The Pencil: inspired by Ohm Micro Walsh Tall

[rastanearian]

Spikedart,
The zobel is in parallel with the driver so it doesn't really impact efficiency. I have only measured them electrically, I have not had time for an acoustic measurement.

 

[critofur]

...That seems in direct contrast to my Ohm Walsh 5 speakers which don't appear to use the best of drivers, and have the signal passing through -WAY- too many components...

Appearances can be deceiving then, I guess. I'm not sure which version of W5 drivers you have, but the ones that I've seen and tested have significant advantages over the Peerless HDS woofers - particularly in terms of bass output.

I had some Walsh 5's on loan for about a year, few other speakers I've auditioned could play as cleanly, nearly that full range at in front of the stage rock-concert level volume. (I used my Onkyo TS-DX787 in "Stereo Direct" mode, playing CD music such as New World Order by Ministry and Sober by Tool with the volume set at "-0db")

I too have been fixated on the idea of "minimalist crossovers" for years now, without any scientifically tested basis - just a "gut feeling" that I want a simpler crossover. I haven't seen any testing, anywhere, that supports audible superiority of simpler crossovers (other than comparing different slopes). Some people prefer LR6, but general consensus (as much as there is one) seems to concur that LR2 is best due to superior even power response, when using drivers capable of performing well with those slopes...

 

[Cambe]

Hello,
I recently bought a pair of Peerless 830873's and Vifa D26NC-55-06's. I want to try the The Pencil design featured here. I know that the tweeter I have is not the Morel MDT-40 or the HiVi RT1L,this is just what I have on hand. Is this workable?

😎

 

[Cambe]

I'm about to build the enclosures can someone help me with making adjustments to port tuning. The design uses a 57mm diameter port,105mm length. I have 1.5", 2.0 " and 2.5" diameter port material. Can someone recalculate the port tuning, based on what I have? My computer is a Mac so,I can't use the normal design software.

Thanks
😎

 

[fwater]

I'm about to build the enclosures can someone help me with making adjustments to port tuning. The design uses a 57mm diameter port,105mm length. I have 1.5", 2.0 " and 2.5" diameter port material. Can someone recalculate the port tuning, based on what I have? My computer is a Mac so,I can't use the normal design software.

Thanks
😎

2.5" dia. @ 5.3" long, or 2 x 1.5" dia. @ 4" long for stock tuning. What are the specs on the woof you're using?

 

[fwater]

Stock enclosure @ 10 liters is too small and tuned too high for the 830873. A bump at 80Hz and 10dB down at 55Hz is predicted; certainly not extracting the potential for that particular driver. 16 liters will get you closer to 10 dB down at 40 or 45Hz...

 

[Cambe]

I am just using Juspur's original spec's for "The Pencil" using the same driver the Peerless 830873.

 

[Cambe]

So, 16L looks better🙂.
Now,what dimensions for box and tuning?

 

[fwater]

So, 16L looks better🙂.
Now,what dimensions for box and tuning?

You can do whatever you'd like for dims! But, if the original designer knows something that I don't (such as actual measured specs), there could be a little trouble brewing here. Let me through this woofer in a better modeler later on today...

 

[critofur]

You can check the box volume/vent tuning that Troels used, he has published at least one design w/a Peerless HDS 5.25 woofer.

BTW, that Vifa tweeter should be ok, if you design a decent crossover...

 

[Cambe]

fwater:I really don't know if the original designer knows something we both don't, like actual measured spec's. I have tried to contact Jusper about this design and so far no response. That is why I am posting here. Please, do check
another modeler and get back to me.

critofer:Just checked the design featured on Troels website for the Peerless HDSPPB830860. 8.2L, Fb= 58Hz, Port= 40mm (ID) x 70mm or 50mm (ID) x 120mm. Like I said above,I do not have any software to use for the enclosure or crossover design. If necessary I will purchase the Morel MDT-40's and use the 2.2 uF capacitor crossover Jusper used. However, the price of the MDT-40's
@ $81.00 ea. from Madisound is not what I really want to do if I don't have to😉

I really appreciate you guys! 🙂
😎

 

[fwater]

Well, I've sworn off WinISD before because of inconsistent (with other simulators) results, but sometimes it's just so quick. Hornresp, which I trust, shows good results in 15 liters (-3dB @ 40Hz), but 10 liters is pretty good for this woofer, too (-3dB @ 50Hz, -10dB @ 40Hz). I say go with the stock enclosure to ease the build. Squeezing out a few extra Hz with a bigger enclosure might be worth it if yo want to shuffle the cab around a bit.

In 10 and 15 liters, this port gives both tunings.

 

[fwater]

BTW, don't drop the bucks on the Morel units. Your tweets will do just fine. A few different values of reasonable caps on hand will let you dial it in with a little experimentation.

 

[Cambe]

fwater, thank you. 🙂
😎

 

[Cambe]

fwater you have Email.😉

 

[bjorno]

Hi Cambe:

As requested in your PM: Submitting simulations using your 'Pensil' data:

b🙂

 

[OhioTanner]

any news on this front? since the other walsh thread was resurrected, a micro walsh could be in my future...

 

[critofur]

Hello,

Are you in Ohio? I moved to Columbus after developing the MicroWalsh series with John at Ohm Acoustics. I'd be happy to meet with you to talk about speakers, if you'd like.

B.t.w., I'd recommended the slightly larger 1000 model.

 

[R. Jamm]

Updates on the Pencil?

Most likely the drivers used in the Pencil speaker are no longer being made-- do you have any suggestions?
Do you have any plans using an 8 inch driver?

 

[critofur]

Ohm uses an 8" driver in the 2000, but I prefer the 1000 model, even though it's a smaller speaker - it's particularly impressive for it's size.