1801B

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1801B Discontinued - 1801C Pending Completion

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Discussion

The 1801 is a two way stand mounted speaker using the SEAS Excel W18E001 and the Hiquphon OWI.

The Woofer

I chose the SEAS W18 driver because I enjoyed the SS8545, but wanted more detail and transparency.  I figured the magnesium cone might perform better.  The W18 motor/suspension is very good too.  The SEAS W18 is almost a perfect match for the SS8545 with respect to T/S parameters.  The peak to peak X-Max is identical between the two drivers at 19mm. The linear X-Max of the W18 is slightly less at 10mm versus 13mm for the SS8545, but 10mm is still a very long linear region compared to most drivers.  The Fs and Qts, and VAS numbers are also very close.   The W18 measures slightly less inductance at .22mh versus .28mh for the SS8545.  The motor structure of the W18 is first rate.  After years of listening I can safely convey that for those of you who like the SS8545, but want more midrange detail - the W18 is the answer.

The W18 cone is brutally stiff, and surprisingly non-resonant in the pass-band.  Dennis Murphy designed the crossover and performed  the measurements.  He said the W18 measured flatter than anything else he has measured up to 2khz.  It has only one resonance mode at about 4.3khz.  This made the W18 very easy to work with.  SEAS did an excellent job on this one.

The Tweeter

I wanted a commensurate tweeter, and had lived with the SEAS T25 for about two years.  It is a good tweeter, but I wanted something better.  Dennis Murphy measured a T25 "peer" and found a substantial knee in the response at about 2100hz.  It also didn't sound any better than a the T25 or a  substantially cheaper tweeter when crossed over at 2800hz.  I wanted to try something else.  Then Steve Shenkel posted the following on the Madisound discussion page:

Stuff For Sale

Posted By: Steve Schenkel <sschenkel@juno.com>

Date: 4/4/2001 00:43

Since everyone else is doing it why not me?

I have a pair of ScanSpeak 9700's I would like to sell for $225.00 for the pair. They have had very little use. I like Hiquphons better.

Steve

The Hiquphon OWI has surpassed my expectations, and Dennis Murphy's expectations too.  I agree with Steve in his assessment of the OWI, and it's relative position in the marketplace. 

The Details

Frequency Response:  The F3 is about 40hz in a 22 liter enclosure.  Sensitivity is between 84 and 85db.  The frequency response is very flat and indicates complete baffle compensation.  Some call this unromantic.  I call it accurate.   

Impedance:  The impedance is 8ohms nominal and dips to a low of 6.2ohms in the bass region.  

Baffle Diffraction:  Driver placement was optimized using Paul V's diffraction simulator then measured for validity.  

Phase Relationship:  The drivers show the appropriate reverse null.

Refinement:  Dennis Murphy's 35 years of crossover experience, 30 years of symphony cello performance, and 100s of hours listening matriculated a perfect crossover.

Size:  The cabinet of the 1801 is 19" tall, 9" wide, and 14 1/4" deep.  A pair of 1801's in cherry wood weigh about 75lbs.

Port:  The speakers are rear ported.

Grills:  I prefer not to use grills and I do not provide them with my speakers.  They cover up the good  lumber I put on my baffles.  Grills also diffract the waveform slightly.

Sound Pressure:  Many folks have asked about how much sound the 1801 will produce.  My thoughts are here.

1801b Kit

$750/pr + shipping

- Measured and matched drivers - The tweeters are matched at the factory.  I match the woofers.

- Cabinet plans: The 1801 cabinet plans may be downloaded by using "right click" and "save as" here.  The cabinet is relatively simple, but some understanding of this task might be helpful for those experiencing trepidation about sawdust making procedures. 

- 14ga Goertz Foil inductors

- Small gauge air core inductors in parallel where higher dc resistance is needed

- Mills wire wound resistors - Choose your values

- SonicCap Capacitors - Subjective comments,

- Schematic:  Surprisingly, it isn't terribly complicated.

- Internal cable: I performed many experiments with internal cable in the 1801s.  After many experiments I have settled on Goertz 20ga 1:14 flat magnet wire behind the tweeter and 14ga Teflon coated, silver plated copper behind the woofer.  In 2007 I discovered that Vampire Continuous Cast Copper is marginally superior, but also more expensive. This wire is offered as an option below.

