Hi all,
Thought I'd share some photos of my Pensil 7.3 I finished last weekend (a week ago)
This is the first pair of Pensil Alpair's I've built and the first loudspeakers I built that I am satisfied with.
Some features and thoughts about the build.
* Veneered after finalising the stuffing. The back is fixed, but I allowed temporary internal access by leaving a side unglued and using clamps to listen with it in place. Once I was happy with the amount of stuffing (325g of Dacron evenly spread), I glued the side permanently.
* Found a massive improvement in sound by fitting 14mm diameter hardwood dowels from front to back. One directly above the vent, the other 30cm down from the top of the cabinet (a bit below the driver). Dowels were cut to a millimeter longer than the internal front/back distance. Then sanded down until it just fits with firm pressure against the front & back panels. Finally glued in place. If anyone is not so willing to do the holey brace, as least try front/back dowels (massive difference for little effort). Results in a much more solid and stable sound.
* 18mm Baltic Birch Ply
* Added threads into the base to allow for spikes
* OFC OCC copper wiring
* 4mm Deltron sockets. Screwed then epoxy glued in place so they will never shift
* Oak veneer with a stain aimed to match the floor. I did test, but on a smaller bit. The larger loudspeaker meant it was on the speaker longer before being wiped off - so it turned out a bit darker, but alright. Next time I'll add equal amounts of water to the stain solution (rather than being pure stain).
* Front, top, back and base are rebated for additional strength. I'll have to share with you some Youtube videos on making quick and cheap tools to support accurate cutting from a circular saw and router. Also used a bench drill.
Sound-wise, well I have some running in to do. Mostly keeping to a low volume with simple music. Occasionally I venture out with volume and music genre, but not been nuts.
Vocals started out as honky then cuppy, but as the listening session progresses to about 3 hours, these effects significantly reduce. I suspect they will be gone after more running in.
IMPORTANTLY they definitely fulfill my requirement to provide satisfaction at low volume levels (when the neighbours are in). The provide an enthralling and exquisite rendition at low levels - never sounding shut-in. Okay the bass reduces a bit at low volumes but you can still hear it and follow the basslines easily.
When the neighbours are out and I have the occasional venture out into normal (not insane) volumes, the instruments develop more body - not least through the support provided by the enclosures.
Currently I have about 12 hours on the run-in clock. I am finding that when I have an hour or two break, the run-in has to start again. I am anticipate that this roller-coaster run-in period will stabilise (yes?).
These Pensils are showing exceptional responsiveness, mainly due to the lightweight cones and overall brilliant design from Mark Audio. Pianos have wonderful tone and space. In fact they excel in portraying the recorded acoustic (WOW!). They are also extremely effective at revealing differences between recordings.
Bass has punch, with body, tunefulness and good presence, but obviously not the heft of big loudspeakers (e.g. ATCs or Audio Notes). It is easy to follow and understand acoustic bass lines - the 7cm driver is unprecedented in its abilities there, remarkably so. Bass seems to improve as the listening session reaches 2-3 hours (bear in mind this is due to run-in and I am anticipating/hoping this duration gets shorter).
This is turning into an outstanding loudspeaker that is helping out with my domestic circumstances - providing quality sound at levels that do not annoy the neighbour.
I hope to give some more updates as time progresses and I get chance to write in more detail about the build.
Andrew
Thought I'd share some photos of my Pensil 7.3 I finished last weekend (a week ago)
This is the first pair of Pensil Alpair's I've built and the first loudspeakers I built that I am satisfied with.
Some features and thoughts about the build.
* Veneered after finalising the stuffing. The back is fixed, but I allowed temporary internal access by leaving a side unglued and using clamps to listen with it in place. Once I was happy with the amount of stuffing (325g of Dacron evenly spread), I glued the side permanently.
* Found a massive improvement in sound by fitting 14mm diameter hardwood dowels from front to back. One directly above the vent, the other 30cm down from the top of the cabinet (a bit below the driver). Dowels were cut to a millimeter longer than the internal front/back distance. Then sanded down until it just fits with firm pressure against the front & back panels. Finally glued in place. If anyone is not so willing to do the holey brace, as least try front/back dowels (massive difference for little effort). Results in a much more solid and stable sound.
* 18mm Baltic Birch Ply
* Added threads into the base to allow for spikes
* OFC OCC copper wiring
* 4mm Deltron sockets. Screwed then epoxy glued in place so they will never shift
* Oak veneer with a stain aimed to match the floor. I did test, but on a smaller bit. The larger loudspeaker meant it was on the speaker longer before being wiped off - so it turned out a bit darker, but alright. Next time I'll add equal amounts of water to the stain solution (rather than being pure stain).
