DIY Folded-Horn Speaker Design from 1955

[BearWolfe]

Here's the one I did... note the amateur text sizes and dimensions
My concern is yours looks different from mine.

I took one wrong dimension for part 7 in the original layout and made it 12 instead of 8 inches. It is fixed now. No wonder I thought it looked a little too off as compared with the original drawing. Additionally, the volume changed to 2479 in^3 and some change that are too insignificant to mention.

 

[BearWolfe]

I've never tried that before. I started mine in horrible LibreCAD, and finished it in AutoCAD, which is definitely way better to use The reason I am sticking with the top and bottom being different, is I already had all the square pieces cut out and started on the angles, before I realized the issues with the original drawing. I had to take a step back, when nothing was fitting but the parts were cut right!

Kubotek offers a "free student version," which is basically the full version with the exception that one cannot do anything commercially with it. And all layouts will have "student" over them when printed.

 

[maxhifi]

Kubotek offers a "free student version," which is basically the full version with the exception that one cannot do anything commercially with it. And all layouts will have "student" over them when printed.

I'm pretty much AutoCAD loyal, with the exception of the times when I have to attempt to use Microstation,

I did like that 3D rendering you did though, it looked nice. I imagine that package makes some decent drawings for you at work.

 

[maxhifi]

I'm really curious now how this speaker is going to sound.. all these wheels spinning to make the plans usable, re-draw it ,learn how to cut a 70 degree angle, etc. But no real talk about the technical side of things. Heck The driver I am using can't even really be considered hi-fi. I have a gut feeling that these are going to join my Popular Electronics Sweet Sixteens in the furnace room, after I play with them for a while.. but am still hoping for the best. If nothing else, I do like a good project.It's 1950s Americana at its best, doing a project like this.

 

[ETLS]

No problem on the miter saw to cut a 70° angle.





This was a scrap board off one of my pallets.

 

[shelly_d]

Imaginative use of the tool. The 70% cut the OP needs is on a piece that is 5" wide. Given the width of the stock (height when put on its side like you have done), and the lack of an easy way to clamp the stock on its edge, I for one, would not try to make that cut. Clearly you comfortable with that saw.

Shelly_D

 

[maxhifi]

No problem on the miter saw to cut a 70° angle.


View attachment 1051325


This was a scrap board off one of my pallets.


View attachment 1051331

That's exactly the angle needed!

I actually had a look at miter saws today, most of them top out at a 45 degree bevel cut.

I've got to wait till Friday to have some time in the shop where I'm not tired (I'm paranoid about using the table saw when I'm not in top shape!)

I went over the plan though, and checked off all the pieces I cut on Sunday... Have only the sharp angles left to do. I'm going to look at Klipsch plans and see if they use weird angles.. I'm curious about that.

 

[ETLS]

The first piece was an auxiliary fence to clamp onto the miter saw's fence @40°. Then I turned the saw to 30°. The smooth cutting of a furniture grade blade along with a gentle touch lowering the blade into the work, it's a piece of cake for me.

 

[maxhifi]

Here it is so far, only the baffle and top to go. It's just mocked up, nothing glued or fastened yet, all the parts are just sitting more or less in place.

 

[maxhifi]

Time to wait for the glue to dry, am getting exited to try these!

 

[maxhifi]

Got the speakers working, playing the first record now.

For now, I loaded them with early 1960s Quam replacement speakers, the closest thing I have to the original Jensens..

This enclosure design is cool, I can't believe how much sound I'm getting from a pair of table radio speakers, it's filling the room with sound, and you can feel bass. This with my 2.5W 2A3 amplifier.

If you put your ear up to the mouth of the horn, there's too much midrange coming out, but an incredible amount of bass.

I want to hear these with better drivers some time, initial results really encouraging.

 

[shelly_d]

Good looking build. I like the old TV underneath the screen for the projector.

 

[BearWolfe]

Your glue dried fast.

Happy listening

 

[maxhifi]

Good looking build. I like the old TV underneath the screen for the projector.

Thank you!

The tv is a 1959 philco predicta, it's fully restored, and we watch it sometimes.

 

[maxhifi]

Your glue dried fast.

Happy listening

Thanks!

 

[maxhifi]

OK so new question. These speaker enclosures make some cheap 1950s/1960s radio speakers sound way better than they have any right to. But they aren't magical, and they're still cheap drivers with no real bass or treble. I played my ADC pink noise test record, and there's very little output at 100Hz, and zero at 56Hz.

So, now that I did the part involving work, now I can do the part involving money. I'm thinking about what driver will work best, ideally it would be a 5" pincushion frame driver, like the originals, but I can go a bit smaller, although not bigger.

I could just order a Fostex, but I can't really tell why I would buy an FE126 versus an FE103, or the cheap Markaudio drivers.. the Dayton, the classic Pioneer 4.5" full range, or maybe even a Bose FR driver? Then there's always all that cool looking straight from China stuff I keep seeing on Aliexpress, and eBay. I'd prefer to avoid whizzer cones, and stick to something paper coned and fairly sensitive. Any suggestions?

 

[vinylkid58]

I think the http://www.frugal-horn.com/FH3.html would be right up your alley. Unfortunately, neither the FE126 or FE103 will give you thundering bass. The Fostex FX120 will give impressive bass, but it's getting a little expensive. The Mark Audio Pluvia 7 & A7.3 are impressive in the FH3, but may not be sensitive enough with a 2A3 SET amp.

jeff

 

[maxhifi]

Not looking for thundering bass, from a single driver, but definitely want some kind of low end.The way I could tell the speakers are bass deficient, is something very simple I've noticed. When you put the stylus down on a record, the sound it makes more or less tells you what the frequency response of a speaker is.

The FX120 appears to be built for bass reflex cabinets? Looks like a nice driver. The 126 is more sensitive than the 103, but they do look pretty similar. I'm not totally sure why someone would choose one or the other. The Mark Audio drivers sure look modern, the CHN-70 looks cool as well. I suspect this old project is probably optimal for none of the above, but now it's built, so I want to fiddle around with it a bit.

I don't mind if I pick a driver which needs slightly more power, there's no reason why I have to use the 2A3 with it. If I can get them sounding really good, I'm going to dress them up a bit and put them upstairs in the living room, the slim profile will look good up there. The 2A3 will remain downstairs with the Klipsch La Scalas

 

[BearWolfe]

I am far from an expert on this, but just looking at parameters perhaps TB W5-1611SAF; 90dB 1w/1m; 60-20000 Hz would work, or do some small modding and use some tweeter with Morel CAW 538; 86dB 2.83v/1m; 35-3500 Hz. The Morel had the lowest frequency response I could find, however, they are not very inexpensive.

 

[Jim Shearer]

My thoughts on the matter--take them w/ a grain (or 2) of salt.

IME, if you want any significant low end, forget the FE126/103 drivers. Never bought any FE126en, but own the FE103en. The 103 has some sort of anomaly in the mids that annoys me.

I used the CHN70 in a build & found it listenable & fun for the cheap price. I have also used the A10.3 in a BIB & really like this driver! But it is IMO rather fragile & wouldn't stand up to any abuse.

Of the drivers you mentioned, I would look at the Pluvia 7. Good price, & should have a good low end.

Cheers, Jim