I am now experimenting with running the SB13PFC full range; NO X/O's at all. Really surprising performance. As long as I use good recordings, I can get away with no crossover. I haven't listened to violin music in this configuration yet. That is one of the most difficult musical instruments to reproduce accurately; the harmonics, overtones, etc can be overwhelming if poorly recorded. I will most likely go back to a small value inductor but have it on a switch so I can easily go back and forth. A lot of streaming audio (youtube, etc.) has too much harshness in the higher frequencies so I would certainly need a low pass here.
The official FR graph for the SB13PFC looks as if there are nasties above about 4,000Hz, so maybe it would sound harsh on, for example, the Bach solo violin sonatas or harmonics as used in various cadenzas? There's also Baffle Step Compensation to consider, unless you put the speakers against a wall.
I've used its big brother, the SB16PFC, again with the Vifa BC25TG and really liked the sound. I don't like the frame shape but the newer version has a round frame.
Geoff
I've used its big brother, the SB16PFC, again with the Vifa BC25TG and really liked the sound. I don't like the frame shape but the newer version has a round frame.
Geoff
Yes, but the round frame version is smoother than the original odd shaped frame.
The break up seems well behaved even at 7 KHz +/- ; the peak is lower in the round frame (13PFCR).
https://meniscusaudio.com/wp-content/uploads/2020/03/SB-Acoustics-SB13PFCR25-8-Data-Sheet.pdf
round frame above
original 13PFC below
https://meniscus.lightningbasehosted.com/wp-content/uploads/2015/11/SB13PFC25-08-Data-Sheet-1.pdf
The break up seems well behaved even at 7 KHz +/- ; the peak is lower in the round frame (13PFCR).
https://meniscusaudio.com/wp-content/uploads/2020/03/SB-Acoustics-SB13PFCR25-8-Data-Sheet.pdf
round frame above
original 13PFC below
https://meniscus.lightningbasehosted.com/wp-content/uploads/2015/11/SB13PFC25-08-Data-Sheet-1.pdf
Thanks, that's interesting.
The round frame versions of these drivers isn't yet available in Oz. The 'square-ish' versions are used in commercial speakers here, which shows you how well they're regarded.
The designer must have owned an Austin "Allegro", a dreadful 70s British car which had a 'quartic' steering wheel shaped like a rounded square, almost exactly the same shape as the SBs. The rest of the car was almost as useless.....
Geoff
The round frame versions of these drivers isn't yet available in Oz. The 'square-ish' versions are used in commercial speakers here, which shows you how well they're regarded.
The designer must have owned an Austin "Allegro", a dreadful 70s British car which had a 'quartic' steering wheel shaped like a rounded square, almost exactly the same shape as the SBs. The rest of the car was almost as useless.....
Geoff
I use a SB13PFC that runs full range in the workshop as a test speaker to pick out hum and other nasties in amp and electronic builds. When playing music it works better than expected and can hear no nasty edgy peaks higher up the range. It's actually a bit laid back.
I also use a little SB10PGC for testing further up the band. If I need more, I can drag out one of my other speakers but the point of these is so I don't have to.
I also use a little SB10PGC for testing further up the band. If I need more, I can drag out one of my other speakers but the point of these is so I don't have to.
I sent an e mail to the parent company that make the Goertz flat foil inductors. They do have some in between values that the major speaker suppliers don't stock. I think I might order a few odd values to play with. They are pricey for sure, almost as expensive as the SB13PFCR! But, I like experimenting and can always use them somewhere else. Does anyone out there have alternate copper foil capacitor makers and suppliers??? We have Parts Express with the Audyn which are VERY expensive. I wouldn't mind having a few different values of copper foil caps to play with but not at over $70 each!!!
