10 inch .05 ft3
12 inch .07 ft3
15 inch .10 ft3

So I think this will work for my final #'s
I Adjusted my box dimensions

Outside .
26.25 H x 24.5W x 35L

Inside
24H x 23W x 33.5L

For a Volume of 10.7 ft^3

Giving away
.14 driver
.5 port
.5 bracing

I end up with a final volume of 9.56 give or take....

How do those #'s check out guys...

How much space do I need between the driver and the floor.... roughly...

Also, taking suggestions/direction/links for the best in Binding posts, and port products.
 

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Discussion Starter · #9 ·
Thanks Willy....
Budget is unlimited on the amp/amps... I know the EP2500 is the most suggested here, and I could get 2 of those, but I have been very interested in aquiring a QSC-PLX3602 to use for both drivers... Can I throw a 2ohm load to the TC-2K's... yes/no.... That amp is 1250 watts @ 4 ohms and 1800 watts @ 2 ohms..

I can get a deal on QSC or Crown or most others... Otherwise I can go with dual EP2500's but my buddy the sound engineer would poo poo me for buying Behringer... :foottap:hehhehehe
 

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Ok I have been back and forth with all design considerations, and have made up my mind on final design. Thanks already to everyone who has gotten me this far....
Especially with some of the most rediculus questions I have had... :)

I'll be going with a Dual Downfiring Ported Box.... Aprox 9.5 cu ft. 270 liters each

This is going to be a set of over the top beautiful large endtables...
I am going to be using 3/4" hardwood for all vertical exposed surfaces, so I can finish nicely, 3/4 birch Ply for top and 1.5" Ply (doubled up 3/4) for bottom driver mounting. The Top of the box will then be covered with Granite. These suckers will be heavy. Bracing will be multiple window braces routed, 3/4 ply
This will take me some time to build, and I will do my best to document with pics.

My dimensions for the box with be something like this... Check my math....
Outside - 26H x 22W x 34L giving me Inside Dimensions of 24.5H x 21.25W x 33.25DL Im getting an Internal Volume of 10.01
Im not sure but guessed the displacement of my 15" TC-2K driver at between .1 and .15 cu. ft. and my window bracing at roughly 0.2 cu ft + or - a bit here...

Can someone run some numbers for me on the port size and length - as well as displacement for the port....
I have roughly come up with 6" port tuned to 16hz at a length of 27" (is this feasible?)
Correct me if Im wrong here....

Also I need to figure out how high I should be making the legs or spacers above the floor.
Still waiting to find out about what Im powering these with, I do have some time...

Posting pics of drivers next to my soon to be crushed SVS Plus/2 and Plus

Warpdrv,

That looks like a neat project. I've built several downfiring subs, including one using Avatar (later Adire) Audio's very first Shiva driver (Shiva #1) purchased by a consumer.
The "Rule of Thumb" that seems to work for downfiring subs is to have the cabinet raised to the point that the "gap" surrounding the bottom is equal to the area of the drivers, note this would be for a solid floor. In your case you may want to raise them a bit more, if they're to be placed on a shag rug. If the subs are located tightly in a corner, then 2x that height will probably be necessary to achieve the "open" area. You've mentioned a 6 inch port, and there are those who would argue that the cabinets should be at least one diameter above the floor. I wouldn't argue with that, as none of this is Rocket Science. I am a little concerned that 27 inches may not be enough for your port, but I haven't checked it, so I could be wrong. Personally, I'd aim to tune the enclosure a bit higher, and even seriously consider a sealed enclosure, as room gain will elevate the lower bass response a fair amount and may result in really Boomy Bass, you might want to look at the F10 of your enclosure in both sealed and ported, as that will tell the tale. If you have a decent amp for your sub you can always EQ it a bit if it seems lacking. I'm sure there are other opinions on this, but this has worked for me.

Best Regards,
TerryO
 

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Thanks Willy....
Budget is unlimited on the amp/amps... I know the EP2500 is the most suggested here, and I could get 2 of those, but I have been very interested in aquiring a QSC-PLX3602 to use for both drivers... Can I throw a 2ohm load to the TC-2K's... yes/no.... That amp is 1250 watts @ 4 ohms and 1800 watts @ 2 ohms..

I can get a deal on QSC or Crown or most others... Otherwise I can go with dual EP2500's but my buddy the sound engineer would poo poo me for buying Behringer... :foottap:hehhehehe
Hmm...what kind of deal can you get on the QSC and crowns? If it is a pretty significant deal, I might would even look into one PLX per sub (wouldn't need one 3602 per, of course). Maybe the PLX2502...

But yeah, one 3602 per would work. The PLX could definitely handle a 2ohm load per channel. I guess you have the DVC TC-2Ks?
 

