The real problem with the little Vifa ia not so much efficiency as it is displacement. It can't keep up with the dual 15s when running loud, it runs out of steam, so to speak. That is mostly X-max. It is just working too hard to move enough air.
John has some suggestions for a bigger speaker with and 18" woofer, mid and tweeter. He'll post details here soon.
John has some suggestions for a bigger speaker with and 18" woofer, mid and tweeter. He'll post details here soon.
Hi all!
I'm full new on this forum and in addition i'm french, so my english might be a bit poor or wrong, sorry in advance for that.
Last year i went to Danemark to visit a friend who present me his custom "ultra+" (4 drivers : 2x15" + 1xfull + 1xtweet) and i really fall in love with the esthetic and THE SOUND!!!
Now i'm ready to build mine and hesitate between the ultra and the ultra+, not sure if the 2nd woofer will bring me a real difference (room of 25m²).
My question is about the amplifier.
I have the choice to buy a NADC316bee from 2015 or a Sony TA-FA3ES from the 90's
Anyone an advice??
Thanks
I'm full new on this forum and in addition i'm french, so my english might be a bit poor or wrong, sorry in advance for that.
Last year i went to Danemark to visit a friend who present me his custom "ultra+" (4 drivers : 2x15" + 1xfull + 1xtweet) and i really fall in love with the esthetic and THE SOUND!!!
Now i'm ready to build mine and hesitate between the ultra and the ultra+, not sure if the 2nd woofer will bring me a real difference (room of 25m²).
My question is about the amplifier.
I have the choice to buy a NADC316bee from 2015 or a Sony TA-FA3ES from the 90's
Anyone an advice??
Thanks
Pano,
I was hoping to do a two way with double 15" woofers, but an acceptable full range/tweeter is hard to find? Might I be better off waiting for John's suggestion for an 18" three way? My concern is that three ways generally involve much more complicated crossovers. One of the attractions of the Manzanita style build is the simple crossover.
Expanding a bit on the Vifa TC9. True mid band half space forward output efficiency is around 84 db/watt/mtr. Used in an OB set up you gain about 4.5 db or so of added mid band output from the rear output, provided the baffle width is greater than 12" and you keep above 300 hz or so. The rear output will droop from around 3,500 hz up due to the shadowing effects of the frame and magnent assembly. So, mid band you have about 89 db of total output at the listening position, which, is more than enough to keep up with a pair of parallel wired GFS 15's. Where you run into trouble is with the Vifa working all the way out to 18Khz, once you input enough power into it and approach about 1/3 the rated 2.4 mm xmax the cone and suround really start to flex alot and you can hear it. Keep the volume down and it is all good. Push it hard it is going to tell you. That is one of the trade offs. The Vifa can really play full range, but to do that the cone and Xmax need to be realitively small.
So, I need a speaker with either significantly greater xmax or cone area--or both. Or, I can wait for the new 18" three way? Or, build a horn for the TC9 which is beyond my capabilities.
Yes. As they say, there is no replacement for displacement. @John Busch how many cc would it need? You told me, but I forgot.
So probably any FR between 88-90 dB sensitivity. A bit less if you want to lean on the woofers more.
dave
dave
Well maybe no "any". With the dual 15 inch woofer you'll want to turn it up and a 3" driver can't keep up when things get loud. I'd think 5" fullrange minimum.
A pair or quad of tc9s will do nicely.
For the quad just reduce the pad, no major mods needed.
I tried a quad last year, more spl potential than I will need till the garage gets done.
For the quad just reduce the pad, no major mods needed.
I tried a quad last year, more spl potential than I will need till the garage gets done.
my concern about using a pair of the tc9's is comb filtering. It seems like this might be a problem?
Given the resolution of those drivers, unlikely a. big issue. And the further you sit the less the (potential) issue.
dave
dave
If you like to sit between the speakers (like a Rodriguez cartoon), you can lose the trap that lowers the rising top end.
If you 'social distance' from your speakers, you'll be fine.
Remember we are crossing from the woofer very low, and there is no crossover between the TC9s.
And even for Shaq, these are not desktop speakers.
If you 'social distance' from your speakers, you'll be fine.
Remember we are crossing from the woofer very low, and there is no crossover between the TC9s.
