For the last two years, ever since meeting T Danley and hearing I could probably cross straight to a 12" using a CD that can reach down to around 5-600Hz, I have worked on that concept.
Built about 6 various-pattern prototype horns that were meant for experimentation, until deemed promising enough to build a pair for stereo.
2 versions became pairs.
H & V degree patterns, ports in corners or middles of horn, mouth terminations (no secondary flares, large 1/4 rounds on primary flares, straight & curved secondary flares), were the variables.
Also played with different cone sizes (8, 10, or 12 inches).
Coax CD's were always the same, 4594HE and dcx464.
All my focus was on improving polars, as both sound and measurements were simply excellent.....and it was the only substantive thing i thought to do trying to find sonic improvements.
All the final versions had close to the same 4ft width despite different H-V patterns.
All sound pretty dang close to each other...too dang close, sigh...all i was achieving were slight lateral changes in sound.
The announcement of the Hyperion, and discussions regarding it and it's close relatives, the SM-60F, SH50, & SH60, caught my attention.
One of the comments often heard about the SH-50 is how it can be relatively hard to locate in space with your eyes closed.
Only occasionally would i hear that phenomenon, and I've always wondered if my builds were missing/doing something wrong.
I chalked being able to easily locate mine up to using a CD all the way down to 500Hz, and saying to myself "How can you not aurally locate a CD handling over half the audio spectrum?".
One thing I found about port location when crossing to a single low/mid cone, is that it makes a 'rob Peter to pay Paul' situation.
Move the port close to the throat to raise the freq response of the cone, and you loose the very bottom end of the cone's response. And of course vice versa if you place the port out in the horn to let the cone dig deeper.
This fact let me realize I couldn't cross to CD higher with a single cone, without further killing bottom end. And I had already been struggling with low end response on every version, all with port centers in the 5-6" from throat ballpark.
So I'm like heck, why not try adding some small mid cones like DSL does.
Plus, my only sonic complaint with my syns has been a sometimes harshness in the HF section in either of the coax CDs. (I've wondered if, despite specs, are they really great when reaching lower.) So adding small mids seemed worth a try,
Well, I call her Syn 9 proto...a 90x60, 31"x19", test sled, with no secondary flares.
Port holes were made, tried, and plugged/patched.... re-holed, re-made, etc.
Using leftover cone drivers.
The small mids aren't even sealed...i just put a couple of wings on the horn to block forward radiation. The 10"s at least have their own sealed chambers.
No matching of CD exit to throat....
Piece of junk, albeit Millennium Falcon style! (With spot on tuning)
DCX464 HF & VHF
four 4fe35 Mids
two 10fe200 lows
Xovers at 100, 250, 650, 3800Hz. All steep lin-phase.
Well, the sound is such an improvement I can barely believe it.
NEVER heard such clarity before from a speaker.
Tonality rocks with real grit and balls down low (along w dual 18n862 subs).
And that disappearing speaker phenomenon is ....well, appearing
This beater is my best build yet.....what's the old moto..."use your eyes, plagiarize" lol...but sincerely, thank you Mr Danley
So much for two years of work on a shortcut version....and forever chasing polars....Lol
Now planning a 60x60, 29 1/2 x29 1/2 primary, with two kappalite 3012LFs and four 4NDF34s.
It it's not an improvement, I can always make another beater
Built about 6 various-pattern prototype horns that were meant for experimentation, until deemed promising enough to build a pair for stereo.
2 versions became pairs.
H & V degree patterns, ports in corners or middles of horn, mouth terminations (no secondary flares, large 1/4 rounds on primary flares, straight & curved secondary flares), were the variables.
Also played with different cone sizes (8, 10, or 12 inches).
Coax CD's were always the same, 4594HE and dcx464.
All my focus was on improving polars, as both sound and measurements were simply excellent.....and it was the only substantive thing i thought to do trying to find sonic improvements.
All the final versions had close to the same 4ft width despite different H-V patterns.
All sound pretty dang close to each other...too dang close, sigh...all i was achieving were slight lateral changes in sound.
The announcement of the Hyperion, and discussions regarding it and it's close relatives, the SM-60F, SH50, & SH60, caught my attention.
