photoshoot OB MK1, at least they sound good

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Nice!
What is the co point? And how much did you attenuate the CD? Resistors or autoformer?

570Hz, I did try C-core autoformer and resistors. I use now many parallel 2W metal-film resistors they sound the best and cost about nothing, wire wound sound harsh due inductivity.
The damping factor improves with the attenuation compared to direct connection to SE-tube amp.
 
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How did you simulate OB in hornresp? I tried looking at your file in hornresp, but I'm a newbie at hornresp. Can you explain how you program the baffle dimensions in hornresp?

Thanks!
In hornresponse start editing driver data in first left corner. It is self lerning just click the fields.

For OB enter first horn field Sd also the second field in third field choose con(conical horn) with length 1 = (1/30 feet).
When simulated choose spl. Then choose combined response enter distance center front to center back around the baffle that can be 45cm then enter -45.

You can import the txt file in previous post to see how it works.
 
Reponse measured on their position in the livingroom.
 

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Reponse measured on their position in the livingroom.
At the burts decay you can see it has only some resonances above 15kHz the response is very tight over the hole band, this passive OB. The sound is very good depth image of different recordings not only depth it even can come towards the listener, voice are very natural and strings of guitar just sparkles in the air and a fundament of subbas witch sounds more supportive without overruling the reproduction.
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Wow, this looks really nice Helmuth. And I just wonder why this tread isn't much longer.

I've been thinking in the same direction myself lately. An OB-bass combined with a horn in a two way system. But, from what I've read in different fora, it seems difficult to design such a system without utilizing a horn way to big for my living room. Meaning a horn with a recommended XO-frequency at 400Hz or below. And from what I understand, there are challenges with the X-over and EQ network because of baffle-step and roll-off. Since I don't want very big horns in my livingroom, I've kind of left the OB-bass+Horn idea, and started to look into different vented-box + horn combos. Even the Onken-box that you seems to like :) Because then a two-way system with xo @ 800-1000Hz should be possible.

It seems like your pretty happy with your design, so I guess you wouldn't agree upon my findings. So I wonder, could you please share a bit on your design regarding xo and eq? Or is this details revealed in another tread?
 
Wow, this looks really nice Helmuth. And I just wonder why this tread isn't much longer.

I've been thinking in the same direction myself lately. An OB-bass combined with a horn in a two way system. But, from what I've read in different fora, it seems difficult to design such a system without utilizing a horn way to big for my living room. Meaning a horn with a recommended XO-frequency at 400Hz or below. And from what I understand, there are challenges with the X-over and EQ network because of baffle-step and roll-off. Since I don't want very big horns in my livingroom, I've kind of left the OB-bass+Horn idea, and started to look into different vented-box + horn combos. Even the Onken-box that you seems to like :) Because then a two-way system with xo @ 800-1000Hz should be possible.

It seems like your pretty happy with your design, so I guess you wouldn't agree upon my findings. So I wonder, could you please share a bit on your design regarding xo and eq? Or is this details revealed in another tread?

XO 600Hz second order, there is no baffle step problem when using a horn.

The polar behavior of a dipole bas system works out the best way in a living room. That polar behavior let it more predict how the waves reflect. 1-2.5mtr from the back wall gives very nice results. With low group-delay like a closed box and with 15" woofers nice sub-bas.

A monopole bass gives much more problems in a room. And a dipole gives more constant directivity that sounds better balanced. I advise OB for bas response.

Nice 1" horn not expensive with the b&c driver and looks good.With 29cm not to big. XO 800Hz third order
http://www.horns.pl/iwata600wh5.html
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Nice jmlc horn for 1,4" driver beautiful horn. Nice short 14cm with 1,4" driver so no coloration.
http://www.horns.pl/jmlc600.html
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Nice 1,4" driver
http://www.rcf.it/en_US/products/precision-transducers/neodymium-compression-drivers/nd650

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This jmlc horn to cross lower.
http://www.horns.pl/jmlc400.html
An externally hosted image should be here but it was not working when we last tested it.
 
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My goodness, that was fast :) Thanks a lot Helmuth.

XO @ 600Hz second order sounds promising. I've actually been looking at this Iwata 600 horn quite a couple of times, and the JMLCs too. Somehow the Iwata 600 appeals the most to me, because they are shorter on the vertical axis. And maybe I think they look cooler than the large doughnuts :)

I've noticed that your upper bass is partly covered by the horn. Could that be a problem around 500-600Hz?

If Auto-techs info is correct I'll have to go for the larger JLMC-400 to get down to XO-600Hz. On the other hand; if the bass-mid-woofer could deliver up to say 800Hz, I would guess that the smaller horns would be preferable?

When it comes to compression drivers, very few are rated down to 600Hz. Could this be conservative, or more correct for extreme PA use?

BTW: I've been looking at a FaithalPro horn too FaitalPRO - Professional Loudspeakers Made in Italy Crites (the Klipsch guy) recommends them down to 500Hz for one of his Cornscala designs. Which I thought was a bit low, at least when compared to the size and lower limit of LeCleachs horn-designs. On the other side, they are relatively cheap at 40-50€ a piece. Some tells they are traxtric (kugelwelle?), but I don't know.

The RCA driver looks good, and good price to. Thanks a lot.

It seems like you have a lot of knowledge and experience regarding speakerbuilding. So maybe you would recommend some proper 15", and maybe 12" speakers that could work with the Iwata600?

I've been looking at the Hawthoren Augies 15". They are relatively cheap too, and look good in the low end. But I'm not sure how they would work up to XO-600-800HZ. Othervice it seems like Eminence or AE is the thing, according to the lore.

I hope I'm not bothering you too much Helmuth.

Regards
 
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