By the way, I sold off a 350 4 bolt main block and a pair of claimer heads with over size 1.5 valve springs, pinned studs. I hated to give this part of my life up just to listen to well wishers that think they know what I want. Wanna help, dig on me.
If you are lost for ideas then a dude in Sweden called Bernt (part of the No Frills Audio group) has an interesting bass. He has two 18sound 21" in a large closed box that he calls Barabas. It should not be hard to guess which 21" it was. He tested it in the garage at full blast at 10Hz and everything started moving and he got groggy so he turned it off. It weighs 100kg. Powered by a 2000W hypex Ucd2k. He crosses them at 73Hz 18dB upwards and 30dB downwards.
Attachments
Rear-loaded subs have a bad reputation among the DIYers I have asked. If building a horn why not seal the back chamber like in the labhorn? Or just go for a box with or without ports.
With a labhorn they say you need at least six of them for some reason. Must be the case for rearloaded as well. One should never just build one pair of labhorns, they say.
Attachments
Last edited:
My PA days are over, as far as I'm concerned. I am fortunate to have mixed a couple National Audio systems. The desk was bigger than your car, and that was just for lighting. I've survived tour bus pneumonia and black beauty endless night driving.
Now that I'm old and recluse, I'll drop one dose of 18 and call it good..
Al.
Now that I'm old and recluse, I'll drop one dose of 18 and call it good..
Al.
Oh, and by the way, I didn't mean I was taking the dirt cheap road. I can't.
The empty 18 box is $170 shipped free. Ad in the $100 Dayton and you got a dirt cheap 18" sub bin for under $300.
Just say'n. Al.
The empty 18 box is $170 shipped free. Ad in the $100 Dayton and you got a dirt cheap 18" sub bin for under $300.
Just say'n. Al.
I found materials for my subwoofer behind the woodshop in their recycling container. 2" thick MDF. 😀 Total cost: $170 for the Lab12 driver.
Hey! Good day for me! I found this from a guy that knew a guy at the parent company and wound up with this:
Last edited:
then I bumped into an old Friend that still has a couple empty TL505's. So we go over and dig one out. Low and behold, I can so easily reach right in the speaker hole and add as much shelf as I like. It just lays in there on top of the struts. Had to see it to know I new that. Been talking to some PL guys that say bridged on 8 ohms 1225 watts RMS and only guess at the headroom. Just keep it at 8 or it will start smelling like a crack pipe. That SI 18 is rated less than half that, so I dunno. If the 505 can be tuned for that driver it should be OK? I'd hate to see it choke to death on it's own woof.LOL
Thanks, Al
Thanks, Al
Last edited:
Well, I'm feeling rather Randy Dick right now. My concerns involved the Rane stereo to mono summing circuit with the weird impedance. Along came this SM-1. Then I was wondering about some secret sauce bridge building. Along came this SM-1. When I wanted to run that 1,000uf motor starting cap on the sub for a 20Hz Hi-pass, I got straightened out real quick. Along came this SCF-1. Sharp cut must be at least 3rd order? I was taught too sharp a cut will make it ring like a Christmas bell. What do I know?
I wanted a small box with a big mouth,LOLOLOLOLOLOLOLOL. That KLH guy with his very cool Iron Law.
Some of you have stuck with me in this thread for some unknown reason and I would like to take the time now to bow my head and ask for forgiveness for dragging you down this path. I started out kind of knowing what I wanted, needed some steering. Now that you guys got me around the track, of course I want to cut my corners and trim my time. I know, I'm a dog.
I tried to download and open up some of those wiz-bang box building wizards. That's as far as I got.
Art tells me I need some extension, maybe 7 or 8 instead of the 4 inches I have now. All I have to do is reach in the hole and place the shelf in the correct position. (had to say it funny).
Not sure how I would test the out-come.(not funny anymore) I have a pink noise generator built into that DOD RTA with the queer looking mic. And a Radio Shack SPL meter (I wasn't allowed to keep the pro gear). I'm gett'n old and don't see too well anymore. 30 years on stage @125 makes me wonder if I could just turn my readers around? At least I can still feel the bass.LOL
Make shure the chains aren't rusted out.
Thanks, Al.
I wanted a small box with a big mouth,LOLOLOLOLOLOLOLOL. That KLH guy with his very cool Iron Law.
