The Q specs remain the same on the 15PR400 match between the 4 and 8ohm version....so best I can say is that the advertised specs for Acoustic Elegance show matching Q specs between the ohm versions so they should likely comply. I cannot hypothesis how much Qes will drop versus goal spec fs.
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They are not the same but they aren't as different as the 15FH500. It all depends on what changes between the different versions.
You can look at the Forumlas in this page and see if you have the other data needed to back calculate Cms, scroll down towards the bottom
DPC FORMULAS
This Scanspeak document shows how to derive it from the impedance measurement
https://www.scan-speak.dk/datasheet/tech/Scan-Speak_Technote01_TS-measurement.pdf
DPC FORMULAS
This Scanspeak document shows how to derive it from the impedance measurement
https://www.scan-speak.dk/datasheet/tech/Scan-Speak_Technote01_TS-measurement.pdf
Thank you for your thoughtful response. It’s great you and your daughter can share this. Perhaps she will be a speaker engineer/designer.
15M played full range – a good large wide range driver played without any crossover components will sound very clean. I expect the 15M leans toward the midrange. Run by itself, it would make a great replacement for the large full range drivers in old tube floor standing console radios. This is a complement to its extended range capabilities; not a cut.
I’m always amazed at how many things a good table radio with a 4” full range driver gets right. 200Hz – 3Khz. No crossovers. Limited displacement and distortion at table radio volume.
TD18+ - I think your choice to add Woof to the TD15M mid-woof is a good choice. Sd vs Xmax; but, plenty of Xmax, for those moments. No replacement for displacement. The Td18+ might even work in 2-way if crossed low enough; Like with a Synergy Horn; Like in the Red Spade setup. Then, this is no longer a real 2-way. The Red Spade setup alternately uses the TD15S for the bottom.
If I recall correctly, you are running your CD and horn pretty low? What crossover frequency?
Strauss – IMO Mastering monitors have a specific job to do; help make a recording that will be acceptable to the vast majority of listeners. That is not the same as most accurate. Smoothness outranks full spectrum detail. I am impressed with their choice of a 2” compression driver run to 400Hz. It looks to be below the cutoff of both CD and horn. Hmm… Well; the pattern of both drivers at 400HZ is similar.
I will try to run my CDs and horn lower and see what happens. Xt1464, Radian 951, 700Hz, LR4. The woofers I’m using right now are a bit compromised in the midrange and deep bass; Denovo 15”. They would like a lower crossover, and a TD15S, or TD18+ on the bottom. It might make a good woofer for a Strauss ‘on the poor’.
Lot of good 2-ways for near field monitoring. I use Focal CMS 65’s. I have never clipped the internal amps. I tried. The volume at 4’ is intense. Still need a TD18+ on the bottom.
I think you have great parts for an excellent 3-way; for mid and far field. Not sure I would slot load the 18+ drivers.
The best 2-way near field I ever heard was my friends ESL-57’s. MLP was 6’ away. The world disappeared in front of them and you were transported to whatever space the recording created. Curved panel; Makes me think of CBT in a directional electrostat before Dr. Keele invented CBT.
For far field; horns/waveguides + whatever works in your space on the bottom. Or, Synergy’s.
Major agreement with your points here:
“Low excursion being the epitome of SQ.”
“see it move, see it distort.”.
“a large 2 way is going to be choice, to sit on top of the status quo sub bass system for SQ.”
FWIW, from the earliest days of publishing specs [normally just Fs, ohms], all the ranges I calc'd were ~ +/-10%, so wasn't surprised when in recent decades both old and new[er] manufacturers said the same.
Attachments
Paul
Thanks for the interaction and good conversation! The thread is full of knowledgeable and well meaning people, so you fit right in. Im at work (was) but I cant help but to reply lol
I too think I have all the ingredients to an excellent 3 way but I believe the HETMM2.5way to be a step forward. It incorporates coupling of the bottom two stages of woofer, and implies high passing the lowest woofer from the tweeter, all the while, allowing one the option of attenuating excursion from the middle woofer at ones own discretion (using a filter to control roll off that is)...still alleviating two sub positions up front...geared towards two corner loaded mains.