And even for Shaq, these are not desktop speakers.
How would you place them? Vertical and close together? Would this provide enough volume to match the two bass drivers?
You "could" low pass one of them so that two carry the low end and only one on the top end. I've done this with the TC9 is a sort of line array. 4 of them carried the low end, 1 the top. It can be a bit touchy. Given the choice, I'd go with a bigger driver - and have done.
A small, vertical line tucked into the curve of the upper woofer.
Wired series/parallel for 8 ohms.
Both your sensitivity and max spl will be raised 6db, hence the lessened reduction on the TC9s.
At 'big speaker' distances, 4 TC9s against each other acts more like an oval driver than a 'line array'.
Up close and personal, it's a different story. SPL and frequency shading become practical.
Wired series/parallel for 8 ohms.
Both your sensitivity and max spl will be raised 6db, hence the lessened reduction on the TC9s.
At 'big speaker' distances, 4 TC9s against each other acts more like an oval driver than a 'line array'.
Up close and personal, it's a different story. SPL and frequency shading become practical.
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Hello again!
I wanted to share my new manzanita 3 way build..
I was taken by OB sound after I build manzanita ultra which was my first DIY build.
Although I enjoyed the sound there was part of me that wanted little bit more performance in the top end.
After playing with Mark Audio drivers (good presentation, but lot of coloration) I decided it was time to try a 3 way build.
I had pair of sb29rdc lying around so why not.. For most part I repurposed the manzanita crossover best I could, working around the few spare inductors, caps and resistors I had on my hands, hence the some weird choices.. Crossover points are around 300hz and 1800hz.
Letting the tc9 take care the midrange (instead of grs) completely transformed the sound signature.
Grs low end is still there, but midrange is much more dynamic and nuanced and speaker is sparkling with details.
Ambient feel of OB is still there, but now with wider soundstage and whole new dimension of imaging and detail.
Overall signature is silky smooth and gentle and works well with all genres, but for some reason I couldn't stop listening classical music..
Response was measured 1.5m from the speaker. <100hz bump flattens when you move speakers further from the rear wall.
btw vifa will get round plastic ring 😀
Thank you John and Pano for inspiration!
Frane
I wanted to share my new manzanita 3 way build..
I was taken by OB sound after I build manzanita ultra which was my first DIY build.
Although I enjoyed the sound there was part of me that wanted little bit more performance in the top end.
After playing with Mark Audio drivers (good presentation, but lot of coloration) I decided it was time to try a 3 way build.
I had pair of sb29rdc lying around so why not.. For most part I repurposed the manzanita crossover best I could, working around the few spare inductors, caps and resistors I had on my hands, hence the some weird choices.. Crossover points are around 300hz and 1800hz.
Letting the tc9 take care the midrange (instead of grs) completely transformed the sound signature.
Grs low end is still there, but midrange is much more dynamic and nuanced and speaker is sparkling with details.
Ambient feel of OB is still there, but now with wider soundstage and whole new dimension of imaging and detail.
Overall signature is silky smooth and gentle and works well with all genres, but for some reason I couldn't stop listening classical music..
Response was measured 1.5m from the speaker. <100hz bump flattens when you move speakers further from the rear wall.
btw vifa will get round plastic ring 😀
Thank you John and Pano for inspiration!
Frane
Attachments
Very cool. Those look great - the feet are a nice touch. Even your impedance plot looks good. 
Thanks for the explanation of the evolution and modification. I don't know that tweeter, but John might, I think he has a lot of SB drivers. This just goes to show what a basically good design can do and how flexible it is.
Let's hope your experience encourages many other to start down this path.
Thanks for the explanation of the evolution and modification. I don't know that tweeter, but John might, I think he has a lot of SB drivers. This just goes to show what a basically good design can do and how flexible it is.
Let's hope your experience encourages many other to start down this path.
Verrr' nice.
The wood grain and wing taper together make them more interesting than imposing.
And your low tweeter crossing point avoids problems with driver arrangement, and lets you keep those pretty baffles.
The wood grain and wing taper together make them more interesting than imposing.
And your low tweeter crossing point avoids problems with driver arrangement, and lets you keep those pretty baffles.