One of the comments often heard about the SH-50 is how it can be relatively hard to locate in space with your eyes closed.
Only occasionally would i hear that phenomenon, and I've always wondered if my builds were missing/doing something wrong.
I chalked being able to easily locate mine up to using a CD all the way down to 500Hz, and saying to myself "How can you not aurally locate a CD handling over half the audio spectrum?".
One thing I found about port location when crossing to a single low/mid cone, is that it makes a 'rob Peter to pay Paul' situation.
Move the port close to the throat to raise the freq response of the cone, and you loose the very bottom end of the cone's response. And of course vice versa if you place the port out in the horn to let the cone dig deeper.
This fact let me realize I couldn't cross to CD higher with a single cone, without further killing bottom end. And I had already been struggling with low end response on every version, all with port centers in the 5-6" from throat ballpark.
So I'm like heck, why not try adding some small mid cones like DSL does.
Plus, my only sonic complaint with my syns has been a sometimes harshness in the HF section in either of the coax CDs. (I've wondered if, despite specs, are they really great when reaching lower.) So adding small mids seemed worth a try,
Well, I call her Syn 9 proto...a 90x60, 31"x19", test sled, with no secondary flares.
Port holes were made, tried, and plugged/patched.... re-holed, re-made, etc.
Using leftover cone drivers.
The small mids aren't even sealed...i just put a couple of wings on the horn to block forward radiation. The 10"s at least have their own sealed chambers.
No matching of CD exit to throat....
Piece of junk, albeit Millennium Falcon style! (With spot on tuning
)DCX464 HF & VHF
four 4fe35 Mids
two 10fe200 lows
Xovers at 100, 250, 650, 3800Hz. All steep lin-phase.
Well, the sound is such an improvement I can barely believe it.
NEVER heard such clarity before from a speaker.
Tonality rocks with real grit and balls down low (along w dual 18n862 subs).
And that disappearing speaker phenomenon is ....well, appearing
This beater is my best build yet.....what's the old moto..."use your eyes, plagiarize" lol...but sincerely, thank you Mr Danley
So much for two years of work on a shortcut version....and forever chasing polars....Lol
Now planning a 60x60, 29 1/2 x29 1/2 primary, with two kappalite 3012LFs and four 4NDF34s.
It it's not an improvement, I can always make another beater
Thanks for the report!
How high can you push the mids?
I think the next improvement would be a "normal" compression driver. A coaxial driver might not be the best option if you don't need strong response under 800hz. They seem to have more issues in the upper mids and highs.
I've never owned one fwiw. Maybe it only looks worse on paper.
Faital HF1440, 18Sound titanium-nitride, Oberton ND72HB, JBL aquaplas, and Eminence textreme all seem like good alternatives to beryllium in a 1.4"/1.5" exit format.
Just a thought.
How high can you push the mids?
I think the next improvement would be a "normal" compression driver. A coaxial driver might not be the best option if you don't need strong response under 800hz. They seem to have more issues in the upper mids and highs.
I've never owned one fwiw. Maybe it only looks worse on paper.
Faital HF1440, 18Sound titanium-nitride, Oberton ND72HB, JBL aquaplas, and Eminence textreme all seem like good alternatives to beryllium in a 1.4"/1.5" exit format.
Just a thought.
Thanks Ernie.
The mids can easily reach 1kHz or above...here's raw.
Yep, I've followed your CD threads with interest, knowing i might someday want to try a normal CD.
But it will probably be one of the last things i try because when raised to 650Hz, I have no complaints with either of the coax CDs. No bite ever then.
I will try raising xover some on this proto, probably all the way to 1.2kHz just to hear, and know what is usable in a normal CD. If listening get's any better than it already is at 650Hz, i might explode out of joy. Lol.
Your list looks line a fine collection...is the rfc950 one you'd consider as well?
Thanks arcgotic.
The 2-flare option has not been discarded.
I start a prototype idea with single primary flares because they are pretty easy to build, and importantly l can disassemble/reassemble them quickly.
This let's me measure the CD in the horn without ports for a benchmark reference to then measure port interference against.
And also allows fairly easy trials of different port locations for their response.
When i get a finalized proto, it will get 2-flares.
Just takes me a little while to get there.