As for crossover to the horn, its too early to say. I theorized 300-400hz xo with this elliptical tractrix tuned to 350hz....burst decay readings are teaching me, and I have yet to see such readings of a horn tuned to 200hz, but at least at 350hz tuning, the resonance of the horns mode is not so intense and seemingly to my knowledge at this point, borderline acceptable for a tuning that is lower than the standard 600hz expected for this size horn...400hz isnt looking bad at all...so its a matter of how steep a xo and what the crossband does well or not so well in practice.... the deeper (lower) the mode the more distortion it carries with it, it seems...this is why I believe the 2380a(?) of the strauss, no less any waveguide tuned higher yet, can have passband, passthrough, the modal area with acceptable consequence. Nevertheless, I've clung to the axi2050 in order to hedge the bet, via max possible sd, since excursion, lack there of, is what we are after.
So regarding the slot load...consider I've turned 2 sources back into a single, on the face of the system, via the slot, pushing lower by a few hertz, which implies that there is some amount of damping going on in the slot, but more effectively active vibration cancellation of the main source of excursion (low bass) and recently I was reminded that compression raises efficiency, so though I did not model a dbl sd woofer in horn resp to test this thought (just thought of how actually), the combined sd vs slot creates a 2:1 ratio, if there is some already known information about this situation please comment...otherwise, the combined sd allows for very low excursion, something around 2mm of excursion at 30hz and 110db (for one side). The 18h+ upper bass is cut short by the modal issues of the slot but hopefully will be able to add sufficient efficiency to compliment the 15m in a significant amount of spectrum. Rarely do you get 3 woofers this large to couple so well
As for mastering monitors. You used the words smooth...smooth to me means without distortion...which is the epitome of sound quality lol, so I'm sure you'll clarify but in my opinion, dynamic accuracy and Fr accuracy is of utmost importance...those two aspects are critical but it just sounds like ending up at chasing scientific sq in the long run....the mastering monitors sold reflect. Neutrality is a good word to sum it up...but once again this essentially, accuracy....does it have to be full range? Well you can't mix or master what you can't hear correctly...
Thanks for the interaction and good conversation! The thread is full of knowledgeable and well meaning people, so you fit right in. Im at work (was) but I cant help but to reply lol
I too think I have all the ingredients to an excellent 3 way but I believe the HETMM2.5way to be a step forward. It incorporates coupling of the bottom two stages of woofer, and implies high passing the lowest woofer from the tweeter, all the while, allowing one the option of attenuating excursion from the middle woofer at ones own discretion (using a filter to control roll off that is)...still alleviating two sub positions up front...geared towards two corner loaded mains.
As for crossover to the horn, its too early to say. I theorized 300-400hz xo with this elliptical tractrix tuned to 350hz....burst decay readings are teaching me, and I have yet to see such readings of a horn tuned to 200hz, but at least at 350hz tuning, the resonance of the horns mode is not so intense and seemingly to my knowledge at this point, borderline acceptable for a tuning that is lower than the standard 600hz expected for this size horn...400hz isnt looking bad at all...so its a matter of how steep a xo and what the crossband does well or not so well in practice.... the deeper (lower) the mode the more distortion it carries with it, it seems...this is why I believe the 2380a(?) of the strauss, no less any waveguide tuned higher yet, can have passband, passthrough, the modal area with acceptable consequence. Nevertheless, I've clung to the axi2050 in order to hedge the bet, via max possible sd, since excursion, lack there of, is what we are after.
So regarding the slot load...consider I've turned 2 sources back into a single, on the face of the system, via the slot, pushing lower by a few hertz, which implies that there is some amount of damping going on in the slot, but more effectively active vibration cancellation of the main source of excursion (low bass) and recently I was reminded that compression raises efficiency, so though I did not model a dbl sd woofer in horn resp to test this thought (just thought of how actually), the combined sd vs slot creates a 2:1 ratio, if there is some already known information about this situation please comment...otherwise, the combined sd allows for very low excursion, something around 2mm of excursion at 30hz and 110db (for one side). The 18h+ upper bass is cut short by the modal issues of the slot but hopefully will be able to add sufficient efficiency to compliment the 15m in a significant amount of spectrum. Rarely do you get 3 woofers this large to couple so well
As for mastering monitors. You used the words smooth...smooth to me means without distortion...which is the epitome of sound quality lol, so I'm sure you'll clarify but in my opinion, dynamic accuracy and Fr accuracy is of utmost importance...those two aspects are critical but it just sounds like ending up at chasing scientific sq in the long run....the mastering monitors sold reflect. Neutrality is a good word to sum it up...but once again this essentially, accuracy....does it have to be full range? Well you can't mix or master what you can't hear correctly...
