gychang said:
This is a set of guidlines i use to estimate XO point...
2 uF on 8 ohms is a 10k XO, Halve the cap value and you double the XO point (ie 1 uF = 20k), Double the cap, halve the XO (ie 4 uF = 5k)
Halve the impedance, you need to double the cap size to maintain the same XO, (ie 4 ohm requires 4 uF to get the 10k XO).
Double the impedance, you need to halve the cap size to maintain the same XO, (ie 16 ohm requires 1 uF to get the 10k XO).
So 1 uF on 6 ohms = 30 kHz. 2 uF = 15k, 4 uF = 7.5 kHz. So i'd start at 2 or 3 uF and add small caps until you start getting too much top, then back off a bit.
dave
gychang said:
It is kinda hard to see, but we are talking about using the same technique PhyHP uses in the KM30
An externally hosted image should be here but it was not working when we last tested it.
http://www.phy-hp.com/English/Products/Details_KM30_450.html
For the 2nd method have a look here
http://www.timn8er.com/coral_open_baffle_project.htm
An externally hosted image should be here but it was not working when we last tested it.
Like Tim, i'd use a piece of wood before wires.
dave
Veil has been lifted, shocking!!
If you have been following the thread, I have been disappoinged with B20 in the Chang cabinet.
I installed the $5 tweeter pictured above, and with help from everyone I installed with 2uF cap, shockingly different sound. Clear and with airiness, can't believe the change in sound. First song was Lee Ritenour, Color Rit. I am sure those are steel wires on his guitar, twinge of high notes are shockingly natural. Truely spine tingling. I now know the other speakers I have been building is not in the same league. Compared to my reference "zigmahornet" with Dave Merrills drivers, it does not place the instruments in the space as well, but overall sounds more full, in particular orchesteral music is much better in the Chang. Without the tweeter, James Taylor had a touch of sinus condition, now he is cured. Do I seem excited??, yes shockingly so. Amazing what science and cheap tweeter can do.
thanks everyone, Scott, Dave, and Ron can be rest assured they have a winner here. Muchos gracias!!.
gychang
If you have been following the thread, I have been disappoinged with B20 in the Chang cabinet.
I installed the $5 tweeter pictured above, and with help from everyone I installed with 2uF cap, shockingly different sound. Clear and with airiness, can't believe the change in sound. First song was Lee Ritenour, Color Rit. I am sure those are steel wires on his guitar, twinge of high notes are shockingly natural. Truely spine tingling. I now know the other speakers I have been building is not in the same league. Compared to my reference "zigmahornet" with Dave Merrills drivers, it does not place the instruments in the space as well, but overall sounds more full, in particular orchesteral music is much better in the Chang. Without the tweeter, James Taylor had a touch of sinus condition, now he is cured. Do I seem excited??, yes shockingly so. Amazing what science and cheap tweeter can do.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
thanks everyone, Scott, Dave, and Ron can be rest assured they have a winner here. Muchos gracias!!.
gychang
if one were to try to replace the dustcap with the tweeter, what is the best way to run the tweeter wires? Do you just hang 'em out front, or is there a more clever way?
AdamThorne said:
That in the end is one of the trickiest bits. If the driver had a vented pole piece it could be run thru there. You could punch it thru the cone, like the main voice coil wires but that should really be done with tinsel. In the end just draping them across the gap is easiest (if you use magnet wire it could at least be done innocuously.
dave
Does that mean you like them Greg? 😀
Hmm. DIY co-ax on the cheap. I like the idea of that, so long as the main unit had the aforementioned vented pole-piece, so the wires could be hidden fron view.
Hmm. DIY co-ax on the cheap. I like the idea of that, so long as the main unit had the aforementioned vented pole-piece, so the wires could be hidden fron view.
Scottmoose said:
No need for cone surgery for me at this time... I am going to enjoy the Chang for now.
gychang
We've been talkig about the DIY coax for a few years here, but there have been problems in a lot of the projects that we have considered.
The Pioneer BOFU and this new tiny tweeter do look like the best combo yet...
One dead end we have discussed involved pro woofers. The 4" voice coil seemed to give lots of room to mount the tweeter, but then the tweeter needed to be highly efficient and cover quite low frequencies which required a BIG tweeter- too big...
In this case the Pioneer driver isn't terribly efficient (91db I believe) so a dome tweeter will work fine. The Pioneer also covers up to pretty high frequencies, so, the tweeter just needs to cover the treble.
The tiny Parts express tweeter is the final piece of the puzzle- it is TINY, and the small dome is perfect for the very high frequencies that it will cover..
FINALLY ... The parts are cheap, so the risks are small...
It seems to me the optimal setup would be a short wooden dowel/phase plug that would taper down a little bit before flattening for the the tweeter to be glued on....The voice coil is 1.5" the tweeter 1.25"
The tinsel lead could be taken from another, destroyed speaker...