Nice extension on those mids. I'm definitely curious if you can hear a difference between 650hz and 1.2khz.
The RCF looks very good for the price and diaphragm size, but still has quite a bit of breakup above 10khz. It would do well with some kind of damping material on the dome. A couple of guys here have improved them that way.
I used to think compression drivers sounded basically the same once eq'd flat, but I've been surprised at the differences I've heard...even when I didn't want to.
The RCF looks very good for the price and diaphragm size, but still has quite a bit of breakup above 10khz. It would do well with some kind of damping material on the dome. A couple of guys here have improved them that way.
I used to think compression drivers sounded basically the same once eq'd flat, but I've been surprised at the differences I've heard...even when I didn't want to.
Hi fluid, yep agreed.
So far, comparing all my builds which have had close to a 1.5 H-to-V aspect ratio, the biggest improvement in mid frequency and up polars, has been in the 1-2kHz range where i get a flipflop around flat tuning made at 10 degrees off-axis.
Like shown on this 0-20 degree set from the current proto.
Secondary's have mitigated about 2/3 the oscillation, but not eliminated it.
I've never been able to make an apples to apples comparison of a single flare vs a 2-flare, because i believe the mouth sizes would need to be the same to do so. (Do you agree?)
I've always just added secondary's to the already built primary and measured the change in polars.
The increased mouth size improves low-mid, upper-bass polars, through lower frequency directivity. It also changes the tonal a little, in a pleasing authoritative way.
But i'm guessing that down-low directivity increase is all due to mouth H-V dimensions and might not matter 1-flare vs two.
The current syn9 proto project has morphed into a pretty large 60x60 with a mouth circumference of 118Hz. Maybe (probably) directivity is all just about Keele's directivity formula, and not about mouth area...but it will be interesting to hear firsthand.
An aside on my evolving take on the significance of polars....
I wholeheartedly embrace their importance, right behind transfer functions.
That said, my current take on them is akin to the take many folks have on phase traces ....that being, once directivity gets reasonably smooth and more gently sloping...polars are no longer a prime candidate for sonic improvements.
I've listened to my existing syns with and without secondary flares alot, both indoors and out. By far the major change in sound has been the low end directivity extension. Better polars in the mid and high end haven't really amounted to much.
The clincher for me in letting go of making better polars my prime focus, is the sound of this syn9 proto.
The addition of the small mids has simply blown away the improvements i've made from smoothing out polars on the same size horn and near equal driver setups. (same CD, same low driver, with added mids/& ports and new low cone port location)
Live and learn, huh
Good thing it's mostly fun LolI'll post the adventure to 1.2kHz.
It seems like the HF1440 would be a good bet to try when i get there.
(agree?)
Yeah, those things we hear when we don't want to, are often the most accurate assessments of all, aren't they! ..
Kinda related to what we hear, don't want to hear, think we hear....etc
The only bias i can come up with on why i like the sound of this proto so much...is well (don't laugh) pot became legal in VA early July.
I've truly wondered if my hearing has changed...but a/b against existing syns, and listening after a few days of no whacky-backy, have convinced me the sonic improvements are large and real.
The HF1440 looks good up high. I'd still like to see high voltage sweeps to see if the dip around 1.5khz is benign or not. Mabat and Legis had the same measurement artifacts with their samples. Reports are positive besides that. I might try one eventually.
Mabat compared the HF1440 and ND3 on the same horn in the ATH thread. It's kind of hard for me to justify moving on from the ND3SN's I have after seeing that.
I recently bought an Oberton ND45 1" driver for another project....if it's any indication, the larger drivers are probably very good as well.
Mary Jane definitely makes every event better
Unfortunately I can't partake very often due to job requirements...
One thing I'm curious about....have you ever compared the XT1464 to one of your synergies with only the compression driver playing?
Mabat compared the HF1440 and ND3 on the same horn in the ATH thread. It's kind of hard for me to justify moving on from the ND3SN's I have after seeing that.
I recently bought an Oberton ND45 1" driver for another project....if it's any indication, the larger drivers are probably very good as well.
Mary Jane definitely makes every event better
Unfortunately I can't partake very often due to job requirements...
One thing I'm curious about....have you ever compared the XT1464 to one of your synergies with only the compression driver playing?
