Building a new OB

mcgsxr · « **Reply #180 on:** 18 Mar 2007, 03:43 pm »

I have used truck bed liner extensively as a "finish".

It will show surface mars just like paint, but the natural finish will help to hide it.

It won't really cover them up though, just distract you.

Depends on how far away you expect to be, and what level of perfection you are after...

DanTheMan · « **Reply #181 on:** 18 Mar 2007, 06:22 pm »

I've always wanted to do truck bed liner finish like JBL pro speakers use. I think it makes a very practical covering. Should make it pretty impervious to most abuse. Are you getting close now Bob? I'm from Ohio, it's the "Show Me" state.

Bob in St. Louis · « **Reply #182 on:** 18 Mar 2007, 08:11 pm »

Well, I'm getting tired of messing with this project and am wanting it to be finished.
The truck bed liner is OUT. (35 views in the Sports Bar and no reply regarding truck bed liners).

I've bought 3 cans of Krylon textured "Stone" paint. That's the final coat. That's going to cover my scratches.

I'd take a picture and show the first baffle finished but the wife is hosting a baby shower upstairs right now and I'm NOT going up there to get the camera.

(Although my 8 year old boy keeps bring the "20something" year old little hotties down here to show them the XBox360 on the 140" screen.) aa
Good boy. Very good boy, keep 'em coming, yea baby!!

{I'm going to burn in hell for that

}

When the girls leave, I'll get the camera.

Bob

JohninCR · « **Reply #183 on:** 18 Mar 2007, 09:31 pm »

Bob,

Not that we don't believe you, but as long as they're 18 or older, get the camera before your son's visitors leave.

Don't be surprised by the lack of replies, this forum is primarily a "buy it ready to plug in" local, not much DIY. I wish I could find that stone finish paint down here. I've made a number of cabs using a vinyl covering that achieves exactly the texture you want. It's easy to apply with contact cement and can cover just about any mistake. The only trick is hiding the edges, which I've done with nice real wood.

Bob in St. Louis · « **Reply #184 on:** 19 Mar 2007, 10:53 am »

They called my a 'perv' when I started hand picking which girls I wanted a picture of. I suppose I was too obvious. Something about 'dirty old man'.
I tried to explain I'm not THAT much older.

Got some baffle pictures though.

Baffle #1 almost finished. Need to secure the crossover and run wires through the rear "leg", or driver support mount. It's as done as it can be visually.

Baffle #2 is assembled, but no more. I had hoped to have the wire mesh on and first coat of fiberglass installed but it didn't happen today.

The wood is courtisy of a local thrift store that didn't have room for someone's old kitchen table. The top is maple and just over an inch thick. I thought this would be nice to install my old Augies in. The SSI Augies are in my old maple baffles. The 800 watt amp that used to power the housewrecker is now powering the Augies. Channel "A" is for the SI Augies, channel "B" is for the new Augies.
Have not had much listening time in this configuration to accurately compare the two generations of Augies side by side.

The Coaxial baffle has been sprayed with Krylon textured paint which was recommended to me by "BRILEY804" (Brad), a member here

(Thanks dude!). Much faster than previous ideas of painting by body shop or truck bed liner.

FRONT:

REAR:

On the left is my old "stop sign mount". The right is the glass baffle, and the various generations of Augies in the middle:

JohninCR · « **Reply #185 on:** 19 Mar 2007, 04:02 pm »

Bob,

Your persistence paid off with a unique and interesting baffle. Later today I'll try to post some pics of the stuff I did over the weekend.

mcgsxr · « **Reply #186 on:** 19 Mar 2007, 04:09 pm »

As a guy who loves bass, I have to say, I am very impressed with the wall of 15's! That must be lots of fun...

Interesting design, these baffles for the Silver Iris - I assume that the lower portion of the baffle is the most critical, that is why the "bulk" of the baffle is located there - it provides a connection to the floor etc?

Just asking, as I have yet to strike out from my stock, standard winged creatures that were built some 2 years ago, but have visions of something new...

JohninCR · « **Reply #187 on:** 19 Mar 2007, 05:27 pm »

Mark,

Something to keep in mind is that with the big 15", baffle shape and driver to edge variability make little difference. The baffle experiments I've been messing with the past couple of weeks have demonstrated how much more important it is for smaller drivers. If you use bass augmentation, very small form baffles can work very very well.

Bob in St. Louis · « **Reply #188 on:** 19 Mar 2007, 06:21 pm »

John - Thanks for the complement. As always, anxiously awaiting to see your new designs as well. Between you and I feeding off each other, we'll be getting radical soon

mcgsxr - Yea, the lower 'skirt' area was my rendition of the typical lower half of a baffle, just "swoopy". It curves inward and scoops rearward as it goes down. The pictures don't do the form/shape justice. If I put a straight edge as a reference point it would be more obvious.
My intention (right or wrong) was to "grab" the bottom half of the rear wave and funnel it rearwards. Thinking it might make a difference.
Seemed like a good idea at the time.

I've only got one finished so an accurate sonic evaluation isn't possible at this time.
I can say that it doesn't suck.

Bob

p.s. Looping some LFE scenes repeatedly from the movie War of the Worlds with (6) 15" drivers is pretty cool.

