Northern California DIY 2004

Post Event Summary:

Activities for the Day:

Speaker Auditions

� Standard Auditions

� Contest � speaker which best fits its design goals

Software Demos

� Soundeasy

� Praxis

Speaker Audition Summary

We saw a wide variety of designs, drivers, etc. during the day.� Open baffle, single driver, two ways, MTMs, 3 ways, unusual rear channel surround speakers, etc.� The smallest must have been 1/3cuft while the largest was around 7cuft!��� At some point, Dave Edeck was worried that things would disappear from the hall, but that wasn�t going to happen with the latter speakers!� We saw some great wood working as well ( more later).

Speakers Waiting their turn (Edwin, Steve, respectively)

Getting Ready to Listen (Barry W)

Auditions In Progress

(Thurman) ������������������������������������������������������������������ John Jackson Acutons (Edwin H)

John Busch with Giants (Steve H)�������������������������������� Andy Newell w/ Open Baffle (Barry W)

Specific Photos/Designs

These are roughly in order of audition. �Only those with photos written up.� Please feel free to send in more comments as I did not get a chance to listen to all of the designs.� More photos would be good too!

Katie Bartas

Read more under �Contest� below.

John Bartas demoing Katie�s� Speakers (Steve H)

John Busch�s or Steve Higgins?�� (Barry W)

Andy Newell:� Open Baffle, Tube Amp Driven

These had a really nice cohesive sound.� Made from ElectroVoice 12s.� Far exceeded my expectations for a single large driver.� Treble, for example was fairly extended.� Also, Andy had some really interesting test CDs.�

Mono Block Amps, Preamp

{Steve H}������������������������������������������������������������������� {Edwin Y}

Speakers

Notice corrugated cardboard to disperse waves (Edwin)��

Greg Dallum

Greg demoed two speakers during the day.�� See comments below on woodworking.

(Steve H)

Dave Brown

Very interesting rear surround speakers.� Tweeters on front and back.� Rear tweeter can be in phase or 180 out of phase.� Woofer/mids face listener.�� From where I was standing, 20+ feet away, I was impressed with the balance of the sound.� I did not get a chance for a close listen.

(Edwin Y) ������������������������������������������������������������������ (Barry W)�������������������������������������������������������

Speaker Limbo:� Dave just can�t get all the way down to the sweet spot!� (Barry W)� Edwin tries but can�t get there either. (Steve H)

John Bartas

These were really interesting.� At some points sounding quite good, but at some musical passages they interacted badly with the room.� John felt the hard surfaces behind the speakers reflected too much of the rear firing tweeter.�� Loved the looks, see woodworking below.�

John Jackson

These had a great sound.�� In the tops, in terms of effortless sound, of many speakers I�ve heard.�� John really likes the Acuton drivers and I have to agree they sounded great.� Big bucks though! �John also described how fragile they are later in the day.� If you get them, treat them carefully!�

(Steve H)�������������������������������������������������������� (Edwin Y)

John Busch

John calls these his �Jokes.�� He says he did it just to prove it could be done.� Well, he did prove it!�

These sounded good (without qualification).� They sounded very good considering the two drivers!��� They use an Eminence 18� wide range driver and a SS 3800 series tweeter which is really a mid tweeter.��

John really likes vocals and these did a great job on a wide range of singers.� Very relaxed sound.� No hint of MR integration issues.�� David Ortega wanted to make a center channel out of them since the group nixed that idea for his vintage Yamahas (just kidding David).�

(Thurman G)� �������������������������������������� (Barry W)

Woodworking:

Ordered alphabetically

John Bartas

By far the most complicated DIY cabinet design I�ve seen in person.� In the top 3 I�ve seen anywhere!.� Its hard for the photos to do it justice.�

Some notes on it:� 1.� No parallel surfaces.�� 2.� The front consists of three panels.��� 3.� The back has a rear firing woofer and rear firing tweeter.� 4.� The side walls are curved.� John laminated three layers of ply together to create the curved sides before cabinet assembly.�� John will hopefully post the process to a web site soon as it does not fit any process I�ve previously seen published.�� 5.� Finish is quite nice.�

