The Napoleons: a Compact 2 Way that punches above its weight - 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 23rd April 2013, 03:48 AM   #1
DDF is offline DDF  Canada
diyAudio Member
 
DDF's Avatar
 
Join Date: Sep 2004
Location: Ottawa
Default The Napoleons: a Compact 2 Way that punches above its weight

The Napoleons are a small DIY loudspeaker designed to deliver a natural tonal balance and clean loud playback from of a small box suited to both small and large rooms, at a reasonable price. This write up was in response to requests from the 2013 Ottawa DIY fest, where the speaker was first shown DIY Ottawa winter 2013

Driver Selection
Off axis response irregularities will detract from speaker tonal balance more in a small room than in a large room due to the greater relative strength of indirect sound, compared to direct sound. To help combat this, a tweeter was chosen with some mild horn loading, and a woofer with a well-controlled extended higher frequency response that could take advantage of it.

The Tang band W4-1720 (Tang Band W4-1720 4" Underhung Midbass Driver 264-872) provides powerful and clean mid to upper bass from a very small sealed box. A vented design was avoided to keep the box small and to avoid box/vent unloading which would compromise the high sound pressure levels desired for larger rooms. The mighty little W4-1720 plays ridiculously loud and clean in this application, and mid to upper bass is rich enough to give a pleasant tonal balance. It’s smooth mid treble allows a higher crossover point so the tweeter can play loud without strain. This is a good sounding driver, but it can still be made to bottom when over driven by drum test discs. Still, it plays clean and loud enough to pass the “I didn’t realize it was playing that loud” test.

The tweeter is the Vifa D26NC55-06. It’s well-controlled off axis response near crossover and its drooping high frequencies off axis reduce “splatter” in a small reflective room. Its distortion is also very low. While this driver is officially NLA, examples can often still be purchased from on-line suppliers.

Box Dimensions
The sealed box is simple and was built using hand tools and a flush trim bit. Half inch mdf kept the box small which in turn keeps panel vibration under control. The box was made shallow to allow true shelf mounting. Woofer center is 3.5” from bottom, tweeter 7.5”. Drivers are centered horizontally.

A different baffle shape (for example due to thicker wood) would change diffraction and affect the response. This could require a crossover change and this design is expressed for 0.5” wood only.

Crossover and Frequency Responses
The crossover is a 6 element second order electrical, in phase driver connection. Special attention was placed on smooth on and off axis response, and a smooth response when standing while listening.
Low pass
L1: 1.5 mH inductor, 0.7 ohms dc resistance (18 gauge air core).
C1: 15 uF cap (not electrolytic)
R1: 1 ohm power resistor (10W or greater)

High Pass
C2: 2 uF cap (not electrolytic)
L2: 1.1 mH inductor, 0.5 ohms dc resistance (18 gauge air core)
R2: 15 ohm resistor, high power (25W or greater)

The full project write up is attached and includes system box tuning, material plan, numerous measurements from 20 Hz to 20kHz, along with design rationale and more detailed build information.

Dave Dal Farra
Attached Images
File Type: jpg 1.jpg (49.7 KB, 1550 views)
File Type: jpg 2.jpg (32.9 KB, 1512 views)
File Type: jpg 3.JPG (33.3 KB, 1478 views)
File Type: jpg 4.JPG (63.0 KB, 1467 views)
Attached Files
File Type: pdf Napoleons.pdf (664.8 KB, 254 views)

Last edited by DDF; 23rd April 2013 at 04:06 AM.
  Reply With Quote
Old 23rd April 2013, 01:48 PM   #2
Mark Kravchenko
diyAudio Member
 
mwmkravchenko's Avatar
 
Join Date: Jan 2002
Location: Perth Canada
Nice!
__________________
Mark
www.kravchenko-audio.com
  Reply With Quote
Old 23rd April 2013, 04:47 PM   #3
diyAudio Member
 
bearberry's Avatar
 
Join Date: Jul 2007
Location: Ottawa
Thanks Dave! These sounded terrific, can't wait to get a set built.
  Reply With Quote
Old 23rd April 2013, 05:13 PM   #4
diyAudio Member
 
Join Date: May 2010
Location: MN
Nice. I built a quite similar speaker not too long ago using the old Genesis tweeter with that woofer. 2kHz acoustic crossover point and almost the same driver slopes too, but a bit more recessed upper midrange and a little downward tilt (I was voicing it for a room that's basically a glass box, so it needed to be extra mellow). I don't know if I'd call the woofer ridiculously loud running without a high pass, but it is surprising how good it sounds at ridiculously high excursion. Oops, just realized you're running it sealed, so that's probably +6dB or so over what I had with a lot of music.

Last edited by dumptruck; 23rd April 2013 at 05:20 PM.
  Reply With Quote
Old 23rd April 2013, 06:56 PM   #5
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
Not a lot of bass I see - however I may have a need for them.
Thanks for posting.
  Reply With Quote
Old 23rd April 2013, 10:15 PM   #6
DDF is offline DDF  Canada
diyAudio Member
 
DDF's Avatar
 
Join Date: Sep 2004
Location: Ottawa
Quote:
Originally Posted by ODougbo View Post
Not a lot of bass I see - however I may have a need for them.
Thanks for posting.
Surprisingly more perceived bass than indicated by the curve, maybe due to lack of compression for a box this size. Hope you enjoy it.

Dave
  Reply With Quote
Old 24th April 2013, 12:03 AM   #7
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
Oh no.... Tweeter is discontinued -
Vifa D26nc-55-06 1" Neodymium Tweeter 264-514
  Reply With Quote
Old 24th April 2013, 02:32 AM   #8
Mark Kravchenko
diyAudio Member
 
mwmkravchenko's Avatar
 
Join Date: Jan 2002
Location: Perth Canada
From the peanut gallery




perception is everything.


And really curves tell only part of the story. Dave is a talented guy. I have heard his other creations. They sound awesome. For the man to be willing to release this it just has to be a keeper.

As for the tweeters. There is a group buy arranged.
__________________
Mark
www.kravchenko-audio.com
  Reply With Quote
Old 24th April 2013, 02:33 PM   #9
diyAudio Member
 
bearberry's Avatar
 
Join Date: Jul 2007
Location: Ottawa
ODougbo, tweeters are still available as mentioned here:
Royd RR3 Replacement Drive Units - Audio Chews: the hi-fi and music community

To clarify Mark's comment about a group buy, I'm doing one for a few people around Ottawa. You're probably as well off to order direct, as I probably can't ship any cheaper.

bearberry
  Reply With Quote
Old 24th April 2013, 09:19 PM   #10
ODougbo is offline ODougbo  United States
diyAudio Member
 
Join Date: Aug 2011
Location: Maryland USA
Bearberry, thanks for the heads up. Also found a pair on Ebay.
  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
Larger chassis Hole Punches rick57 Tubes / Valves 36 10th July 2006 08:31 AM
Buffalo Ironworker punches & dies mobyd Parts 0 10th May 2006 11:25 AM
Advice on Greenlee Punches Requested SRMcGee Parts 2 15th November 2005 12:37 AM
Handmade Electronics Metal Punches? was ist los? Tubes / Valves 0 22nd September 2004 02:54 AM
A weight vs. linear weight gary f Multi-Way 1 2nd April 2004 01:23 PM


New To Site? Need Help?

All times are GMT. The time now is 09:05 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright ©1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2