[gooberdude]

I've found that these Hawthorne SI's really take to adding Ace hardware adhesive felt to the stamped frames...the baffles themselves have 2 layers of poly blend felt also.

Just paying a little attention to reflective surfaces really changed the performance..  these big 15's simply disappear into my room now.






I've recently found Black Hole Pad..its very musical for damping material.   a 1cm square piece of it smack on the rear of the comperssion driver did good things too.

grounding the frames is worthwhile as well..

I don't often see pics of felted & grounded OB drivers, so I have to inquire...



matt

[mcgsxr]

Interesting development, and certainly a unique look!  Glad it sounds good.

I have not yet damped the basket of my b200, though Planet10 does recommend it, so some folks out there are on the same wavelength Matt.

As for grounding the basket - that is - post of the amp to the basket, not - post of the speaker to the basket, right?

[corloc]

I have just damped the baskets of my B200's.  I used Duct Seal from Lowes.   It does smooth things out a bit.  As for grounding the basket.  I did that with my Fostex Fe206e's, but I didn't hear a great difference.   So, I have not done it to the B200's. 

[Bob in St. Louis]

"Do OB fans often damp speaker baskets or felt the baffles???"

Not yet, but it's on my "to do" list. 
Are your going to replace the black felt with red felt in December Matt? aa

Bob

[gooberdude]

Hey Jeff,

the basket grnd wire is attached to the neg speaker post on the X-over....the black one.   I've also had the bare wire end go into the Neg Speaker post on the compression driver.  In both locations the tweak worked the same, but after discussing with some knowledgeable folks it was determined the right way was to attach it to the X-over speaker binding post.   All i do is stick the bare end into the banana plug part of the Neg sp post, i don't screw it down with my anti-cables.   its held in place with duct tape...

Now, you could also attach it to the Neutral leg of a powercord or even the neutral side of the outlet in a wall outlet...but that may involve a long length of wire.

Both my grnd wires are about 18" in length.      

I think this statement makes sense (please correct me if i'm wrong):    Felting the baffles & the frames has either eliminated, or vastly reduced, the degredation that these pieces impart to the OB puzzle.  Essentially, its as if the drivers and baffles have disappeared acoustically...yet they are still performing their intended functions.   It'd be like going out on a date with Paris Hilton where she pays BUT she never sais a word...    (all the good w/none of the bad)

If one of the keys to OB is making sure the backwave does no harm, then to my ears, i've found a good way to do that...   acoustic treatments are important here too for sure, not just felt!

they do look weird - but being so low to the ground & all black helps 'em disappear visually.  

There are killer views of Lake Michigan, Navy Pier & Wrigley Field from this room, and having 35 inch tall floorstanders has always detracted.  Another huge plus is I don't have blinds, the views are that good & now i don't have to worry about the Sun bleaching expensive wood veneer.  the SI's in small baffles make my somewhat large room seem much larger...

this weekend i'm heading home to see mom after knee replacement, just before Mother's Day.  i'm going to make 2 new baffles out of Birch and see what happens.    Hopefully the SI's are broken in, or close to being 100% anyways.    Out with the Oak and in with the new...  it should be interesting if Birch does sound better.   Ultimately i plan to adhere 2 - 3/4" baffles via Green Glue that Hawthorne now sells by the tube.


thanks for replying Jeff..i get so lonely in the OB forum  

Bob, i'm in Chicago...black shirts, black pants, shiny black shoes.   its a City/urban thing!
Has that Taiko drum track destroyed the Sterling Augggies yet??   have you shattered any windows??  Or, are you still stuck on the "what do you do with the drunken sailor?" track???     

GD

[Bob in St. Louis]

Bob, i'm in Chicago...black shirts, black pants, shiny black shoes.   its a City/urban thing!

OK dude, gotcha! 

Has that Taiko drum track destroyed the Sterling Augggies yet??   have you shattered any windows??  Or, are you still stuck on the "what do you do with the drunken sailor?" track??? 

Haven't got it yet.......

Bob

[gooberdude]

hmmmmmm, it was mailed out last Weds i believe - or even earlier.

If neither you or Jerrod receive them this week i'll make new copies.     Every few years up here there will be a news report of garage's full of mail that are discovered when old carriers die...their families usually find them.

Often i can get a letter to StL in 2 days, sometimes it takes 2 weeks though.

[Bob in St. Louis]

Yea, everyday when I drive up to the mailbox, I get all excited only to find......... junkmail
no cd's.....
You guys have me all worked up about the "Taiko drum driver torture disk".
Maybe it'll come today

Bob 

p.s. By the way Matt, nice monoblock amps you've got for sale dude!!

[robert1325]

I have been looking for some felt but can't  find it locally,  what is a cheap online place to buy it?  for baffles and basket ....    Adhesive would be the easiest.   

I'm in the Netherlands BTW.

[gooberdude]

Hey Robert,

maybe ACE Hardware ships internationally?    that's what the green felt is.  It required 4 indiv $5 packs.

does your town have a local fabric store?  where do the women buy raw bulk fabric??   find that answer & you should find felt...  If you can find it locally use spray adhesive to adhere it to your baffles.  I'd only use felt with the adhesive attached on the baskets themselves...the spray stuff would be a PITA to remove from all the legs, inside & out.  the ACE stuff peels off free of residue.


