or Avebury hybrid or whatever you want to call it. It is a combination of BLH and FLH to produce a 102 dB 1w/1m fullrange !
One day I decided to put the Aveburys in corners and noticed an immediate improvement in the stereo imaging. However the corner loading tip the scale a bit toward the bass and make them a bit heavy. So I decide to measure them using Radio Shack SPL meter and warble test tones. Below is the plot of one Avebury in a corner
One day I decided to put the Aveburys in corners and noticed an immediate improvement in the stereo imaging. However the corner loading tip the scale a bit toward the bass and make them a bit heavy. So I decide to measure them using Radio Shack SPL meter and warble test tones. Below is the plot of one Avebury in a corner
Attachments
The Avebury is rated 92 dB from 300hz and up, which is the sensitivity of the Alpair 12P driver. I was using a 2A3 SET amp and was looking for ways to improve the sensity of the Aveburys and a looking at the plot, the thought of adding a front horn seems like a good thing to try. So I proceed in making a 160Hz round paper horn
http://www.diyaudio.com/forums/full-range/232200-started-building-160-hz-paper-horn-6-fullrange.html
After months, I finally got 2 horns to try , the first one looks sad since I was learning how to make horn with it. The 2nd one is much nicer looking. I intend to make a 3rd one some time to replace the 1st prototype. Here is how they looked attached to the Aveburys
http://www.diyaudio.com/forums/full-range/232200-started-building-160-hz-paper-horn-6-fullrange.html
After months, I finally got 2 horns to try , the first one looks sad since I was learning how to make horn with it. The 2nd one is much nicer looking. I intend to make a 3rd one some time to replace the 1st prototype. Here is how they looked attached to the Aveburys
Attachments
Now for the measurement of the Avebury with the 160Hz horn
The blue is the Avebury, the red is Avebury + 160hz horn
The sound is much larger, thanks to the 26 in mouths. It is much more life like. Imaging and presence is spooky real. Looking at the plot, it is obvious that the top end needs some help.
So I added some 106dB bullet tweeter horn crossed over at 5K. The next plot shows the final response in yellow with the bullet tweeter horn
The blue is the Avebury, the red is Avebury + 160hz horn
The sound is much larger, thanks to the 26 in mouths. It is much more life like. Imaging and presence is spooky real. Looking at the plot, it is obvious that the top end needs some help.
So I added some 106dB bullet tweeter horn crossed over at 5K. The next plot shows the final response in yellow with the bullet tweeter horn
Attachments
There are a couple dips at 1K and 2K that I will try to smooth out may be with some sort of phase plug for the horn. Overall the project is somewhat a success in transforming a 92dB fullrange BLH to a 102 dB BLH + FLH. I can now enjoy musics at satisfying volume with the dial on my Bottlehead 2A3 only turned 1/4 of the way.
even if the sound hadn't improved, i think they way cooler now.
i would have thought avebury would dig a lot lower than those measurements show?
i would have thought avebury would dig a lot lower than those measurements show?
I'd take the LF measurements with a pinch of salt, unless they're averaged over many different listening positions: the room will have a massive effect.
I'd also expect we're seeing some LF rolloff from the SPL meter itself, though it may well have been calibrated. That's an unknown at the mo.
Chris
I'd also expect we're seeing some LF rolloff from the SPL meter itself, though it may well have been calibrated. That's an unknown at the mo.
Chris
Horns can be fun on FR drivers, but they'll suck whatever high-end there is unless you have a very hot driver. I had a similar experience with the FF85WK in a small BLH where I added a foamcore front horn and then needed an FT17H on top.
IG
IG
The unmodified Aveburys get to about 40hz in room. The peak at 100hz makes it look like the response drops fast . With the front horn, I had to back off the volume so usable bass drops off around 55hz
Nice job on the second horn!! Practice makes perfect.
Take a look at my paper horn page and notice the rim I added to the mold. You might consider this because it creates a stiffer, deeper, more elegant looking rim edge at the mouth.
Take a look at my paper horn page and notice the rim I added to the mold. You might consider this because it creates a stiffer, deeper, more elegant looking rim edge at the mouth.
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