4 way system - Synergy horns + tapped horns

Having read various good things about Synergy horns over the years and researched a fair bit, I decided to take the plunge.
A home built pair of horns that could also be used outside, but under cover at a wedding was the motivation.
I'd read the Danley patents, lots of Synergy build info threads etc.

I decided to go with the SH-50 geometry and dimensions.
There's lots of info on them.

i wanted to reuse a pair of Eminence Kappa 12As that are in my existing 5 way system mid bass horns.

They have T&S params not far off the drivers Danley uses.

For indoor use and setting up I would use the same DSP unit I already have.
Outside I plan to use a Behringer DCX2496 and 3 PA amps I already have.

Existing tapped horns (also a Danley design) world provide the deep stuff.

I made my plans and sizings, angles etc and started a test build from cheap chipboard I had in store.

Basic structure





These would initially use per horn;

1x HF BMS 4550 1" compression driver (same as Danley SH50s)
2 x MF Celestion 5" closed back (the Misco 5" drivers Danley uses are not easy to come by)
1 X LF Eminence Kappa 12A

Hence the limited taps and ports.
A full complement would be 4 X MF and 2 X LF.
Doubling the drivers adds around 6dB efficiency - not necessary for in room.
Outside yes!



Trial fit of the drivers



For this one I would only use a half back cover. I figured, 1 LF driver, half the reflex box volume.

I was careful to ensure a smooth conical to round throat transition.

Decided the flares needed more rounding / smoothing..



I had some bitumen deadening mat left over. Applied that. Made it heavier and dead!
Dished the MF tap holes.



First one ready for a test run..



Propped up in place.
One Synergy horn up against 3 separate front loaded horns and a Raal Lazy Ribbon tweeter!

More to follow.

Having got the SH50 alike in place and wired up, I did some prelim sweeps to see what was what.

I've heard sweep tones so much over the years that I can hear (even with ear defenders on), a smooth sweep Vs a bumpy one

Out of the box testing the Synergy as a 3 way, with only a 1st order hi- pass on the HF and no other XOs anywhere, things looked pretty good!

The unique combination of Danley's design - horn cutoffs, acoustic XOs and 1/4 wavelength magic coming together for a pretty smooth FR out of the box.

The blue plot is with all drivers in phase and a bit time aligned.



The red plot was with MF out of phase, just to see..
I could have fixed that by changing the time alignment but found all drivers in phase to be better.

Each driver looked like this

HF with/without a bit of EQ



MF raw and with some EQ to kill off unwanted higher frequencies



LF with and without EQ. Lots of extra energy high up..



I first levelled off the raw setup, 1st plot with some PEQs where needed to level it.

Had a listen.

Having one side 5 way horn system and one side Synergy 3 way + sub was interesting.

Listening in mono, one side is difficult for me.
Listening to both sides in hybrid was odd.. What was what, which was giving that sound?

Then I used more PEQs to shape the natural design created slopes and knit then together. Spent lots of time on time delaying to get the phase flatter.



This is as close as I got to a flat phase!

Smoother sound, but still difficult to discern what was what.. only one side.

I then tried usual 4th order XOs everywhere and hardly needed any PEQ.

The phase was doing its usual steep XO, off the chart wrapping around thing.

Listening to the two at the flick of a switch gave me an insight into the Danley phase coherent thing, I'd only thus read about.

The measuring and what I heard gave me enough confidence and energy to build a second horn.

More to follow ...

On with the 2nd horn

I decided to try a couple of things differently.



-No bitumen sound deadening mat.
-Full volume rear reflex cover

Otherwise construction, taps and ports etc was the same.

These are quite large in normal hifi context but nothing like the midbass horns I've had in the past, 3 in 1 is compact.
They are just 0.6m deep. Compare that with the Exponential midbass horns that are 1.3m!

Lifted into place



Danley has written about aligning the angle of the cabinet rear to the side walls to reduce room reflections.
This is quite toed in but does work very nicely.

The pair. Rather like looking into the abyss in relaxed low light conditions.



Note the now redundant tractrix T-200 horns and drivers on the left.
Much less room occupied!
I sit farther away or can bring them forward if I want.

More on the sound soon.

Having got the pair i could really evaluate the overall sound compared to my reference 5 way horn system.

Immediate takeaways
- the HF was clean and precise but for me lacked tone or character.
Everything was there, but that certain character and quality the Vitavox S2s have in spades was missing.

- building the second horn with a full rear enclosure volume was wrong.
1 X 12" LF needs half the reflex volume.

Here's a right (half vol) Vs left full vol LF plot. What a difference!



Whooa! Where's my almost down to 50Hz gone

I took the thing apart and modified the baffles and also covered the horn and reflex enclosure internally with bitumen sound deadening material.
At the volumes I play at indoors I could not hear resonances, but outside at higher volumes it seemed prudent to apply.

Here's the plot with it fixed



- the bass quality was actually very good.
A seamless blend of horn bass and reflex bass was giving better punch and kick to the bass than my long fully front loaded horns!
Character of the bass was nice. No tap or port sounds.

