[Doug Kim]

Hello

My 1801b kit was finished last Wednesday(5/12).
The speakers are still in breaking-in period, but they sound amazing.
I will post about the sonic quality after they are fully broken-in.

Here's brief description of my kit. I bought a kit (drivers + crossovers + extra) from Dave and I hired John Bateman of Baltimore for building cabinets. He's the one who helps building several Murphy Blaster products.
Although the completion took somewhat long time(4-6 weeks, what about other builders?), his work is great and very very satisfactory. Most of all, he's my neighbor!
My cabinet has birdseye maple finish and grill option. I usually don't put the grills on, but I need them in case my nephews and nieces visit my place. The cost for cabinets is $300 for pair. Front baffles are 1" MDF, and the rests are 3/4". I filled first and second section of cabinet with poly-fil I bought at WalMart, as Dave recommended.

Here's some pictures.

Left, grill off.


Right, grill on.


BTW, how long does it usually take 1801b to be broken-in? I feel bass is lacking after 3 days, but I sense it's getting better day after day.

Doug

[David Ellis]

Your neighbor does very nice work.  If the internal joints of this cabinet equal the outside appearance, those cabinets are excellent - and very cheap too!  The 1" MDF on the front is slightly thinner than what I build, but should be fine.  

Although the completion took somewhat long time(4-6 weeks, what about other builders?),  

That's very fast!  It's obvious he doesn't have bad eyes and two small children at home.

I filled first and second section of cabinet with poly-fil I bought at WalMart, as Dave recommended.

Actually, I recommend stuffing as pictured here: http://www.audiocircle.com/index.php?topic=10239

I don't think precision matters though.

BTW, how long does it usually take 1801b to be broken-in? I feel bass is lacking after 3 days, but I sense it's getting better day after day.

Every woofer I send has spent 8-24 hours on a continuous sine wave.  They are broke-in.  If you think the bass is getting better, the change is most like subjective.  If you want more bass there are two avenues.

1.  Move the speakers closer to the back wall.  This will affect the mid-bass and the deep bass.

2.  Make the port slightly shorter.  I suggest removing port material at 1/2" per test.  

My room is big and soaks a bunch of bass.  My speakers sit closer to the wall and have a slightly shorter port.  Not all rooms are the same.

Dave

[stvnharr]

Doug,
Nice speakers.   I always have liked birdseye maple.   Birdseye veneer is quite expensive, so nice when you don't have to buy the whole sheet.

Here's some more "experience" with 1801 bass.
Dave's words are 100% correct.  
The 1801 is highly influenced by room gain, ie. wall reflection.   If you have a large, especially wide, room the only way you get much room gain is to move the speakers closer to the back wall and sacrifice some of the typical 3-d-ness of the sound.   I have a narrowish room and get a fair amount of room gain.   Then I have to play with speaker placement to deal with the sidewall reflections.
BTW, the cardas website, www.cardas.com go to insights and then room setup, has a very good and simple method for speaker placement.

I shortened my port A LOT, down to 3 inches, without ill effects.   The bass increased and there was no boom.   I'm sure I destroyed some of the roll-off characteristics, but the increase in bass was better.
The only way to get more bass is to suppliment with a subwoofer as the W18E just doesn't go all that low.

Steve

[JoshK]

Very nice looking cabinets!  Really like the real wood trim look!  Makes the added touch very nice.

[Ravi]

Doug, you may wanna try removing some polyfill.  Its a ported cabinet so any stuffing in the center volume of the cabinet will destroy the bass tuning.  Just line the walls.  No real need to line the braces.  This is just from personal experience.

Enjoy the speakers!

[David Ellis]

 Its a ported cabinet so any stuffing in the center volume of the cabinet will destroy the bass tuning.  

Could you please post the details of what you found during your stuffing experiments the the string titled "How I stuff my 1801s"?

[Doug Kim]

Thanks to all for advices.

I'll try removing the stuffing in the center section, and will do the lining the walls. What's the name of that black thingy which Dave lined the wall? Egg crate? I should get some next time I go to WalMart.

I put the speakers a little closer to the back wall, and changed the amplification from Ayre AX-7 to Oddyssey Stratos. It helped. Now the bass is better than before.

To Dave : Thanks for the book you sent me. I replied but it seems my hotmail was junked again. I'm a Christian, so your book was quite interesting to read.

Doug

[David Ellis]

I'll respond to this query in the stuffing string.  If we keep remarks about stuffing in the stuffing string, future readers will find these remarks easier.