The XT1464 is a little bit nicer and smoother than the syn horns, with only the compression driver playing. This is comparing within a +/- 20 degree window.
It makes me wish for a big OS horn with port holes, and cone-driver mountable rear surfaces.
The XT1464 high frequency directivity rolls off considerably more at 30 degrees, than a 60H syn horn.
I can say, despite the fact the XT1464 is a little better at HF/VHF than the syn horns, the overall sound of the syns is better than than the XT1464 used over a single 12", or 18", or in a MTM with 12"s. (all using same xover to CD, same tuning).
The integration of drivers acoustic centers in the syns dominates i think...making the lower octaves foundation flow into the HF/VHF much better....with greater overall clarity.
It's like the integration improves the HF/VHF too.
It makes me wish for a big OS horn with port holes, and cone-driver mountable rear surfaces.
The XT1464 high frequency directivity rolls off considerably more at 30 degrees, than a 60H syn horn.
I can say, despite the fact the XT1464 is a little better at HF/VHF than the syn horns, the overall sound of the syns is better than than the XT1464 used over a single 12", or 18", or in a MTM with 12"s. (all using same xover to CD, same tuning).
The integration of drivers acoustic centers in the syns dominates i think...making the lower octaves foundation flow into the HF/VHF much better....with greater overall clarity.
It's like the integration improves the HF/VHF too.
That makes sense. 3D printer sounds very tempting right now.
I want the best of both worlds.
Or I'll have to settle for some janky looking extensions to the Ciare horns I have.
I probably should've went with these in the first place
Red Spade Audio PSE-144
I want the best of both worlds.
Or I'll have to settle for some janky looking extensions to the Ciare horns I have.
I probably should've went with these in the first place
Red Spade Audio PSE-144
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That Red Spade horn has always looked intriguing.
I feel kinda lucky not to have had a 3D printer bug get close enough to bite.
Mainly because I've become a fan of very large horns, and can build and modify them fairly easily out of B-Birch. Large 3D seems like a big stretch today.
Also have to admit i think 1000Hz and up, is less important than 1000Hz and below. (like a lot less)
So I'm willing to live with a little HF/VHF blemish, to get more mid-range and bass excellence.
I feel kinda lucky not to have had a 3D printer bug get close enough to bite.
Mainly because I've become a fan of very large horns, and can build and modify them fairly easily out of B-Birch. Large 3D seems like a big stretch today.
Also have to admit i think 1000Hz and up, is less important than 1000Hz and below. (like a lot less)
So I'm willing to live with a little HF/VHF blemish, to get more mid-range and bass excellence.
In principle if you change more than one thing then you cannot fairly decide what was the cause of any difference found.
To avoid the low end directivity change the mouth sizes would need to be kept constant to remove that variable but I don't think it is necessary to see the benefit of the secondary flare. It is the same thing as properly terminating an OS waveguide. An abrupt termination is no good from the point of diffraction, reflection and consistency of the polar response. You can see all three get better in the graph I posted above as well as the extended directivity to lower frequency from the bigger mouth.
When I was simulating rectangular guides I found that if the aspect ratio was more than about 1.2 then odd things started to creep in that couldn't be tweaked away.
This sounds somewhat contradictory but I think I see your point
For me the reduction of reflection and diffraction from the better mouth termination is more useful but it does also seem to come with better polar control. As it is hard to have one without the other I suspect it is tricky to tell if something more obvious grabs your attention.
This is interesting and could point to there being a optimal bandwidth for the ported drivers to operate in. There was also discussion on the ASR thread about how the ports in the horn don't behave quite the same as a bandpass would outside the horn that there is the right place along the length for this effect to be greatest.
I am starting to think that the coaxial used in the SM60F might well be the best arrangement.
One thing you could consider with the choice of CD is whether it is producing a flat wave front or more spherical. Flat suits an OS horn and conical's work better with spherical sources.
There was some speculation that the BMS4550 in the SH50 was a good match because it produced a more spherical wavefront. I asked Tom about measuring it on the ASR thread but his answer didn't really help me to think of an easy way I could do it.
