[SET Man]

...

Oh yeah, about room treatments:  I have hardwood floors, a glass door, and three windows with one directly behind the listening area.  Room treatments would probably fix the problem, but aside from putting a curtain on the window behind the listening area there's nothing else I can do due to WAF.  The other windows on the side wall already have curtains, and the glass door is located next to the speakers on the rear wall.

Hey!
   
   Well, sound like your room could be the root of the problem.  You have a lot of hard highly reflective  surfaces in your room. Curtain on all  window will definitely help. And a small area rug...  a bit on thick and puffy side on the hardwood floor in the middle between the speaker and your seat would help also. Maybe she could help you pick the rug

    Of course if you wife say no than you have to choice but tinker with the speaker

   Good luck.

Take care,
Buddy

[Tone Depth]

Oh yeah, about room treatments:  I have hardwood floors, a glass door, and three windows with one directly behind the listening area.  Room treatments would probably fix the problem, but aside from putting a curtain on the window behind the listening area there's nothing else I can do due to WAF.  The other windows on the side wall already have curtains, and the glass door is located next to the speakers on the rear wall.

How about mounting some hooks in your ceiling near the back wall.  Then hang up a medium to heavy carpet only during serious listening sessions.  Maybe the carpet could be on your floor during other times.

[JackD201]

Oh, I dig, offset.  Yeah, that helps.  Don't know how the grills deal with diffraction but off setting the tweets will make edge diffraction arrive at different time intervals and less noticable is my bet in the end.  I THINK that's the reason some designers (a lot of Brits, for example) do it.  I make pads that extend out to the cabinet ends regardless.  We good?

Excellent 

[EthanH]

Wanted to give an update to this thread.  My last move was building an impedance flattening circuit.  The circuit helped a bit, but I still was not where I wanted to be.  Before ordering any new parts or taking out the soldering iron I thought it would be best to make sure that there were no mechanical issues going on.  I remembered how much of a difference it made it when I replaced my cheapo particle board stands with cement blocks, so I decided to check if there were any resonances that might be contributing to what I was hearing. 

A few days ago I pulled the drivers and installed some foam in between the drivers and the cabinet.  I heard an immediate improvement that was far greater than what I heard with the impedance flattening circuit.  Bass definition and impact went up a notch or two and the lower treble immediately smoothed out considerably.  These were my first diy speakers and I figured that it would be fine if I just tightened the screws down without installing any sort of gasket between the drivers and cabinets; boy was I wrong!

I'm going to listen to these some more and see if I still have the itch to fiddle around.  So far I really like what I am hearing.    One concern though is that the foam makes the tweeter faceplate stick out maybe a millimeter from the cabinet, so I may try to find a thinner gasket material or install some sort of diffraction pad.  I've also been considering putting a bypass capacitor (something oil filled or otherwise known for liquidity) on the tweeter for awhile now, but I'm going to hold off on that until after I've lived with this latest tweak for awhile.  So far I'm very pleased with the improvement gained just from installing the foam.

[jimdgoulding]

Ethan-  It might be helpful to know about your room and where you have your speakers and seat placed in relation to one another and your room's boundaries.  Maybe managing your acoustics will yield a little or a lot improvement above what you have now.

[BobM]

I've also been considering putting a bypass capacitor (something oil filled or otherwise known for liquidity) on the tweeter for awhile now, but I'm going to hold off on that until after I've lived with this latest tweak for awhile. 

Here's a few additional thoughts:

It's not always the tweeter that makes things sound forward. For instance, if the tweeter is crossed to the mids at about 3000 then it's really only producing very high frequencies andharmonics. The foprwardness would be more in the midrange. It's very easy to test this out. There's usually a damping resistor on the + leg of the tweeter crossover. Raising the value of this resistor by .5 would make it lower in output. All you need to do is add another .5 ohm resistor in parallel to the existing one to see how this works and if the forwardness goes away. Tres simple if it works. But it may only reduce your sense of air and space, which is not really too good a solution then.

You could try playing with internal cabinet damping. It's probably full of some kind of batting material. You could just add some more and see what that might do for you (basic fiberglass would probably be OK as a test), or go whole hog and line part of the inside (usually the back wall) with Black Hole 5 and see if that works better. But it can be a little costly for a trial and error kind of test.

Do you have any silver wire in your system? Copper will give you a more burnished sound and be less forward sounding than silver wire.

Enjoy,
Bob

[EthanH]

Jim:  I'm sure the room is far from optimal.  I am in school so space is limited.  System is in a bedroom with windows (with thick linen drapes) on one side wall and the wall behind my bed.  On the wall behind the system is a door (with windows) into my office.  On the other side wall is a wooden door leading into my kitchen.  When I'm not just listening to background music I put the speakers about 7' apart and 18" from the wall, and I just chill on the bed.

BobM:  I hear you on the tweeter.  FWIW the crossover is LR4 at 2khz.  I may end up experimenting with the tweeter level a bit.  I'm actually not sure if it's better to reduce output above 5khz or between 2.5-4khz, as I'm able to do either; any suggestions there? 

With regard to internal cabinet dampening, I use NoRez on the top, bottom, and back wall, and .5" foam everywhere else. 

