Thanks Geno and Tony—-I might play around with this in the near future.  The doorstop idea is an easy and cheap way to gauge whether this will be preferable in my rig before I commit to more aesthetically pleasing solutions.

Regarding the switch, if you look at the last picture I posted, the unit is easily bypassed by plugging the positive speaker cable into the amplifier binding post instead of the circuit board.  

Also, since the circuit board simply does nothing with the negative, you have the option of plugging your cables into the negative on the board or the negative on the amplifier.  I choose the amplifier to remove more weight and strain from the board.

Obviously this isn't going to fit very many non-decware amplifiers despite the standard spacing, so for those users it is recommended to solder some wires to the input side that can then connect to your amplifier.

Another trick is to simply install a pair of binding posts crimped down on the board at which point the board has binding posts on both ends.  Also in this instance as long as the polarity is observed it does not matter which end of the board is the input.  That makes it real easy to put it at the loudspeaker if that works better for you.

-Steve

Steve,

Is that still a 36ohm resistor as originally design or is the 30 or 40ohm?

This thread has been languishing for about six months now.

After reading Steve, Randy, Kamran and others comments on the Fast 15’s I bought a pair.

Mounted them in a pair of sand filled, dual 15 open baffles that I had from years past.

Now we are well over one thousand hours on ‘em.

Here we have a very simple system, Mac Mini, Teac DAC and a Chi-Fi 300B amp.  Exclusively streaming the music.

In this 14’ by 28’ well treated room, we have never had music sound better!

Also, there are a pair of custom made 15” woofers powered by a plate amplifier.

Thanks to everyone for convincing me that this would be a good speaker  to buy.

My guess is that folks are sitting on the edge of their seats for the new platinum 15's .

Hi to everyone, I am new to this forum and would really like to a big thanks to you for such valuable inputs in each topic, I really enjoy reading the posts and find very useful for me.

I have recently ordered a pair of Lii fast 15 and impatiently waiting for the delivery by the weekend to hook them up to Fisher 800C tube receiver.  That might be odd question and already searched but did not find any relevant topic in the forum, I wonder if I can use the open baffle speakers with speaker stands?  Through the years I have changed a lot of loud speakers and used several stands too.  I have now a nice pair of angled stands and want to know if anyone has tried with OB speakers with similar stands, I mean if there is any downside to sound quality or makes any good improvement?

Thanks in advance.

This is my existing set up, everything is backed to the wall and will make a rearrangement once I receive the drivers and leave some distance with wall.
I used to locate my speakers to my ear level when I am sitting in the room so I am keen to use the stands.  But if the soundstage is that good as everyone advised I won’t need stands.

These baffles look to me like "no baffle" at all. I have been playing for months with the F15 alone directly on the floor while I was thinking of what kind of baffle I would use. I can tell you'll miss the beauty of these drivers.
If you want OBs, do as Steve has done, a rather big piece of wood and plan to place them far away from your walls when you listen.
From your pictures, I am not sure you have the space for it. You know, big drivers need big space.
The good thing with these drivers is you can place them very very near the listening position and you'll get it all at low level.

- Have you ever seen the JBL Paragon ? ...The top of the line for JBL.... How far the drivers are from one another....2m at the most....this means if you respect the usual triangle, the listening position is also at around that same distance from the baffles, which is very close. That is exactly how I listen at them after moving them around for months (mine aren't OBs), then I push them back against the walls after listening.
I hope this will save you time in you setting.

Thanks Tooppy for your reply, much appreciated.
Size of my baffles not much different than the ones we see in this topic in previous pages and decware web site, so I believe mines seemed you smaller in the pictures.  I would love to get bigger baffles and may have them whenever I move to a bigger place but my current music room not very big to accommodate bigger baffles at the moment.  I totally agree with the distance between the speakers should be large enough and I can move them up to 10 to 15 ft if required, have enough length cables to chase them.  Based on both feedbacks I will remove the stands and play around the room to locate the baffles to get best result. Thank you.

It's not a stupid question and there are a number of ways to mount drivers to a baffle.

Smaller drivers you can get away with using small No. 8 or No. 10 by one inch long or so wood screws directly into the wood. Metric equivalents are fine.

15s are heavier drivers and I believe need a bit more support.
Some might disagree, but it kind of depends upon how thick your baffle is.
3/4 inch material is not much to grab for a wood screw. Thicker baffle and wood screws No. 10 size would be fine.

