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Discussion Starter · #1 ·

I have a pair of Cerwin Vega RE-38 15s that I’m planning on re-coning and using as HT subs.  I know they may not be the best HT sub choice but I already own them and they have some sentimental value. 

 

I’m considering an “end table” build due to the room layout, placement, and Feng Shui (WAF) and would love some feedback on how I should approach the build.  I’ve already modeled the concept in sketch up as shown below (minus the ports).

 

  

 

Here’s where I plan on placing the sub:

 



 

 

I’ve calculated the internal volume of the end table to a have a similar internal volume as the combined existing RE-38 enclosures. 

 

 

        =

 

Should I separate the chambers so the subs technically have their own space or combine them? 

 



Or combine them?

 



 

 

Slot or round port?  Dual or single?  Should I have dual round ports out the bottom or one slot on one side and another slot on the other side? (current RE38 config has dual 14” x 5” ports for each cabinet). I’m guessing I’ll need to decide on what type of port and the volume they have to be before I can consider the bracing. 

 

          

 

or

 

 

 

 

 

 

 

What type of effect does their 180 degree, opposing orientation have? Or doesn’t it matter?  Will the Glass/plexi glass cause any type of interference/issues? Is it too close to the woofer?

 

Any advice is welcome and thanks in advance

 

-Ben
 

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Do you have the T/S parameters for the drivers?
 

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Go with some different drivers. Those are probable midbass drivers. No point in spending all that time and money no nice looking encloses and then using low end drivers.
 

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Quote:
Originally Posted by Manic1!  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub/0_50#post_24521879


Go with some different drivers. Those are probable midbass drivers. No point in spending all that time and money no nice looking encloses and then using low end drivers.
D'oh. I missed the pic with them in their original cabinets. I agree with you they're midbass drivers and not suitable as subs.
 

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Discussion Starter · #5 ·

Thanks for the heads up, guys!  Even though they sound AWESOME and hit hard with 400 watts each, I was kinda of wary of using them because of their thin paper cone.  Oh well, back to the drawing board.  Do you have any suggestions on which subs I should use for the idea/design above?

 

Here are the closest T/S parameters I could find.  Finding the specs for my model is near if not impossible.

 

Fs (Hz) 31.4

Qms 4.08

Qes 0.35

Qts 0.32

Vas (Liter) 3.88

RMS (ohm) 3.1

Mms (kg) 63.7

SPL (dB) 97.2

Bl 9.9

Re (ohm) 2.7
 

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Quote:
Originally Posted by BigBlockPyro  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub#post_24521995


Thanks for the heads up, guys!  Even though they sound AWESOME and hit hard with 400 watts each, I was kinda of wary of using them because of their thin paper cone.  Oh well, back to the drawing board.  Do you have any suggestions on which subs I should use for the idea/design above?


Here are the closest T/S parameters I could find.  Finding the specs for my model is near if not impossible.


Fs (Hz) 31.4


Qms 4.08


Qes 0.35


Qts 0.32


Vas (Liter) 3.88


RMS (ohm) 3.1


Mms (kg) 63.7


SPL (dB) 97.2


Bl 9.9


Re (ohm) 2.7

These subs will cry for their mama big time when they are exposed to HT LFE. The resonant frequency is rather high for what you are looking for. Good for mid-bass module though. Goodluck
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by jpmst3  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub#post_24522251


I am loving the designs. I hope you have can find a suitable driver to get the project started.



What about UM-15s?
 

Thanks!  Your Ebony and Ivory subs are what inspired me to go the end table route!  10-4 on the UM15s.  I've been eyeballing those as an option.

 

I may have to re-visit my approach and opt for a pair of 18's like yours.  I have an 18' x 30' theater/entertainment room and I think I'll need dual sub locations to effectively fill the room evenly.  I'm not sure if a single, dual 15 box will suit my application.  If I need two subs, I don't have room for another end table.  
 

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Quote:
Originally Posted by BigBlockPyro  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub#post_24522335


Thanks!  Your Ebony and Ivory subs are what inspired me to go the end table route!  10-4 on the UM15s.  I've been eyeballing those as an option.


I may have to re-visit my approach and opt for a pair of 18's like yours.  I have an 18' x 30' theater/entertainment room and I think I'll need dual sub locations to effectively fill the room evenly.  I'm not sure if a single, dual 15 box will suit my application.  If I need two subs, I don't have room for another end table.  

