Tapped Horn For Car

[mwmkravchenko]

Ok here it is in all it's glory:



THE UNHORN SUBWOOFER

You may note that this is a set of measurements. The exterior is 16.5 x 13.25 inches. All the points are there to set up your own should you care to give it a try. My sugested method is simple. Cut out the top and bottom. Mark out the points that are on the plan. Cut some strips of wood at 8 inches width and lay them on the rectangle vertically and set your lengths. Don't measure the points. Actually set them on the bottom and mark them in place. This eliminates measurement error. If you use PL Premium polyurethane adhesive most of the joints can be left square and you let the glue expand into the crack. If you take a look at the construction pics you see the methods I use of taping the joint, using the tape as a hinge and then taping the other side of the joint as a means of clamping. Any questions I'll be happy to help.

Important note.

This is optimised for the driver mentioned at the outset SDX7 from Creative Sound Solutions. Other drivers will not get you the same results. If you feel like playing around with other drivers in something similar the simulation input screen has been posted.

Don't ask me if driver X,Y or Z will work. The answer is a resounding no. I tried many other drivers that I have on hand. This is an as is design.

Henkjan I see that you sell these drivers in Europe. If you plan on using this design please note me as the designer. I put quite a bit of effort into this and I hope whoever makes it will be pleased with the results.

I have but one comment. This puppy woofs good.

OK two comments.

I have to wonder the amount of code typing Mr. McBean did to get the level of accuracy that he has achieved. Not only has the response been close to that simulated, the impedance curves are fairly accurate to. My hats off to you sir.


Mark

[Henkjan]

Ok.. construction time again (once I have time)...

isn't ½" rather thin?

Mark: I intend this for my own car, but if anyone else wants it, I'll give full credit to you of course

[mwmkravchenko]

The time to construct this box.

It took me 2 evenings about 4 1/2 hours. I've been a cabinet maker for quite a while. So thats not a fair evaluation.

My guess is that a newbie may take about 6 to 8 hours. If all the pieces are cut out then you have only to cut the holes for the drivers and fasten them to the plates. It's all depending on your level of experience. Remember that the drivers must be sealed to the holes that they are fastened over. I used closed cell foam stripping. You can use what ever you feel confident in.

The hole diameter is 5 7/8 " and you should round over the sharp edge of the hole that the driver sees. This little driver has quite a bit of excursion capability. I used a 1/2" radius round over bit in a router. But patience with sandpaper or an appropriate rasp ( round file or half round file ) will work to.

It's not really all that difficult to make. I forgot to post the height of the horn pieces on the drawing so I will do that below.





Eva knock yourself out and build this. Then play with it untill you have improved it. Or listen to it and enjoy it. Your choice.

Mark

[mwmkravchenko]

I forgot the wiring plan.

Using the driver mounted in the mouth wire it up + to - on the other driver and - to + on the other driver.

What I did was wire both of them up, run the wires out of the box and set them up as described as a parallel load for the amplifier. Which means I twisted the positive of the driver in the mouth with the negative of the driver in the horn. And the negative of the driver in the mouth with the positive of the driver in the horn.

This gives you a nominall 4 ohm load. It also gives you the greatest efficiency from the horn as both drivers are compressing the air or rarefying the air at the same time.

If you can't figure out which is positive or negative then get ye a 1.5 volt battery and place it quickly across the termials or wires. Positive to positive will push the driver away from the basket.

I'll tart up the box and take some picks later.

Mark

[mwmkravchenko]

Tapped horn for car posted on DIYAUDIO

Put in your vote if your interested.

Mark

[GM]

I get this error message when I click on the link:

Invalid thread specified. If you followed a valid link, please notify the webmaster

GM

[mwmkravchenko]

I posted a thread in a forum that is for comercial companies I guess. So because I have no arrangement with DIYAUDIO at this moment the thread can not function. Because I have no idea if anybody is interested in this design I don't know it it is worth paying for a commercial thread. A classic catch 22.

SO if it makes sense and is permissible by the moderators post your interest here.

Or if I can find out what I have to do to keep the webmeister happy I will do that.

Mark

[GM]

OK, then by 'interest', do you mean WRT providing flat packs and/or assembled in a customer specified level of finish, or.........?

GM

[mwmkravchenko]

Hi Gm

You are always hitting the nail on the head.

Remember it is designed for a small area ( I know that you understand this Greg ) But I haven't tried it out in a room yet. You never know

I'm sure a flat pack would be easy for most people. Flat pack as in: All holes cut and drilled, angled cuts made up and top and bottom traced out so that tab "A" fits into slot "B" type idea. A trained monkey could put that together. Would ship with an updated version of the thread on a CD I'm guessing.

Finished box would make some sense if it were simple. As in Fords any colour as long as it's black type idea. Bed liner is easy to do and economical. This is for cars after all. Or raw and the individual puts on the carpet.

Type of material is going to determine the cost as well. If people are happy with 1/2" MDF then there is quite a savings in material. If you want to go with Baltic Birch ply then obviously there will be a premium in the cost. But from an engineering perspective. Almost any 1/2" panel material, even OSB would work well as there is such small areas that are unsupported it makes precious little difference structurally. The idea of midrange ringing in MDF is moot as this box will never see anything above 100hz mainly.

.

Custom finish is something that would obviously cost more. But it such a small box that it is really easy to do in a fairly short time frame.

Mark

P.S. I'm working on the thread in the vendors Bazarr. I've made a couple of inquiries and am hoping something will happen.

[GM]

Greets!

If a proper loading plug is used at the apex of a room corner, I imagine it would make a pretty decent music 'sub', especially for filling in below the 'BVR' style horns popular on the 'FR' forum, but then I assume I'm 'preaching to the choir' .

GM