And Now For Something REALLY BIG

[JRKO]

ok Im still pot bound!!

As I understand:

terminal 1 = input
terminal 2 = output
terminal 3 = gnd

at the moment I have input & output wired but gnd goes strainght from the phono to the gnd on the board = full volume no control.

Would the gnd wired from phono to terminal 3 then to gnd on the board sort this?

here is the spec of my pot

im confused.......please halp (because even with only one ear working this is annoying 😀) There are so many different wiring 'options' espoused on the net...........

according to http://sound.westhost.com/pots.htm 3 is input, 2 is output and 1 is gnd AAARRRRGGGGHHHHHHH

 

[buzzforb]

Just use you mm to find different points of pot. If connected to 1 and 3, you should get total resistance of pot. If connected to 2 and 3, you should be able to vary resistance. Consider what a volume pot does and simply use mm to figure out what goes where.

 

[JRKO]

tnx buzz

I have 10k across 1 & 3 and I have 0~10k across 1 & 2 as well as 2 & 3 meaning.....

aww I dont know what it means. Its 3am, I'm half deaf, cant wire a damn pot and my cat just crapped under my desk.......damn cat

'Kicks cat out of bedroom, goes back sleep until at least 4am'

 

[JRKO]

okay, throwing cat out woke wife 😡 so I got banished too!!

All I can discern fro the above is that terminal 2 is output. I think........
O crap I dont know. How can build a NP KT and fail at sorting a pot of all things?

'sneaks back to bed as wife snoring' - no dear you don't snore (much) must be the cat.......

 

[JRKO]

just my stoopid gnd wiring holding it back.

Do or die test at 6am. It was wither gonna work or play full volume...........IT LIVES

now my miniDSP is somewhere in the snow near Heathrow so maybe, soon......

 

[buzzforb]

Good to hear. Dumb cat!😀

 

[JRKO]

OK descisoin time

one of louis lovely hand turned tractrix horns http://www.diyaudio.com/forums/vend...z-wooden-horns-sale-interest.html#post3317748 made for a 600hz cutoff

or the 8 cell 8 Cell Multicell Horns for JBL,Beyma,Altec, | eBay

Still loving the 8 but the tractrix is cool. Pulling the trigger today so jump in guys!!!!!

 

[GM]

Depends on how wide a 'sweet spot' you need. Tractrix beams with increasing frequency much more than a multi-cell.

GM

 

[djn]

I run 350hz round horns and they do beam like crazy bit I only sit on the sweet spot so that is ok

 

[JRKO]

I'll be running 600/650 absolute lowest down a room 11' wide and prefer a wide sound spread as possible as possible. Sound stage is usually an illusion these days, mastered into a recording rather than carefully coaxed from the actual performance of years gone buy

chalk up 2 for multicells!!


Pano is a 'cell type guy (no I dont mean top bunk, keeps a pet cricket and steals your meds)

So thats 3 to the multicells!!!

And me makes

well 4 and I'm the dealer so house wins!!!

 

[derwhalfisch]

Think of it as multicells first, rather than multicells instead 😉 You're gonna have tractrix horns also, soon enough.

 

[JRKO]

I like your thinking.........

 

[JRKO]

Getting back to how Keith builds his multicells, earlier posts on the subject:

"Because of the widening of the of the entrance it keeps all the 15 appertures the same area never thought about it before. they could be tapered if you prefer that would give the outside 6 cell slightly more area"

I guess he means widening at the external cells. I think its because his cells start from a flat plane rather than radiating out, as if from a central point.

What thinks you?

Just thinking on the above, doesn't that mean the outside are a different length to the rest?

Good questions. I certainly don't know.

Ok he's come back with a bit more info - "yes the cells are slightly shorter on the outside banks but the throats make up the differance by being longer on the outside edges"

Does anyone out there speak 'multicellular' fluently? Pano, how are the start of the throats arranged in your horns? Cal maybe you can shed some light?

I doesn't seem 'right' to me 😕

I believe the cells on my horns are all the same length, but could not swear to it. I'll measure them and show you a photo of how they join together as soon as I can.

Pictures are best. You can see the arrangement at the throat. All horns are the same length and form a radial curve at both the throat and the mouth. The waveguide takes the round exit from the driver and makes it rectangle to enter the horn.

We are hoping that you will buy a set and tell us! 😀

So his horns are different because he builds the small end to a flat surface not all horns the same length leading to a rounded sent of entrances - his way makes sense now. I dont know whether to ask for a change or not thou

 

[JRKO]

Spoke to the man himself and have decided to go with his design. He sends then things to the US, GB, Australia, Japan so they must be ok. His feed back is great

 

[JRKO]

ok miniDSP has arrived. Sat useless in its box until I have something to use it for. Horns are on order and should be a week or 2 now.......

cant wait........

just need to sort preamp

Emkens will happily do 750hz and below until new 15's are ordered. 15FH500 http://www.faitalpro.com/products/LF_Loudspeakers/product_details/index.php?id=151060100 are looking good - esp as they are £50 cheaper, EACHthan the 510 ferrite version!! slightly higher Qes & Qts and lower BL but should be good in a 4cuft box tuned to 45hz gives a -3db fig of 47hz. Plenty low for me in my smaller room.

A bigger box is possible so any ideas welcome

 

[Pano]

So you bought the horns instead? Not going to build them?

 

[JRKO]

At the moment I cant get myself to concentrate and lose my temper for less than 10 min which is not conducive to paper making.

I will however be coming back as soon as I'm stable to this Idea. Person, made to measure paper horns turn me on.........😉

for noe £180 8 cells will have to do 🙄

Maybe my paper set will be 15 or 18's!!!!!!

 

[IG81]

Emkens will happily do 750hz and below until new 15's are ordered. 15FH500 FaitalPRO | LF Loudspeakers | 15FH500 are looking good - esp as they are £50 cheaper, EACHthan the 510 ferrite version!! slightly higher Qes & Qts and lower BL but should be good in a 4cuft box tuned to 45hz gives a -3db fig of 47hz. Plenty low for me in my smaller room.

A bigger box is possible so any ideas welcome

With this driver (15FH500) in a small room, I'd go with a 4cuft to 5cuft (net Vb) box tuned to Fs. It will play lower than your 45Hz tuning and the sloped response will possibly be better adapted to your room response. At least that's how I tuned my TD15M's in my small room and I like it. This also keeps a certain ammount of room for high impedance drive such as SET amps, which should also benefit from the tuning at Fs for maximum power transfer.

IG

 

[JRKO]

top tip therer IG, tnx

-3db at same place but gentler slope

 

[IG81]

The 15FH500 also looks like it has a fairly problem-free response both on and off-axis. One should keep the crossover below 1kHz to maintain good dispersion though - probably where you'll end-up with your large horns.

IG