Mr Chang: I agree, just enjoy your speakers "Don't fix 'em if they ain't broke" 😉
\
The Pioneer BOFU and this new tiny tweeter do look like the best combo yet...
One dead end we have discussed involved pro woofers. The 4" voice coil seemed to give lots of room to mount the tweeter, but then the tweeter needed to be highly efficient and cover quite low frequencies which required a BIG tweeter- too big...
In this case the Pioneer driver isn't terribly efficient (91db I believe) so a dome tweeter will work fine. The Pioneer also covers up to pretty high frequencies, so, the tweeter just needs to cover the treble.
The tiny Parts express tweeter is the final piece of the puzzle- it is TINY, and the small dome is perfect for the very high frequencies that it will cover..
FINALLY ... The parts are cheap, so the risks are small...
It seems to me the optimal setup would be a short wooden dowel/phase plug that would taper down a little bit before flattening for the the tweeter to be glued on....The voice coil is 1.5" the tweeter 1.25"
The tinsel lead could be taken from another, destroyed speaker...
Mr Chang: I agree, just enjoy your speakers "Don't fix 'em if they ain't broke" 😉
\
Variac said:
In my book, the combo is about perfect for now. I only picked the tweeter because the other one was sold out!, talk about luck.
I listened for nearly one hour today, getting behind my latest project, Suzy Chang cabinet...
gychang
Hey Greg, glad you like the little tweeter! I figured 2uF would be plenty, I often use them with just 1uF.
Getting them in front of the driver can make a subtle difference, but that may well depend on your rig. Try a temporary center mount, like the wooden rig shown above. Decide if it's really worth it.
I don't know if yours came with the little foam pieces in the box, but I leave those on the tweeter when in front of the whizzer. Even add a little felt sometimes. Worth playing with.
Those are great looking speakers. How much more did you spend on wood and glue than on drivers?
Getting them in front of the driver can make a subtle difference, but that may well depend on your rig. Try a temporary center mount, like the wooden rig shown above. Decide if it's really worth it.
I don't know if yours came with the little foam pieces in the box, but I leave those on the tweeter when in front of the whizzer. Even add a little felt sometimes. Worth playing with.
Those are great looking speakers. How much more did you spend on wood and glue than on drivers?
panomaniac said:Hey Greg, glad you like the little tweeter! I figured 2uF would be plenty, I often use them with just 1uF.
Getting them in front of the driver can make a subtle difference, but that may well depend on your rig. Try a temporary center mount, like the wooden rig shown above. Decide if it's really worth it.
I don't know if yours came with the little foam pieces in the box, but I leave those on the tweeter when in front of the whizzer. Even add a little felt sometimes. Worth playing with.
Those are great looking speakers. How much more did you spend on wood and glue than on drivers?
Tiny tweeter makes the world of difference, totally surprised. No foam or felt came with the tweeter. Indeed the plywood, glue, etc, cost more than the driver!!.
Enjoy your great mods on amps, wish I can do that. I am going to try t-amp mod but already failed to build amp6BASIC...
gychang
The Super 12 came to mind reading through all this.
http://www.enjoythemusic.com/magazine/equipment/0600/super12.htm
Congratulations on a great build.
The design process and evolution is fascinating.
http://www.enjoythemusic.com/magazine/equipment/0600/super12.htm
Congratulations on a great build.
The design process and evolution is fascinating.
gychang said:
Well just stick to speaker building then, you're doing a great job! My woodworking skills are awful, so I generally hide all my mistakes under some sort of covering.
Your big BLH are a nice looking design, well executed. I might even try them sometime in the future - (but no photos).
It does sound like the Pioneer BOFU and the little Neo tweet might be a great, low cost combo. Not exactly "full range" but close. Driver cost - under $60 US for the set!
panomaniac said:
I refused to give up on the amp!, those tiny things are frustrating at times, now I have a magnifier and will go slowly...
Clearly winning combo in my book (BOFU+Neo tweet).
gychang
Couldn't we simply "vent" the pole piece ourselves with a drill? Use magnet wire to hook up so we only remove the most minimal amount of magnet. Any reason why that wouldn't work?
Kensai
Kensai
I wonder of the filings from drilling would be attracted to the magnet and cause havoc
Yep! If you look at the field gap between the VC and the magnet there aint much room. Lowther owners (underhung VC) live in fear of debris in the motor.
ron
Yep! If you look at the field gap between the VC and the magnet there aint much room. Lowther owners (underhung VC) live in fear of debris in the motor.
ron
Cal Weldon said:
There is also a tendency to remove the magnetism from the magnet. I have seen it done, but the guy was able to completely disassemble the drivers before drilling, and conveniently had a magger in the shop.
dave
- Status
- Not open for further replies.