(Steve H)�������������������������������������������������������������������� (Thurman G)

You can see that John executed the design beautifully, but like many of us, he�s gone back and changed things.� Remember, do mock-ups till you are happy with the sound and then build a stunning cabinet.� Many of us, myself included, whish we had!�

John Busch

Impressive sound, but �pullin� your leg�� on the woodworking. �;)

(Steve H)

Greg Dallum�s

Great tight fitting cabinets.� Very nice finish.� �Greg�s comments on them:� �the speakers that I built were veneered with Tape Ease, 2-ply, red oak.  The edges were routed and inset with solid red oak quarter-round.  The cabinets were finished with Minwax natural stain and Minwax satin polyurethane.�

(Thurman G)

John Jackson

John�s still working on his speakers, but everyone loved the wood used for the top half�

(Steve H)

Contest Summary

Not all people auditioning speakers brought the forms for the contest.� About 7 speakers were entered out of 15 or so auditioned.

The contest required the audience to compare the design intent of the speaker to how successfully that intent was met.� Thus, a pair of really expensive speakers might get beaten by an inexpensive pair because the latter was a better fit with its original objectives.

It turned out that two lower cost designs ranked very high with the audience.� These two were ranked A- and B+ respectively.��

Sorting out the feedback (Barry W)

Winner:� Greg Dallum�s MTs

Here�s Greg�s description of his speaker objectives:�

Summary of Objectives:�� I wanted to build 3 pairs of fairly good speakers for my twenty-something kids.� They all live in apartments, so a fairly small size was desired.� I was looking for good extension and driver quality at an affordable price.� I came across the Embla design and it seemed perfect.

1) Detailed Objectives:

Targeted cost -� approx. $100.00 ea.

Expected completed cost � around $100.00 ea. or $200.00 per pr.

Target listening levels - Mostly low to medium levels (I�m sure that�s a lie!).

Target sound characteristics - Neutral overall, good midrange with some bass extension

i) Intended listening environment � small to medium living room

ii) Desired look - Natural wood finish with rounded hardwood corners

Creating the speakers - The box is the same internal volume as the Embla plans but the baffle dimensions were changed slightly to accommodate the extra internal bracing and 7/8� MDF.� I used JustMLS and LspCad Standard for crossover measuring and modeling.� My microphone is an uncalibrated Panasonic WM-61A capsule in a brass wand with a preamp of my design.� The boxes are veneered with TapeEase 2-ply red oak.� Finished with Minwax Natural stain and Minwax Satin Poly.��

2) Work in Progress (YES / NO ):� NO

3) Speaker Data:

Type - 2-way passive TM

i) Alignment - Bass reflex, measured Fb is 56.5Hz.

ii) Crossover description � Slightly modified Embla crossover. ��3kHz. crossover frequency.�� The tweeter has a rising response, so the crossover was modified slightly to flatten this out.� Some other crossover component values were changed for my application.

Drivers Used � (1) Seas� P17REX - 6.5� poly. woofer, 8 ohm (Madisound).� ������������������������� ����������� ��(1) Seas 25TAFC/D - aluminum tweeter,� 8 ohm(PE buyout).

Runner Up:� Katie Bartas� speakers.� �����

Katie�s Objectives included low cost, capability to play loud but detailed, and she wanted the wild paint job too!� The speakers used an Audax 210z0 woofer and the Hi Vi Rt2 tweeter.�

Greg�s Speakers (Steve H)������������������� ���������������������� �Katie and her speakers (Barry W)�

����������������������

Other Photos

Software Demos

(Barry W)

PartsExpress Goodies

HiVi R1L Round Spiral Planar Tweeter (Barry W)

Thanks:

Sponsors

� PartsExpress

� Soundeasy

Event Photographs

� Thurman Gillespy

� Steve Higgins

� Barry Waldron

� Edwin Yang

Room rental arrangements, onsite logistics, etc.�

� Dave Edeck

Demos

� Praxis:� Mark K

� Soundeasy: Jonathan Z

Web Site

� Steve O�Toole

Other

� All those who helped with extras such as room setup, room clean up, etc.