5 way system, horns and more. From the beginning to now

[Multiway]

I'm glad I found this place!

Here's a look back on my system's creation and evolution, through (may take a while to get to present day though ).

Please feel free to ask questions, as I can't retro post all the details.
I'll do my best to answer.

In the beginning...

It started out with my 1st hearing AH conical horns with Vitavox S2 drivers, lashed up crossovers, with L-pads and crocclips galore!
This was back in 2010/2011.

We crossed them in above a pair of rect Tannoy GRF speakers. Tannoy tweeter disabled.






I thought, what an interesting sound.

The horns and S2s went home with the owner.

I was gonna get me some of this action though..

I set about a 'little' DIY project.

I had lots of high quality 21mm birch plywood!

Design





Gluing up



I acquired a pair of used JBL2435Be drivers. Good for 1000Hz and up.
They are used in their 3s in JBLs Vertec sound reinforcement array systems.

Driver held in place.
I had know idea how they'd sound - keepers or not?



Pair on the bench.
12 sidestm to round transition handled by carefully feathering 2 pack filler.
Took ages to the critical 1.5" throat perfectly round (essential).



Crossing them in at 1000Hz and using the Tannoy react GRF as mid / midbass / bass



I was pretty pleased with the result.

A friend of mine / ex-work colleague, I_Should_Coco, was the inspiration and guiding light as I learned the horn ropes.

More, much more to follow..

Next up, they multiply

 

[Multiway]

Liked the horn treble sound and wanted more.

I set about creating some mid frequency horns to go from around 400Hz to 1000 or so Hz.

After some research and asking horn friends the JBL2482 phenolic driver looked interesting. It might play down to 300 or so on the right horn in a domestic hifi setting.
Here is one with JBL adapter (I wouldn't use that). Alongside an uber cheapie Eminence tweeter.



Took a couple of weekends, scaled up for the lower cutoff Freq..

Crossover on the GRF suitably lowered.
L-Pad etc.
I was using passive air cored inductors and CrossCap capacitors.



I liked what I heard. Detail and rich lush sound the Tannoy cone could only dream of!

I planned a mid bass horn.
Frequency to be from around 90Hz to 400Hz.

Modelled in Hornresp (David Mcbean's excellent horn modelling tool), using an Eminence Kappa 15A.

Construction ongoing.



Driver chamber









In room lashed up to test.
Lots of X/O parts and L-pads.



First attempt at a stack.
Still using the Tannoy GRFs for sub 100ish Hz.
I would later move the upper mid horns to ease level.



Friends had said "you haven't heard bass until you've heard horn bass".
From what I was hearing at this point and the sound that was unlocked, I started to believe them!

Next up, the Hornresp models.
Even deeper horn bass and more.

 

[Multiway]

At that time I was using a single Tube amp. A 6SN7 / KT88 project / home build.
Here it is.



As just a power amp, all aglow.



Simple 2nd order crossover design.
Remember to reverse polarity of every other driver..

I was pushing the JBL2425bes higher to 1250Hz.
Used Bessel - probably should have used L-R though..



The resulting measurements

Tweeter, playing too low!



Upper mid horn



Mid horn. The horn cutout playing in faster than the 334Hz as calculated..



Mid bass



All 4 drivers from the listening position.



Pretty rough and ready.
+/- 5dB in room at listening spot though.
Lots of refinement possible.

 

[Multiway]

Wanting proper deep bass, I'd read good things about Tapped horns.
I researched and set about making a pair.

The design and modelling



Using Eminence Kappa Pro LFII drivers.



The resulting Freq prediction.
Not too worried about the combing. "They all do that sir", X/O to take care of.



Construction started




Compression ratio for the driver



Driver access hatch



Hatch cover



Driver fitting



1st one complete and carried around.
Over 100kgs..

 

[Multiway]

Measuring the tapped horn subs showed that the X/O was not pulling the frequency down.
Driver impedance rising with frequency?
A Zobel was required.



This brought them under better control



Positioned inside the tapped horn subs.