As for cable, the internal speaker wiring is tinned copper.  I use copper WLM speaker cable and cheap-o molded RCAs that came with my CD player. 

[BobM]

I would try to reduce that presence region of 2.5k-4k, just a wee bit. But first I would replace the molded RCA's with some nicer copper ones from any number of manufacturers. That could certainly be part of your problem. As a last resort I would look at that tinned copper. It can make things a little hard sounding compared to pure copper.

Merry Christmas,
Bob

[Duke]

I'm actually not sure if it's better to reduce output above 5khz or between 2.5-4khz, as I'm able to do either; any suggestions there? 

I definitely suggest reducing the tweeter's output in the 2.5 - 4 kHz region.  I didn't realize you had that capability or I'd have posted a response sooner.

Your speakers apparently have a very flat on-axis response, which means that off-axis where the tweeter's pattern is quite wide you will have excess energy.  This excess energy is in the lower treble region where the ear is most sensitive.  Don't fret about your speakers being no longer "flat"; the on-axis measurement doesn't paint a complete picture and in my opinion what's happening off-axis is more important.

Best of luck to you.

[DaveC113]

I'd make some simple copper ICs using good wire and decent connectors.

26g 6N copper w/ cotton insulation. You might call and ask if they still sell the woven-helix IC wire, it's 8 strands of copper and has a warm sound with a lot of bass. A simple star quad would be good too.

http://www.jupitercondenser.com/index.php?option=com_content&view=section&layout=blog&id=6&Itemid=64

Switchcraft RCA plugs work good and are cheap:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SC1138-ND

[EthanH]

Thanks for the responses; I'll try to get my hands on some neotech rca cable and make something half decent.

Duke and BobM, the off-axis stuff makes sense and I am going to order the parts I need to reduce the treble between 2.5-4khz.  I'm wondering how far I should bring it down.  The graph below will give you an idea regarding my options:

http://www.zaphaudio.com/audio-speaker17-tweeterrolloff.gif

Right now C6 is at 6.8, and I'm considering bringing it down to 4.7; does this sound right, or should I lower the output more or less?  Thanks again for the advice!

[Duke]

Hi Ethan,

That curve and the corresponding capacitor values are EXTREMELY useful.  Zaphaudio, I tip my virtual hat to you.

The capacitor values shown are not the only viable ones; by showing you the curves as well, you can deduce that a continuum of values will produce a continuum of curves.  So 4 microfarads or 5 microfarads are not wrong; they're within that continuum, though not explicitly depicted.

You might consider something like this:  Get a 4 microfarad cap and two 1 microfarad caps.  This will enable you to try 4, 5, and 6 microfarads.  Or get some other combination of caps that will allow you to try several different values (and thus several different curves).   

This is really pretty exciting.  You have the opportunity here to tune the crossover to your particular situation.  Order some caps, clean out the ol' ears, and have at it!

[EthanH]

Sounds like a sensible approach.  I will give it a shot and report back; thanks again!

[EthanH]

Been a while, but I thought I'd report back with my results.  I played around with the upper midrange level, and it definitely changed the presentation.  After some experimenting I eventually found a level that seemed to work well in my room, and that was a big step in the right direction.  Thanks Duke!

I also played around with mechanical resonances a bit, and bought some putty to treat the woofers with.  Well, the cumulative effect of the capacitor change and dampening have really brought these speakers to a new level - not only are they the least fatiguing speakers I've ever owned (which I guess isn't saying all that much, as I've only owned B&W and Totem before these), but the bass and resolution have now exceeded my expectations.  It's a very vivid, powerful, but non-fatiguing sound, that is basically right up my alley.  I'm moving to a new state and have been trying to sell a lot of stuff lately, and had these up for sale on here for about a week.  As much as I'm going to hate packing these up and loading them in the U-Haul, I had to take them off the market since they just sound too damn good now!

I have to say that modding is a lot of fun.  I'm already thinking of what to try next: dampen the inside of the front baffle with putty?  bybees (*gasp*)?  swap out the steel laminate inductor in series with the woofer with a mundorf zero ohm?  It's all quite fun.  Thanks again for all the help!  

[walkern]

I have one other thought regarding the forwardness of your system, unrelated to the room or speakers.  I've found that some input or driver or phase splitter tubes in some EL34 based power amps can contribute some upper midrange or lower treble glare or emphasis.  Blowing huge bucks on exotic NOS 12AX7s or 6DJ8s is not recommended unless you've recently won the lottery, but dumping cheap Chinese tubes in favor of something with better design and construction (often the Russian small tubes are copies of classic European or American designs) may help.  Just a thought.  I've found swapping out those tubes at the front end of amps to make a more profound difference than swapping the output tubes.

Best of luck.

Neil

[jimdgoulding]

Tweeter surround pads like what I make will reduce your off axis response and reflection above the crossover appreciably.  If possible, try placing your speaks further off the wall behind them and placing your seat to compose an equilateral triangle or nearly so.  This will give your stage more openess and room for instruments and relax the intensity/glare to what I suspect you are hearing.  Don't toe them in all the way.  Experiment.  Cheers.