- the mid range was quite restrained. I'm comparing 2 X 5" paper cones to a large format alinico magnet JBL2482, 4" diaphragms and 2" throat on a large tractrix horn!
I also concluded the drivers needed to break in a bit.
This would take a while at home volume levels and normal hours of use.

I set about trying to improve the BMS 4550 1" compression driver sound.

I use a 5W EL84 SET amp for the HF.
I took the tube damper rings off both the EL84s and the 12AX7 tubes.
This gave a more rounded and interesting, less clinical sound.
I removed the XO in DSP and put a 1st order Cap in its place.
I also tried a resistor before the cap to soften things (well known trick).
This all helped but the house sound of the BMS was what it was!

Meanwhile over a couple of weeks the mid range drivers did break in and the sound became less restrained.
I even had to revise the EQ on them a bit.

I played around with the flat phase set up and found it vastly more to my liking verses using normal 2nd / 3rd / 4th order crossovers and phase alignment over the XO area.

I was able to get a sound I was confident would be good outside for small / medium parties.
Not there yet with hifi sound..

After extended listening and much EQing I was having a really hard time with the BMS 4550.

As a test to check what I was missing from my old system, I made a Vitavox S2 on Le Cléac'h / SH50 hybrid + subs.



Of course I lost the Synergy horn phase coherence thing!
But I gained the HF sound I love!

If high frequencies were missing if have to solve that somehow.

I asked around if a deeper diaphragm to driver exit compression driver could work on a synergy horn.
I'd seen a picture of a TAD2001 on the end of a build.

The general consensus was it would work fine.

That was it. I had to try it.



S2 removed from the Le Cléac'h horn I made some 3 to 4 years ago.



Luckily I'd turned 2 sets of Vitavox S2 / S3 adapters years ago



The larger S2 Vs BMS4550.



1" Vs 1.5"
.

Trial fit.

I cut off what I could and then carefully enlarged the throat of the horn, creating a 1.5" mating face and smooth wave guide.



The S2 hangs out.
Sealed in with foam. I will turn a nice cover ring sometime.




Back in place.
A quick measure and set up.
The S2s integrated easily with little EQ.
I carried on using the 3uF cap XO.

The difference was impressive!
Gone were the thinner rather clinical tones of before.
I had the Vitavox magic back!
And the Synergy benefits too.

I will also turn some adapters I can fit to the horns to be able to fit the BMS 4550s back on for outdoors / venue use!
A simple screw in taper that fits the Vitavox adapter ring - good solution.

More on sound refinements and tuning the DSP setup next..

After the initial setups, I spent a lot of time measuring, improving, tweaking, refining.

Many setups, I lost my way and found I was mysteriously setting the LF driver ahead in time to get the flat phase, compared to the MF and the HF.
That isn't right!
Physical measurements put the LF less than 1ms away, definitely more delay as its nearer.

I went back to an older set up where the LF polarity was reversed.

This instantly maintained the flatish phase and required time delay settings that made sense.

More recently
I've been reading and re-reading lots of threads regarding folks experiences of the sound these horns make, indoors verses outdoors, room treatments, positioning etc etc. Also comparing the SH-50 and the SM-60(F).

My takeaways

-Some didn't like the BMS 4550 sound (me included).

- the odd report of slightly muddy waters in the upper bass (less so when used outside).

- The SM60F sound was not necessarily an improvement over the SH50 (horses for courses?). Some reports that the coaxial sound was a bit ragged.

These are interesting comments and the ensuing discussions very helpful in my deciding what to do next - if anything

So, where am I now?

I've addressed the BMS4550 sound - replaced it with a compression driver (Vitavox S2), I really like the sound of.

Personally I've not found the upper bass an issue at all - with EQ to stop the LF playing over the MF..

Easy to do with DSP, very much harder to address in analogue and still preserve the phase purity.

Without any EQ its pretty good still, but there is some colouration / that muddiness that was reported.

Now I've got the setup just where I like it, the sound is very, very good indeed.

There is still the question of what amp to use on the MF cones.

Presently I've not the slightest inclination of going back to the Le Cléac'h HF, Tractrix MF and Exponential LF'ish setup.

The tests of left channel old system vs right channel SH50 and the hybrid with Le Cléac'h HF with SH50 MF and LF verses the full SH50 both (with the same Comp Driver) gave me all the info about the relative strengths and weaknesses of the setups.

Perhaps it has also taken some time to make new neural pathways, for me to fully appreciate the Synergy sound?

A/B comparisons are all well and good, but we live with a system and its 'house sound' across many tracks and genres, over days, weeks, months, good recordings, bad recordings, new material, others music tastes etc.

The DIY SH50, admittedly somewhat tweaked, is certainly fulfilling my expectations and requirements.

I'm even thinking of making some grille covers, funky colour or something like bronze perhaps.

I played my system for a musical friend today. Plays guitar much better than I

He's into the heavier side of things, think artists Tool and the like.
He was quite happy that I opened with ACDC Tunderstruck
Then played some Tool tracks for him.