On some YT, mandolin, violin, etc. MUST have a low pass for sure. After the upstairs neighbors are awake; I will put on some violin sonatas on the SACD player and try with and without the LP inductor. I have heard many violin solos live; the upper harmonics, overtones, etc are so natural. I think some recordings get it wrong here; maybe the microphone??? Maybe the lower resolution digital recording machines introduce a falseness of their own??? My old trusty NAD CD player of over 10 years died recently. I have several SACD hybrid CDs so I bought a used SACD player. It is a Sony, very nice sound even though it is older technology, even regular CDs sound much better than the NAD ever did! The point is; if a well recorded violin on the SACD player sounds "right"; I will most definitely put a switch on any LP inductor so it can be by-passed for the better recordings!
Audyn True Copper Cap 2.2uF 630V Copper Foil Capacitor
The $100 capacitor! NOT unless I have a $1000 mid or tweeter (which I do NOT!)
The $100 capacitor! NOT unless I have a $1000 mid or tweeter (which I do NOT!)
Magic and lucky 13! I have been playing a SACD of violin music; followed by a SACD of piano music. I tried 0.12 mH and 0.14 mH on the SB13; the magic number must be 13!!! 0.12 is too bright and 0.14 is too dull. These are 14 AWG regular wire wound inductors. It happens that I can get a Goertz flat foil 14 AWG in 0.13 mH! The cap. on the tweeter is also in play here. 1.5 uF is a little too much; 1.0 uF is not enough...lucky 13 again! I have some 1.0 Jantzen Superior Z caps with 0.33 uF and 0.033 uF as bypass. A resistor in series before the tweeter caps is...drum roll...13 Ohms!!! Well, it works for me anyway. If any of you have very sophisticated sim software; I would be very curious what the math and science predict! I know I am happy with the results; just curious. I WILL eventually get the REW going to make you measurement guys happy! Now on is JJ Johnson; trombone from my old home town of Indianapolis. This is a great CD; "Heroes", a large brass orchestra with also piano, sax, etc...great HiFi for a standard CD...check it out; also JJ Johnson "Brass Orchestra" titled CD...
More info on the LP. If you look at the impedance curve, you will see a rapid rise. This is why I am asking about "sophisticated" sims. Using the basic 1st order calculator, when you plug in 8.1 Ohms, you get -3 dB at 10 KHz with an inductance of about 0.13 mH. The curve shows maybe 25 Ohms at 10 KHz, obviously a huge difference from a nominal 8 Ohms. I can tell you for sure that the values I am using; 0.12 or 0.14 mH do a good job of removing harshness and too much brightness at the very top end from certain recordings. On some recordings, I can get by with no inductor at all and run these little guys true full range. I am NOT using a Zobel or any other impedance compensation. I do these listening tests with the tweeter out of the circuit so am not being fooled by that influence. Using the impedance curve at the higher frequency to calculate a filter in this case it would be 25 Ohms giving an inductor value of about 0.4 mH for -3 dB at 10 KHz. I tried a 0.39 mH, way too much attenuation of the upper mids and treble. I did not try any test tones yet or any measurements yet either. Again, a "sophisticated" sim would be useful here. It doesn't really matter in the end as I am happy with my results; it would be interesting for sure though to know more about the complex impedance say from 2 KHz all the way past 20 Khz.
Thanks Celef! What I think is that the wiggles at 4 KHz and above aren't as bad. I will get my mic and interface back soon and then try some measurements. Just my music listening tests would say it is more flat and smooth than the OEM FR but I haven't done a "real" test yet so maybe my hearing is getting worse above 4 KHz instead of above 8 KHz like it used to be!??
I just did some quick test tones and seeps; ears only. Without the tweeters in circuit. One one side I have 0.12 mH and the other side I have 0.14 mH. The response falls off above 4 KHz here. When I short across the coils, that goes up in level above (4 KHz) so it is not my hearing. The tweeters take over nicely in this region; I may still need to play with attenuation on them but I think I have the X/O about right. I will order the Goertz 0.13 mH soon. We can call this design "Lucky 13"; why not!?
