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Discussion Starter · #1 ·
Hey guys - I'd appreciate some input. I think I might be making some things more complicated and expensive than it needs to be. I'm trying to spec a set of subs for my in-progress HT space. I'm still building - no riser or stage or soffits yet - no door either - but I want to get my sub system up and running so that I can integrate some modal control features and maybe placement into the design before I get all my finishes and woodwork bought and installed. I've built with decoupled framing (room-within-a-room) including the ceiling atop my poured concrete foundation, green glue, three layers of wall board (OSB, 5/8Drywall, 5/8Drywall) on standard 16" centers.


My room is medium-small at a volume of about 2000-2300 cubic feet - 12x22x9 or so. I would be glad if I could get to reference down to below 20Hz, but I'm a little flexible on the extension; maybe not so flexible on the output.


I have already built a set of three Cheap Thrills for LCR, and I'll build something else for surrounds. I'll be doing all the setup and calibration myself and would like to keep everything sealed in hopes of improving my success in calibration as well as ultimate extension. I'm not quite set on integration and setup theories for multiple subs, but reference output and minimal seat-to-seat variation are central design goals, so I was thinking a MiniDSP or maybe some kind of BFD and four or more subs. I prefer rack-mounted amplification and have as much as 2 20-Amp circuits I can dedicate to them, in a closet outside the room, so fan noise is not an issue.


What is an issue is space. 6 seats in the room will eat up a lot of real estate, so a small footprint would be best. I can fit a couple boxes behind my screen wall, but I figure at least two will need to be out in the room. And of course, the budget is always an issue. I'm sure I could go buy a handful of orbit shifters or something and make it work, but I live in world with limited funds, like most of the DIYers I'm sure.


My initial plans were to start with 2 CHT SS-18s and add more later, but at this point I'd rather get four integrated properly from the beginning while the budget is still flowing and I haven't gotten used to a particular system - strike once, strike hard, no mercy Sir! ya know? Now I'm hoping that I can get it done with 15s or a mix of 18s hidden and 12s or 15s out in the room. I'm a noob to some of this (really all of it, though I've done a lot of research) so I'm not sure what I can expect from these sorts of designs and what it'll really take to get me 115dB with a respectable amount of THD in a room of this size.


Would you buy two stereo amps and give one channel to each sub? Would you just buy one amp and wire them all together, using only one channel of EQ? What's the reliable way to get to my goals with minimal size and expense? Anyone have a setup they think would fit the bill? Am I silly to think a sealed system is the way to go?


Thanks for your feedback, in advance.


Fred
 

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4 ea RS18 or UM15 should get you what you want, assuming you get them enough power.




This is showing four rs18s each in 4 ft3 with 900 watts each, and four um15s each in 3 ft3 with 800 watts each. Both are over 115db at 20 hz. This doesnt account for any room gain.
 

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Discussion Starter · #3 ·
Thanks Jay! It looks like 15s should be good - though I'm happy to entertain other ideas if someone has a different take on this.


So that'd be 4 of these drivers http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-514 ($760)

Four of these cabinets (or build my own) http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-7082 ($500)

And 2 EP2000 http://www.parts-express.com/pe/showdetl.cfm?partnumber=248-746 ($600)


Would you spring for the EP4000 or something else entirely to get some future-proofing or additional headroom?


Anyone have any other ideas as to how I can get this done reliably for less than $1860 plus finishing and 12 cubic feet?
 

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Quote:
Originally Posted by HopefulFred  /t/1483014/recommendations-for-sealed-reference-system#post_23559382


Thanks Jay! It looks like 15s should be good - though I'm happy to entertain other ideas if someone has a different take on this.


So that'd be 4 of these drivers http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-514 ($760)

Four of these cabinets (or build my own) http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-7082 ($500)

And 2 EP2000 http://www.parts-express.com/pe/showdetl.cfm?partnumber=248-746 ($600)


Would you spring for the EP4000 or something else entirely to get some future-proofing or additional headroom?


Anyone have any other ideas as to how I can get this done reliably for less than $1860 plus finishing and 12 cubic feet?

You can get the cabinet with woofer for $60 less


http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-7097


$1048 for 4 ea.


A pair of EP4000's would give each driver about 650 watts each RMS. That is the minimum power level you should be looking at. That will bring you right to 115db, if the output from all 4 drivers are "mutually coupled" compared to a single driver with 650 watts. The room should help you a good bit down near 20hz.
 

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Discussion Starter · #6 ·
I thought there might be a package option somewhere around there. Thanks for the link.


I was thinking that the driver was 2 ohm - but you're saying I'd be better to drive both VCs at 4 ohms. I wasn't sure if there was a difference between driving one VC or both (apart from the impedance).


Is the sale at $275 a regular thing, or do I just need to keep my eyes open?
 

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The highest output and most efficient use of power would likely be a quad RE-18 IB powered by a pair of CV5000's or clones.


If you don't want holes in your walls, than a pair of dual-opposed HO-18's powered by a pair of EP4k's would be a common alternative, but not as beefy or efficient; but still a solid design.


That said I didn't go with either of those, I went in the direction of quad LMS-18's with clone power and quad PA-18 kick bins sprinkled about.
 

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Quote:
Originally Posted by Jay1  /t/1483014/recommendations-for-sealed-reference-system#post_23559767


It's dual 2 ohm VC's, meaning you can wire the sub for 1 ohm or 4 ohm. I'm not aware of any amps outside of car audio stable at 1 ohm.

I wouldn't recommend it, but the Sunfire amps could handle 1 ohms loads with ease. People use the Carver/Sunfire amps in industrial settings (shaker tables), and you can practically arc weld with them.
 

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instead of two ep2k's, try and get a nu6000DSP, it's just as expensive but it also has all the EQ/XO stuff you'd need (and watts).

Quad 15's at dual 8-ohm.



The only amp that I know of that is dual 1-ohm capable is the Crown iTech. That's how I run some of my subs. But... there goes the budget
 

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Quote:
Originally Posted by HopefulFred  /t/1483014/recommendations-for-sealed-reference-system#post_23560336


You'd prefer two channels of AMP/EQ over four? I was figuring a MiniDSP would be the more complete solution.

Mini DSP would be my choice. The EP's are also known to roll off a lot lower than the Inukes.
 

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My experience with multiples..... My main system was quad 15's upfront and center. Measurement from the LP showed little variation from seat to seat from 10hz to 55hz. The big variations in FR was 55hz to 80hz ( the receivers lowpass ) and the null at the LP.....


I used tuning subs to the side of the listening position, one on each side of my sofa. This procedure allowed me to "fill" in the response where it needed to be to get the FR flat......


So, this is quite different from welti/devantier or Geddes. ALL the subs used to tune must be as capable as the mains. I'm sure my little 240watt plate amps gave up first, but that didnt stop me from realizing they arent really filling in a few Db here and a few Db there. They need to be full range subs ( between 20hz-80hz ). I realized this when i ran them alone and saw through OmniMic that there was almost no signal at all in the null of the seating position generated from the front of the room by my main subs. That null was not a problem from the side position, almost a nearfield position which hasnt been discussed here.


So, there are variations in subwoofer placements, experimenting will uncover them other than welti/devantier and Geddes...... This is exciting news !!!!!!
 

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Quote:
Originally Posted by kgveteran  /t/1483014/recommendations-for-sealed-reference-system#post_23561814


My experience with multiples..... My main system was quad 15's upfront and center. Measurement from the LP showed little variation from seat to seat from 10hz to 55hz. The big variations in FR was 55hz to 80hz ( the receivers lowpass ) and the null at the LP.....


I used tuning subs to the side of the listening position, one on each side of my sofa. This procedure allowed me to "fill" in the response where it needed to be to get the FR flat......


So, this is quite different from welti/devantier or Geddes. ALL the subs used to tune must be as capable as the mains. I'm sure my little 240watt plate amps gave up first, but that didnt stop me from realizing they arent really filling in a few Db here and a few Db there. They need to be full range subs ( between 20hz-80hz ). I realized this when i ran them alone and saw through OmniMic that there was almost no signal at all in the null of the seating position generated from the front of the room by my main subs. That null was not a problem from the side position, almost a nearfield position which hasnt been discussed here.


So, there are variations in subwoofer placements, experimenting will uncover them other than welti/devantier and Geddes...... This is exciting news !!!!!!

So just out of curiosity, would adding some cabinets with something like a pair or trio of JBL 2226's for use in the frequencies between 60hz and 100hz be a big help?


I just purchased some of the 2226's for a guy on Craigslist yesterday and plan on trying this out in my theater room as mid-bass cabinets, but this is going to be a slow process as I have no earthly idea on cabinet size, ported versus sealed, power requirements, and how to properly implement and blend them with my Sierra-1's and UM15's.
 

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Quote:
Originally Posted by Martycool007  /t/1483014/recommendations-for-sealed-reference-system#post_23561901


So just out of curiosity, would adding some cabinets with something like a pair or trio of JBL 2226's for use in the frequencies between 60hz and 100hz be a big help?


I just purchased some of the 2226's for a guy on Craigslist yesterday and plan on trying this out in my theater room as mid-bass cabinets, but this is going to be a slow process as I have no earthly idea on cabinet size, ported versus sealed, power requirements, and how to properly implement and blend them with my Sierra-1's and UM15's.

As long as you measure first to see where the problem areas are and your tuning subs are capable of keeping up with the mains when called to duty, my first subs fell short due to incapable small plate amps
 
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