- Bi-wire 3-way binding posts rethreaded for brass nuts.

- Port tubes:  Double flared port tubes from Precision Sound Products

- Driver gaskets:  I occasionally use gasket material.  If the driver flange recess is flat, then it's unnecessary.

- Mounting screws:  Black #10 pan head screws for the woofer and black #8 flat head screws for the tweeter

- Good solder:  Cardas Quad Eutectic solder from Soniccraft

- Stuffing Material:  Foam stuffing for the cabinet walls and polyester batting for behind the woofer.

- Unlimited technical support:  Many folks are very afraid of building speakers.  It is time consuming, but not difficult.  I expect and welcome questions during the construction process. 

- Not included:  Wood, and all cabinet related materials

- Option + $175: .1uf Sonicap Platinum bypass capacitors (6).  Eventually I will overcome my personal dilemma regarding the cost of these capacitors, but I use them in my personal speakers and fully affirm the benefits they provide.  The impact is immediate and obvious.  Commentary   

- Option + $75:  Crossover Assembly.  Subjectively, I charge a premium for this because it's tedious work and I truly believe the layperson can be successful in this endeavor.  The crossover is surprisingly simple and there are many illustrations in the crossover plans.

- Option + $30:  Dave's stuffing brew.  After years of listening to the 1801s, this is the combination of Black Hole 5, acoustic foam, and polyester batting I prefer.  This option adds 2lbs to the 1801 kit and slightly raises the shipping cost.  Subjectively, I would like to convey that the the impact of the Black Hole 5 is very modest due to the already very solid 1801 cabinet.  As such, the standard foam & poly batting delivered with the 1801 kit is already sufficient for 90% of folks.

- Option + $15: Vampire Continuous Cast Copper internal cable.  14ga for the woofer and 18ga for the tweeter.  I find this wire extremely good, and prefer it over any of the cable I have used/tested.  It's very clean, presents excellent dynamics, and has no grit/grunge.  Subjectively, I believe this is a wise option for anyone with better source gear that is willing to purchase better external speaker wire too. 

Cabinets for your Kit

Jim Salk is semi-retired, and has an incredible touch with hand rubbed finishes.  Jim worked in recording studios for many years and has excellent hearing.  He is a fine gentlemen with a charming and encouraging wife.  Jim tends to specialize in exotic veneers and woods. His results a are striking.  Jim's work isn't free, but is easily on par with the finest home decor.

 Salk Sound

Completed 1801b

$1500/pr + shipping

 - Cabinet skeleton - braced 3/4" MDF on the sides, top, and bottom.  Front and back are 1 1/4"+ thick composite

 - Cabinet exterior - Select Grade cherry wood lumber/veneer

 - Cabinet finish  - 3-5 coats of pre-catalyzed lacquer with a honey amber tint.  comments

 - Large 14ga Goertz Foil air core inductors in series

-  Small gauge air core inductors in parallel where higher dc resistance is needed

 - New for 2003 - SonicCap capacitors - comments

 - Mills wire wound resistors - Choose your values

 - 18ga Vampire CCC between crossover and tweeter.

 - 14ga Vampire CCC between crossover and woofer

-  3-way bi-wire posts with brass nuts internally

 - Capacitors, inductors, resistors are measured and matched within 1%.

 - Connections - Firmly crimped and soldered with Cardas Quad Eutectic.

 - Drivers - Measured and matched within 3% with respect to Thiele & Small parameters

 - Drivers - measured and matched within 1db with respect to frequency response.

 - Premium Stuffing material - Black Hole 5, acoustic foam and polyester batting.

- Port tubes:  Double flared port tubes from Precision Sound Products.

 - MLS Gated Time Response measurements provided with completed 1801s:

    - On axis

    - 45 degrees off axis

    - Reverse polarity

 - Option + $200: 10-12 coats pre-catalyzed lacquer with honey amber tint - rubbed flat to a high gloss-   comments

 - Option + $175: .1uf Sonicap Platinum bypass capacitors (6).  Eventually I will overcome my personal dilemma regarding the cost of these capacitors, but I use them in my personal speakers and fully affirm the benefits they provide.  The impact is immediate and obvious.  Commentary