Cool! Glad I could inspire.



A sealed 18 simplifies the build for sure, but you sacrifice a lot of output vs. ported. If you still want to keep the size down and go sealed, I would recommend the UXL-18 if you can swing it fiscally.
 

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Discussion Starter · #11 ·

If I can't make the end table work, these are my other options:

 

1). Place two cylindrical subs behind AV screen or two subs inside the stage/shelving unit.  Unfortunately, i feel a lot of effort will be involved to minimize vibrations.

 



 

 

2). Place two cylindrical subs near wall pillar and wet bar.  This should give decent coverage and blend in well.

 



 

Thoughts?  My apologies for the slight deviation from the end table but it is still in consideration.  I just want to toss out all of my possibilities.
 

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Either one may work well. However, it is difficult to tell which of the placements will work best without trying them.


I like the idea of a completely stealthy system like your first options.


If you have existing subs you could test them in the proposed locations.
 

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Discussion Starter · #13 ·

You're right.  Testing would be best but the Cerwin towers are all that I have currently.  Furthermore, the drywall is not up yet so all testing would be futile.  Kinda bench racing right now and gathering opinions from the masses with more experience that me.  

 

I agree, I like the end table better but when I upgrade to a larger "L" couch that sub location will cease to exist and it won't really fit anywhere else. 

 

decision, decisions, decisions 
 

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Quote:
Originally Posted by BigBlockPyro  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub#post_24522924


You're right.  Testing would be best but the Cerwin towers are all that I have currently.  Furthermore, the drywall is not up yet so all testing would be futile.  Kinda bench racing right now and gathering opinions from the masses with more experience that me.  


I agree, I like the end table better but when I upgrade to a larger "L" couch that sub location will cease to exist and it won't really fit anywhere else. 


decision, decisions, decisions 

That's tough, but I would definitely test with the room mostly completed before I let the saw dust fly. You might end up a with a terrible null at your seating position that cannot be corrected without moving the subs...
 

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A few things;

1.) Love the end table design

2.) I used my CV 12"s back in the 80's to build a stealth dual 12 vented woofer perimeter bench seat in basement system.

3.) The cylindrical sidewall sub option looks like a winner for a variety of reasons

4.) How about an ottoman/footstool sub? Can't say I've ever seen it executed, but I've always been intrigued by the idea. With proper EQ and time alignment, seems like a cool idea....

a.) proximity lessens room effects and smoothes FR.

b) proximity lowers distortion by lower operating levels.

c) proximity lowers low frequency contamination outside the space, by lower operating levels.


Just a thought, I guess maybe I've seen such a build, but no real recollection. Certainly other viable alternatives, ... best of luck
 

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Discussion Starter · #16 ·

Quote:
Originally Posted by FOH  /t/1523991/dual-15-cerwin-vega-end-table-ht-sub#post_24523688


A few things;

1.) Love the end table design

2.) I used my CV 12"s back in the 80's to build a stealth dual 12 vented woofer perimeter bench seat in basement system.

3.) The cylindrical sidewall sub option looks like a winner for a variety of reasons

4.) How about an ottoman/footstool sub? Can't say I've ever seen it executed, but I've always been intrigued by the idea. With proper EQ and time alignment, seems like a cool idea....

a.) proximity lessens room effects and smoothes FR.

b) proximity lowers distortion by lower operating levels.

c) proximity lowers low frequency contamination outside the space, by lower operating levels.


Just a thought, I guess maybe I've seen such a build, but no real recollection. Certainly other viable alternatives, ... best of luck
Thanks, for the kudos. That's not a bad idea!  I'm planing installing a truck tailgate under the window in the back of the room (you can the boy out of the country but not the country out of the boy) or a sitting bench.  I could re-purpose the CVs for in the bench or under the tailgate for listening to music.  Better run that idea past the gooder half 
.  ....maybe I'll draft that up and post it later

 

As for the theater end of things, I think a dual DIY sonotube in the corners or behind the screen build will be the best option.

 

I've wrestled with a ottoman build concept and don't like the fact I would have to run a wire to the center of the room.  Although, I bet I can find a flat wire or conceal it with a decent throw rug. 

 

pgwalsh built an awesome ottoman with a 21" Maelstrom and even had it upholstered!  http://www.avsforum.com/t/1340095/maelstrom-21-ottoman-build

 

Plus, it doubles a foot massager!!! 
 
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