A better JBL 2405 tweeter was borrowed.
It was a bit too quiet though.



Running the upper mids higher ment that I could cut down the size of those horns.
Here reduced. Meant the stack height could be reduced, room for the tweeter and sound more focused.



The overall room Freq response.
Pretty rough on the bass.
Massive 35Hz room mode to deal with..




I tried some damping foam.
Also raised the mid bass horns to parallel to the floor.



Boxed up the crossover parts.
Observing adjacent inductor placement.



Next up.
Taming the room modes and amps galore

 

[Amir]

good luck

 

[Multiway]

No luck was required..
Measuring, reading up and sound engineering

Next on the agenda was going multi amped.
This would allow me to try removing the L-Pads.

I didn't really know if it was going to work or be better, so I didn't at first invest much on amps. A couple of small cheap T-amps as testers.
I then acquired a larger quite heavy Topping T-60 amp for bass trials.

I also aquired an Icon Audio EL84 set amp to test.



Then another SET amp as I really liked the sound on the compression drivers, and another T-60



The T-60s outperformed the KT88 tube amp on both midbass and tapped horn sub duties!
Higher damping factor giving better cone control.
A 15" driver in a horn is pushing / pulling something like 0.5kgs of air, so it needs some power and damping factor to do it - more on that later..

Removing the volume equalising L-pads was like the proverbial veil being lifted from infront of the horns!
The drivers could really perform with clarity and speed.
No going back!

What about that huge 35Hz room mode?

I acquired a couple of Antimode sub DSP frequency correction units.

These inset between preamp and amp, and using a mic that came with them, played chugging noises, measured the room response and set it up in a couple of minutes.



The results.

Before


.


They instantly transformed the bass to a much truer, accurate and articulate deep bass then I had ever heard from a hifi.

Deep church organ and electronica (things like Yello) and other modern mixed music were transformed.
The kind of bass you can never have from a turntable / vinyl since the cartridges are tuned down below 35Hz, as all they'd pick up would be the TT bearings rumble and possibly the stylus dragging along.

The rats nest of 5way connections.
Neatly tidied
However there was / no hum or noise.



I was by this time using a TVC, Transformer Volume Control.
I modded it with much better transformers and even fitted a stepper motor volume control with remote. That worked nicely.

Around this time I started physically time aligning the system.

Something along these lines in principle.




The tapped horn subs being 2.4m long and around 10ms later then the rest could never be physically aligned.

Using Holmimpulse.
Much later I would get into phase aligning instead.



Next up a 'run what you brung' hifi show

 

[PeterA]

I find these threads very interesting. Thank you for sharing your project and system. Very interesting reading.

 

[Multiway]

Thanks for that

I needed more flexible mounts for the upper horns and tweeter.

Some 1" tubular steel and a MIG welder and I had a strong better looking pair of stands.

Checking the height of a partially made one.



First trial using ratchet straps to hang the horns.
Worked but was not that stable.



Next thing I worked on was the way the horn mouths affected soundwave propagation out of the horns and into the room.
This can be simulated by the Hornresp tool.
It's easy to compare different profiles.
Conical, Exponential, Tractrix, Le Cléac'h etc.
Right angle edges on horn mouths don't make for smooth exit. Lots of turbulence.
Hope for that affect the sound I wondered?

First test was too make the mouths of the conical horns rounded.

I deployed some form pipe insulation and work careful cutting and taping got a smooth result.



This did result in a smoother more integrated sound.

I decided to modify the horn mouths of the upper frequency.

Gluing



Rounded and smoothed with a drum sander





Looked nice too.



Trialling done foam on the tweeters.



I also did the mid horns to match

You can also spy a new tweeter. Enter the Real Lazy Ribbons.
My end game tweeters! More on those later.

 

[heihei]

Incredible dedication and fascinating thread

 

[Multiway]

I modified the stands so they were wider (fitted around the mid bass horns).
Also changed from ratchet straps to threaded bar with crossbars for stability.