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If the 12PR320 is as good as the 12PR300 then it is a hell of a woofer. The sound is incredibly natural and organic, very very linear, extends well in the higher midrange. Useable for high fidelity applications well into 2Khz or so. The powerful magnet, and stiff yet very light cone, make for a very precise and transparent low mid range. Bass is tight and clear, with good intelligibility.
I have indeed a 2-way with Faital Pro 12PR300 paired with a modified Beyma TPL-150H. I added subs, up to 60Hz. The result is stunning.
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I too have used the 12PR300 but with a SEOS 12 and CDX1-1745 and flanking subs. Sounds absolutely wonderful (to me - of course!
)Attachments
We did
The 12PR320 is the obvious partner for a 2 way that is almost full range.
'Preaching to the choir!'
Plagiarism is the sincerest form of flattery!
Specs nowhere near close, but from faded memory its [imagined 1/2 octave smoothed] response looks close enough to my [quad] mid '50s Altec 515B to overlay it if the roll-off is shifted backwards to ~5 kHz.If so, one 'sweet' sounding 12" on a par with my 12" reference, Altec's 414B and unfortunately just as expensive
[inflation adjusted].
Well I finally made some real progress, thanks so much fluid, for baby sitting me...again...
So using these formulas I get the correct values for the 18h+ (Thank you God)
I continue to get the wrong values for the 15m's......
I was inspired by another to use the prediction of WinIsd parameters and the trend is the same.....It is the off vas value that is throwing off my DATs reading for the 18H+'s....possibly due to break in or the baffle its mounted on.
I'm just thankful that it is only the 15m's now that are in trouble....The q specs are way off and thats a problem as everyone knows.....break in is not going to cure a Qes,Qts, that is double its intended value is it? John has offered a refund if the driver is sent back and measures off.....I will take him up on the offer asap but I must consider if I have not made an error somewhere here....
DATS predicts vas
Could Qes really make it from 0.766 to 0.35?
Recap
incorrect Vas throws off BL prediction of DATS....Qes, Re, Sd, Fs, strong affects Bl prediction
Mathematically reverse engineering BL shows the 18H+'s to be within spec and the 15m is still out of spec
Using WinISd prediction to reverse engineer Bl shows same results
John has offered refund for driver if he measures it and it turns out the 15m is out of spec.
Problem
Qes is the main issue here in reaching the 23TM spec.....can Qes eventually reach .33?????
Alternative Questions....I see you guy discussing these Faital Drivers....Why is it that no one is ever discussing Acoustic Elegance 15m.....Why would the Faital 12" be better than the Faital 15"s....
progress has been made
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You are welcome
Making sure that your measurements are accurate is important and adding mass to cone can be tricky to get right and that will throw your Vas readings out if you stuffed it up.
Make sure that you use something you can weigh accurately and place in a ring near to where the voice coil would be underneath.
You can make an impedance measurement easily with REW a soundcard and a resistor of known or measured value. This would be a good double check to make sure it matches the DATS and like in the documents I attached in the last few posts lots of information can be found from those measurements.
Impedance Measurement
If it all works out the same then you might as well send them back if nothing else but to get confirmation from the manufacturer of the values.
Could it be that AE drivers are boutique, hard to get hold of, cost a lot of money (more so outside of the US) and people seem to struggle to match the manufacturers specs when they measure them
I have bought two lots of Faital drivers from France and had them delivered to Australia within a week both times for a very reasonable price. Measured by lots of people and are almost always within expected tolerances. I wouldn't say they are the best drivers money can buy but for most use cases the difference would be hard to tell if they fit the overall system design.
Not in my world....... can't remember if I've posted this, but the pioneers recommended loading the driver with a sealed box that raised Fs 1.56x and whatever net volume it was was increased by 1.44x = Vas, so with DATS, add enough weight to lower Fs at least 1.56x and it should overpower the suspension sufficiently to get the most accurate measurement you're likely to get and it is what it is.........
For us Down Under, might be because delivered a pair of:
- Acoustic Elegance 15m = $1600 AUD
- FaitalPRO 15PR400 = $600 AUD
The only (albeit important) spec I can see in the AE's advantage is its Le?
Would be terrific to see some charts for these drivers because I don't seem to be able to find any on the AE site?
I've got 15FH520, they both measured out of spec qts almost .54 and fs 46Hz. Was told the driver needs to be warm to meet the spec but never reached it despite many tries. I'm amateur so my measurements could be wrong. Otherwise no complains. Have used old Beyma driver instead since it plays lower in the same enclosure. Three way speaker.
Yes it would. At least so some frd and zma files could be created to play with before purchase.