[Ruben1]

I have been an audio enthusiast for several years progressing from SS electronics to tubes and then going from CD’s to LPs as the primary source. For some time now I have been wanting to improve my speakers (Klipsch Epic CF 3) so a year ago I decided to make my own as I am fairly handy. Since I love the sound of horns I decided my speakers would incorporate them somehow. I also wanted something different than the box type speakers which are so common (to include the ones I had) so my research led me to the open baffle design which interested me both from a sonic point of view as well as aesthetics.

I researched the open baffle designs and read as much as I could to make sure I understood all the relevant design parameters which must be accounted for in order to get a good sound (and not just have good looking speakers).
The results are the speakers you see in the pictures. The drivers and crossover are from my Series 1 Klipsch Epic CF 3. The woofers are 10” and the signal is crossed at 1500 Hz.
I am absolutely amazed how incredibly deep the base goes. The highs are crystal clear and blend perfectly well with the woofers.
The whole thing took me 2 weeks to make with the horns taking half the time. Everything is solid red oak except for the baffles which are red oak plywood. The horns weigh 12 pounds each and are made of ¾ inch red oak wood floors which I had in the garage as a left over from when we redid the floors in the house.
After listening for a while I tested the system using the Stereophile test CD3 looking to see how well the lower frequency response is and obtained the following readings using an SPL meter:
Frequency       SPL
200 hz             98 db
160                 98
125                 94
100                 87
80                   85
63                   82
50                   88
40                   85
31.5               75
25                  70
20                  64

In any case I wanted to share this project with everyone here.

[Chops]

That's by far the best incarnation of Klipsch speakers I've seen yet. You could also add in a little EQ boost from 100Hz on down to get a little better bass response.

Also, why the fans on those amps? They're tubes, they're supposed to get hot! 

[scorpion]

Very nice build ! 
I would try to move the speakers a lillte more into the room away from the wall behind at least.
I think that would improve bassresponse a bit without altering balance.

/Erling

[roymail]

Ruben1, could you post a pic or two of the rear of your speakers?

btw, awesome job on them! 

[Ruben1]

Here are some pics of the back:

[6thplanet]

Nice build man! Especially the horn, that turned out nice! I see the wings are on hinges, what have you learned from positioning them?

[Ruben1]

Thank you.

With regard to the side panels I found the speakers to sound best when they are open 13 inches. I am including a picture of what I mean by this to best visualize it.

I am also including a pic from the front so you can see what they look like when set in this position.

On a related but different note I need some help interpreting the readings I took with the Stereophile CD3 test CD and my SPL meter.
I took readings with the panels set at different opening levels and recoded the values but I am not sure how to interpret the data. I have an interest in understanding, from an empirical data analysis point of view, what is taking place so any interpretation is greatly appreciated.

These are some of the db readings per frequency measured:

Frequency     Panels Fully Closed        Panels half open          Panels Full Open   
             
200 Hz                   97                            97                              95
160                       98                            98                              95
125                       92                            94                              94
100                       86                            86                              88
80                         86                            86                              89
63                         81                            82                              83
50                         88                            89                              90
40                         85                            88                              89
31.5                      75                            75                              78
25                         69                            70                              71
20                    64                            64                              71

Thank you.

With regard to the side panels I found the speakers to sound best when they are open 13 inches. I am including a picture of what I mean by this to best visualize it. At 13 inches they are close to full open.

I am also including a pic from the front so you can see what they look like when set in this position.

On a related but different note I need some help interpreting the readings I took with the Stereophile CD3 test CD and my SPL meter.
I took readings with the panels set at different opening levels and recoded the values but I am not sure how to interpret the data. I have an interest in understanding, from an empirical data analysis point of view, what is taking place so any interpretation is greatly appreciated.

These are some of the readings:
Panels fully closed :


The room has the following dimensions: 12 ’ X 12’ X 9’. Not ideal to say the least but it is the only room I have to dedicate to music. I do have wall treatments.

So, what are these readings telling me?

Thank you for any and all interpretations.

Ruben

[Nate Hansen]

First of all, how do you have this setup? Is the SPL meter on a stand, in the exact same position for each set of readings?

Hard to say about the difference at 200 without seeing any higher than that, but maybe some resonance from the wings being closed. Room suckout at 63hz. The fully open 'wide' baffle seems to provide the best low end gain, although to me the closed position would be better........guess not. Somebody mentioned eq.......and I'll go further and suggest active xo/eq. Running the woofers up so high I'd like to put a steep high pass at 35-40 to keep excursion down, to lower the modulation of the mid range.

I'd be interested in some higher measurements to see how your crossover region looks, the fr of the woofers will not be the same as if they were in the box, and your custom horn will change things as well.  I'm not to sure that the stock crossovers will work very well here, you've created a whole new speaker.

Any way you can get a computer in your room? If your spl meter has an rca out you can get some measurements. It'll be a lot easier to see this graphically.  As far as I know they're fairly accurate in the bass region, and should give us a good idea of what's going on in the xo region......

Very cool looking!

[Gothover]

Very nice looking speaker. What mid horn are you using?

Dave

[Ruben1]

Hello everyone and happy holidays. its been a while since I posted here.
I want to share with everyone some upgrades I made to my original open baffle design. As you can see I added a simple "grill" to the woofers for protection and incorporated "horns" to the woofers as well as I love the sound of horn speakers.

The improvements in sound quality were modest but noticeable. The greatest perceived improvement was with imaging and base response. I suspect there now is a narrower sweet spot as far as listening positions in the room but for me this is OK as I have only one listening seat/position in my music room. Overall I am please with the results and will keep this modification. I suspect sensitivity was increased as well but have no objective evidence to be certain.

Once again I kept to using solid red oak in keeping with the rest of the speaker.

The rear flaps are still adjustable and I am having fun playing with them to adjust the base response to my listening room and taste. 

[Poultrygeist]

Great job. I love to see how OB's continue to evolve.

[mick_n_ca]

I know this is an old thread but had to comment on how beautiful the horns look...how are they holding up and would you share more details on design?

Cheers,
Mick