Bob, its gotta go!   This past year i've been getting sick of the upgrade-bug & have decided to find the light at the end of the tunnel.   My amp came back from Belles better than ever but i still want tubes.  My sources are 100%, acoustic treatments 100%, rack 100%, amp 100%, power cabling 100%, IC & Sp cable 100% and music collection 95%.  the only thing i want is a tube 'somewhere' and the TVC + its active sibling will fit the bill...100%.

i'm selling everything to buy the Active Preamp from Promitheus Audio.  i own thier TVC preamp and this Active is made to go in-line with it.

Now that my Imod has replaced my CDp, i have this entire shelf just sitting there.  its home to a Pro-Ject Speedbox TT speed controller and nothing else..

i'm sold on tubes for sure, but for me, they are gonna be in the preamp stage...not the amp.

[ctviggen]

The only detriment to their being low to the ground is that they'll tend to energize certain modes more than others, such as the floor-to-ceiling room mode.  Since these are open baffle, though, they might not be that bad.  For instance, an 8 foot ceiling would have a mode at about the 1100 feet/second divided by 8 feet = about 138 Hz (at sea level; it'll be slightly higher in Chicago).  If you can experiment, put the speakers on boxes and see what happens. 

[JohninCR]

Bob,

The fundamental modes between parallel boundaries such as the floor/ceiling occur where the distance between them is 1/2 wavelength, or 70hz for an 8ft ceiling.  Also, the speed of sound is affected more by temperature and humidity, although temperature generally decreases with increased elevation.  Sound travels slower with decreased temperature, so the modal frequency will be lower.

[Bob in St. Louis]

Is elevation really that much of a concern since he's in Chicago? They aren't that high up there.

Bob

[gooberdude]

Keep in mind I live 200' up in the air....     


I will raise these guys and see what happens.   If i had a gripe its that the musicians are all 5' tall or less, nothing is quite lifesized, but getting closer all the time.

thanks for the suggestions...    I'm headed home this weekend & might make a few more baffles.  I might also get my Dad to buy me a router and a tool to make perfect circles and rabbet's.

I'd like to stick with my 'lean-to' configuration though initially.

OB gurus, do you think it would be worth the effort to make a 2nd pair of identical baffles just to see if I can hear how birch sounds as compared to the Oak i'm now using?     Or, should i just get void free Birch (3/4" thick) and move on with a new design???

i've been tinkering with an idea where the baffle ends up looking a lot like Darrel Hawthorne.   so weird!
its similar to my current baffles but has a long goat-tee in the front to elevate it.

matt

[JohninCR]

Matt,

Your soundstage is low because of so much tilt on your baffles.  You're firing the rear wave into the ground, and the rear wave has a big impact on the big, tall, wide open soundstage of OB.  Put a book or something under the end of each rear leg to get the baffles closer to 90deg with the floor. and hear your soundstage get much higher.  The only real problem with having your drivers so close to the floor is the greater early reflections of higher frequency content.  The transition from half space radiation due to the floor boundary can also be problematic with low driver mounting, because the transition occurs higher in frequency with low driver mounting.

[gooberdude]

Thanks John,

i found exactly the opposite during the 1st few weeks I had these...i do need to re-address it though since the drivers are more settled..
 
Originally i had them barely tilted back, 5-10 degrees and the musicians were under 3' tall and screaming in my ears.    On axis with the compression driver, originally, is not my cup of tea & was not a 'laid-back' sound...

After tilting them WAY back the musicians became much taller, and adding the towel under each woofer seemed to increase this even more.  i know a beachtowel can't offer much absorption & am aware that my floors reflect sound in a big way.    In one pic there's a white blanket on the floor, that's pretty much a permanent fixture and was with my boxed speakers too...

i do think that trying to keep a similar angle but from a foot off the floor would be good to try.

Ultimately i may buy a raw Duet frame from hawthorne, but not until they release the Sterling Auggies.  that may get me where i want to be.  funny thing is i don't need subs at this point.

I can easily change the angle by moving the rear legs, takes a minute per baffle....

for now, its cool having 15" woofers that are nearly invisible and out-of-the-way...

matt

[hurdy_gurdyman]

If i had a gripe its that the musicians are all 5' tall or less, nothing is quite lifesized, but getting closer all the time.

Matt,

If you can get a musician sounding 5'4" tall, you'll have realistic a musician, especially if the musician is playing a hurdy-gurdy.

Dave

[gooberdude]

I was hoping that Yo-Yo Ma was sitting down during the recording process...turns out he's 4' 9".

ba dump bump...


For a year or more i've had a good 'stage' in my living room, but every so often i'll hear a shop system, namely the one here   www.vanlspeakerworks.com  and some of the sounds come from darn near the ceiling.    the ceiling in his room is not quite 7' tall, so its mainly the hands of a stand-up bass player that get way up.    I have all the separation I ever dreamed of now, just want more....

a lot of this might be my room though & the fact the dope-as-all-get-out SI's are sitting indian style on my carpet.