Home Theater Forum and Systems banner

1 - 18 of 18 Posts

·
Premium Member
Joined
·
26 Posts
Discussion Starter #1
I picked a couple of these up from the b-stock bin to try some new projects.
I have a behringer A500 to play with on this project, and am thinking of picking up a Reckhorn B2.
So far I have modeled out a 1.5ft³ sealed enclosure at 230W.
I put in a 3db peq at 30 and a highpass at 10. The biggest problem with the model is the cone excursion approaches 20mm around 25Hz. Is this a realistic concern or a theoretical modeling issue?
I want a small enclosure and ported is an option, but I couldn't come up with a realistic port tuning(20-30) for a 2ft³ box size without port air velocity jumping off the scale.
Another reason for the small sealed, is that this may end up in a 2.1 channel system. But I would like to see what it is capable of.
I have two of these subs to play with and may build both alignments.
IB is pretty much not an option here.
Are there any other build ideas out there for one of these?
 

·
Premium Member
Joined
·
26 Posts
Discussion Starter #4
Good call on the pr Mike.
I had thought about a set of DIY tower speakers with these anchoring the lows. If I decide to do that, I will use the PRs
1.6ft³ 2-10"pr 500gr
3db peq @20
highpass @17?
The downfall is that the pr cost is approaching what I paid for the driver, and I hadn't planned on spending a lot of cash on this build. Especially right after the first SS18 build. I still have another RL-p18 in the box waiting for a nice LLT.
This will probably end up in a 2.1 Music system.
 

·
Premium Member
Joined
·
19,397 Posts
PR's would definitely get more output from the sub. Yellow is sealed with 230 watts, HPF at 10 hz and 2 db of boost at 20 hz.

The pinks are what the sub can do in 2 cu.ft with a pair of the CSS APR 10's. One model is tuned to 23.3 hz with 6 washers added to each PR. The other is tuned to 20.7 hz with 8 washers. Both models are with a 500 watt amp with a HPF at 20 hz.

ed 11.0.JPG
 

·
Premium Member
Joined
·
26 Posts
Discussion Starter #6
Here is a vented version without pr.
Vent adds 25" of height to the box, at 22HZ. I can reduce the size if I increase the tuning freq, but where is the fun in that?
1.167ft³ @ 22Hz
Vent=2"x12"x110"
Here is the sketchup.
 

Attachments

·
Premium Member
Joined
·
19,397 Posts
That won't work due to the port length being too long. The first port resonance is 61 hz, it needs to be 125 hz minimum if crossing over at 80 hz with a 4 th order crossover. You're also giving up low end output in such a small box. 2 cu.ft with a 1.5" H x 12" W x 46.5" L port would tune the box to 22 hz and place the first port resonance at 145 hz and your port air speed would be 19 m/s with a Hi-Pass filter at 18 hz. You'll also gain 3 db in the 20 - 30 hz range.
 

·
Premium Member
Joined
·
26 Posts
Discussion Starter #8
Wow! Thanks Mike. I completly forgot about checking the port resonance.:doh:
After reading your post with the new port size I tilted my head funny(trying to figure out how that 1.5" was going to work when 2" was high) and decided to check air speed again on my computer and it was hitting 54 with your model. I knew yours would be right so I checked my settings and noticed that was in air velocity was set to ft/s.:doh:
I feel like a big dummy after waisting a ton of time and some of yours playing with models, that I threw out because air speed was off the chart....:R
I will get another sketchup posted later.
Thanks again Mike.
 

·
Premium Member
Joined
·
26 Posts
Discussion Starter #10
Much better...lol
I like this design a lot better and WAF is higher too.:bigsmile:
I am not crazy about the looks of that window brace and will build it better, but for sketchup purpsoses it is much easier to draw.
 

Attachments

·
Premium Member
Joined
·
26 Posts
Discussion Starter #12
I am almost finished (ready to paint) and will post some build pics soon.
Would there be any advantage in stuffing or lining this box?
It is braced better than the original drawings indicate, but the port has no bracing inside of it.
 

·
Premium Member
Joined
·
26 Posts
Discussion Starter #14
I started painting tonight.
Here is the first set of pics. I thought I took more pics during the glue up, but I can't seem to find them.:scratch:
The first few are of the two faces being laminated. I think I was using every clam I could find room for...lol
One of the outer box being glued up, and and one of the vent section being glued. You can see one of the braces being used to keep things square on the vent.
I will try to get a few more before I install the driver.


Oh yeah! Guess what the last pic is(just a little suspense for ya).:D
 

Attachments

·
Premium Member
Joined
·
26 Posts
Discussion Starter #17
As promised here are a few pics. I am really pleased with the textured look and feel of this box. I used 3 coats of Valspar satin black latex enamel and a thick nap roller. After that dried, I applied 6 coats of satin spray lacquer to protect the finish.
It will be a few weeks before I hook it up to the A500 for testing. In the mean time it is hooked up to an old BIC 100 subwoofer amp for break in and it is obviously starving for power. I think this would pair really well with a PE240 plate.
I have noticed a leak and may need to add a foam gasket under the rubber factory one.
I did not line or stuff the box(seems strange not to...lol).

This is a pic of the bracing.


You can see both ends of the port in this pic.


Just a few pics of the driver!






A good representation of wiring the voice coils in series.


Finished sub


Finished sub sitting in living room.:sneeky:
 
1 - 18 of 18 Posts
Top