| Re: H290C Horn/Waveguide [message #73777 is a reply to message #71929] |
Tue, 11 September 2012 09:24   |
skywave-rider
Messages: 104
Registered: May 2009
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Viscount |
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FYI, got the H290Cs yesterday and immediately installed them in my home rig. This is a temp setup, as I eventually intend to do a 3Pi build.
But, even in my non optimized rig, I can tell you the H290C sounds superb. In comparison to the QSC HPR 152i, which I think is excellent and have been using for several years, I hear less "distortion." That may relate to modes in the WG, not sure. The feeling is that the H290C is cleaner.
[The "rig" is: JBL 123A-1/DE250/H290C/4Pi crossover with 20dB attenuation as per Wayne's chart and C1 removed. Running with horn on top, not in baffle, temporarily.]
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| Re: H290C Horn/Waveguide [message #73809 is a reply to message #73777] |
Thu, 13 September 2012 09:37 |
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Wayne Parham
Messages: 18796
Registered: January 2001
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Illuminati (33rd Degree) |
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Glad your new waveguides sound good to you.
Interestingly, your impressions are the same as mine. I've measured the H290C and I've listened to it, and my listening impression seems subjectively more of an improvement than the measurements show. The H290C waveguide just really sounds natural to me.
Other people have said the same thing too. There's been enough time now for people to install their new waveguides and listen to them. The feedback I'm getting is very positive. I'm hearing a lot of similar opinions, using phrases like "smoother", "less distorted", "more natural" and "cleaner sounding".
The measurements are good, but the old H290 measured surprisingly good too, better than most waveguides out there. So by response measurements, you might not expect much difference between the Eminence H290 and the new Pi H290C, maybe not even enough to hear. While the H290C's oblate spheroidal / elliptic cylinder flare profile is the best shape, in my opinion, other profiles can be nearly as good provided they are close enough. But the H290C is better sounding, probably because it stays true to the OS/EC flare profile. Comparison of measurements don't really show this improvement as much as one might expect.
Of course, the measurements I'm talking about are just response and polar measurements, and they will only show very strong internal reflections in the form of response spikes. Smaller reflections won't show up in a response chart, and it may be that this is the difference. It would make sense, given the OSEC waveguide/horn generates the least (HOM) high-order modes. So I think the difference, while subtle, is audible.
I'm also pleased to hear your comparison of the Pi H290C with the QSC waveguide. I've received emails from a few others that compared it with the JBL and SEOS waveguides as well. I'm getting unanimous feedback that the H290C sounds better. This, again, I attribute to the pure OSEC flare. Other manufacturers deviate from it for one reason or another.
The new H290C waveguide just sounds better. I thought maybe it was just a proud papa thing, but since I'm getting feedback that the H290C sounds "smoother", "less distorted", "more natural" and "cleaner sounding" than the old Eminence H290 and other waveguides, I'm starting to think it isn't just me. Many people are reporting back positive results like this.
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| Re: H290C Horn/Waveguide [message #75922 is a reply to message #75909] |
Wed, 20 March 2013 21:26 |
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Wayne Parham
Messages: 18796
Registered: January 2001
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Illuminati (33rd Degree) |
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The H290C is the best 90°x45° horn/waveguide available, truly a no-compromise design. So naturally, I would suggest it for any DI-matched two-way speaker or constant directivity cornerhorn.
The loudspeaker models I make using that waveguide are the ones I found to be the best out of a few dozen that once made up my line, so I find them to represent the best of the best. I wouldn't make any other design choices than those.
That said, there are plenty of other similar components that work very well. An example is the Eminence Kappa line of drivers, which are very similar to the ones I use in some of my models, and which have been used by many DIYers on this forum. There are lots of others too, lots of ways to "do it right" but of course lots of ways to do it wrong too.
So my suggestion is to study the links in the Pi Speakers FAQ, especially those in the "Crossovers" and "Simulations and Measurements" sections. Also look at the "General Information" section, especially the post called "Notes for the DIYer". It has links to some of the most useful notes for designing speakers like these. For example, "Crossover optimization for DI-matched two-way speakers" describes my exact crossover design process including a video showing how to measure the forward lobe by finding the vertical nulls that mark its edges.
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| Re: H290C Horn/Waveguide [message #75936 is a reply to message #75935] |
Thu, 21 March 2013 15:28 |
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Wayne Parham
Messages: 18796
Registered: January 2001
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Illuminati (33rd Degree) |
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The crossover change is simple: Remove capacitor C1 and add a 16Ω resistor Rs across the compresion driver. Alternately, there is a position on the board for this resistor so you can install it there if you want instead of hanging it across the driver terminals. The Rs position on the board is right beside C1.
Here are some additional comments by Bill Epstein, followed by waveguide design philosophy information:
The finish of production waveguides is satin. There are actually samples of many different ABS blends shown earlier in this thread, and that's why it's hard to tell what the finish is. There was a glossy blend I tried early on, and another blend that was a little less glossy but still shinier than what we eventually settled on. The final ABS blend I chose creates a black satin finish. An example is shown in the photo below, a picture of a four π loudspeaker with H290C waveguide:
four π loudspeaker
As an aside, I chose the ABS mixture largely for its dimensional stability and consistency. The mold shop gave me samples of waveguides using several different mixtures to evaluate, some that were really shiny, some that were more dull. Some held dimensions well, others less so. I placed a priority on dimensional stability, and the ABS blend that is most consistent tends to be less shiny, more of a satin finish.
ABS plastic is a mix of three substances, styrene, acrylonitrile and butadiene. The proportions can vary from 15% to 35% acrylonitrile, 5% to 30% butadiene and 40% to 60% styrene. By varying the mixture, you can achieve different properties. Higher styrene tends to make a shinier finish, but we found a little bit less tends to make the device more dimensionally stable, more uniform through the hold and cooldown cycles of the molding process. Since we prioritize dimensional consistency over finish, that sets the material to one with a surface that I would characterize as being satin black.
If you want a different finish, the waveguides can be painted. Enamel adheres very well to these waveguides, so you can spray paint them to be glossy, flat or even a different color.
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, the technical details of the H290C and installed them without changes to the boards. Even before the crossover change I could hear an expanded soundstage in general and clearer exposition of the minor themes of a musical score. When I woke up and corresponded with Wayne I added the Rs resistor that softened the mids. Further discussion revealed that I also had to snip C1.