Viridian · « **Reply #189 on:** 19 Mar 2007, 09:27 pm »

Quote from: JohninCR on 15 Mar 2007, 11:27 pm

Sorry, forgot to link a pic in my post the other day. The white one is the nautilus shape I've never liked as a baffle. The 3 test baffles pictured all work very similar. A prize goes to whoever figures out the function of the black one first. After this week's tests baffles, I'm not sold on the premise that very thin flat baffles eliminate edge diffraction. The front and rear wave diffraction may net to zero, but as Rudolph pointed out a while back, there seems to be a lot of directionality in the diffraction effects, so they don't cancel each other out. I'll get better proof once I do up some thick wooden flat baffles of similar shape to compare. I still don't know how I'll do the black one thick with big roundovers.

John, I'm new to the game but I will guess on the function of the black baffle. It is essentially the same as the nautilus but just in a perpendicular curved plane. How's that for a guess? You commented that the sound was very similar for the 3 baffles. What does that mean? Good or bad?

nodiak · « **Reply #190 on:** 19 Mar 2007, 10:12 pm »

Hi Bob, good to see you got the Kenny baffles to work!
Don

JohninCR · « **Reply #191 on:** 19 Mar 2007, 10:27 pm »

Viridian,

You got it. That piece of PVC is the baffle and attaches to the backside of the driver. The purpose is the same as the others, to provide a different "D" (travel distance Differential for the rear wave) all around the driver. Instead of forcing the rear wave further to the side like is typically done, I forced it rearward different distances. I was pleasantly surprised how well all 3 crude attempts worked to smooth the dipole ripples above the baffle cutoff.

I used wood to build 2 pairs (one for FE167's and one for B200's) very similar to the colored test version. I want to do some more sanding before pics, but they're sounding great as-is, so I've been too busy listening to get motivated to take them off. Also, I still working out in my head how to pull of the PVC version using wood, and which addresses edge diffraction. Plus I need something to match for my woofers, that are just magnet mounted with no baffle at all. Though I like the look of the egg shaped baffle, it's kinda artsy, so most may not like it.

Viridian · « **Reply #192 on:** 20 Mar 2007, 03:39 am »

John, would there be any advantage to mounting a mirror of the pvc baffle to to rear of the driver? I don't know what orientation would work, match the notches or rotate? I would experiment myself but I just got outbid on a pair of EV Wolverines, so I have to wait for something else. So, I live/listen vicariously through you guys.

BTW, thanks much to all you OB fans, I have learned so much lately.

Erik

JohninCR · « **Reply #193 on:** 20 Mar 2007, 04:09 am »

Quote from: Viridian on 20 Mar 2007, 03:39 am

John, would there be any advantage to mounting a mirror of the pvc baffle to to rear of the driver? I don't know what orientation would work, match the notches or rotate? I would experiment myself but I just got outbid on a pair of EV Wolverines, so I have to wait for something else. So, I live/listen vicariously through you guys.

BTW, thanks much to all you OB fans, I have learned so much lately.

Erik

Erik,

That piece of PVC goes only on the back of the driver, and the other speaker would require one cut in the opposite direction. If you cut it well, you could create it with just one angled cut and one cut square to the length of pipe forming 2 equal and opposite pieces.

The reason I brought up the similarity of response is that, the PVC form is without question the smallest way to smooth the dipole ripples. It achieves the same smoothing effect as the larger flat shapes. The compromise is what it will cause in terms of rear wave axial response and edge diffraction, but what it demonstrated was clearly worth the minimal effort, especially since I had a 6ft piece of 6" PVC laying around.

Bob in St. Louis · « **Reply #194 on:** 20 Mar 2007, 12:09 pm »

Quote from: nodiak on 19 Mar 2007, 10:12 pm

Hi Bob, good to see you got the Kenny baffles to work!

HA HA Don!!
You know the funny this is....At one point during the build process I stood back, stared at the baffle and thought the exact same thing.

If I was better with the software, I paint the baffle orange in Photoshop, and maybe put some 'eyes' on the driver. Anybody wanna give it a shot is more than welcome! aa

Tr3vWh0r3 · « **Reply #195 on:** 20 Mar 2007, 12:40 pm »

There you have it, the Kenny OB.

nodiak · « **Reply #196 on:** 20 Mar 2007, 02:45 pm »

Bob, your sense of humor is appreciated ! (I admit I was wondering how you'd take the reference...)
BTW, I bet your HT room sounds great!
Don

Bob in St. Louis · « **Reply #197 on:** 20 Mar 2007, 05:09 pm »

Don, No problems man. It's all good!

Yes, it does sound great!!!!!

Ok, Trevor. You are the man. That's cool as hell. I can't believe you spent that much time.

...........Now....how about the rest of the Southpark characters?

Tr3vWh0r3 · « **Reply #198 on:** 20 Mar 2007, 06:44 pm »

I actually threw that together pretty quick before school this morning.. Believe me, I didn't take much time on it!

As for the rest of the characters..

Bob in St. Louis · « **Reply #199 on:** 20 Mar 2007, 07:00 pm »

Quote from: Tr3vWh0r3 on 20 Mar 2007, 06:44 pm

As for the rest of the characters..

No problem Trevor!

Thanks for making Kenny a reality!

Bob