Im a little lost here about this Purifi TL thread,, but where to put the
the damping.
You are so active xrk971!
Could you sketh up something?
And also an Xsim with Dayton audio rst28f-4rd without WG-300 or what crossover you recommend.
It's nearfield listening listening for me,
desktop.
I have the speakers mounted in a 10L old box and it's the best I heard!
But going to build these TL!
Love you for your DIY affort!
the damping.
You are so active xrk971!
Could you sketh up something?
And also an Xsim with Dayton audio rst28f-4rd without WG-300 or what crossover you recommend.
It's nearfield listening listening for me,
desktop.
I have the speakers mounted in a 10L old box and it's the best I heard!
But going to build these TL!
Love you for your DIY affort!
Hi Solve,
I tried damping with one wall of the labyrinth covered with eggcrate foam and without. Both times the rear chamber of the TL adjacent to the driver is completely covered in eggcrate foam. I think I like the version where the labyrinth has one wall covered in foam per the original sketch is best. It helped to reduce a 300Hz resonance bump. You can completely substitute the eggcrate polyurethane with melamine foam and that will be even better. The melamine won’t rot in 20 years and absorbs the back wave better.
Here is sketch of the damping plan, use 10cm melamine sponges if possible or the thinner eggcrate foam. Not 2in thick eggcrate in labyrinth as that would construct flow too much. The last bit of foam on back wall is something I think may help but not tested yet. If you made a removable back wall that can be adjusted. Else, there is risk it may be too much damping. But I think the 1cm thick melamine should be fine there.
Regarding XO for RST28F without waveguide. I have not measured it as such as I don’t have a baffle for a plain tweeter. You will need to measure that yourself and I can help with the XO if you provide the FRD file in your baffle.
It will not have the proper time alignment for Harsch passive XO so 2nd or 4th LR will probably work. Also maybe explore Harsch with inverted RST28F like I did on the foam core LS3/5A.
RST28F and DC130A Foamcore Homage to LS3/5A
Good luck!
I tried damping with one wall of the labyrinth covered with eggcrate foam and without. Both times the rear chamber of the TL adjacent to the driver is completely covered in eggcrate foam. I think I like the version where the labyrinth has one wall covered in foam per the original sketch is best. It helped to reduce a 300Hz resonance bump. You can completely substitute the eggcrate polyurethane with melamine foam and that will be even better. The melamine won’t rot in 20 years and absorbs the back wave better.
Here is sketch of the damping plan, use 10cm melamine sponges if possible or the thinner eggcrate foam. Not 2in thick eggcrate in labyrinth as that would construct flow too much. The last bit of foam on back wall is something I think may help but not tested yet. If you made a removable back wall that can be adjusted. Else, there is risk it may be too much damping. But I think the 1cm thick melamine should be fine there.
Regarding XO for RST28F without waveguide. I have not measured it as such as I don’t have a baffle for a plain tweeter. You will need to measure that yourself and I can help with the XO if you provide the FRD file in your baffle.
It will not have the proper time alignment for Harsch passive XO so 2nd or 4th LR will probably work. Also maybe explore Harsch with inverted RST28F like I did on the foam core LS3/5A.
RST28F and DC130A Foamcore Homage to LS3/5A
Good luck!
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Im not sure I understand your skectch.
Those oblique line means?
"If you made a removable back wall that can be adjusted"
I thinking removable sidewall. 🙂
Those oblique line means?
"If you made a removable back wall that can be adjusted"
I thinking removable sidewall. 🙂
I just ordered another set of Monacor WG-300 waveguides from soundimports.eu. About $53/pair including tax and shipping to US. They are list 10Euro ea.
Homepage - SoundImports
Homepage - SoundImports
Hey X,
Given you have a 3D printer, why not make your own waveguides? Augerpro has generously shared his design and it caters to the RST28F dimensions.
Given you have a 3D printer, why not make your own waveguides? Augerpro has generously shared his design and it caters to the RST28F dimensions.
Printing a 7in dia waveguide is a slow process and the filament cost is probably more than the 10 Euro price tag of a WG300. It's easier to print the adapter. I will try it one day but if a commercial one is available and inexpensive, better to buy it.
Does the RST28F fit the WG300 qually well? Is the output of this combination also as well behaved?
Never mind, I just saw that the RST28F is supposed to work on the waveguide as well. Although the (axial) frequency response appears to be significantly different at certain ranges. Also, how well behaved is it non-axial, 0° - 60° horizontally?
Can the bigger grille of the RST28F be removed without too much risk of damaging anything? Would this allow it to be mounted to the waveguide without additional felt?
Can the bigger grille of the RST28F be removed without too much risk of damaging anything? Would this allow it to be mounted to the waveguide without additional felt?
I never measured polars for the RST28F. At 0deg they are very similar so I would say the polars will be similar. The felt spacer seems to do a good job of adapting the WG300 to RST28F. Listening to it -the off axis variation within 60deg was undetectable by ear.
Here is 0deg:
Here is 0deg:
My new set of WG300 waveguides just arrived. That was pretty quick - shipped from Sound Imports in NL. 10Euro for a made in Germany waveguide with shipping was about $50 for the set. Nicely made with brass thread inserts in the back. Much better than 3D printing at home. Just print the adapter is more effective.
STL file for the adapter plate is here:
Simple Passive Harsch XO Using PTT6.5 and RS28F in a Waveguide
STL file for the adapter plate is here:
Simple Passive Harsch XO Using PTT6.5 and RS28F in a Waveguide
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Cool guys, good too see that you have the wave-guides in hand.
Solve,
Sorry if this has been already discussed before, you have the PTT6.5 woofers and decided on the cabinet design?
Solve,
Sorry if this has been already discussed before, you have the PTT6.5 woofers and decided on the cabinet design?
That's a very nice fit Solve! It might provide even better coupling and reduce and driver-waveguide reflection dips near the throat.
Nice! Great to see that someone else will try this. I would add some melamine foam or felt on on one side of the labyrinth walls though.
Good luck on your build!
Is it necessary to time align the WG-300 to Purifi?
I tried 0.16 ms delay on Purifi and like the sound but don't know if it's right?
I tried 0.16 ms delay on Purifi and like the sound but don't know if it's right?
Did you consider the dt-300 tweeter that the wg-300 is designed for? Cursory looks appears that it might be a candidate. I have no experience with this tweeter nor how it sounds bit it is used in some decent projects and has recommended crossover point of 2k with good power handling. I have the ptt6.5 coming in 8 ohm and am considering your TL but have no suitable tweeter so am on the hunt. Maybe the HDS is worthy also?
I have not considered the DT-300. I have lots of RST28F's and now just got a pair of the aluminum version RST28A's. The factory does not have a frequency spectrum? Specs ook similar except it is 8ohms so the XO would have to be redone.
MONACOR: DT-300
MONACOR: DT-300
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