* Front, top, back and base are rebated for additional strength. I'll have to share with you some Youtube videos on making quick and cheap tools to support accurate cutting from a circular saw and router. Also used a bench drill.
Sound-wise, well I have some running in to do. Mostly keeping to a low volume with simple music. Occasionally I venture out with volume and music genre, but not been nuts.
Vocals started out as honky then cuppy, but as the listening session progresses to about 3 hours, these effects significantly reduce. I suspect they will be gone after more running in.
IMPORTANTLY they definitely fulfill my requirement to provide satisfaction at low volume levels (when the neighbours are in). The provide an enthralling and exquisite rendition at low levels - never sounding shut-in. Okay the bass reduces a bit at low volumes but you can still hear it and follow the basslines easily.
When the neighbours are out and I have the occasional venture out into normal (not insane) volumes, the instruments develop more body - not least through the support provided by the enclosures.
Currently I have about 12 hours on the run-in clock. I am finding that when I have an hour or two break, the run-in has to start again. I am anticipate that this roller-coaster run-in period will stabilise (yes?).
These Pensils are showing exceptional responsiveness, mainly due to the lightweight cones and overall brilliant design from Mark Audio. Pianos have wonderful tone and space. In fact they excel in portraying the recorded acoustic (WOW!). They are also extremely effective at revealing differences between recordings.
Bass has punch, with body, tunefulness and good presence, but obviously not the heft of big loudspeakers (e.g. ATCs or Audio Notes). It is easy to follow and understand acoustic bass lines - the 7cm driver is unprecedented in its abilities there, remarkably so. Bass seems to improve as the listening session reaches 2-3 hours (bear in mind this is due to run-in and I am anticipating/hoping this duration gets shorter).
This is turning into an outstanding loudspeaker that is helping out with my domestic circumstances - providing quality sound at levels that do not annoy the neighbour.
I hope to give some more updates as time progresses and I get chance to write in more detail about the build.
Andrew
Attachments
Oh by the way, the rest of the system.
Laptop -> Musical Fidelity Async USB to Coax converter -> Audio Note Kit DAC 2.1 Signature -> DIY 300B interstage monoblocks with 6C45P gain/driver (and battery biased cathode) -> Pensil 7.3M
The amps work particularly well with the Pensils. Delicate yet bold and musical.
Almost all of the signal chain is self-built!
Andrew
Laptop -> Musical Fidelity Async USB to Coax converter -> Audio Note Kit DAC 2.1 Signature -> DIY 300B interstage monoblocks with 6C45P gain/driver (and battery biased cathode) -> Pensil 7.3M
The amps work particularly well with the Pensils. Delicate yet bold and musical.
Almost all of the signal chain is self-built!
Andrew
Very nice and neat system/room!
All your system is to die for... mmmm those valves
What are those under the TV set? LPs?
Do you have pics of the dowels you mention?
Happy listening
Thanks for the kind comments everyone.
@gaston, yes they are LPs under the TV. I'll be moving my LP12 downstairs soon.
Coincidentally, tomorrow, a friend of mine is selling me his oak Isoblue shelves
I'll take some photos for the thread and will include some more of the loudspeakers and close-ups of the amps.The dowels are regulars hardwood ones from the DIY/hardware store. 14mm diameter and you can buy them in 1 meter lengths to cut to size. Make two per cabinet. The back is not removable, so the dowels can be cut and sanded to a fraction of a millimeter longer than the front-to-back depth - to exert some holding pressure between the front and back panels. This effectively helps to "short circuit" a lot of acoustic resonance. Fit one 30cm from the top of the cabinet and the other just above the vent. Both ends should be positioned dead-centre across the loudspeaker's width.
I concertina'ed the Dacron stuffing length-ways, to lay inside. With big scissors you will need to cut slits in the stuffing to just over halfway along its width, at the point where the top dowel would be - to nicely slot the stuffing around the dowel. It should just rest on the bottom dowel.
Cheers,
Andrew
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Looks very nice! I have bought a pair of 7.3M's.. Since we have some 22mm MDF he 'insists' that i use that for building the Pensils. (I originally planned on building the FH MK3). But i am in doubt if i should build them out of MDF.. These are probably pretty easy and cheap to build with the MDF.. I guess i could build a pair of FH out of some 18mm ply later but..
I have bought a pair of 7.3M's.. Since we have some 22mm MDF he 'insists' that i use that for building the Pensils. (I originally planned on building the FH MK3). But i am in doubt if i should build them out of MDF.. These are probably pretty easy and cheap to build with the MDF.. I guess i could build a pair of FH out of some 18mm ply later but..- Status
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