[pecker]

Your neighbor does very nice work.  If the internal joints of this cabinet equal the outside appearance, those cabinets are excellent - and very cheap too!  The 1" MDF on the front is slightly thinner than what I build, but should be fine.  

Actually, my vision is pretty lousy.
I just wanted to mention that the baffles are 1.25" thick, rather than the 1" that Doug stated. I used the same bracing scheme per your drawing, but did not spend time making the braces pretty.

Regards,
John

[Doug Kim]

Oops. My mistake. Yes, now I remember that I asked the front baffle to be built with 1.25" thickness.
Sorry about that.

Doug

[Doug Kim]

(follow up)

I changed the stuffings of my 1801 kits. I did (almost) exactly as Dave did. Lined second and first sections with Blackhole 5, and netted poly-fil behind woofers.

Any improvement?
Absolutely they sound better. Bass is fuller and the mid is richer.
I will post a full review after more serious listening and comparison with other speakers.

Great kit, great cabinet.
Thanks Dave and John.

Doug

[David Ellis]

Doug,

I am glad you heard a change in the stuffing.  Could you please describe what the stuffing was (in detail)?  Please post this in the other forum titled "How I stuff my 1801s."  I'd like to probe you on this.

Dave

[pem]

Dear all,

I have just ordered a kit. I take benefit of the 8 weeks shipping delay to study how to build the cabinet.

As far as I understand, the front and rear panel are 3/4" thick.
However, they seem to be thicker on photos I have seen. In a previous post of this thread, Dave said that 1" is thinner that what he usually uses.

I think I do not understand something.
I would be pleased if someone could explain me where is my mistake.
If 3/4" MDF is finally used, is it necessary to reinforce the front panel?

 many thanks,
 Pierre-Etienne

[David Ellis]

As far as I understand, the front and rear panel are 3/4" thick.

Per the plans the MDF specified is indeed 3/4" thick.  However, the front panel will be 1 1/2" thick after the hardwood lumber is added.

The back panel can certainly be made 1 1/2" thick.  I haven't a/b tested this, but a thicker back panel holds up better to the knock test.

Ultimately, both the front and back panel could be made 1 1/2" thick.  This leaves 12" depth internally.  The external depth will be 15".

Hopefully this makes sense.

[Al Garay]

Doug,

Can your friend build more cabinets? There's a person who just visited my house who is going to order a pair and might want to contact your cabinet builder.  Did you end up using BH5? Where did you place it?

Dave,  what about using baltic birch instead of MDF?

Al

[David Ellis]

Dave, what about using baltic birch instead of MDF?

Excellent question and... well... I don't know.

This is one of those things on the list of "things to do".

I have used baltic birch for bracing recently, but dont really think it has much/any impact.  It cuts easier than MDF with my router.  My router bits remain sharper when hogging material from the blatic birch plywood.

Eventually I'll purchase a vibration sensor, and offer a very good paper on cabinet materials.  Combining this with port energy should prove very interesting.  Theoretically, a weak cabinet wall will soak/pass more bass and leave less energy for the port.  The quantity of vibration, and quantity of port energy, SHOULD be inversely proportional.  I was planning to do this with 1/2" material, 3/4" material, 1 1/2" material.  I might even use concrete/ceramic.  I wasn't really planning to try plywood.

My hunch with plywood is initially... no.  I really think the stuff will vibrate too much.  However, a few years ago somebody in speakerbuilder magazine did a test with plywood and found it okay.

[Al Garay]

I believe that Andy's (awm's) 1801 cabinets are made of plywood. No MDF. And used BH5 as well. I cannot hear any degradation in sound between our speakers. Sure helps avoid the mess of MDF dust.

Al

[awm]

Hi, guys --Al, almost.  My cabs are a combo of plywood and MDF.  I used MDF on the inner layer of the baffle, the bottom of the cab, and the internal braces, as these would all be hidden areas once completed.  I used ply on the rest, the exposed areas, as I just finished and stained the ply.  Bottom line -- I've heard my 1801b's and Al's 1801b's extensively and don't notice any difference that I could attribute to the ply.  I've also heard that for the highs and mids, ply is superior to MDF.  Don't ask me to dredge up the link, though, as I can't.  And, I've heard MDF is, too...  

Andy

[pecker]

Doug,

Can your friend build more cabinets? There's a person who just visited my house who is going to order a pair and might want to contact your cabinet builder.  

Al

Al, you can point your friend here: diybox

[Al Garay]

Hi John,

I passed the information on to Kevin. If he goes through with building the kit, your cabinets would be tought to beat for the value.

thanks,

Al