I prefer to use T-nuts for larger drivers or for drivers that I might switch out and exchange from time to time.
Or T-nuts are great if you might need to add damping material or perfect the tuning through the driver cut out and have to remove the driver a few times.

I usually add a drop of super glue to the T-nut part when I install those. Don't get any glue on the threads!! Let it dry completely to be sure. Only takes a minute or two.

Even with the super glue, I like to come in from the back side of the baffle and add a small wood screw to the back of the T-nut to make sure it can never come out, unless you want it to.

I use 10-32 or 3/16 fine thread size most of the time and just long enough to poke through the baffle and T-nut.
I would avoid slot head screws.
Phillips are fine. I prefer Allen head or Torx head. Much less chance of your tool slipping out of the drive slot and damaging an expensive speaker component.

I have a triple thick layer of plywood, MDF and plywood baffle and my F15s are mounted with 1/4 20 T-nuts, installed the way I suggested using 2&1/2 inch Allen head bolts. Wood screws might be fine for my thicker baffle, but I tend to over build for stout on things that are going to vibrate.

If you've never used T-nuts here's a pic.

Funny!
I've had way more tear outs with Hurricane nuts than with T-nuts. But then as I install mine, nothing can tear out.

My baffles are mock-ups as well, but I had some extra panels sitting around destined for shelving. I eventually want some decent looking hardwood to ramp things up a bit.

It sounds like you know plenty about what to do, already.
Give them a try!  
If yours are the Fast 15s, it might be different from my F15 experience. Several here have those newer version drivers. And some are pleased with them.

I do want to offer one word of advice as a person who almost gave up on his F15s early on.

Let them break in for a while before you judge them too harshly. It took over 100 Hrs for mine to loosen up enough to reach the published Fs spec.
They were sounding pretty good after only half that time, but still had nothing below about 100Hz.

Give them time.

Great catch!

My room is small, too and I have scaled down Steve's Big Betsy baffles.
Mine are 36" high.

I do miss that bottom octave sometimes, though. 90% of the time, I don't, but I play all kinds of music.
I bought a pair of the Lii Audio W15s to augment when I need to.
I put my woofers in a Linkwitz style H baffle.

Hey DD, thinking about missing the lower bits, I thought I remembered that you have F 15‘s, not Fast 15s like the thread title. Just hoping for clarification since the Fast 15s are supposed to go down to 30 or so. Am I remembering correctly that you have F 15s rated to around 50? My room accentuates the very low end, so it’s a quandary for me as to whether to buy Fast 15s with the option of some variation on the Steve’s filter, or F 15s and likely trying to integrate a tweeter… Why I’m asking.

FWIW, I too struggled with whether to replace my F15's with the Fast 15 drivers in my OB speakers. I just fell in love with the F15's at Decfest back in 2018. The only shortcoming I had with the sound quality was the limited treble response.

I learned that several folks online had replaced the stock binding posts on the F-15 speakers, as they were mostly brass. So I took the plunge and replaced the stock posts with KLEI Naked Harmony pure copper binding posts. The change kept the midrange magic and to my ears extended the treble response quite a bit.

Anyway, just my experience with these excellent drivers. These were LiinAudio's original F15's. I believe they made some minor changes a couple years ago to the original design.

HK

Same Od DD,

Unfortunately I can't recall all of the changes, but do recall that the binding posts remained the same. I think changes were noted in the original Decware F-15 thread. Alternatively you might email Lii Audio. I've found them very responsive to inquiries.

Here is a link to the thread on the F-15 modifications I performed: https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1595420877/8#8

HK

HK and DD,

Thank you both for these great stories of experiments. Especially glad to hear that you were able to bring up the treble HK with KLE posts. I really like KLE stuff for the most part. When I was working a lot on my Torii MKIV, I guess I was about halfway through modifications, so a lot of stuff had been changed by ear to my liking, then mostly repeated improvements in clarity from lack of smearing… more resolution and speed. I had been asking around about binding posts, and a number of people said that Cardas copper with silver plate, and rhodium flash, were really good. So I went for them, and after putting them in my wife was out in the kitchen adjacent to the music room, and said wow I think that was the best change yet. And I agreed.

This was most likely able to be heard more easily from all the previous work, but the musical clarity throughout the spectrum seemed better as I recall, everything opening up and more complex, including all the rich harmonic information I so love. My memory anyway from quite a few years ago. So not absolutely trustworthy, but pretty sure it was not mainly a tipped up top. Just to say that I thought it was a really good overall improvement for my sound. So thanks for the tip and reminder HK. I probably would’ve changed the posts on F-15 or Fast-15 anyway, but I wouldn’t have thought of it as a potential tool that might bring the treble into balance with the F-15s.

