Synergy Horns. No drawbacks, no issues?

[Pallas]

Eldam,
For home use, I am not sure why one would need the JBL D2 CD. I find the sound from the ScanSpeak 10F/8424 fiberglass cone so much more natural and smoother than a compression driver squeezing its guts out to handle a 1.2kHz XO in a horn. I was pleasantly surprised to find that the circa 18kHz top end on the 10F/8424 in open face application, once horn loaded in a tractrix, magically appears to hit 22kHz easily and with gusto, and still have that fiberglass magical smoothness of tone but with fierce attack that plays piano like I have never heard before. I think the powerful motor and the slight compression effect of a 2in square throat all work together to allow the highs to come through in the Trynergy. Having heard this, I am reluctant to go back to a compression driver pushing 1.2kHz to 20kHz. For home use, I can easily hit ear pain levels with no audible strain on the driver, so it's now a natural choice.

Wait - you've horn loaded a Scan Disco 10F and gotten better HF extension out of it? Do you have axial FR and polar maps of the design?

 

[Eldam]

maybe the highest frequencies are >= to H2s ? >15/18 K Hz (after the highest natural roll off of the 10F/8 ?

For me it's ok with my 46 !

 

[SpeakerScott]

Wait - you've horn loaded a Scan Disco 10F and gotten better HF extension out of it? Do you have axial FR and polar maps of the design?

Agreed...I'm curious about that...one would think once you've hit the mass loaded corner you're not going to get any more out of the thing....unless the cone is so flexible you're not using the whole thing?

 

[xrk971]

Wait - you've horn loaded a Scan Disco 10F and gotten better HF extension out of it? Do you have axial FR and polar maps of the design?

Yes, surprised the heck out of me too. Listening to it, high hats, cymbals, etc come through with great detail and crispness. No ringing.

Here is polar with 4ms gate. The 7.5k dip is the cone to throat dia cancellation. I am working on improving that with a custom phase plug 3d printed to match 10F cone to horn throat.

More info in thread:
http://www.diyaudio.com/forums/full...-trynergy-full-range-tractrix-synergy-84.html

Here is in-gated operating with bass assist provided by four 6.5in woofers:

 

[Eldam]

I have also some hope with the famous stifer aluminium 2"

 

[SpeakerScott]

Yes, surprised the heck out of me too.

Yes..they sure do get out to 20k...wow...

 

[SpeakerScott]

I believed the M2 could be Xoed lower around 700 or 800 Hz ! But in all case as it has to shipped from US, it's a no-go for me ! Hey Cop21 ! (Is it the policeman n°21 ?)...

You don't necessarily *want* to go lower, nor *can* you necessarily go lower. There is a critical relationship between the phase of the midrange low pass response, tweeter high pass response and cutoff/flare rate of the horn. Explained in the patents. ;-)

I really don't know how sound a synergy design and have a non understanding of the patent (No I didn't read it !)... But the non too much expensive Trynergy with foam is appealing me !

Please go study the patents, and purchase the paper referenced in one of them:

Design Factors in Horn-Type Speakers, Daniel J. Plach, October 1953, Volume 1, Number 4. This is critical for understanding the concept of flare rate, cut-off frequency and how the Synergy design makes use of a variable flare rate along the horn length.

Also...in a post a little farther along you asked if the woofer in a Synergy is just a vented driver....and the answer is no, yes, maybe...because it depends.

The low frequency alignment can be sealed or vented, and at very low frequencies the output of the driver isn't horn loaded. Often however, the woofer is used up to a frequencies where the driver is horn loaded. And therefore depending on the frequency the output isn't horn loaded, then it is and in between...not really...but maybe.

Scott

 

[Eldam]

Wow ! Can be a challenge for me to understand it...

I stayed on the idea of what the guys of FR FAST team are doing for XO and also around the 700 Hz of Gedlle paper, and more or less on what is the life in music played by one speaker : something 80 Hz to 800 Hz !

Too simple ? Yeeeeeeeeees I know

Here now people play with 3D polar map etc... Argh ! Give me the time of my lazyness to understand more!

 

[xrk971]

The Trynergy is really a FAST setup with the full range driver handling above 400Hz and woofers handling below. That gives it a distinct advantage of being coherent and close to transient perfect above 400Hz. I even used a Harsch XO for integrating the woofers to the full range to get that added transient alignment.

The Synergies (proper CD at apex and typical 1.2kHz XO) are at minimum 3-way speakers to go from 100Hz to 20kHz - except for Weltersys' SynTrippi which did a hat trick with the BR redirect and driver cone filler plugs to extend the HF reach.

But the Synergy designs don't have the inherent single driver to cover the critical telephone band from 600Hz to 6kHz where the phase coherence and time cohenrence are critical for imaging and realism. With proper XO design, like Bwaslo's Cosyne, they can be flat phase and resemble a single driver.

