|
[DIY] Horn on Polish speaker - STX |
Post Reply 
|
Page <12 |
| Author | |
ceharden 
The 10,000 Points Club 
Joined: 05 June 2005 Location: Southampton Status: Offline Points: 11748 |
 Post Options
 Thanks(0)
 Quote Reply
 Posted: 29 August 2005 at 2:29pm |
|
So what's the solution? In the case of my own design I'm trying
to minimise the throat chamber, approximate an exponential flare and
minimise the angle through which the wave has to turn, i.e. avoid
180deg bends in the flare.
|
|
 |
|
|
Timber_MG
Registered User 
Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
Quote Reply
Posted: 29 August 2005 at 3:04pm |
|
No folded horn will ever resemble the straight version exactly, but
there has been research into the topic, quite notably finding the form
of WH Geiger's horn folding spreadsheet.
An exponential flare shouldn't pose to much of a chalenge, it is those which have potentialy interresting applications in making for a better transition to a given effective radiation angle (BDEAP) which pose more of a chalenge. I hear MS Paint is quite likely to make cab simulations more interresting soon. (i kid you not) |
|
|
|
|
rastaman
Registered User
Joined: 20 May 2005 Location: United States Status: Offline Points: 421 |
Post Options
Thanks(0)
Quote Reply
Posted: 29 August 2005 at 5:13pm |
|
Because I didn't know what the heck you were talking about I had to google it.
Which led me to this speakerplans thread in which you posted the URL Which led me to this wiki That BARK horn thread looks kind of interesting for information in itself, some kind of HD15 forebear? |
|
|
|
|
Timber_MG
Registered User
Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
Quote Reply
Posted: 29 August 2005 at 5:32pm |
|
The HD15 forebearer is the Turbosound TS something or other. The Bark
might well be an improved HD15 of sorts, though I am not very well
aquainted with the history behind big mouth speakers. Perhaps Rog (now
that the good man is back) or someone else can provide a little
background information.
Sorry about not searching for a link before posting. Seems like I won't have to trawl google images for suitable images either and you found it without my checking cornu.de ;-) BTW, read up EVERYTHING Bill (William Geiger I think) has EVER posted on that forum. Some real gems on horn theory in there. |
|
|
|
|
james folkes
Old Croc 
Joined: 08 January 2005 Location: United Kingdom Status: Offline Points: 3064 |
Post Options
Thanks(0)
Quote Reply
Posted: 30 August 2005 at 9:38am |
|
whoa! that's quite some resource. it's a bit impenetrable for my current level
of understanding, i need to read everything ten times and continualy cross reference. thanks though, clearly very useful info. james. |
|
|
|
|
tb_mike
Old Croc
Joined: 01 October 2004 Location: New Zealand Status: Offline Points: 2744 |
Post Options
Thanks(0)
Quote Reply
Posted: 31 August 2005 at 10:49pm |
|
No need to find every post,Heres a few goodies including a link to powerpoint presentation on waves in horns. |
|
|
|
|
james folkes
Old Croc
Joined: 08 January 2005 Location: United Kingdom Status: Offline Points: 3064 |
Post Options
Thanks(0)
Quote Reply
Posted: 01 September 2005 at 7:28am |
|
bookmarked, i thank you sir. there's a lot of broken links in the older stuff
but the majority of the text is still available. lots to keep me busy whilst i have a bad back anyway. james. |
|
|
|
|
Disco Stu
Old Croc
Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
Post Options
Thanks(0)
Quote Reply
Posted: 03 September 2005 at 5:44pm |
|
This is quite an interesting topic as im pondering my first horn at the moment and im planning on using the Bandpass element like in the tubas As with the tubas the front chamber in this guys design seems to vent into the "horn" but im trying to work out first of all what decides the size of the slot that marks the transition between the BP and the horn section and then and then working out how the bandpass and horn elements interact - can anyone give me a reasonably basic explanation - is it literally a case of modelling a BP4 enclosure in WinISD and then whatever port size it comes up with thats the size of the port that will vent into the horn section? Then do i just design a horn that cuts off say 10-30 Hz above the lowest frequency i modelled for the horn section? I know its a stupid complex horn to start my modelling with as fitz does all sorts of weird and wonderful things at the driver end of his but its useful to me because i will never use more than 2 cabs per side so I need the extension even if it sacrifices some efficiency and also because it irritates me that i cant get my head around the whole design process which is driving me to learn Also just out of interest can anyone tell me how you would model the super long port in this guys design in hornresp? Is it just an expansion that doesnt expand? So timber, mike, anyone who thinks they can help please do Thanks Stu |
