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Discussion Starter · #1 · (Edited)
So, I have a unique situation where my "studio" is in my basement, and there's a 24"x24"x10" pass through midway on the wall between my listening space and my "tool room". I was thinking of using that to add a third sub above the centerline of the room a la Gedde's approach. I currently have a pair of PE 315HF4s in separate 2.0cu ft sealed enclosures (generous OC703 stuffing inside). They are perpendicular to each other within my primary 9x7x22' space, which actually has an additional leg to form a T-shaped space.

Right now I'm within 5db with some PEQing between 40-120Hz with a 85.9Hz LP xover. I'd love to tighten that gap just a smidgen, and even out the response throughout the overall listening space.

So, getting to the point. I was thinking of ditching one of the 315s for an 8ohm version, and then add another sub in that centerline space. I was considering the CSS SDX10, and the TC Sounds Epic 10 but they're only offered in 4 Ohm versions. There's the PE 265HF of course, but does anyone have a recommendation over that for under $300.00. This is purely for music, and really nothing that goes below 40Hz. Sealed cab probably.

Edit: I'm not locked into a 10" driver for this BTW. I just mentioned it because of the limited depth I have to play with in that space. I also just measured the space, and my original estimate was off. I have a 14" depth and a 29" width and height to use.
 

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Hi Paul,

Can you draw a picture or take some photo's to clarify what you are trying to do.
The part I don't fully understand is "there's a 24"x24"x10" pass through midway on the wall between my listening space and my "tool room". I was thinking of using that to add a third sub above the centerline of the room a la Gedde's approach."

Cheers,
Bill.
 

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Discussion Starter · #3 ·
Hi Bill. Try to ignore the dust, the entire space is in a state of flux right now. This said, if you look to the left of the photo, there is an inkjet printer in the space (passthrough).

 

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Hi. For an "above centerline 3rd sub" mostly for music, I would lean towards something that's

1) Very inert. In fact I would build dual a opposed sub.
2) Reasonably sensitive + a less powerful amp. No need for a 2500w amp for this kind of goal.
3) low inductance for operation up high. With three subs, I would raise the crossover point closer to the 110hz range without a hint of localization, as this will also improve the linearity of your mains. All three subs don't need to play up this high, but it'll also improve your frequency response up to around 130hz or so give or take. Of course your room will dictate what's really gonna happen.

I recommend the dual opposed route, because you can make it into a tall tower!

For example, 2x Scanspeak Discovery 26W/8534G

Height - 85"
Internal Depth - 10"
Internal width - 14"

Sounds crazy, but this will give optimal damping qtc = .65

It will be a tall tower, so stuff / brace adequately and use 4" OC703 at the top and bottom panels.

F3 = 42hz
F10 = 23hz
Sensitivity = 88 to 91db from 40hz to 100hz and 91db above 100hz.

Max modelled SPL =

[email protected] with 29w
[email protected] with 46w
108.5db @50hz with 80w
112db @ 60hz with 140w
115db @ 80hz with 230w

Not only will it be optimally damped thanks to lots of box space, and capable of quality output, but it will be well balanced thanks to being dual opposed, despite being a good 6-7 ft above the ground. More importantly, because sensitivity is high from the dual 10" 88db drivers, you will be free from dynamic compression that normally plagues many subwoofers. The SDX-10 for example, does give you more output down low thanks to higher x-max, but it will need more amp power to do the same amount of output first, most likely. What d'ya think? Too big? It's possible that there's superior drivers out there, in terms of box size requirements and xmax, but this discovery suggestion was to keep the cost and F3 low, but sensitivity unusually higher.

Total impedance will be around 4 ohms since the discovery is 8 ohm nominal, but I don't see any reason for concern. A good ~100w - 200w plate amp should have no difficulty driving this sub for your goals, and sound quality will excel.
 

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Discussion Starter · #5 ·
That would certainly be one impressive looking cab being 85" tall, but I think it may prove difficult to integrate with the space in the room. I would love to do this in the opposing corner of the room (rear). However, if it ends up causing more trouble in the frequency reponse, then I'm doomed, because I can't just move it around to find a better location.

I have a Crest CA6 that will be powering that *side* of the room. Provides about 500W into 4Ohms. I originally bought it to power the pair of 315HFs that I have. So, the power is available, but I'm always for a more efficient solution.

Definitely something to think about though in the search for satisfying low end!
 

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However, if it ends up causing more trouble in the frequency reponse, then I'm doomed, because I can't just move it around to find a better location.
The nice thing about adding more subs is that it won't ever cause more trouble, even if placement is bad. And since it's above the center line, it definitely addresses the vertical mode differently.

What are your thoughts on a ceiling mounted infinite baffle of some sort?
 

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Discussion Starter · #7 ·
I suppose this is true, to some extent. I believe the 7ft cabinet still introduces a level of complexity that limits flexibility. The IB idea could be interesting - I could mount that directly into the passthrough mentioned earlier. It would have a 18ftx8ft room to dump it's back end into. Ceiling mounted isn't really an option though. Good idea on the IB, I have to look into this!
 

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While AE does make some fine, fine drivers, they are pricy and the lead times can be ages long. It'll likely arrive, but don't be surprised if you have to wait 9 months to over a year for it to finally come. John Janowitz just doesn't have the supply to keep up with demand... the drivers are made-to-order.

I too would love to have some TD15s but it's just not realistic from a money paid --> patience perspective for me.
 

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Discussion Starter · #10 ·
9 months? Ouch. Though it's just in the idea phase, I was somewhat hoping to do something during the winter months. I suppose the IB315 from Fi might work though.
 
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