 

[Legis]

My synergies are also single driver from 500Hz to 20khz.

edit. btw, I would differentiate the acronym "CD" to cover only the term "constant directivity", this is the meaning what I have learned to use it with. Compression drivers are just comp drivers/drivers/comps etc.

 

[turk 182]

CD
could be "compact disc", "compression driver", "constant directivity", "clear day"
sorry i have a pet peeve when it comes to contractions and acronyms (and don't get me going about "texting") we all try to save keystrokes but it can cause unnecessary confusion.
oh and "comps" could mean compressor/limiter's which in the the PA and recording world can help save compression drivers!

perhaps we should collaborate on a list of acceptable contractions (waf had me baffled for a while)

 

[xrk971]

Hi Legis,
Oh sorry forgot that you actually can get your compression driver to go that low. Does it sound strained or have more distortion when played that low? That is conventional cone driver territory. I also see a thread where there is a $36k GOTO "bass" compression driver. I don't understand how that can work because bass is all about displacement and moving lots of air.

 

[Eldam]

The Trynergy is really a FAST setup with the full range driver handling above 400Hz and woofers handling below. That gives it a distinct advantage of being coherent and close to transient perfect above 400Hz. I even used a Harsch XO for integrating the woofers to the full range to get that added transient alignment.

The Synergies (proper CD at apex and typical 1.2kHz XO) are at minimum 3-way speakers to go from 100Hz to 20kHz - except for Weltersys' SynTrippi which did a hat trick with the BR redirect and driver cone filler plugs to extend the HF reach.

But the Synergy designs don't have the inherent single driver to cover the critical telephone band from 600Hz to 6kHz where the phase coherence and time cohenrence are critical for imaging and realism. With proper XO design, like Bwaslo's Cosyne, they can be flat phase and resemble a single driver.

How is the Trynergy sounding with a upper Xo at 700 hZ ?

 

[Legis]

Hi Legis,
Oh sorry forgot that you actually can get your compression driver to go that low. Does it sound strained or have more distortion when played that low? That is conventional cone driver territory. I also see a thread where there is a $36k GOTO "bass" compression driver. I don't understand how that can work because bass is all about displacement and moving lots of air.

500hz is pretty typical xo for bigger 2" exit (4" voice coil) comp drivers like I use. One could cross them even a tad lower in a big horn that loads the driver better than a conical. BMS coaxial drivers can also take ~350-400Hz xo to my understanding. No strain with 500Hz xo in an adequate horn.

I understand GOTO bass compression drivers are cone drivers with hefty motors put in a "compression driver format". Think it as a woofer from a synergy horn, that has a built in front chamber and phasing plug with some compression ratio (= injection port) and also a back chamber. That is pretty much the basic structure of a compression driver and driver used in this configuration are physically identifiable as compression drivers. In synergy horns we build those chambers and compression slots out of wood and create a compression driver like circumstances for the woofers.

 

[Eldam]

Legis,

Any thoughts on the M2 which is not exactly a compression driver ?

 

[Pano]

BMS coaxial drivers can also take ~350-400Hz xo to my understanding. No strain with 500Hz xo in an adequate horn

They are rated down to 300Hz, power rating down to 400 Hz. I'm trying to build a horn big enough to find out just how low they will play. At low drive levels, of course.

I have never heard the GOTO bass drivers, but would be curious. A buddy showed me photos of a system he visited in Cyprus where the GOTO bass horns extended outside the house itself, almost to the street!
The "normal" drivers are very good, if given the right crossover. Way out of my price range, tho.

 

[winslow]

Which M2?

Legis,

Any thoughts on the M2 which is not exactly a compression driver ?

 

[Eldam]

JBL D2430K

 

[xrk971]

How is the Trynergy sounding with a upper Xo at 700 hZ ?

It works fine with a XO at 700Hz from standpoint of the full range driver. More work needs to be done on the bass drivers to reduce front chamber volume to get it to extend up high like that. The way mine are setup with no chamber volume block filler it rolls off around 550Hz.

 

[Eldam]

I was meaning at ears, not on the paper ?

Ok I understand now it can not be tested by you if the volume of the woofers cabinets has to change... and maybe the T/S parameters of the woofs itslves !

I was also asking in the case the FR-88EX could be choosed instead the 10F/88... as the littliest Sd can ask for a higher XO ! It was also to know how could play the 100/700 Hz range in a synergy with at the same time the 3" playing higher (so more towards the center of its cone = less break ups and reflection of the suround of the 3" cone through the 2" port)... Less "distorsion" (=bad interactions I mean) ????



I have to try myself when I will prototype with cardboards with the woofs cabinets !

thanks X

PS : at the ears I have a doubt between 10F & FR-88EX on your hearing tests to choose one, but seing the tests of John Krutkh (Zaph) on the 10F but 4 ohms version, I have no doubt than the Scan Speak should be the one to keep !