You could 3D print the throat and use a more complex round to square transition, keep the flat side walls and then use foam to construct the mouth flare (which would allow more optimal curves than just a secondary flare). https://www.stereonet.com/forums/topic/232459-klipsch-k402-replica-build/
I can't help but notice the similarities to my single flare conical. Mine is 29x12" mouth size and uss the 1" exit BMS4550 crossed at 1050Hz. It sounded great despite pretty terrible polars and waistbanding. Vertical pattern control was lacking.
I'm sure a secondary flare will make major improvement there but if you really want good polars, you should go the ATH direction. A 60 degree axisymmetric horn with optimized throat and mouth rollback would be just thing if you could figure out how to make one in a plus size
If you are adding mids you should definitely go to a 1" exit CD. I'm sure you will appreciate a CD whose top end is smooth prior to equalization. The BMS4550 does not sound harsh when crossed at 1050 with a 24 db electrical slope, which turned out to be 48 db acoustical.
I really like the 4NDF34; wish I had used them. I'll bet 4 of them are good for your SPL levels down to 200 Hz or so.
I'm sure a secondary flare will make major improvement there but if you really want good polars, you should go the ATH direction. A 60 degree axisymmetric horn with optimized throat and mouth rollback would be just thing if you could figure out how to make one in a plus size
If you are adding mids you should definitely go to a 1" exit CD. I'm sure you will appreciate a CD whose top end is smooth prior to equalization. The BMS4550 does not sound harsh when crossed at 1050 with a 24 db electrical slope, which turned out to be 48 db acoustical.
I really like the 4NDF34; wish I had used them. I'll bet 4 of them are good for your SPL levels down to 200 Hz or so.
When I was simulating rectangular guides I found that if the aspect ratio was more than about 1.2 then odd things started to creep in that couldn't be tweaked away.
This sounds somewhat contradictory but I think I see your point
This is interesting and could point to there being a optimal bandwidth for the ported drivers to operate in. There was also discussion on the ASR thread about how the ports in the horn don't behave quite the same as a bandpass would outside the horn that there is the right place along the length for this effect to be greatest.
I am starting to think that the coaxial used in the SM60F might well be the best arrangement.
One thing you could consider with the choice of CD is whether it is producing a flat wave front or more spherical. Flat suits an OS horn and conical's work better with spherical sources.
There was some speculation that the BMS4550 in the SH50 was a good match because it produced a more spherical wavefront. I asked Tom about measuring it on the ASR thread but his answer didn't really help me to think of an easy way I could do it.
I read TD say somewhere, that a 1.6 aspect ratio is the upper bound of usability.
Very interesting that you see 1.2 begin to creep into in detrimental territory.
I know my comment on polars sounded contradictory...(i'm conflicted over it myself Lol).
Polars/directivity is like everything we try to optimize in audio i guess...just when is enough good enough ?
Yep, to port placement in the horn making drivers act differently than when outside the horn. That is what i think is probably the issue with using a single cone under the CD. It appears the port location has to be optimized for either for higher extension, or lower extension.
The sm60f does look like a nice solution...especially for home audio.
Wish DSL would sell the molded horn alone
As you no doubt noticed, TD said the ring radiators (like I'm using) tend to focus sound to the center of the exit...dunno what kind of wavefront that means? I do wish he had expounded more on your questions...
Oh, a real forum newbie question for you or any helpful soul (i must have skipped some elementary school classes haha)...
How do we make posts where we insert a series of comments in the middle of posts we are replying to... like you did in your reply to me #14.
I apologize for not having learned this already, and making my comments easier to follow.
Yep, those kinda things look neat.
I'm seeing them as down the road options, as i feel i'm still learning and progressing with the straight sided conicals.
For now i don't have the $$$ for purchasing such 3D printer trials, or the willingness to invest the time into all the transitional work.
I did at least try curved secondary flares made out of 2" foamboard. Unfortunately they resonate above a certain SPL, with no way to eliminate it.
(It was a bitch to make them too....)
Hi grec,
What mid drivers are you using? Where crossed? Port(s) sizes and locations?
Interesting you found 2 more pleasing than 4.
I used four 4fe35s instead of two, because it was clear they would still be the weakest section in the proto synergy.
The 60x60 i'm working on now has four stronger 4NDF34s, and even those will be the first driver section to run out of headroom.