ATH330EX + Selenium D2500Ti-Nd.
For some reason I'm always happy with this driver, no matter how it's used.
And there's a big mismatch of the exit angle in this case.
BTW, this is the same driver in a bigger horn with a conical throat extension, starting at the phase plug exit:
http://www.at-horns.eu/exar-story.html#d2500
For some reason I'm always happy with this driver, no matter how it's used.
And there's a big mismatch of the exit angle in this case.
BTW, this is the same driver in a bigger horn with a conical throat extension, starting at the phase plug exit:
http://www.at-horns.eu/exar-story.html#d2500
Last edited:
The same 1" driver (Peerless DFM-2535) in three different (free-standing) devices, from small to large:
- I think a different approach is needed. It seems to make the most sense to separate the horn and the whole extension part, as it was done in the original experiment. Since the directivity limitation of a 1.4" throat seems still acceptible, the horn part would start at this diameter and the extension part could be more flexibly optimized for a particular driver, including a possible throat ring. The question is what throat angle of the horn to choose. In the experiment this was 6° (total), so maybe something around this value.
And again, it just shows that it doesn't make sense to waste time with small devices.
- I think a different approach is needed. It seems to make the most sense to separate the horn and the whole extension part, as it was done in the original experiment. Since the directivity limitation of a 1.4" throat seems still acceptible, the horn part would start at this diameter and the extension part could be more flexibly optimized for a particular driver, including a possible throat ring. The question is what throat angle of the horn to choose. In the experiment this was 6° (total), so maybe something around this value.
And again, it just shows that it doesn't make sense to waste time with small devices.
Last edited:
Could you post associated impedance plots as well? Thanks! Look how the dip ~2kHz is replaced by peak on the last device. It seems one could have ~flat frequency response at least with this particular driver, choosing something in between. I assume this stuff is readily seen in the impedance plots, and if it is one could optimize for smooth FR comparing driver impedance to waveguide impedance.
edit. actually, the datasheet shows no (driver) impedance wiggle around 2kHz, so all of the differences are from the waveguides and how it's impedance affects the response?
https://products.peerless-audio.com/transducer/438
edit. actually, the datasheet shows no (driver) impedance wiggle around 2kHz, so all of the differences are from the waveguides and how it's impedance affects the response?
https://products.peerless-audio.com/transducer/438
Last edited:
I will do the electrical impedances separately later, but I'm not so optimistic it will be that easy. The question is what is a "waveguide impedance" - where to look at? At the phase plug exit of a driver, or even closer to the diaphragm? Certainly at the exit of a driver it's too late, as the exit section has its effect. It's a coupled system which only a part of we know something about separately.
I think we would need to start modelling the whole drivers. Way above my pay grade.
I think we would need to start modelling the whole drivers. Way above my pay grade.
Last edited:
What kind of difference simulated throat impedances have (from ABEC)? Frequency response wiggle between 330EX and the 460-36/EXT are almost opposite ~1-4kHz, perhaps the simulated impedances gives a hint. Perhaps results are specific to this driver, but perhaps there is some information to be extracted.
The DFM2535 seems to be nice test subject for this kind of stuff, with very smooth response.
The DFM2535 seems to be nice test subject for this kind of stuff, with very smooth response.
I think the electrical one is implied and I think that would be the most interesting to see. It all reflects, albeit lumped, to the electrical side - and if two different WGs use the same driver individual, the difference should be the WG - no?
At 10k, there is a 4 dB difference at the widest trace - its some...
//
How about:
Use the impedance jig with REW as usual but also capture what comes out of the jig as an ordinary sweep - now one can do all the analysis of a microphone measurement e.g. distortion, waterfall .. what not, but the view is now on the electrical "impedance" domain... see to that noise level is low - one now has a giant microphone at hand
//
Use the impedance jig with REW as usual but also capture what comes out of the jig as an ordinary sweep - now one can do all the analysis of a microphone measurement e.g. distortion, waterfall .. what not, but the view is now on the electrical "impedance" domain... see to that noise level is low - one now has a giant microphone at hand
//
Looks great! I'd like to try that horn with the 65CDN-T with Troy's custom-made rear chambers. Any hope for this being made available as a full kit on Cults in due course?
For those interested, this is what 7 Biquads can do on these devices i.e. well within MiniDSP 4x2 HD capabilities.The same 1" driver (Peerless DFM-2535) in three different (free-standing) devices, from small to large:
View attachment 1293860
View attachment 1293861
View attachment 1293862
- I think a different approach is needed. It seems to make the most sense to separate the horn and the whole extension part, as it was done in the original experiment. Since the directivity limitation of a 1.4" throat seems still acceptible, the horn part would start at this diameter and the extension part could be more flexibly optimized for a particular driver, including a possible throat ring. The question is what throat angle of the horn to choose. In the experiment this was 6° (total), so maybe something around this value.
And again, it just shows that it doesn't make sense to waste time with small devices.
Actually with the MiniDPS much steeper slopes could be easily implemented on top of advanced EQ.
Last edited:
The question is: With the same driver, does a known change in throat impedance lead to a predictable change in SPL response, given that the change in the throat (acoustic) impedance is all we know?
We can easily measure SPL of a combination driver+horn, and we can (also quite easily) calculate the throat impedance of the horn. What else do we need to know to predict how will the SPL change if the throat impedance changes? If we were able to calculate this, it would be a win. But I don't think it's this easy. It would be too simple
Sorry, I don't follow.
Last edited:
There's a high chance
I'm just going to redesign the large kits in the way I mentioned before, i.e. split them into a main body and an (optional/varaible) extension.
- As for the rear chamber for the 65CDN-T, I would swear I saw it measured somewhere but now I can't find it anymore. Do you know where it was? I looked at HF1440 what are the options in this regard, and its design is a lot more complicated. Not so easy, but maybe something could be done about that resonance. It may not be necessary but it would look better.
Last edited: