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Open Baffle Epiphany!

With the slot loaded, you have a chamber resonance from the value of the size of that slot. You have to make sure you stay well away from that.

One of the worst sounding woofer sections I've heard was a version of a slot loaded. I've also heard one with a horn for above it, that had a punch that could kick the snot out of 'ya.

I look at all of those variations as a cross between the OB and the box. Where do you want to be between the sonics of those?

EV3
 
Poultrygeist said:
Folks are calling them SLOBS (slot loaded open baffles ) for short.

Dayton_RSS390_T-Pole_2.jpg
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That's a great looking SLOB design.

Poultrygeist said:
Four opposed woofers per side in these SLOBS and the wife approval factor may be less of an issue.

250928d1395608110-nagaoka-s-venner-bmc-200-bb-450sch.png
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Now these are really beautiful looking. They look like they may be ripole. It's my understanding that SLOB and ripole design subwoofers behave similarly.
 
In order to get 'OB Rev2' off the ground in a more expeditious manner, I think I will go with the Tang Band 8” FR W8-1808 (or as close to it as I can get) with two Eminence Alpha-15 woofers per side.

Think I'll go with the simpler config from the Quarter Wave site - http://www.quarter-wave.com/Project10/Project10.html – attached picture is from the website. Just not a full 5' wide with folding wings.

Poultrygeist said:
<snip>
I read the following quote from Jacob George designer of the world class Rethm speakers which use Lowther drivers with bass augmentation:

"Use the wide bander as a wide bander with no restrictions whatsoever. No filters. And just bring in the bass to fill in what the wide bander can not do"
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The Dahlquist DQ-LP1 is active low pass and passive high pass (I believe – will double check to be sure) so we are good to go with running the TB's FR and rolling the highs from the Alpha-15's. Easy to dial in the best low pass frequency on the fly with the DQ-LP1.

What kind of power requirements should I anticipate from the dual Alpha-15's? I was thinking of grabbing a Crown or QSC pro amp to cover the bass.

Alright then.....off to start gathering parts and other such fun things. :)
 

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Poultrygeist said:
A 100 watt plate amp is plenty of power for dual Alphas connected in parallel which gives a 4 ohm load.
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Thank you. Good to know that they don't require a bruiser.

I grabbed a Crown X1000 (~300w/ch @ 4ohms) just in case. It will be good to have as I get further into the OB addiction.

Have you tried driving them with tubes? I was also thinking about driving them with my Quicksilver Monos (~50 watts with EL-34's).
 
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TubeHiFiNut said:
Thank you. Good to know that they don't require a bruiser.

I grabbed a Crown X1000 (~300w/ch @ 4ohms) just in case. It will be good to have as I get further into the OB addiction.

Have you tried driving them with tubes? I was also thinking about driving them with my Quicksilver Monos (~50 watts with EL-34's).
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Since moving to OB's I've only owned low power SET amps. But I'd give the Quicksilvers a try. They're awfully nice to use ( won't say waste ) on woofers.

I'm currently driving my four Alphas in stereo with this single Dayton APA 150.

picture.php
 
You are right - no sense in burning tubes on the subs.

Decided to grab a Crown X1000 for the subs.

I'll use my Quicksilver 300B SET monos on the Tang Bands.

DQ-LP1 for the electronic crossover.

Will get my speakers ordered from Parts Express and see when I can get this project on my woodworking friend's calendar.

I love it when a plan comes together. :smoke:
 
Ok I think they'd be some rebadged bottles. Quite possibly Shuguang. Arr they mesh/punch plated?

Sent from my X10a using Tapatalk 2
 
davidro said:
Ok I think they'd be some rebadged bottles. Quite possibly Shuguang. Arr they mesh/punch plated?

Sent from my X10a using Tapatalk 2
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Oh sure.....now I have to step over amps and speakers to get back where these are right now. ;) :D

This time, I'll take pictures for you. :)
 
Although I'm seeing more OB build all the time, it still surprises me that more people aren't taking the plunge. OB's inherently have a very pleasing and natural sound free of cabinet resonances, and is a much simpler build for a beginning DIYer.

In my recent build and first attempt at speaker building, the complexity would have been far greater had it not been OB. I also believe the results would not be as good as they are.

Edit: But then again, it also surprises me that more people don't augment their bass either.
 
I am waiting to build some OBs as soon as I find a complete plan that documents everything. I want to go passive 2-way though. I read the plans for a nice looking build by MJK, but the Fostex driver used is no longer available.
 
you can use a variety of drivers in that MJK project 9 design. i'm using 8" audio nirvanas and used visaton b200s before that.
 
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