For what it´s worth I use a FMR Really Nice Preamp to power my mic and the RTX Analyzer as audio interface.
The RNP has switches for setting gain (like the RTX) which I like as it helps make measurements more repeatable. Nice build quality too. There is a used one for sale on Reverb.
The RNP has switches for setting gain (like the RTX) which I like as it helps make measurements more repeatable. Nice build quality too. There is a used one for sale on Reverb.
You can get an M4 for 270 bucks on Amazon. Oh, and I forgot to mention it even has a power switch, which is rare for a bus powered interface.
I bought a new M4 on eBay today for $269.00. I decided the RTX solution wasn't the right one for me due to the need for multiple power connections, boxes and it's not as portable.
You'll be very pleased with the M4. Its a bargain for the performance. I can get good results running both my SM7B and TLM103 through it, which isn't the case on other cheap interfaces due to the amount of clean gain they both need. The direct monitor provision is also great and the latency is in the lower single digits. In an AB test it was virtually impossible to distinguish the M4 from my Apogee mastering converters, which is impressive for a bus powered interface.
Here is a first concept for a throat adaptor expansion aiming to produce a more "cylindrical" shaped wavefront at its rectangular output, as it seems that this would be beneficial to the TAD TH-4001 and Yuichi A-290 bi-radial horns. It is nice that a 1.4" size driver provides ample length for phase transition. The use of "bumps" as shown is not quite optimal (e.g. small diffraction at the edge of the "bumps"). Still I would expect this expansion to work well, better than my Custom prototype #1, which is already better than the off-the-shelf options I have tried.
There is obvious similarity to some transitioning waveguides that are out there. I wonder if anyone has seen this concept applied in throat adaptors before?
There is obvious similarity to some transitioning waveguides that are out there. I wonder if anyone has seen this concept applied in throat adaptors before?
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Yes, pinching the throat does seem to be one of the few options you have so I'll be curious how it works out.
Are you using a support under the driver that removes the strain on the adapter?
Are you using a support under the driver that removes the strain on the adapter?
No need for support. The adaptor is made of PETG and is strong enough - at least for this driver.
Perhaps. In any case, strain with regards to vibration or breaking may be different things, there are many variables however I'm working with PETG at the moment and I find it can tend to break along layer boundaries..
It looks like your layers have simply not bonded properly during the printing process. This is not the material’s fault but a printer adjustment issue.
PETG can be a pain to print (stinky, stringy, sticky and all) but after appropriate adjustment of printer parameters it is very high strength and durable. It is known to be much better than PLA for parts submitted to physical stress.
PETG can be a pain to print (stinky, stringy, sticky and all) but after appropriate adjustment of printer parameters it is very high strength and durable. It is known to be much better than PLA for parts submitted to physical stress.
You could be right, I have a lot yet to try. It should be clear that I broke this myself to test it.
What temperature have you been using?
What temperature have you been using?
A local mechanical engineering firm print these for me. What I know is the temperature is high for layer bonding (which is critical as you showed) and it must print slow. They print half scale versions to validate their adjustments for the specific PETG material used and the adapter shape.
Thank you for asking. It depends what you mean by simulation. If you mean something like computational flow dynamics, then the answer is no. (not my field)
The shape is mathematically-computed from a model derived from simple logic. For instance the drawing explains the key principle for spherical to cylindrical transformation. Once the throat expansion has been generated by my software, it calculates the surface area every few mm from entrance to exit, and compares these areas to the target hypex areas. I look at the errors and decide if I want to make changes to the model.
As an example, Prototype #2 that is currently printing does not have a flat roof. The height profile from entry to exit is elliptic, starts at 4 degrees (same as the driver exit half angle) and finishes at 0 degrees (same as entrance of the wood horn). This smooth transition also happens to increase a bit the volume in the middle of the adapter which yields a better fit to the series of objective hypex areas.
In the end, I trust measurements and listening results, and since this is DIY, an iterative improvement process (improve, build, measure, repeat) keeps me happy
.
The shape is mathematically-computed from a model derived from simple logic. For instance the drawing explains the key principle for spherical to cylindrical transformation. Once the throat expansion has been generated by my software, it calculates the surface area every few mm from entrance to exit, and compares these areas to the target hypex areas. I look at the errors and decide if I want to make changes to the model.
As an example, Prototype #2 that is currently printing does not have a flat roof. The height profile from entry to exit is elliptic, starts at 4 degrees (same as the driver exit half angle) and finishes at 0 degrees (same as entrance of the wood horn). This smooth transition also happens to increase a bit the volume in the middle of the adapter which yields a better fit to the series of objective hypex areas.
In the end, I trust measurements and listening results, and since this is DIY, an iterative improvement process (improve, build, measure, repeat) keeps me happy
.