Built a set of "Pensil" speakers this week. Just finished them and hooked them up to the little K-12G amp I built. So far, they are very, very good! I'm comparing them to my KEF L:S50 Metas and they are actually holding their own. The bass response out of these 6.5" full range drivers is amazing. Tight, Fast...Very well defined. The vocals are quite "Up Front", I like that....Imaging is nearly as good as the KEFs.......Efficient, the little 8w/ch amplifier drives them to louder than I would ever listen. A very easy build. Nothing complicated. Fun project...
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5.25” drivers :^)
The A10.3 take a significant time to get to their best, how many hours do you have on them?
dave
The plywood "skin" over a skeletal frame is a neat idea. I am a little confused by the picture of the backside of the front baffle, the diagonal braces don't appear attached to either side of the framework or am I seeing things...??
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No, it is conventional construction. Built out of 1/2" Bamboo Plywood. Very stiff, but I was concerned about "oil canning" with such a thin substrate. Those diagonals are just glued 3/4 X 3/4' strips to dampen the panels. There are then two cross braces. I added them but with no dimension longer than 12", I really don't think they are necessary. The cabinets pass the "tap test" with flying colors.
I ordered a roll of 1/4" carpet jute pad and it arrived 10 minutes after I assembled the second speaker.... So I took them apart again and lined them on all interior surfaces. I also put pollyfill behind the driver. But they then lost a lot of the presence that I was enjoying when they were totally unlined. I removed the driver and pulled all the pollyfill out. Much better, but still not as "exciting" as with no fill. More listening is needed and a certain break-in period is required. I wonder if all that diagonal "oil canning" bracing was enough to break up internal standing waves and no interior dampening is needed? Comments?
Break-in deniers be damned, I’d be inclined to give them at least 100hrs of running time before assessing requirements for dampening fill. FWIW, the numerous pairs of Pensils and similar Scott/Dave enclosures I built all included provision via full perimeter clearing and closed cell foam tape to remove the back panel for easy access to adjust fill.
Sorry, what does this mean?... I built my speakers with removable backs also. For the same reason you do, modifying fill.
Lots of listening and comparing....I removed all the polyfill and only have all interior panels covered with 1/4" carpet jute. Because of the bracing on the interior it ends up being very convoluted when stapled in place. This has to help with interior standing waves. The "exciting " sound is back.
The efficiency is nearly identical to the KEF LS50 Metas. Interesting because I thought these would be about 5dB more efficient. The bass is amazing. But I'm not a big bass fan. I attenuated it by trying a whole bunch of stuff in the port. In the end, a piece of Polyfill rolled up did the trick. I might have to put a screen over it to keep it in place like the Dynaco A-25 speakers had. Since the port is on the bottom they really shake the floor. Putting your ear down at the port is a bass experience! I might put them on stands to see if this modifies the bass.
Amazingly...Zero crossover components. The driver is simply directly wired to the amplifier!
Last night while comparing to the KEFs and switching wires back and forth, many times I was mistaken as to what speaker I was listening to. They are amazingly similar. $1600 vs $350......
So far, extremelt pleased.....I might even spend more $$ and veneer them.
(Equipment Used...Node2i (Tidal/Quobuz), Gustard X16 DAC, Zero Zone tube preamp, ICE Class-d 200 w/ch amplifier)
The efficiency is nearly identical to the KEF LS50 Metas. Interesting because I thought these would be about 5dB more efficient. The bass is amazing. But I'm not a big bass fan. I attenuated it by trying a whole bunch of stuff in the port. In the end, a piece of Polyfill rolled up did the trick. I might have to put a screen over it to keep it in place like the Dynaco A-25 speakers had. Since the port is on the bottom they really shake the floor. Putting your ear down at the port is a bass experience! I might put them on stands to see if this modifies the bass.
Amazingly...Zero crossover components. The driver is simply directly wired to the amplifier!
Last night while comparing to the KEFs and switching wires back and forth, many times I was mistaken as to what speaker I was listening to. They are amazingly similar. $1600 vs $350......
So far, extremelt pleased.....I might even spend more $$ and veneer them.
(Equipment Used...Node2i (Tidal/Quobuz), Gustard X16 DAC, Zero Zone tube preamp, ICE Class-d 200 w/ch amplifier)
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Folks are asking about plans... http://www.frugal-phile.com/boxlib/pensils/Pensil-Series-set-100711.pdf
Typo thanks to iOS auto correction, sometimes you have to type the actual spelling half a dozen times, and it still gets modified. The word should have been cleat-ing.
Thanks for posting this. Great job on the construction. I built a pair of these about a year ago and have been very pleased. I do need a bit more power because my amp only puts out 2 or three watts. I used the Alpair 10p drivers. I am also glad you compared them against another speaker that is considered high quality. I had nothing to compare mine against except some IEMs that I have. Now I am even happier. Pearl Acoustics sells something similar for around 4000 USD. I'm sure its not the same thing but uses similar drivers and very high quality cabinets. I uploaded a video of my project on YouTube under "Alpair 10P design build listen". Hope to upload more DIY projects in the future.
Today I did something interesting. I used an integrated amplifier that has a balance control (NAD C320BEE).....I put one KEF LS50 Meta on one channel and the Pensil on the other. I put them side by side......Setting the Node2i streamer audio output to Mono......Then I listened to music turning the balance control left to right.....Other than the Pensil having deeper bass response, there was not a whole lot of difference. Using a hand held SPL meter the efficiency is nearly identical. Of course this test does no show imaging, sound stage and other speaker attributes......and with my 15Khz top end hearing, it isn't showing what is happening above this frequency. But the overall tonality is nearly indistinguishable. After over 5 hours of listening, with three different amplifiers (Tube K-12G @8w/ch, First Watt F5v2 @ 50w/ch and ICE Power Class-D @ 200w/ch) I'm still quite pleased with these speakers.
Harder than it seems. Getting the surface fom not being wavy was not acheived. Our first try at this was a failure and burned nicely.
The second one, we made a mold first, made the curved panels and then fitted those over the ribs. The mold took a lot of time and used a vacuum bag.
[imghttps://www.planet10-hifi.com/boxpix/Ellipsa-inside-1000.jpg[/img]
We used the same curved panels to build a curved Pensil7.
dave
Those are old Pensils for old drivers. This might be a mire useful link. https://frugal-phile.com/boxes-markaudio.html
Also check the Pensil threads, they ahve not all been linked, and some not drawn. If you don’t see what you need ask. There are Pensils fro almost all MA (and L-Stylo for FF105/125wk, so not limited to MA).
dave
Where did you get ½”? We would have loved to have access to that thickness.
Do note that most people do not interpret the tap test. A thud is not good, it should have a sharpish higher frequency think.
dave
KEF rate it at 85dB, A10.3 is about 87.
Do keep in mind t£4500 (he cost of buying retail. The closest commerical loudspeaker is the Sibelious at $4500, Better built than the KEF, if it was a mass-manufacture it would be cheaper (in many ways).
dave
There are specific Pensils for A10 (in the original plans), !0.2 (as in the pic), 10.3, and 10p. The old plans ar egood as they are the only ones that show a holey brace option.
They are not interchangeable.
dave
They are not interchangeable.
dave