Some of you have stuck with me in this thread for some unknown reason and I would like to take the time now to bow my head and ask for forgiveness for dragging you down this path. I started out kind of knowing what I wanted, needed some steering. Now that you guys got me around the track, of course I want to cut my corners and trim my time. I know, I'm a dog.
I tried to download and open up some of those wiz-bang box building wizards. That's as far as I got.
Art tells me I need some extension, maybe 7 or 8 instead of the 4 inches I have now. All I have to do is reach in the hole and place the shelf in the correct position. (had to say it funny).
Not sure how I would test the out-come.(not funny anymore) I have a pink noise generator built into that DOD RTA with the queer looking mic. And a Radio Shack SPL meter (I wasn't allowed to keep the pro gear). I'm gett'n old and don't see too well anymore. 30 years on stage @125 makes me wonder if I could just turn my readers around? At least I can still feel the bass.LOL
Make shure the chains aren't rusted out.
Thanks, Al.
Al, I said more like 20 inches of port extension, but try as much as you can put down still leaving 3.5" from the back and see what that tuning ends up as. Use duct tape to seal the temporary ports together, after deciding on the tuning use some calk between the joints.
If you want a deeper tuning, the shelf needs to continue at a right angle going up the back of the cabinet, leaving 3.5" space, although reducing the space to a lesser dimension will tune lower with less distance. If you cover the outside two ports on the front and just work with center duct you can tune a lot lower with a given length, but the port may "blow" at high power.
The DOD RTA and pink noise will give you a good idea of the cabinet response if you test outside. Inside, lay the TL505 on it's side (port vertical), put the mic equal distance between the cone and the port about 18" away, laying on the floor. Further back and you will be reading the room, not the sub.
You can also stick the mic in the port and see roughly where the tuning is, it will look like a hump on the RTA centered on Fb.
1/3 octave is a big range, sine wave sweeps (or individual tones you can download or find on various test CDs) will tell you where the cone movement is least (Fb), it takes inches on a long big port to make much difference.
Have fun!
Art
Last edited:
Good solid info, Art! You can not imagine the great joy you have brought to my empty life.
Yes, I will have a lot of fun with this.
Thank you so much, Al.
Yes, I will have a lot of fun with this.
Thank you so much, Al.
Al,
I just ran some sims in Hornresp using your driver in a 170 liter (505 size) enclosure using a port about the size of the center port area (42.875 sq inch).
Hornresp says a round port 24Hz Fb would be 33" long, your 505 shelf port probably would only be more like 25".
The port still would need to bend and go up the back of the cabinet.
With a 24 Hz Fb at 79 volts (a lot more than the PL can probably put out) the 3.5 ohm driver stays within 22.5mm excursion from 19 Hz up, one meter SPL around 120 dB at 25 Hz, 124.5 at 40 Hz, and 123 dB at 100 Hz.
The 22Hz tuning Stereo Integrity recommends would make the response dead flat.
If we raise the tuning to 36Hz, the response tilts up at the bottom, +6 dB at 44 Hz compared to 100 Hz. The lower 24 Hz tuning will sound "tight", the higher 36 Hz tuning will sound more "boomy", kind of like a Wurlitzer jukebox run through an octdivider 🙂.
Don't get how you plan to get around the low impedance issue, a bridged amp sees 3.5 ohms as 1.75 ohms, and the PL ain't gonna like that.
Art
I have an infatuation with these stub horns like EV made back in the 1990's and now with Xoc1's version. I have no idea why Dalaney would build something beat to death by EV, having it acclaimed, and then emulated by a lap top wiz.
I think I will run the Art Mod TL 505s and come in real close as a second. That makes me the first loser. When you run out of money, I'll be there for ya!
Seriously though, I wonder how a BR cab would run with a short horn, all things told w/o all the CGI. (I know it is a tapped horn) or not. The 505 is smaller. The Iron Law may not take into horn loading.
If we placed the apropriate driver into each cab and drove these the same, would there be a creditable difference between the two?
Thanks, Al..
I think I will run the Art Mod TL 505s and come in real close as a second. That makes me the first loser. When you run out of money, I'll be there for ya!
Seriously though, I wonder how a BR cab would run with a short horn, all things told w/o all the CGI. (I know it is a tapped horn) or not. The 505 is smaller. The Iron Law may not take into horn loading.
If we placed the apropriate driver into each cab and drove these the same, would there be a creditable difference between the two?
Thanks, Al..
Last edited:
- Status
- Not open for further replies.