He said ordinary 'hifi' falls a bit short of shock and awe

He was amazed at the Sound PRESSURE Level effortlessly achieved by the SH50s!

I explained the background of them, and how pared down mine are compared to full driver compliment

Then onto John Butler Trio and Nils Lofgren for some lively acoustic guitar.

Could not get over the level of detail and speed.
Noted the soundstage too.
He's using headphones and ear buds mostly.

Played a couple of room shakers too, just to really shock and awe.
These typically have 25 to 30Hz bass, no problem rattling your fillings with fidelity.
Workout for the tapped horns
Skipped the 18Hz church organ - wrong target audience

I'm still impressed by these things too.

Gonna be interesting times ahead demoing..

More reading and learning.

Apparently a few Home Theatre setups used SH50s.
Bill Gates and George Lucas are ones of note.
This was a few years ago so who knows now?

Our daughters have been wanting a Home Cinema room.

The 5 way round horn system never had the room coverage for it.
Not so the Synergy horns.

That got me thinking of turning my room into a dual purpose hifi / home cinema room.

How to allow 2 channel hifi in 4/5way with existing amps, and then do 5.1 with the SH50s as L and R and Tapped horn subs as Sub?

Can probably do without a centre, the cinema guys reported some SH50 setup like that.

I thought about a all new DSP 5/6/7.2 pre amp that can feed my various power amps and configure to each - does such exist.

On another thread on here, miniDSP flex 8 Home Theatre was mentioned.

Thinking about this long term, that might be just the thing..



Anyone experience of the SQ from these with a horn setup? Not just for HT but HiFi also?

As long as it could have multiple setups with different PEQs / X/Os for hifi and then other setup for 6.2, that can be configured to the different inputs, it could work.
They must have thought of all this?
More reading up required.

Room plan idea. 6 seater.






Centre and rears, not shown.
The white things are the tapped horns

A low wide hifi equipment table also required.

Another reclining sofa and 2 reclining chairs should arrive next week.
Ditto a 65" QLED screen.

I'm even planning a raised platform for the rear seats for better sound and vision.

I cleared all the unnecessary crap out of the room and put the 2 seater sofa we have and two other chairs in.
Then listened to the system on soundtracks to see.
Plenty of crash and boom from the tapped horns

One consideration is that for hifi, I like the SH50s quite forward.
For Home Theatre they need to be farther back. Test sitting in various positions confirmed this.

I made a track that 2 patio door runner wheels can glide in.



This allows me to lift the SH50 slightly off the support foot and elegantly slide them between the 2 positions.

Much more to do for this project once the furniture and TV etc arrives.

schlager said:

Great to see your synergy horn build. No doubt that the design is so very different from most out there and thus represents the music a bit differently, that it takes a bit of time to get acclimated to.
The MiniDSP Flex 8 should be noiseless on a horn system, according to its specs.

Click to expand...

The dispersion control of these is great for my room.
They can handle all sorts of music and volumes with ease.

I still pinch myself at times that they sound so good.

Later this year I hope to get to play them in a large well acoustically sorted hall, for a bunch of enthusiasts. Should be interesting.
The tapped horn subs I use at home are too big to transport - so I'll probably hire a Danley TH118 for the day to get that bottom octave or so.

If only physics didn't require such big things for great deep loud bass

I recently started using REW.
Don't know why I stuck with Holmimpulse so long.

After some small tweaks

For some reason I can't upload more measurement images now.
Will try again later.

My next project will be to build a 60 degree horn centre (will fit the existing rear enclosure).

Then I'll know if 50 degree or 60 degree suits my narrowish long ish room best.

Here's a first attempt at a spectrogram. Famous Indian Rope trick.. Tommy Cooper

I forgot to post up what a highly respected audio forum guy and high end phono stage and amp builder wrote having been here for a listen.

This is the guy who first got me interested in building and listening to horn systems.
He gave me invaluable advice to get started on the journey.
That was some 13 years ago now!


"Popped to Steve’s yesterday to have a listen as I’ve been interested in a pair of these for a long long time, but it’s not really been possible to hear any.

These sounded absolutely phenomenal and I need a pair!

Hard to characterise as they are incredibly even across the range and don’t really highlight any particular range or characteristics. We played all sorts through them and they basically just played the music. There’s no sense in any particular range being accentuated.

Vs traditional multi-way horns, they’re much more coherent and there’s no sense of individual drivers. You don’t really get that “horn” sound, they remind me of a really good pair of headphones, very intimate and detailed but do the horn thing of zero stress when the volume is turned up.

They’re also relatively compact for what they are and you could get away with a small sub below the main horn, albeit you’d lose some of the performance of the tapped horns.

So, go figure, looks I need to build a pair as well!"

iansr said:

I wish you were nearer to me as I’d love to hear them ! Yet further confirmation that I absolutely must get a pair !

Click to expand...

Come to the New Forest / Jurrasic Coast for a holiday, drop in and listen to the Synergy horns