Allowed for accurate fine adjustment




Better pic of the Raal Lazy ribbons



Around this time I was demoing the system to some WigWamers .
The Scalford idea came from a few who thought it would be fun.
I can't recall who said it, but words to the effect;
"This rig has to make it to Scalford"

Scalford was an annual show organised by the WigWam hifi fora for owners to bring their gear and run it.
Not commercial hifi, all owners
It was well attended.
Not quite sure they were ready for a system like mine

I thought the tapped horn subs might see more SPL so some bracing could be in order.
They also looked much more purposeful and cooler, I thought

Mods done on the decking.
Trolley acquired for moving in prep for Scalford.
Weight over 100kgs each!



Next up, ...and we're off

 

[Multiway]

The big day arrived.

Pete (I_should_coco) - the main specification inspirer and advisor hired a long wheelbase van, we packed up and off.





The van was pretty full!
My system, Pete's valve testing gear, loads of vinyl, as Guy would bring a very nice Voyd turntable with him.

I'd been told the doors to the place were large so the 90cm wide mid bass horns should fit.

When we arrived we found out we had a large room but it was a modern block and the doors were only 70cm wide!

Trusting no-one, I'd brought a saw along in case. I measured up..
A neat cut along a top section of each big horn and a section was removeble.





Lots of friendly helpers, keen to hear the system ASAP were on hand and everything was in the room in next to no time!

Once in place, the mid bass horn sections were tacked in place.

Getting set up.
Where and what would sound best was a blank canvas.

The room was a good size for a big system

It was very undamped and clappy though.





I set up the tapped horn subs room correction. They measured and worked best firing towards each other.
Just like at home!
Sweet spot was set to be the 2nd or 3rd row of chairs back.
Lots of seating and standing room.

Initial playing it sounded bright.

We played it very loud that evening!
The 5 WPC Icon Audio amps were just tickled to produce prodigious volumes!
Horns are very efficient!

 

[Multiway]

I stuck to CDs while dialling in.

Next day, show day, lots of enthusiasts arrived to see and hear, and the more the better the sound (room damping).
We always had a crowd.




Pete ran a popular valve testing clinic



I played all sorts of music, classical with deep church organ sounded fantastic.
I even connected up an iPhone to play a request or two.

It was the first time people had seen or heard tapped horn subs.
Even in that large space they pressurised the room effortlessly. Providing the same sort of expansive deep bass when called for, that I was used to at home.

Yello and other electronica as well as deep church and cathedral organ provided a good demo of capabilities.



A Viole da gamba piece sounded fantastic, so much timbre and character, in the afternoon it evoked a spontaneous round of applause!

I met so many enthusiasts.

Many wanted a selfie along side the horn stack that was taller than them



What a day!

I managed to get some time off and go around a selection of other rooms.

Then time ran out.
We packed up, drove home & unpacked.

Huge thanks to Pete and everyone who helped. All who visited, lots of positive comments and enthusiasm.

I had the following day off, and set about re-installing it all back at home. Phew!

Had it all up and running by the afternoon.

Next up, Tweeter waveguides, exploration of other horn profiles..

 

[Glide3]

Simply awesome!!! Very inspiring and thanks for the journey!

 

[Multiway]

Thanks Glide3.

After the show I tried a waveguide on the ribbon tweeters.
They raised the efficiency a bit but no tangible impact on their sound.
They also raised the height of the stack so less integrated - I wanted to go the other way..




Frequency plot red without, green with



During this period I got my hands on a pair of Autotech 600Hz Tractrix horns.

With the JBL2435be drivers.
A different mounting system - clamped onto the rear vertical post.



Potential to lower the stack height





Next enter a pair of Tractrix T-200 horns from Autotech.

JBL2482 mounted up.



Slightly different mounting challenge.
Required an angled shaped piece of birch plywood to cup the horn



Waveguides removed. Height reduced.
Can see the tops of the stands just.



Next up; new upper mid drivers and turning horns

 

[Multiway]

I had aquired a secondhand Vitavox S2 compression driver.
Soon after I acquired a another one.