|
|
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
|
|
|
|
Disco Stu
Old Croc
Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
Post Options
Thanks(0)
Quote Reply
Posted: 03 September 2005 at 5:49pm |
|
Bill fitzmaurice said to me that at frequencies below 100Hz there it makes little difference if you use 180degree bends as he does in several of his designs because of the long wavelengths but he does intend his cabs to be crossed over no higher than 120Hz i think which is the case with most subs and he says the lower the better so i presume timbers comment about the resonances is true above that in the tubas Stu |
|
|
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
|
|
|
|
Timber_MG
Registered User
Joined: 27 March 2004 Location: South Africa Status: Offline Points: 1454 |
Post Options
Thanks(0)
Quote Reply
Posted: 03 September 2005 at 7:11pm |
|
Aye, generalizations. It is not the specific frequency as much as the
acoustical dimention. Double the frequency halve the wavelength.
However the human hearng gets more perceptive of audio properties at
different frequencies, peaking at around 2kHz.
The problem is not only one of a resonance as much as non-minimum phase behaviour. So while the FR plot migth be less affected, the lower midrange (assuming a high bandwidth device and one neeeds to think about the significant 2nd and 3rd harmonic content under load) might well be off. It is all about compromise. The big thing is about getting the useable bandwidth of cabs up as it makes the intended application more flexible. If I were to cross my little 12"/1" Tops at 80Hz and play loud live (as opposed to electronic music) they'd probably not keep, but if I could have a clean cross around 150Hz they'd have a much easier time keeping up. About the Bandpass behaviour (sorry if OT) : what is the acoustical dimention around Fc? Does any form of constriction in the throat make a difference (as the device is pretty much an open ended tapered resonant pipe around "fc") |
|
|
|
|
Disco Stu
Old Croc
Joined: 03 March 2005 Location: United Kingdom Status: Offline Points: 2487 |
Post Options
Thanks(0)
Quote Reply
Posted: 04 September 2005 at 12:39pm |
|
I agree about the intended bandwidth being right but that all assumes that your devices are output matched i.e. for a balanced sound in any music you want the transition between your midbasses and subs to be seamless and also that you have your cabs in a stack With what i do (mainly small venue live music) if you have something like an HD15 kicking our what is the bulk of your low vocal frequency and these HD15s are on the floor your vocal is going to have a harder time carrying over the heads of the audience and also as a suitable cross you are looking at needing an MT122 in order to keep up This i first found when using my 15" reflex subs with my 2x10" tops - the vocal bottom end just got completely lost and sounded horribly thin crossed at 120Hz take that down to 100Hz and it improves a little and down to 80Hz even more but then your 2x10 cab is now having to put out all of the kick of the system that your subs should be doing So for a system where you have a full balanced stack yeah but with live music where vocal is on top i have to run my tops full range and then use an aux send on the desk to put the majority of the bass and kick frequencies through the subs - not ideal but now i have my double 12" cabs I should be able to use my crossover for that purpose and not just to essentially EQ and filter the bins However of course putting the kick frequencies through the 12" cabs will still compromise everything else thats going through them so i might find i just stick to what im doing now but have a much fuller sound from my tops due to them being Paudio SN12MBs rather than Eminence Beta 10s Stu |
|
|
All you need to know is:
Sensitivity + Power Handling - Power Compression = Max Output My acts: www.myspace.com/thebowiexperience www.myspace.com/scheisseelektronisches |
|
|
|
|
Post Reply
|
Page <12 |
| Tweet |
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
![RSS Feed - [DIY] Horn on Polish speaker - STX](forum_images/rss.png "RSS Feed: [DIY] Horn on Polish speaker - STX")
Topic Options
ceharden wrote: