135Hz Segmented Horn Midbass Build

[pcgab]

Those are looking pretty awesome!

 

[JShadzi]

Those are looking pretty awesome!

Thanks! I appreciate you following along!
Javad

 

[JShadzi]

You know in Goonies at the end when the pirate ship sails out and the cop says "holy Mary...Mother of God!"...?

Well that's sort of how firing these things up for the first time was like!

First some finishing details.

Rat Rod passive XO, low pass around 125hz

Mounting the drivers

Dual opposed configuration

XO installed and split to top section

Aaaand, wala

Did some quick XO tweaking and ended up with this, bass is about 3-5db down and I'm going to try Biamping to even that out before resorting to active.

Initial impressions...WOW, this is the type of speaker that gives you a physiological response to music, I find my heart rate and pulse raising listening to my reference music. Bass is prodigious, like shake your hair and other body parts powerful, SPL is effortless, I hit 50% volume on my Adcom preamp and it sounded like the house was rattling from the inside out, volumes easily 115db+ at 1-meter, and that's on less than 300 watts or so per channel (Adcom GFA-555).

Fun stuff! Will keep playing with them!

Thanks,
Javad

 

[manninen]

if you have all the active channels try to set it up as cardioid bass, that would be fun to hear

 

[JShadzi]

if you have all the active channels try to set it up as cardioid bass, that would be fun to hear

For now I'm staying passive for simplicity sake but yes, that would be fun to try on active, and I have everything to easily do it, will keep you posted!

 

[JShadzi]

I did some more XO tweaking and they are sounding very good, I also was able to bring the bass up to the level of the midbass horn.this is a blended sweep gated to 5ms

Close up on the bass FR, comparison with both ports open and one plugged, actually quite close to the models if you consider room resonances

I demoed them for some friends last night, Tricycle Film and the BB's track 1 almost resulted in a few cardiac arrests with the incredible dynamic range of that album =)

Javad

 

[JShadzi]

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

 

[JShadzi]

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

Seos24, 135HZ Horn and Quad 18" Subwoofers Diana Krall - YouTube

 

[JShadzi]

And a couple more pics

 

[hajj]

Biggest headphone set ever!! 😀
These look seriously nice!
I'm sure you have probably mentioned this before, but what's the driver compliment?

Btw, twisting your cables this way might add some capacitance to the cables

 

[JShadzi]

Biggest headphone set ever!! 😀
These look seriously nice!
I'm sure you have probably mentioned this before, but what's the driver compliment?

Thanks! Details are in the thread but Radian 745PB 1.4", B&C 12PE32 12" and 4 Dayton PA460 18" in each.

Btw, twisting your cables this way might add some capacitance to the cables

I've never considered it would as the twisting is quite minimal, but since you brought it up it piqued my interest...

See below

The longest wire I made...



And the test leads clipped together.



As you can see no capacitance, but I keep hearing about this from people on FB, definitely a myth that needs to be debunked.

Thanks,
Javad

 

[hajj]

Thanks for the info.
As for capacitance, it is something I had personally witnessed on a 4 meter cable run that i had braided and twisted tightly.
But as you say, your twisting is minimal

 

[bappe]

So exactly what is the problem with a bit of capacitance in loudspeaker cables? Twisted leads will never be a problem unless you run old 800 Ohm speakers with current output amps.
Inductance is more of a problem, especially to some tubes amps.

//Anders

 

[hajj]

Since JShadzi is using passive XOs, any additional capacitance should be accounted for, that's the point i was trying to make

 

[manninen]

thats all about wiring, lets talk about how time coherent this is without delay

 

[bappe]

Sorry if I came on a bit hard about the cable issue...
It's just that I have heard this claim many times and it is just wrong. A normal twisted pair may have 100pF/m capacitance, resulting in 1nF for a 10m run of cable. This will never offset a passive XO.
Let's go back to the more interesting horn topic 🙂

//Anders

 

[rhapsodee]

How does the 4x vented 18 keep up with the front loaded horn? Works well?

As midbasses go, how would you rate the dayton Pa465s against the more exotic European 18s? EDIT: Just realised that these are the pa460, not the Pa465s. How much difference between the 2 of them?

Any need for a subwoofer, for the lowest octave?

Incredible build BTW. Is this for yourself or its going to its final home?


Slightly different note, have you ever thought of using the dual 18s per side in a Ripole or w frame dipole? Much more compact, and perhaps tighter bass compared to the vented monopole, due to the differences in room pressurisation?

Cheers!

 

[carpenter]

Super project Javad! Love the pics and enjoy reading about the results of your efforts.

 

[JShadzi]

Super project Javad! Love the pics and enjoy reading about the results of your efforts.

Thanks so glad you're enjoying it, that's why I do it!

 

[JShadzi]

How does the 4x vented 18 keep up with the front loaded horn? Works well?

They keep up easily, see my next post

As midbasses go, how would you rate the dayton Pa465s against the more exotic European 18s? EDIT: Just realised that these are the pa460, not the Pa465s. How much difference between the 2 of them?

I've been VERY impressed with them and was skeptical due to the price, they have half the xmax of the 465 but IME the 465 gets cranky above 6mm or so excursion anyway, so I'm not sure I'd spend the extra. I haven't stressed these 4 out yet.

Any need for a subwoofer, for the lowest octave?

These go flat to 20 in room no problem, but they won't hit peak output with anything under 35hz.

Incredible build BTW. Is this for yourself or its going to its final home?

Thanks! Just to do and learn from, and get to experience, I'd like to list these up for sale soon as I really don't have the space for these long term and I'm hungry to do new projects =)

Slightly different note, have you ever thought of using the dual 18s per side in a Ripole or w frame dipole? Much more compact, and perhaps tighter bass compared to the vented monopole, due to the differences in room pressurisation?
Cheers!

I'd like to play with that subwoofer configuration in the future, but not something I've wanted to take on up till now.

Javad