At £3250 each new, these drivers were end game for me.
I didn't pay that of course!
Used extensively in cinema's and theatre's in the 50s and 60s and probably later.
They are also currently in Vitavox's own speakers and the mighty Vox Olympians of course.
I would soon hear the Vitavox sound again!

The interesting and huge info resource website of Romy the cat, where he extrolled the delights of S2s and their usage was inspirational. They require specific handling to get the best out of them - don't cross too low!
Pete also had at least one pair, and other enthusiasts I knew would follow too.

I sent them off to Vitavox in Bristol and had them recharged (alinco magnets), new latest (most desirable) spec diaphragms and set up / tested.

They arrived back performing like new!






I then set about turning a pair of tractrix 550Hz horns for them and learning how to cut large threads for the screw on adapter.



Main flare and throat

 

[Multiway]

Cutting the large 16TPI thread into a composite. Easy to cut as first attempt.

Required an imperial lead screw on the lathe


Screwing on test




Mounted on horn





Frequency plot



Their sound was nothing short of magical!
So fast, so detailed, so dynamic, so right/good sounding.
I'd never heard anything like it!
I still use them to this day on the 3uF cap crossover. It is a match made in heaven.
I've changed the horn size and type since a few times - more on this later, but the S2s remain.

Next up; new mid bass horns

 

[Multiway]

I'd been on Hornresp again looking at a more compact mid bass horn solution.

Exponential / Hyperbolic profiles looked interesting at the 100 - 400Hz range.
A much more compact round hyperbolic horn was possible.

I would use the same Eminence Kappa 15A drivers.





68cm internal diameter instead of the 12 sided conical 1m across!
70cm is a usual small domestic door opening

Hornresp output the profile and the measurement at 1cm intervals, along with the angle.

I set to work

Rings of birch plywood, to be glued up.





I then made a horn rotator to help work sanding using the trusty drum sander.



I brought the 'small horn' in to compare, and fitted a new smaller driver chamber / plumbed in.



Initial tests weren't that promising.
I ended up enlarging the throat and making the driver chamber of less volume.



Once this was done the frequency response was much better.
The stack could be lowered too.
Equalled more integrated sound.

I moved the stack infront of the tapped horn subs. This gave for a wider more interesting soundstage.

 

[Multiway]

Here's the before and after frequency plots.



First I added bags of sand to the driver chamber.



Then I tried expanding foam.
Much lighter but of solid volume.



Cling film and baking parchment to protect the chamber and driver.

Here's everything settled in




Next up I wanted to try a DSP solution with all the drivers time aligned!

I could physically align the drivers apart from the tapped horn subs.
The horn path is 2.4m long. That's about 10ms, way to far to get them near enough, or the rest far away enough.

I was by this time looking at DSP X/O / room mode control systems.

miniDSP was one. Behringer DCX another cheapie.
There was also a thread on DIYaudio about a new DSP X/O DAC 8 channel project that looked very promising (more on that later).

I bought a couple of Behringer DCX2496s.

They only did 3 stereo channels, so 2 were required to conver all 5 channels of mine.

Here they are.



I got one for the left channel and one for the right.

I plugged the measuring mic in and let it auto align the whole lot, including the tapped horn subs.
Chugging, chuffing noises ensued.

Alignment was achieved but the overall sound quality is the DCX2496 was subpar.



The ability to test and shape crossovers was interesting. Trying steeper slopes on the tapped horn subs and removing the Zobel gave positive results.
Couldn't get away from loss of SQ on the upper channels though.

I even tried modifying them with nice coupling caps, this improved things a bit but not enough.

The TVC pre was replaced by a nice Puresound L10 tube Preamp.
This gave a bit more sparkle to the sound.



Next up; more turning and a proper high quality DSP Pre / XO / DAC solution.

 

[Chop]

I love custom horn systems. Mr Multiway, thank you for this fascinating thread. As someone who would love to be able to do this but is completely mechanically cack handed, I am absolutely awestruck by your dedication.

Regards

Wayne