B&C DE250 on Dayton H812

Was looking at some horns allowing a low ~800 Hz crossover for the DE250.
Came over this French site which shows fantastic extension and linearity with the Dayton H812 horn:

Grand Comparatif de Compressions 1 pouce - JustDIYIt !

FR-DE250.jpg


But Ampslab (Michael Chua's) measurements of the same combo doesn't give the same picture at all... Even if you look past the smoothing differences.

https://ampslab.com/blog/2020/06/12/dayton-h812/

H812_B3.gif


The measurements of the D220TI matches up pretty good tho :scratch2:

Any experiences with this horn out there?
 
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If anything, it's an inspiring project and may give insight on using a different 1" driver... That Peerless in the thread looks very good for the $ and would best the D220ti based on my limited knowledge. I've some Celestion drivers that are similar to DE250s and that Peerless driver is still one I am dying to try.

I feel like a 1" driver crossing at 800hz is really ambitious... But I am also of zero authority on speaker design. Hopefully one of the experts see this.
 
Ampslab (Michael Chua's) measurements of the same combo doesn't give the same picture at all...

It is always difficult to make judgements based on data given by somebody and that sometimes (although very rarely) includes the manufacturers themselves. And many a time, the data we obtain ourselves may deviate from that in the datasheet for various reasons (horn, baffle, chamber, power, distance and many more)

Do remember that all the loudspeaker companies have employed people to post favourable reviews of their products all over the internet to boost sales. So if I were you I might trust a datasheet but when it comes to internet content, I am not very sure. However, this is exactly where forums, members, their personal experiences and wisdom come to our rescue.
 
Hello,

Another person who has quite a lot of experience with using this horn decided the lowest he could cross it over was higher than what you are wanting. You might want to look at his material on the web. I will try to attach a review of his kit, which last time I looked was still for sale. However he does offer full plans for free and lots of interesting documentation on his design process and decisions. FWIW.

Pi Speakers - unmatched quality and state-of-the-art performance

Regards,
Greg
 
I feel like a 1" driver crossing at 800hz is really ambitious... But I am also of zero authority on speaker design. Hopefully one of the experts see this.

800 Hz is no problem for home use 🙂 That's also where Geddes crosses his designs with the DE250. Here's a smaller XT1086 with much less low end extension crossed at 1 KHz (see attachment). Almost 25 db down at FS

Hello,

Another person who has quite a lot of experience with using this horn decided the lowest he could cross it over was higher than what you are wanting. You might want to look at his material on the web. I will try to attach a review of his kit, which last time I looked was still for sale. However he does offer full plans for free and lots of interesting documentation on his design process and decisions. FWIW.

Pi Speakers - unmatched quality and state-of-the-art performance

Regards,
Greg

I couldn't find any info from PI Speakers on it. If crossing to a 15" woofer, then yeah it's not gonna hold directivity low enough to match. Looking at plots its about 120 degrees at 1 KHz, so a smaller woofer should work.

Michael Chua crosses at 800 Hz with apparently great results (D220TI, not DE250 tho):

Dayton H812 horn + Selenium D220Ti – AmpsLab
 

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What has that to do with the topic at hand? I.e the DE250 and D220TI on the H812 horn and disparities in measurements.

You've asked if anyone has experience with that horn, or am i mistaken ?

....Any experiences with this horn out there?

You didn't ask if anyone has experience with any particular driver in that horn. You've mentioned two different types of drivers youself.

Kudos on your reaction to a guy trying to help.
 
You've asked if anyone has experience with that horn, or am i mistaken ?

You didn't ask if anyone has experience with any particular driver in that horn. You've mentioned two different types of drivers youself.

Kudos on your reaction to a guy trying to help.

I appreciate the reply! But I couldn't find any references to the H812 horn in that thread, and just the link without any context doesn't help much 😉
 
Isn't Dayton H812=Celestion H1 9040-P ? It is per link in your opening post of the thread.

Project in thread i linked uses Celestion H1 9040-P with Peerless DFM2535. You can compare it with JustDIY.it measurements for a reference.

It's all there.

Measurements provided by Rese66 aren't the best possible but are good enough to see if Cedric from JustDIYit smoothed it too much or not.
 
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But Ampslab (Michael Chua's) measurements of the same combo doesn't give the same picture at all... Even if you look past the smoothing differences.

They are actually pretty similar when you factor-in smoothing, distance (mic. from horn mouth), and how the horn is mounted (either on cabinet or w/ no cabinet).

The differences above 2kHz are likely smoothing and distance.

The differences below 2kHz are likely mounting (or not): bounded and diffractive elements.
 
Isn't Dayton H812=Celestion H1 9040-P ? It is per link in your opening post of the thread.

Project in thread i linked uses Celestion H1 9040-P with Peerless DFM2535. You can compare it with JustDIY.it measurements for a reference.

It's all there.

Measurements provided by Rese66 aren't the best possible but are good enough to see if Cedric from JustDIYit smoothed it too much or not.

Oh yeah seems like it! Thanks, seems I have some reading to do 🙂

They are actually pretty similar when you factor-in smoothing, distance (mic. from horn mouth), and how the horn is mounted (either on cabinet or w/ no cabinet).

The differences above 2kHz are likely smoothing and distance.

The differences below 2kHz are likely mounting (or not): bounded and diffractive elements.

I'm most confused by the differences in low end extension. It's down a whopping 14 db at 600 Hz in Michael Chua's measurements compared to 1-2 db in the ones from JustDIYIt. A whole lot more than can be attributed to mounting differences.
 
I can say from personal experience the 16 ohm version DE250 sounds a bit different than the 8 ohm for reasons I can't quite explain. It doesn't have the raspy midrange of the 8 ohm variety and appears to also have more controlled low end rolloff without the excessive resonance of the 8 ohm model.

The other option I'd recommend is the Celestion CDX1-1745 or CDX1-1730. The latter one is a bit more open sounding up top but somewhat fragile in power handling down low. My choice for home audio is the 1730 but the midrange of the 1745 is a touch warmer.

The D220ti is a competent driver for the money but it has quality control issues and its hard to get a pair that match closely in FR up top. Very clean sounding driver if not pushed too hard down low on the right horn, especially the HM25-25 expo horn.
 
its odd, because this difference between the 8 and 16 ohm versions is consistent. I think it may have to do with the VC mass and venting of the former. I was going to order some 8 ohm VCs for my DE250s but the ones I received from PE were previously installed and returned, so I ended up with them already in used condition. I do like the sound of these drivers, but they definitely can benefit from some extra damping material in their rear chambers - that skinny little strip of foam doesn't do that much.