Hello all.
I am working with a set of Yamaha NS 6390 / 6490 bookshelves. As these speakers are going to be built into a zenith allegro console. (I am just jamming them in the cavity of the console, box and all.) I am not going to spend much time with the speakers until I rebuild the complete cabinetry of the console.
That said I intend to place a 2" x 2" dense Oak cross brace side to side, and a 2" thick piece of paper backed insulation on the inside rear panel.
Any other low budget mods having to do with fill or bracing that I should do while the woofers are out of the cabs ?
Jeremy
I am working with a set of Yamaha NS 6390 / 6490 bookshelves. As these speakers are going to be built into a zenith allegro console. (I am just jamming them in the cavity of the console, box and all.) I am not going to spend much time with the speakers until I rebuild the complete cabinetry of the console.
That said I intend to place a 2" x 2" dense Oak cross brace side to side, and a 2" thick piece of paper backed insulation on the inside rear panel.
Any other low budget mods having to do with fill or bracing that I should do while the woofers are out of the cabs ?
Jeremy
Since they are already coated from the factory, the pot applicableuzzlekoat tweak is not applicable.
Ductseal on the baskets? What ar ethey wired with? What does the midrange canonet look like?
dave
Ductseal on the baskets? What ar ethey wired with? What does the midrange canonet look like?
dave
I'd like to give a sneak peek inside the box just to see what kind of filter is used. Saw them about a year ago while sneaking at offers on ama.. Zzz.. The cheapest 3 way on earth made by a respectable brand such Yamaha must contain a secret....
BTW yes... Braces... I was to say why not isolate them instead of fastening to the console chassis.
Ps. Oh.. Consoles... Why not keeping them with the back removed... It goes together with my first sentence about the crossover...😏
BTW yes... Braces... I was to say why not isolate them instead of fastening to the console chassis.
Ps. Oh.. Consoles... Why not keeping them with the back removed... It goes together with my first sentence about the crossover...😏
Historically, damping is just one of each parallel sides (typically top or end furthest from the vent, one side, back) with the least amount of density required and any cross bracing should include preloading the driver a bit along with the usual driver tweaks posted on the 'FR' forum.
Tying panels together is good -- side-to-side and top-to-bottom both. Corner fillets may help if the original construction is less-than-ideal. Bit more complicated would be a 2-piece brace that is something like a c-channel enclosing a solid beam with a lossy "glue" in between them. The C channel only attached to one wall and the solid beam attached to the other. That means any vibrations in the respective panels become shear displacements in the glue (where they're effectively turned to heat).
Also, placing one of the braces close to the back of the woofer magnet and having a compressed piece of foam between the brace and magnet may reduce basket vibrations.
I think I have all the questions.
The mid-range are indeed sealed back. The crossovers are caps to the mid and the tweet! Thats IT. These are known for harsh highs because of the lack of band pass for the mid. (and lots more bad stuff.) They will be isolated from the console with rubber feet.
I am only looking for mechanical things right now as I want to put this thing back in the corner as a novelty until I re open my outdoor wood shop. Out doors in Northern KY kinda sucks for the most part when trying to do detailed work.
So you guys agree with braces what about fill?
Jeremy
The mid-range are indeed sealed back. The crossovers are caps to the mid and the tweet! Thats IT. These are known for harsh highs because of the lack of band pass for the mid. (and lots more bad stuff.) They will be isolated from the console with rubber feet.
I am only looking for mechanical things right now as I want to put this thing back in the corner as a novelty until I re open my outdoor wood shop. Out doors in Northern KY kinda sucks for the most part when trying to do detailed work.
So you guys agree with braces what about fill?
Jeremy
I fear the mid is closed back... 😏🧑✈️I'm overthinkin' "it
Yes, but is is a box or an “enclosed” mid with its own steel enclosure.
dave
Already posted my damping thoughts and that 'fill' was originally for making a cab (~) aperiodic (~dramatically lower system Qt/sysQ), so would need to be packed to a high density, though don't know/have the math to at least calculate a starting point beyond this link that you might can scale from: https://www.ranger5g.com/forum/attachments/box-builder-fill-er-up-pdf.35156/
This is the bracing I ended up with.
