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Get familiar with the reaction system: Introducing the Reaction System
Fourth Summer Project
Re-purposing a pair of PE glass black 0.38 cabinets. These originally houses a DSA175 and RS32 design, said drivers, baffles, and crossovers sold to Ani a few years ago.
This iteration will utilize Viawave 1st gen ribbon and Rival carbon fiber 5" midbass.
Had to spend time tuning tablesaw and router table this AM, and have the first baffle insert piece done. Will route some holes in it and glue the other piece over it, and add some faceting.
Yeah, I'm busy as hell on DIY, but some of these have been in the works in some form or another for years.
I have a signature.
Comments
That combo will sound great, I suspect.
Will it make it to Iowa?
These might make the journey. I'm not sure what I will be bringing, though.
I was quite happy with my build that used the Rival 5" - pretty decent drivers.
Started gluing up baffles today. Will do edge treatment and driver cutouts tomorrow.
1" roundover and some smoothing applied. Up next is extensive body work to not only take care of the voids in the cheap plywood, but to also blend the baffles to the cabinet.
Important to note, I only have one pair of cabinets left to repurpose - some old Realistic T110. Not 100% sure yet, but will likely be an 8" 3-way.
Looking good Johnny. The round over looks asymmetrical at the corners, sanded manually? I bet that took a bit of time... looks right, though.
But my big question is... where are you getting the energy to do all these projects?
TomZ
**ZARBO AUDIO ** https://www.youtube.com/channel/UCEZUyvobRaFQSTl6NdOwgxQ
Energy is from opportunity, asymmetry is because the final sculpting will not occur until a few more stages of blending the baffles to the cabinets happens. The old PE gloss cabinets were, themselves, very asymmetrical. Nice enough finish but whatever process the factory used left one about 3mm taller and quite a bit of material removed resulting in out of square. I first encountered this when I had Roman build a set of baffles to the dimensions provided by PE.
Body work can be messy!
Just a suggestion, I know that the pink stuff is cheap, but I find that the 3M platinum is much easier to work with, and I am all about making my life easier.
There is a progression involved - first coats are always hot and heavy, and the cheap stuff is just a better option at this stage. Most of it gets sanded away.
Follow up coats will utilize a better product.
This is how I learned autobody, anyways.
That's cool, I just have a dislike for the way the pink stuff sands, but I have done the same thing in the past, when I wanted to get started and all that was available was Bondo. I just try to keep better stuff in my stock pile now.
Do you use a "cheese grater" file to smooth out the Bondo before it fully hardens? If not, it saves a lot of time.
Yes, I do, incidentally. Like I said, how I was raised in auto body.
In my dad's years of autobody, he always preferred "Rage Gold", but it's hard to find around here now that he isn't in the business anymore, so I just use the Bondo junk from Walmart. It's not as good as the better stuff, but it does the job.
Yeah, Rage is good stuff. Couple paint stores in town here carry it.
Little bit of driver porn...
Had some tearout on the cheap ply, so still a WIP on the woofer rebate.
Are you going to finish over the gloss black of the cabinet? What is the finishing plan?
Yes, I have already sanded down the entire cabinet with the intention of re-spraying the entire thing. I will be applying high build primer to the baffle and adjacent parts of the cabinet prior to the base/clear color coat.
Successful primer test. Rust-Oleum automotive filler primer and the factory finish are compatible. Simplifies things.
First (very heavy, very sloppy) coat of primer. Lots of work yet to do to blend the cheap plywood baffle to the MDF cabinet.
The block sander tells no lies.
Now to rest for a couple three weeks before color coating.
Looking good👍🏻
Still resting... The shrinkage is telling tales...
Also, today marks 23 years of marriage to Mrs. JR. We celebrated with a weekend out at a Hard Rock Hotel, and tonight I cooked ribeye and fondant potatoes:
So as everything adjusts to the temp and humidity, the seams are starting to ghost? I think the not a khanspires show the seams more now than when it was fresh. Maybe this is why?
The food looks delicious but I'd rather have the truck. What year, 72'?
Yes, 72.
I pour the primer on heavy in last stages because it hyper shrinks.
Next step will be block sanding them one more time, inspect for lines/dimples/etc and repair those with glazing putty prior to applying the color coat.
If you apply the primer in multiple light coats, you can probably sand and paint in a few days - but I pour it on heavy so it takes a long time to cure, the only way to know when it is ready is when you put your beak right on top of it and when you can no longer smell primer, it is done doing what it does.
Thought I would share a few tuning details...
Enclosure volume is 0.37 cubic feet. Tuning will be ~50Hz via a 2" Precision port around 7.5". Modeling done with 0.5 Ohms added series resistance and 20W of power.
Modeled extension:
Modeled excursion:
Modeled SPL in 2Pi space:
Modeled port velocity:
Decent extension for a 5" driver with reasonably cone control below tuning. It doesn't run away until 40Hz so it should be safe to crank it for most genre of music. Here is the excursion at my typical listening levels:
That is derived by changing the input voltage until modeled SPL reaches 91db, with baffle step losses that emulates 85db peaks. This is a listening level I have determined over many years is my personal comfort zone. As can be seen, there is full driver excursion protection to 20Hz. This should offer a satisfying experience with minimal distortion on the bottom end. The midrange quality on Rival drivers is well known, and the Viawave ribbon is about as good as it gets.
Anyways.
So basically, F3/6/10 of 50/43/38Hz.