Sharp assumes that damping will slow down the spped of sound. This has been shown to be false (the actual change in harmonics is due to the line taper0.
Joe worked from an early iteration of Augspurger's work, which althou on par with Martin's work at the time, has not been extended or refined. Martin has advanced things considerably since then. Also, after developing the line using George's (skimpy) alignment tables, and then arbitrarily shrunk everything... then he made a mistake when measuring, the erroneous results of which "confirmed" that the arbitrary shrinkage was OK. Turns out the original Thor TL is correct for only 1 driver.
To get any accurate analytic results you need to use MJK, either the free tables or paid for worksheets.
Short Thor is short because of the mass loading of the terminus.
dave
Nice to see the holey braces i have championed, but you did not take advantage of the driver braces -- these help improve downward dynamic range.
dave
Is that 6m8H (6.8mh) coil value correct?
Or, should it be 0.68mh (0m68H)?I ask because the resistance given for the 6m8H coil in your schematic is 0R18 which happens to be nearer 0m68H 14gauges resistance and the 6m0H 14 gauge coils is 0R67. For the Solen Perfect Lay coils.
I am sorry Dave? You have championed a holly brace? I must be misguided soul.
I think I will wear my holly braces for Xmas Mass.
It looks like R-Carpenter has added a separate layer behind the front baffle for added rigidity, that would help transfer the driver's basket energy to the cabinet.
Nice looking build R-Carpenter! What are your plans for the exterior? I've wanted to use Usher drivers too. Got a link to your calculations and build?
Inquiring minds want to know!
Ron
Nice looking build R-Carpenter! What are your plans for the exterior? I've wanted to use Usher drivers too. Got a link to your calculations and build?
Inquiring minds want to know!
Ron
Heya, thanks. No link and the calculations are long gone.
sorry. I can dig up the info between my home and work computer. The crossover was 4th order electrical. In the begining I had 4 db BSC added but the speakers ended up back to the wall and BSC was taken out. Attached is the impedance of 2 woofers in the filled line and FR.
This project is actually about a year old and was sold to a friend.
I added a layer of elastomer to the back of the front baffle. I do find it very effective but speculation aside I am a happy owner of the accelerometer so all the guessing will be gone soon and Plywood vs MDF or bracing every which way can be verified.
The idea was to build a similar TL based on the same method that D'Appolito used but with the more budget minded drivers. At that it was a success. The exterior was not fancied up. All corners took 3/4 round over and satin black lacquer.
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Has anyone compared Jimangie's most recent LR4 crossover with the one he designed a couple of years ago. People seemed to like the earlier version. He thinks the current version is better, but I have not seen anyone describe the difference in sound. It looks like the current version moves the crossover point up about 500 hz
88,
That stands to reason, moving the XO point 500 hz would sound that way.
While voicing my XOs, I changed the value of a cap to add a touch more sparkle to the mid/top end. I'm a happy camper now.
acold7,
Many of us have found sonic happiness with a tube preamp and a SS amp driving the mains. YMMV.
A friend is working on my F5 that I fried, I was impressed with the clarity and volume from a smaller wattage amp. Have you considered a DIY amp?
Ron
I will be building a small thor next month and I have a couple of questions, this will be my first build:
1) Is there any sound quality difference with putting the XO outside of the speaker cabinet?
2) Is there any sonic difference with deleting the speaker posts and going directly from the XO to the Amp with the speaker cable? I dont even know if this is possible
1) Is there any sound quality difference with putting the XO outside of the speaker cabinet?
2) Is there any sonic difference with deleting the speaker posts and going directly from the XO to the Amp with the speaker cable? I dont even know if this is possible
If it's your first speaker build you might want to mount the XO on the outside so that it can be changed -- or you need an XO board of a size and placement so that it can be removed and altered. I don't know too many Thor builders who haven't tweaked their XO's.