THE PENCIL: inspired by Ohm Micro Walsh Tall - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st December 2007, 02:24 PM   #1
Juspur is offline Juspur  Denmark
diyAudio Member
 
Join Date: Feb 2005
Location: Near Copenhagen
Default THE PENCIL: inspired by Ohm Micro Walsh Tall

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Drivers: Peerless 832873 and Morel MDT-40 (tweeter).

Cross-over is just a 2. order Linkwitz Riley for the tweeter at 6 khz, 1,8 uF in series + 0,39 mH in parallel - Because the Peerless is ultralinear and has a natural rolloff at 6 kHz with 12 dB/octave rolloff

The enclosure is 10 liter, 71 cm tall, 12,1 x 12,1 cm internal.
The port (on the back of the speaker) has 5,7 cm, length 10,5 cm.

The "tweeter-protector" on top is just a pencil-holder turned upside down

The costs is about US$ 500/euro 300 total for a pair. It's easy to build, and don't take up much space (except the sound, which is very spacious

The sound is fantastic - very dynamic, slam-bass, and a very natural soundstage. This is a speaker, where I don't skip music, but listen to music, I previously wouldn't have - THE PENCIL simply plays MUSIC... Try it, build it.

Click the image to open in full size.

Click the image to open in full size.

Regards, Jesper
  Reply With Quote
Old 1st December 2007, 03:33 PM   #2
diyAudio Member
 
ashok's Avatar
 
Join Date: Jun 2002
Location: 3RS
Looks great. I built some speakers firing upwards with a deflector cone above it and a tweeter above that . Pity I have no pictures . It was made for a friend in the 80's and I guess the unit isn't alive anymore.
Maybe you should have a grille perforated like the tweeter , for the mid/bass also .
Theses kinds of arrangements do give a very spacious sound but if I remember correctly , it didn't give a rock solid image like some standard speaker arrangements do.

Great job.
__________________
AM
  Reply With Quote
Old 1st December 2007, 03:46 PM   #3
Badge is offline Badge  United States
diyAudio Member
 
Join Date: May 2004
Location: Oregon
I would have chosen a much lower X-over point, but that is a just my perspective. The MDT-40 is a good tweeter. I have a pair and my plan is similar but will use the B&O omni reflector approach.
__________________
The freaks stick together, they are a tight old crew
  Reply With Quote
Old 1st December 2007, 04:04 PM   #4
GDJ is offline GDJ  Canada
diyAudio Member
 
GDJ's Avatar
 
Join Date: Oct 2007
Location: Edmonton, Alberta, CANADA
Very nice job! Love the look of the pencil holder.
  Reply With Quote
Old 1st December 2007, 04:07 PM   #5
49 - for the 18th time
diyAudio Member
 
c2cthomas's Avatar
 
Join Date: Oct 2006
Location: Near "Music City" (Nashville Tennessee)
Similar to this: http://www.diyaudio.com/forums/attac...amp=1176356499
Perhaps a little of Mamboni Magic or BudP EnABL Voodoo!!! I have found that my Walsh 5 remakes are very nice speakers in respects to being an "omni" directional type of speaker. I find them great for my HT and general listening.
__________________
DIY audio can be expensive but getting to see things go up in smoke - that's priceless!!!! ..... "whatever - call it brainfart of Mighty ZM"
  Reply With Quote
Old 1st December 2007, 05:19 PM   #6
Juspur is offline Juspur  Denmark
diyAudio Member
 
Join Date: Feb 2005
Location: Near Copenhagen
Quote:
Originally posted by Badge
I would have chosen a much lower X-over point, but that is a just my perspective. The MDT-40 is a good tweeter. I have a pair and my plan is similar but will use the B&O omni reflector approach.
Yes, the Morel is a very good tweeter. Not very fond of xovers in general, this is the most minimalistic I found useful. 6 db/rolloff is - in my opinion - not steep enough in general to protect tweeters properly . The standard xover-point in the 2-3 kHz range is generally bad, from an listening point of view (our ears are very sensitive in that area). So to create speakers where the crossoverpoint isn't audible, you'll have to either move upwards in frequency (as I do) - or down, which makes huge demands for the tweeters in 2-way systems.

But THIS Peerless bass/midrange is exceptional for this kind of speaker - a very wide frequency range, no peak at the upper frequency, and a natural and fine roll-off... See datasheet here
  Reply With Quote
Old 1st December 2007, 05:25 PM   #7
Juspur is offline Juspur  Denmark
diyAudio Member
 
Join Date: Feb 2005
Location: Near Copenhagen
Quote:
Originally posted by ashok
Theses kinds of arrangements do give a very spacious sound but if I remember correctly , it didn't give a rock solid image like some standard speaker arrangements do.
You're right - the image is not sharp as "**** in snow", but more "natural" - I'd say it pretty much reflects the image at an acoustic jazz-concert with no electric amplification.

Regards, Jesper
  Reply With Quote
Old 21st February 2008, 01:52 PM   #8
diyAudio Member
 
Join Date: Nov 2007
what is damping foam? anyone?
  Reply With Quote
Old 21st February 2008, 04:53 PM   #9
Juspur is offline Juspur  Denmark
diyAudio Member
 
Join Date: Feb 2005
Location: Near Copenhagen
Any damping foam - I've used foam from a mattress.

BTW, I've changed the x-over. Now it consists of only a 2,7 uF in series with the tweeter. Simpler, and recommended by ear
  Reply With Quote
Old 21st February 2008, 05:34 PM   #10
Tyimo is offline Tyimo  Hungary
diyAudio Member
 
Join Date: Nov 2002
Location: Hungary
Jesper!
Nice speaker!
Could you tell me how you speaker works?
Is the midwoofer radiating upwards or down into the box??
Is it connected in phase or in reversed phase?

Greets:

Tyimo
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
DIY Walsh Driver cjh Planars & Exotics 39 1st November 2012 12:42 AM
Ohm Walsh 2 - can i cut these pool strainers off? ark Multi-Way 14 13th November 2011 05:30 AM
Micro Jacks and Micro Pins for board-board connection jazzist Parts 1 12th May 2008 03:02 PM
JAN 5676 pencil tube Telefunken brand. jean-paul Swap Meet 0 24th August 2006 06:21 PM


New To Site? Need Help?

All times are GMT. The time now is 02:52 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2