Something Stirs in the Workshop

[IslandPink]

It would be nice to see the plot a bit bigger, but it looks like the phase is going as well as the amplitude.

[vinylnvalves]

It obviously does something strange around 500hz, the drivers resonance I assume.

[vinylnvalves]

It would be nice to see the plot a bit bigger, but it looks like the phase is going as well as the amplitude.

es2503.png (61.87 KiB) Viewed 4574 times

[IslandPink]

This is a different plot... but OK, the upper curve ( eg. at 1kHz ) , this is the phase - correct ?
What's the lower curve this time ?

[vinylnvalves]

Same data, just zoomed in. Lower curve is the SPL v Freq curve - with a 2 dB scale, not 10db - so obviously looks more peaky. The phase curve is the same, it’s annoying you cannot add legends on the plots.

[vinylnvalves]

Looking at cone drivers instead of the planar drivers for better HF extension, these seem to be about the best from a brief look. https://kjfaudio.com/wp-content/uploads ... v-2021.pdf

Not as smoother response as the planar drivers though. Probably better bottom end grunt as 4 of these per channel will have more SD. Poorer integration to the throat of the horn, so maybe more distortion. Anyone get any collecting dust, I could borrow to trial? Promise not to let Chris connect the crown amp to them.

[IslandPink]

I'm sure that you need a ribbon for the top-end !

[vinylnvalves]

If I were to add another driver for the top end, it would be something like this https://doc.soundimports.nl/pdf/brands/ ... -sheet.pdf to keep synergy with the other drivers if planar. Another driver will add lobbing and other issues, at which point the concept fails the design brief.

[vinylnvalves]

A link to the paper about acoustic lens to reduce beaming https://www.aes.org/tmpFiles/elib/20230201/19881.pdf

Could this really allow a 2 way horn system with a coaxial compression driver........

[vinylnvalves]

Looking at 2” drivers again, saw these reasonable FR curve, any one any experience of theses drivers...https://www.visaton.de/sites/default/fi ... WS%205.pdf

Still not convinced that the planar drivers are dying around 10khz. Still a sparkle, and when I put a 12 kHz wave through them I can hear something. Chris’s measurements equipment will tell me quickly whether my mic is out of calibration or not.

[IslandPink]

Yes, i forgot about mentioning that, as I commented elsewhere, my measurements have that problem, Chris was able to verify a calibration error and set my mind at rest.

[vinylnvalves]

found a blog from Joseph Crowe, about a full range driver he tested in the es250 horn. Bigger driver than i thought that would be suitable. https://josephcrowe.com/blogs/news/scan ... e-250-horn These drivers four per side wouldnt meet the cost v performance i set, unless their peformance is outstanding.....

[steve s]

Looking at 2” drivers again, saw these reasonable FR curve, any one any experience of theses drivers...https://www.visaton.de/sites/default/fi ... WS%205.pdf

Still not convinced that the planar drivers are dying around 10khz. Still a sparkle, and when I put a 12 kHz wave through them I can hear something. Chris’s measurements equipment will tell me quickly whether my mic is out of calibration or not.

I have a pair of frs8 in my motorhome with a pair of mark audio drivers doing the low end, I really like the visaton driver, it sounds dynamic amd life like to me but I've only paired them up because they sound right together .. no measurements !

[vinylnvalves]

Thanks Steve
The visaton driver looks reasonably flat

Capture4.JPG (62.95 KiB) Viewed 4030 times

Price for 4 is less than one planar driver, so worth a punt. Will have 50% more Sd so will have to see if its bottom end is better. The 10khz spike may not occur when horn loaded, if not a notch filter can tame it.

[vinylnvalves]

I haven’t bit the bullet on getting some FR cone drivers for this horn yet, as I cannot see a cone driver being better than the planar for most of the frequency range. The challenge with the top end being the only reason to do so. I have been thinking of the merit of a secondary rear firing tweeter, to give a more dispersed HF, like the Snells etc used, and whether that would help fill in above 13k?