I too have experienced how different levels of stored energy at various frequencies can contribute to undesirable results. You seem to have corrected this issue which should correlate well with your subjective listening experience. Good work!

But how will the phase rotation of the 4th order work with the midrange driver? Looking forward to see some measurements of this filter in a lp/hp crossover situation.

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

I'm going to go out on a limb here...but I have not experienced this as an issue in crossover design. From my experience, if the slopes match at the crossover then all is well. I'm referring to the measured response of each driver with the intended passive filter. To me, what matters is that the summed acoustical and electrical transfer functions combine to form the target slope. So that means you can combine whatever order you need to achieve the desired slope. Horns have a very steep drop below the cutoff frequency of the horn, which requires the low frequency to have a much higher order electrical filter to match the strong acoustical filter of the horn's response below cutoff. If I am wrong I would like to know what metric shows me this. I always get a flat response through the crossover region if the slopes are symmetrical.

Excuse me Joseph, but how come there is “dramatic improvement” in CSD? To my eye stored energy just evened out across the spectrum (there is more “ringing” than originally) and it rings exactly as long as before…?

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

That's correct, the improvement is just a you say, an evening out across the spectrum. Looking at it closer I don't think it's fair to call it a resonance, as the time scale is only 0.92ms deep. It's just the natural pistonic decay of the diaphragm. Most manufacturers have the time scale at around 6ms. So we ae straining at micro details in the data. The burst decay shows full decay by 6 periods across the spectrum, so not something that's even close to audible anyways.

@tomekwhite

8 ай бұрын

@@JosephCrowesDIYSpeakerBuilding I’m actually willing to agree with your assessment regarding audibility of this decay, however in this case you also have to agree, that mentioned “improvement”/“evening out” is purely theoretical - if the decay/“resonance”wasn’t audible in the first place then mentioned improvement is only “on paper” (still isn’t audible anyway).

Have you tried digital crossover like minidsp;

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

I've tried the Hypex FA123 which is very low distortion and noise. But I've not tried some of the latest MiniDSP products. The third channel on the FA123 is lower power than the other two channels and only meant for HF drivers. So it sounds fantastic.

That's WAY too much work and money thrown at fixing $1200/pair super tweeters! You still end up throwing away lots of sensitivity in the end. Fostex seems to publish just as fake measurements as Beyma does for TPL AMT tweeters.

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

ouch...you're not wrong.

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

The horn lens I developed has also addressed all of the issues with the tweeter where it will likely be just a very simple filter. But yes, why should one have to "fix" such an expensive tweeter. josephcrowe.com/blogs/news/fostex-t900a-with-horn-lens-no-2258

Worthless, sorry, no instruments play Above 8000. Nor would you want to hear anything that plays that high.

@JosephCrowesDIYSpeakerBuilding

8 ай бұрын

I routinely do crossovers and the response above 8kHz is very critical to the overall sound quality. Why would think instruments don’t play that high? Do you not know there are harmonic resonances that easily extend in to that region that give the instrument its distinct tone and character?

@firstdaddy

8 ай бұрын

Not sure where you get the idea there are no instruments that play beyond 8KHz. The clarinet, flute, piccolo, violin, and pipe organ all can play to 8KHz or higher.

@davidkclayton

8 ай бұрын

@@firstdaddy you're probably right you could probably get an instrument to go beyond a reasonable scale but is that something you want to listen to? Here's a fun experiment for you. Get yourself a tone generator play an 8 kilohertz tone, I think you'll find that uncomfortably High pitched.