135hz Semented Midbass Horn Build

[fdieck]

Putting the LOUD back in loudspeakers. I'm putting my fingers in my ears just looking at the pictures.

[scottvalentin]

Nice Javad! I worry for your hearing but that is a very impressive system!

[JavadS]

My initial goal with this setup was to get it working nicely on a totally passive XO, and if you think about it, this is an incredibly powerful and efficient speaker system that could be run off any receiver or 100 watt amp and hit well over 110db or more. It's a very modular setup and very easy to set up and take down.

Next step was to make it fully active, which I did today. By going active I hoped to time align the horns, play with various XO slopes and flatten the frequency response.

I'm using an OpenDRC DA8 from miniDSP



If you're interested in this unit it's really nice for the $355 price, the only catch is it only has a digital coax input, which I was able to use an optical output on my Mac headphone jack and I used a simple converter to go from optical to coax.

An Adcom GFA-555II runs the 4 PA460, and a 4 channel Adcom GFA-2535 running each pair of horns.


XO slopes I've been playing with but are currently 48db between the high and midbass horns and 24db between the subs and midbasss. I ended up with 3-4 filters on each channel, quite minimal considering the flat response.

I ended up with 1.7ms of delay on the high freq horns, switching it on and off in hard pressed to hear a big difference, but it is slightly noticeable. I've played with time alignment a number of times and I'm led to believe a lot of people make a bigger deal of its importance than is reality. All measurements are nearfield at one meter centered on the Seos24



Basic setup in minidsp



The PEQ filters on the high freq horn



Individual driver response and combined



Comparison to the passive setup, (disclaimer,I could have spent more time on the passive setup to improve the response no doubt), also note a subsonic filter at 30hz



Distortion is very low, less than 1% above 100 at 100db, less than 9% down to 20hz









Overall this configuration does sound better, it's more coherent and the flat freq response sounds better.

Bass measures quite hot nearfield but is only about 3db hot in the listening position, plus I like bass . If I haven't said this already, listening to powerful and dynamic music on these is a totally immersive experience, I find myself pausing the music to catch my breath at times, heart racing.

They easily produce full spectrum response at 115db including bass, the entire house shakes and the walls rattle from the inside.

Despite this the dual opposed configuration is vibration free, the horns never move a nanometer. I haven't stressed or maxed out the subs yet, with only "6mm" xmax these $95 subwoofers astound, with this much cone area bass is accurate and effortless. I really wish you could all come over and hear these =)

Thanks!
Javad

[JavadS]

I wish I lived closer, I would love to hear these. Huge speakers can be a visceral experience. Well done Javad.

Thanks Nick! Boy would that be fun, definitely wish we were closer, and yes these things are a lot of fun =)

[ugly woofer]

I wish I lived closer, I would love to hear these. Huge speakers can be a visceral experience. Well done Javad.

[JavadS]

LOVED reading through this thread! Maybe in my next house, with a BIGGER listening room!

Glad you liked it! =) Javad

[skvinson66]

LOVED reading through this thread! Maybe in my next house, with a BIGGER listening room!

[JavadS]

And a couple more pics

[JavadS]

Here's a video of them playing some Diana Krall, with detail shots as well

[300Z]

I'd say they are equal in quality and performance, I've been very impressed with this 745PB, it happily plays from 500hz up and at 120+dB, clean and clear. Build quality of both is excellent, and the pair measure almost identically to each other.

Thank you for the input. I'll consider them next time I do a project.

[randyohoh]

I think that you'll need to breathe in phase with the music.

[JavadS]

How does Radian compares to the likes of B&C?

I'd say they are equal in quality and performance, I've been very impressed with this 745PB, it happily plays from 500hz up and at 120+dB, clean and clear. Build quality of both is excellent, and the pair measure almost identically to each other.

[300Z]

How does Radian compares to the likes of B&C?

[Wolf]

Radians are awesome!
Wolf

[JavadS]

One last touch on these, I wanted to do some nice speaker wires that always stay with this set. I started with 6 strands of 18g cooper wire.

We were all out of unicorn dust silver wire at 034Motorsport so this had to do.



I twisted the 3 wires together as positives and negatives then twisted those together. The fun part was passing all that through some 1/2" clear shrink tuning, I should have used 3/4" but I wanted it to be tight.

Some ends have banana plugs and others have spade connections.

These are the main wires that go to the sub XO input



I cleared over the bodies to insulate them









Then the wires out of the XO into each sub and up to the midbass XO





And installed







Horn L pad finalized, this configuration allows quick and easy swapping out of resistors to adjust the L pad w/o any soldering.





Thanks!
Javad