Keruskerfuerst is definitely trying to turn this into a 2-way design problem for himself instead of a fullrange with supertweeter as indicated by the manufacturer. A two way is not what the OP wants.
BTW, the tweeter is a horn and shows 2 resonances on the data sheet, at ~2.2 and 4.5 kHz. The tweeter graph has a logarithmic impedance plot with no scale bars.
BTW, the tweeter is a horn and shows 2 resonances on the data sheet, at ~2.2 and 4.5 kHz. The tweeter graph has a logarithmic impedance plot with no scale bars.
I do, No Filter on 8" Fullrange and only 0.47uF on T90a
and many others do if you search "Fullrange with SuperTweeter"
to OP, why dont you try what people have suggested and hear it? keep it if you like it, hate it then change it.
>>> No Filter on 8" Fullrange and only 0.47uF on T90a
The manufacturer recommends playing the full range driver without any filters and connecting a tweeter with only a capacitor between 1 and 1.5uf. This is just a suggestion. Above someone suggested a .47uf cap and I think I saw someone recommend a .68uf. Any and all of the above work but it’s up to the listener to decide what sounds best. Adding additional crossover components can also work and be made to sound good.
There are many ways to enjoy these drivers. Personally, I’d let the full range driver play without any filters and experiment with several different capacitors to find the sound that’s best. The high crossover point of the capacitor creates a gradual 6db slope allowing a blend between the two drivers. It’s not a cutoff point of 10kHz, rather a gradual blend between drivers.
The manufacturer recommends playing the full range driver without any filters and connecting a tweeter with only a capacitor between 1 and 1.5uf. This is just a suggestion. Above someone suggested a .47uf cap and I think I saw someone recommend a .68uf. Any and all of the above work but it’s up to the listener to decide what sounds best. Adding additional crossover components can also work and be made to sound good.
There are many ways to enjoy these drivers. Personally, I’d let the full range driver play without any filters and experiment with several different capacitors to find the sound that’s best. The high crossover point of the capacitor creates a gradual 6db slope allowing a blend between the two drivers. It’s not a cutoff point of 10kHz, rather a gradual blend between drivers.
As was said, what you want to do is blend the tweeter in to supplement the full range driver. This is not like the XO in a 2-way speaker.
Based on my experience of using an Eminence APT-80 to supplement a Fostex FF225wk, just try the different caps to find the one that sounds best to you. Forget about calculating the XO point.
Also: try pointing the tweeter in different directions. If you point it at the listener, the center to center distance between the FRD and the tweeter are so large that the phase relationships are untenable and will vary depending on the distance and angle of the listener from the central axis of the driver. When experimenting, I found most recordings sound best to me when the tweeter is pointed either at the ceiling or into the front corner of the room. Just play around with it until you find what works best for you. Who cares what anyone else thinks?
Cheers, Jim
Based on my experience of using an Eminence APT-80 to supplement a Fostex FF225wk, just try the different caps to find the one that sounds best to you. Forget about calculating the XO point.
Also: try pointing the tweeter in different directions. If you point it at the listener, the center to center distance between the FRD and the tweeter are so large that the phase relationships are untenable and will vary depending on the distance and angle of the listener from the central axis of the driver. When experimenting, I found most recordings sound best to me when the tweeter is pointed either at the ceiling or into the front corner of the room. Just play around with it until you find what works best for you. Who cares what anyone else thinks?
Cheers, Jim
I use the calculators just as a starting point ONLY. I ALWAYS use my ears as the fine tuning with very familiar recordings.
I am using a Fostex T90A with a capacitance of 0.74 uF. I got that value by pure experimentation and critical listening. 0.68 wasn't enough and 0.82 was too much for my personal listening tastes. The X/O calculated F3 is above 27 KHz here BUT, we are dealing with a tweeter with 106 dB sensitivity, sometimes reaching 108 dB! I tried various 2nd order X/O's and could NOT get the sound "just right". I am over 60 so I need the boost on the top octave but with just this 1st order here, the sound blends very well with my fullrange; I cannot tell where the fullrange drops off and the tweeter takes over so I have meet my "personal" goal here. Trust your own ears!
You have 2 variables to experiment with. This is the fun part of diy. You can vary the crossover frequency with different value caps, and the output level of the tweeter. I suggest that you start with the fostex values, and then change the cap value in a sequential way, and adjust the output by ear. (Generally I find that as the crossover frequency increases the output needs to be increased.)
As was said before there is also pointing the tweeter in different directions as another variable.
In this sort of adjustment, there is no absolute right and wrong. The Fostex values might suit you, but they might not.
As was said before there is also pointing the tweeter in different directions as another variable.
In this sort of adjustment, there is no absolute right and wrong. The Fostex values might suit you, but they might not.
Hi Jim - following on from your point above, would you mind telling me which of the attached options for the placement of the T90a super tweeter you would expect to produce the best results, and therefore which one you would probably go for if you were me? I’d only be using a 1.0 to 1.5uf Cap on it.
I watched the YouTube video attached ( YouTube ), which supports your suggestion and it just made sense to me, but some people in another thread i started this week, have said option A and although I’d love to experiment, i just cant: Once I’ve cut a hole, its cut, and i have to use it. I don’t have the luxury of spare time, ply or even a workshop to experiment. I also have a 6 month old baby!! I feel like B or C would be best sound based on the YouTube video, balanced with aesthetics.
Thanks in advance, Jim.
Attachments
Hi Wayne,
Whether B, C, or D would work best would depend on the room & speaker placement.
That said:
I see no need at all for cutting a hole in the box! Assuming you are talking about this tweeter:
Fostex T90A Top Mount Horn Super Tweeter
Madisound shows it on a little 'stand' composed of two dowels connected together. Don't know if that little stand is included with the T90A, but either make something like it or another sort of holder. If you cut a hole in the box so that it works for your current location, what happens if you need to re-arrange the room or move house? Besides, the T90A is so pretty, I would hate to hide it inside the box!
Whether B, C, or D would work best would depend on the room & speaker placement.
That said:
I see no need at all for cutting a hole in the box! Assuming you are talking about this tweeter:
Fostex T90A Top Mount Horn Super Tweeter
Madisound shows it on a little 'stand' composed of two dowels connected together. Don't know if that little stand is included with the T90A, but either make something like it or another sort of holder. If you cut a hole in the box so that it works for your current location, what happens if you need to re-arrange the room or move house? Besides, the T90A is so pretty, I would hate to hide it inside the box!
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