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Discussion Starter · #13 · (Edited)
Hmm...what kind of deal can you get on the QSC and crowns? If it is a pretty significant deal, I might would even look into one PLX per sub (wouldn't need one 3602 per, of course). Maybe the PLX2502...

But yeah, one 3602 per would work. The PLX could definitely handle a 2ohm load per channel. I guess you have the DVC TC-2Ks?
I can get the amps at wholesale, which equates to a bit better pricing then the internet.... Now... here is where Im not sure of all the different ways to hook up my drivers, and the 2 ohm / 4 ohm scenario... I have single voicecoil 2K's, so maybe that limits me as to the ways I can hook them up...
Thanks for bringing that up Willy... So I can get the right power to these things.

Most electronic supply shops sell binding posts. It depends on what type you want.The only 6 inch port that I'm aware of is from Thriller Audio.
http://www.thrilleraudio.com/detail.aspx?ID=536
Excellent, those ports are what I came up with also, lookin like the best product out there, shy of doin it yourself... appreciate that mike...

and I have had my eye out there for something that will fit the bill for binding posts, and have found stuff at PE... but I have time and will keep shoppin around.. :)
 

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I have single voicecoil 2K's, so maybe that limits me as to the ways I can hook them up...
Thanks for bringing that up Willy... So I can get the right power to these things.
I might go for a bridged PLX-2502 for each TC-2000 then. That should be similar in price to one 3602, right? Yet for you it would provide close to twice the total delivered power.
 

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Discussion Starter · #15 · (Edited)
Sorry if Im uneducated here on what power I should be looking at, 2ohm or 4ohm..

Would it be different if I was using a dual voice coil... Could someone explain what the best way to hook up these subs...? Or provide a link so I can educate myself...

thanks...

P.S. >>> I think I might just end up saving some money here, and grabbing a pair of the Behringer EP2500's instead... I think enough people have been happy enough with them... Unless enough people here bark up and tell me Im doing the wrong thing..
 

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Sorry if Im uneducated here on what power I should be looking at, 2ohm or 4ohm..

Would it be different if I was using a dual voice coil... Could someone explain what the best way to hook up these subs...? Or provide a link so I can educate myself...

thanks...

P.S. >>> I think I might just end up saving some money here, and grabbing a pair of the Behringer EP2500's instead... I think enough people have been happy enough with them... Unless enough people here bark up and tell me Im doing the wrong thing..
Well you have the SVCs, which have a nominal impedance of 4ohms. So either you can bridge an amp per driver, or run a single amp with 4ohms per channel.

The pair of Ep2500s would work ok. I was just suggesting the PLXs since you said you got a discount...they can handle the bridged 4ohm load better than the EP2500.
 

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Discussion Starter · #18 ·
Well you have the SVCs, which have a nominal impedance of 4ohms. So either you can bridge an amp per driver, or run a single amp with 4ohms per channel.
Thanks Willy... That straightens things out in my mind, so I know what Im looking at... The amp is a little while off anyways, so maybe i'll make it a Christmas present to myself, and drop the major coin... The Pair of PLX-2502 looks to be the one if I were go that route..


Warp, I can't wait to see this project! I was actually thinking of doing my next sub with a slate top, so this will be especially interesting for me. I can't remember, did you decide on the locations yet, or are you still debating?
Hey Owen... Ultimately thats the least of my worries right now... I can always move them about to see how they work out later... Today I was out on my Motorcycle to go check out different hardwoods... Kettle Moraine Hardwoods They have some unbelievable looking wood, some extremely expensive, but very pretty... Gotta click on hardwoods and then Scroll down towards the bottom for their listings of imported... Still haven't made up my mind, and I will have to figure out how much I will need...

I got a long road ahead of me, but Im really looking forward to the end result.:T
 

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Thanks Willy... That straightens things out in my mind, so I know what Im looking at... The amp is a little while off anyways, so maybe i'll make it a Christmas present to myself, and drop the major coin... The Pair of PLX-2502 looks to be the one if I were go that route..
I think it'd be worth it, even if it has to be an xmas present to yourself.

Here is a bit of experience from a user had with EP2500s and QSC PLX-2402s. He has was powering Adire Brahma 15"s.

http://www.avsforum.com/avs-vb/showthread.php?p=10286439#post10286439
 

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Today I was out on my Motorcycle to go check out different hardwoods... Kettle Moraine Hardwoods They have some unbelievable looking wood, some extremely expensive, but very pretty...
I wish they had pictures, I'd love to see some of that exotic stuff. I haven't even heard of a few of them. What about your marble top, have you picked out what you want to use, or are you still looking at that too? It will be a lot easier I guess when you have one picked out. You could always browse some high end kitchens online and in magazines to get some good ideas for combinations.
 
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