Two 1" x2" oak. They are surprisingly ineffective according to the " bang it with your knuckles" test. I am sure that once the drivers are mounted there will be some improvement compared to the non braced box.
The box volume is .877, that value includes the loss from the woofer and braces. Using the math from this article
https://www.ranger5g.com/forum/attachments/box-builder-fill-er-up-pdf.35156/
I will be using exactly .877 x 1.5 pounds of fill, 1.3155lbs. errr umm I mean I will be using exactly half of the pillow stuffing that I scavenged from a mysteriously missing couch pillow
.
Here are a few pics of this thing. It is going to be forgotten about for a few months as the wood shop is not climate controlled. (under the car port.)
Maybe I'll recap the Empire Grenadiers.
Jeremy
Two 1" x2" oak. They are surprisingly ineffective according to the " bang it with your knuckles" test. I am sure that once the drivers are mounted there will be some improvement compared to the non braced box.
The box volume is .877, that value includes the loss from the woofer and braces. Using the math from this article
https://www.ranger5g.com/forum/attachments/box-builder-fill-er-up-pdf.35156/
I will be using exactly .877 x 1.5 pounds of fill, 1.3155lbs. errr umm I mean I will be using exactly half of the pillow stuffing that I scavenged from a mysteriously missing couch pillow
.
Here are a few pics of this thing. It is going to be forgotten about for a few months as the wood shop is not climate controlled. (under the car port.)
Maybe I'll recap the Empire Grenadiers.
Jeremy
As you are building them in, you could more easily just glued a bit of MDF to each side. Internally, a 1 inch dowel is a fine brace.
If they are sealed, you can measure the Q and see if stuffing would help the bass extension. You can usually squeak a good 5 Hz Fs that way. You do it by MEASURING THE Q, not some WEB calculator.
If they are sealed, you can measure the Q and see if stuffing would help the bass extension. You can usually squeak a good 5 Hz Fs that way. You do it by MEASURING THE Q, not some WEB calculator.
As you are diving into speakers, I suggest doing broader online searches for "measuring loudspeakers" I use my WooferTester now, but in the "old days", it was a signal generator and a meter. Of course, these days, a PC can be the generator, so you only need a multimeter.
I recently went through a pair of the 5” Infinity Primus 2-ways, and started with a brace that was exactly as you have described, but when I went to do my usual addition of filling, the bass dropped off. I returned the skimpy bits of material that came with them and it returned.
I did manage to flatten a bit (3db)of the 100hz peak by placing loosely rolled up a bit of bubble wrap and taping it together, about the size of a beer can. I put it up above the woofer and port so it didn’t interfere with that.
It looks like those speakers you have are sealed, and run the woofer directly without any crossover, and the mids/tweeter each have a 4.3uf/1.5uf cap in series as a filter for protection. In my experience, those will sound ok at moderate volumes if nearly completely stuffed with medium density closed cell foam. This is expensive to purchase, however it is often used as a packing material, an sometimes can be scrounged. Fiberglass insulation would be an option too.
I did manage to flatten a bit (3db)of the 100hz peak by placing loosely rolled up a bit of bubble wrap and taping it together, about the size of a beer can. I put it up above the woofer and port so it didn’t interfere with that.
It looks like those speakers you have are sealed, and run the woofer directly without any crossover, and the mids/tweeter each have a 4.3uf/1.5uf cap in series as a filter for protection. In my experience, those will sound ok at moderate volumes if nearly completely stuffed with medium density closed cell foam. This is expensive to purchase, however it is often used as a packing material, an sometimes can be scrounged. Fiberglass insulation would be an option too.
I have never heard of using closed cell foam as fill in a speaker. Sometimes on the walls. Open cell foam is normal. If sealed, fiberglass ifs fine, but the preferred material is synthetic stuffing. Cheap pillow stuffing works OK, but the stuffing sold through places like Parts Express is better. Cheap. One can stuff a box to get about 1/2 Q out of it. It also helps reduce the reflections back through the cones.
How much stuffing and how dense you only know my measuring the response or Q.
How much stuffing and how dense you only know my measuring the response or Q.