Your tweeter set up sounds pretty wild and cool DD. I can’t say I’m particularly averse to simple crossovers. Seems like done with nice parts, and by sound, they can be pretty good. But yes, if you can get around it all the better.

That said I’m really glad for HK‘s reminder of how much connectors can change things. I don’t think I have any stock connectors on my Decware I use. Whether RCA or binding posts, or IECS. At least with my older gear, using relatively state of the art stuff for upgrades, all were notable improvements in resolution, speed, and clarity for me. That it could bring up the treble of the F-15s, sounds like a great first start, and may be all thatI might want too.

I’ve just found over years that the higher frequencies are not necessarily “needed,” but they can enhances the realism of the sound for me if done with finesse. That said when I hear the platinum drivers, though the recordings and utube presentation leave things to be desired, to me they sound too sharp and clear. So being able to tune these things is important to me. Also Steve’s reaction to the stock Fast-15s registered for me. And his finally finding the filtered versions “juicy“ sounds intriguing as well. Not quite sure what that means, but guessing wetter and maybe more harmonically rich?

Thank you both for these experiences. Nice to have more information in mind as I try to sort though these choices!

Hey Gilf,

I used the Cardas posts on my Torii MKIV, one of the early ones, now pretty old. And Steve is not using the same posts these days, presumably changing because the newer choices sound better to him. So I can't comment on how the Cardas might compare to them. But compared to the old posts, for the level of resolution and refinement I grew to crave with a succession of successful modifications, the change was well worth it for me. How much is context from the progressive mods bringing out the posts qualities, I can't guess.

Also, I have a set of KLE Silver binding posts I have been meaning to try in the same position as the Cardas, but I have not taken the time to make that comparison... everything sounding so good, not much incentive. But I look forward to seeing which I like better. I really like KLEs better RCA connectors for ICs.

On my speakers, I pretty much bypassed the posts, replacing them with bronze bolts and thumb nuts and making them so the speaker cable ends do not touch the bronze. I did this by using a pair of bronze washers with teflon washers inside them, and wrapping the area of the bolts the spades might touch with teflon tape. Then through a small hole (later sealed) in the crossover plate I ran oversized teflon tubing with 18 gauge UPOCC silver wire that was direct soldered to the interior wires and crossover parts. Outside I made a small coil of the silver wire wrapped loosely around the brass bolt and against the speaker side teflon washer. So screwing down the thumb nut squeezes the spade of the speaker cable against the silver coil that has a teflon washer for backing. A pretty convoluted setup, but once done it worked really well for me... pretty close to no binding posts I think. I have parts and nice boxes to move the crossover parts and connections all outside the vibrations of the speaker cabinet, but have not gotten around to that project either... A main incentive of this besides sonic refinement is that I would make it so I can easily change crossover caps and coils and resisters, making experimenting funner and easier.

Hope this helps.

Will

Gilf, I agree with your observation that, especially after a certain level of system/room refinement, it is amazing what one good upgrade can do in the long, long chain of parts and room work. But also, when imagining back to my beginnings of getting more serious with home music, I recall the new excitement of having an awake, "player in the room" sound with my first Decware setup... In this room, with a relatively decent front end, cables, and Decware MG944 speakers and SE34 amp (well before Anniversary modifications were happening) I recall being able to hear every change then too.

DowdyPrime,

I don’t have much experience with the F15s outside of Decfest but the Fast 15’s have been an incredible addition to my rig.  Almost 1 year and 4 months later, I’m still in awe of how they have scaled with each successive improvement in upstream components, the most significant of which is my Sarah.

That said, I can’t get rid of the itch to explore other OB speakers.  The two I have on my shortlist are the Caladan by Clayton Shaw and the Pure Audio Project Duet.  Maybe, I’ll get to scratch that itch this year. Maybe not. Let’s see—-in the meantime, I am more than satisfied with what the Fast 15s continue to bring to the table.

Hope this helps.

I have a Caintuck open baffle speaker and upgraded from the F15 to the Fast 15 drivers. I prefer the Fast 15's as it has a deeper low end and a more extended high end. I found it to be a better balanced speaker than the original. There is one qualification to this. The highs of the Fast 15's are elevated, with a peak around 6 kHz. To compensate, I bought the Fast 15 network from Decware and that made the highs listenable and let the strengths of the drivers shine. They are a great bargain.