Goertz 0.13 mH on order. I will also try Mudorf EVO oil/aluminum 1.0 uF with and without a bypass cap. I think with a higher resolution capacitor at 1 uF and no attentuator on the tweeter, that might be what I need. Worth a try anyway. The EVO caps aren't that expensive compared to others. I have ClarityCap, Janzen Superior Z and Standard Z, Audyn, Solen and others. These silk dome tweeters have a peak around 13 KHz which helps me but some caps tend to exaggerate this. I need the higher SPL above 10 KHz but not at the cost of harshness or graininess....more later
DX25BG60-04 - Tymphany
The "Vifa" silk dome I am using. Low Fs, high output and high power all. With FerroFluid; I prefer no FerroFluid when given the option but at this low cost, no complaints.
The "Vifa" silk dome I am using. Low Fs, high output and high power all. With FerroFluid; I prefer no FerroFluid when given the option but at this low cost, no complaints.
Now on Coltrane and Miles; best of... Until my new X/O parts get here, I'm trying different combinations of caps on the tweeters. A very good combination seems to be a 1.0 uF Jantzen Superior Z by passed by an Audyn "Cap Plus" 0.15 uF and also a CDE 940C 0.015 uF. Those of you that make fun of bypass and my experimental methods are missing out! This combination sounds better than my experiment with the copper foil cap. YES, REALLY! The top octaves of the piano have never sounded better on this little 2-way. I have a parallel combination of high quality resistors "in front of" the caps. No need for an L-Pad arrangement here since I don't need an almost constant impedance for Vacuum Tube (Valve) amplification.
Audyn Cap Plus 0.15uF 1200V Double Layer MKP Metalized Polypropylene Foil Crossover Capacitor
https://www.parts-express.com/Jantzen-0534-1.0uF-800V-Z-Superior-Capacitor-027-476
So, experimenting gets me where I need to be and that keeps me occupied and happy. Again, if you don't experiment like I do, you are missing out for sure! Also, these differences most likely can NOT be measured by home based testing. I trust my ears; the Musician's training almost ALWAYS over rides my Engineering and Technician knowledge and experience...FWIW...
Audyn Cap Plus 0.15uF 1200V Double Layer MKP Metalized Polypropylene Foil Crossover Capacitor
https://www.parts-express.com/Jantzen-0534-1.0uF-800V-Z-Superior-Capacitor-027-476
So, experimenting gets me where I need to be and that keeps me occupied and happy. Again, if you don't experiment like I do, you are missing out for sure! Also, these differences most likely can NOT be measured by home based testing. I trust my ears; the Musician's training almost ALWAYS over rides my Engineering and Technician knowledge and experience...FWIW...
Celef or others; can someone do a "quick and dirty" sim on my tweeter, cap and resistor? I assumed 4.5 Ohms on the tweeter to calculate attenuation. My combination series resistor before the cap is about 3.5 Ohms. That gives me -5 dB. My combination of capacitors is about 1.165 uF. The tweeter again below.
DX25BG60-04 - Tymphany
Thanks!
My neighbor still needs my mic and interface; he is using it for writing and recording some new songs so I told him to hang on to it for as long as he needs. So REW measurements can wait for now.
I like this combination quite well. I also like that I can get away with 1st order X/O. I do this whenever possible; the gentle slopes sound best to me under the right conditions and I like the "blend" of drivers sharing some of the same frequency band. I know this goes against many other methods and can be controversial for sure! Borrowing from my Chemistry Professor, call this a "homogeneous mixture" if you will.
DX25BG60-04 - Tymphany
Thanks!
My neighbor still needs my mic and interface; he is using it for writing and recording some new songs so I told him to hang on to it for as long as he needs. So REW measurements can wait for now.
I like this combination quite well. I also like that I can get away with 1st order X/O. I do this whenever possible; the gentle slopes sound best to me under the right conditions and I like the "blend" of drivers sharing some of the same frequency band. I know this goes against many other methods and can be controversial for sure! Borrowing from my Chemistry Professor, call this a "homogeneous mixture" if you will.
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