[gotmikey]

I wanted to post pictures of my 1801F's I just finished, but don't have a server or whatever I need to post pics.  Anyone wanna host my pictures?  Send me a PM.  By the way, these speakers are, to say the least, incredible.  I'm listening to CD's I don't even listen to on a normal basis.  I can honestly saythese speakers have taken me to another level in 2 channel audio.  I have my Paradigm Studio 80 v.2's already posted for sale at Audiogon.

[Ravi]

gotmikey, you've got great taste in speakers  

Couldn't agree with you more, these babies make music like few others can.

About the pictures, why don't you upload them to this website?  Click on Gallery, and then New Album.  Then upload away.  Look forward to seeing some pictures!

[Foxyb]

I am delighted that the 1801fs are so good, as I am just building some in the UK just now, with 18mm birch ply carcases, double thickness front baffle, and some sound deadening pads.  I hope that my construction provides the same results as yours. I expect the veneering to be quite a problem, as apparently I have to put the grain of the wood veneer perpendicular to the substrate grain, which of course is up and down!
I may do an initial build with the drivers semi-rebated to allow me to decide how to veneer the cabinets to fit into the living room decor, which is light wood.

Any ideas/ sources of inspiration?

I am hoping/ expecting that connected to my John Linsley Hood amp that they will blow away my old Heybrook HB1s (should be easy), and that they will bring my jazz and rock to life.

[gotmikey]

If anyone wants to see my semi-finished speakers, go to hometheaterforum.com and check under DIY and Advanced projects under 1801F.

[David Ellis]

I appreciate you posting these results.

Hopefully sometime this fall I'll have something formally published concerning this project.  I have experienced a couple of a/b comparisons with the stand mounted and floor mounted versions of the 1801b.  The sound quality is almost indistinguishable.  The bass is a little different.  The midrange was different in 1 setting.  There is still some more experimentation before formal bennediction.

Dave

[gotmikey]

Your welcome, Dave.  The 1801F's are currently out of commision as I am applying the veneer to them, but I've been busy lately so back burner for now.  I haven't done any port tuning yet and was wondering what length your port is for these?  I know you state that I should trust my ears, however I always like to have a starting point.  Even without the port tuning the speakers still sound outstanding.  Midrange is just heavenly.  I'm building another pair for my home theater very soon.  Overkill?  Probably, but it gives me an excuse to cut some wood!

[David Ellis]

Actually, I just use the standard length port.  

The port impedance essentially creates a resonance inside the cabinet that pumps bass through the port.  A longer port will have a higher impedance and lower bass tuning.  A shorter port will have a lower impedance and higher bass tuning.  The trick is to get the port reinforcement to match the roll-off of the driver. A longer port will sound leaner and a shorter port will sound more boomy.

[Foxyb]

Dennis Murphy in the Madisound discussion forum considers the benefit of 3/4" baffle rounding significant.

The 1801f I am making leaves only 6mm width outside the edge of the woofer.

Is it worth me putting in a 6mm roundover on the edge all along the baffle?
Should I attempt to put an 18mm roundover near the tweeter on the sides (and top as well)?

Also, do I need more than an 18mm thickness of birch ply on the rear baffle to damp vibrations? I am planning on a panel of auto sound damping, to tackle this in any case.

Nice to see a picture of a light-coloured 1801f - mine also will be veneered in maple.

[gotmikey]

Yo, Foxy I think that a roundover is negligable with regard to sonic performance due to the fact that there is a really really small amount of material on the sides of the woofer already.  I personally wouldn't risk the baffle face for a such a small roundover radius that probably won't make a noticeable difference.  That's me though.

[gotmikey]

Yo, Foxy I think that a roundover is negligable with regard to sonic performance due to the fact that there is a really really small amount of material on the sides of the woofer already.  I personally wouldn't risk the baffle face for a such a small roundover radius that probably won't make a noticeable difference.  That's me though.

[David Ellis]

Well,

I ain't sure when Dennis made the remark about the significance of the roundover, but Dennis and I a/b auditioned the 1801b and 1801bf 2 weeks ago.  Neither of us could hear any difference in the midrange.

On a 9" wide flat baffle there is a measurable ripple on axis with the tweeter using a gated time response and square baffle edges.  This disappears with an in-room sweep.  It also varies when off-axis.  I have found very neglegable ripple with the narrower 1801f baffle - even with a gated time response.

The gated time response is essentially an anechoic response, and the sweep is an in-room response.

Even when using a 9" wide square cornered baffle, there is no audible impact at my ears.

Given the example of $20k+ speakers, some use a rounded baffle edges, and some do not.  I believe this exemplifies the theory, measurement and science regarding this matter.  While there is some measurable impact with drivers mounted in the center with square corners, the impact really isn't so audible.  Some guys might claim to hear something, but would likely not pass an a/b test.

Insofar as the thicker/thinner cabinet walls, I really don't know.  This is one of the things I need to resolve before formal bennediction of the 1801f.  

However, a thicker back wall won't hurt anything.

Dave