Fi BL18 in a Tapped Horn, maybe a very stable Driver? - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 22nd October 2013, 08:11 PM   #1
diyAudio Member
 
Join Date: Jul 2013
Default Fi BL18 in a Tapped Horn, maybe a very stable Driver?

Hey Guys, ive searched for a high excoursion 18 inch driver, which is able to work in a small tapped horn ( not the 18Sound 18NLW9600).
I found out that the FI BL18 seems to be very stable, and does a nice frequency response for a car hifi driver.
here you go:
https://www.fndaudio.com/detail.asp?...&SID=643296239

The groupdelay is very high, thats the only thing i dont like.

What i like is that the the excoursion is 15mm of 18mm @ 1,5kw

So here a calculations with Hornresp:
http://image-upload.de/image/KerQle/10b76ee173.jpg

ive been so amazed that folded that horn in Google Sketchup, and its really small.

http://image-upload.de/image/bvYTSV/5463d45c59.jpg

Dimensions are 910mm x 700mm x 572mm.

i know that the bracing must be very strong, cause there are 302gramms of moved mass.

maybe youve got some suggestions to this simulation, is it a testbuilt possible or necessary?
  Reply With Quote
Old 23rd October 2013, 03:30 AM   #2
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Greets!

With such a high compression ratio, it may not be able to handle much power at low distortion, so odds are that to use all of its Xmax will require a considerably larger cab.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 23rd October 2013, 05:47 AM   #3
diyAudio Member
 
Join Date: Feb 2010
Location: Sweden
Hello wBorchers, thanks for sharing your findings, it's allways nice to see new takes on the TH magic.

(the folloving terms are 4-segment sim based)
I usually aim for a S4 greater or at least equal to Sd, and a S2 no less then 1/3 Sd, preferably higher, also depending on the application, a shorter L23+L34 usually bosts the sensitivity and lessen the groupdelay and other less attractive factors since the size of the driver it self drives the size of the horn, but this is folding dependent.

Keep in mind that a 18" usually has lesser cone stiffness and magnet assembly "power" for lack of a better word, relativly to what we ususally find in smaller transducers such as a 15" or 12".

Just some ramblings
  Reply With Quote
Old 23rd October 2013, 07:14 AM   #4
diyAudio Member
 
Join Date: Jul 2013
Hi GM
"With such a high compression ratio"<

im new in the "tappedhorn business" ^^, can you tell me were you see how high the compression ratio is and why thats a reason for the horn to play with high distortion at high power levels.

hi martinsson

usally i am trying to keep L23 and L34 as short as possible, that last horn ive done has been for the 18Sound 18W1000, S2 is about 600 for this Speaker.

What i searched for is 18 inch speaker, which is able to handle low frequencys with high sensitivy in a small horn.
for example:
the 18Sound speaker needs 600cm to play linear, the Fi BL needs only 340cm.

my last 18Sound Tapped Horn is Keystone folded and has 408 Liters. This Horn is smaller and plays lower.
  Reply With Quote
Old 23rd October 2013, 04:33 PM   #5
GM is offline GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally Posted by wBorchers View Post
Hi GM
"With such a high compression ratio"<
Greets!

The compression ratio [CR] is the ratio of driver effective piston area [Sd] compared to the cross sectional area [CSA] of the throat it's loading or in this case the area at 'S2', which as Martinssen noted should be limited to Sd/3 [3:1 CR] at most for any high power app and many drivers can't even handle this much unless it's marketed as a compression horn driver or at least has a high power rating in a small band-pass [BP] alignment as some car audio 'sub' drivers do.

Only one way to know for sure though, so if you decide to try it, please let us know how it performs and hope you don't damage the driver in testing.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  Reply With Quote
Old 23rd October 2013, 05:18 PM   #6
diyAudio Member
 
Join Date: Jul 2013
Okay the CS S2 is smaller than 1 / 3 SD.
usually i am working with 1/2 SD for the CS S2, so about 600cm.

i just wanted to call attention to this driver, cause its extremly stable cause of its big excoursion, and its ability to play low notes in small horns.

The Fi BL18 Horn is 910mm x 700mm x 572mm and is able to play until 37Hz.
The Tapped horn with 18Sound 18W1000 i want to build is 950mm x 850mm x 532mm and is able to play until 48hz. And this is what i like, and i just wanted tell you that this driver is maybe usable for stable high SPL Tapped horns. I just wanted to share my discovery with this forum

if got money enough i am sure ill test that built.
  Reply With Quote
Old 23rd October 2013, 07:21 PM   #7
MemX is offline MemX  United Kingdom
diyAudio Member
 
Join Date: Sep 2013
The Stereo Integrity HT18 driver has ~23mm XMax (seems to vary from what I've seen online, between 20mm and 23.5mm, but XMech seems to be ~35mm so there is a safe buffer zone) and is $219 shipped in the US, I believe.

Alternatively you can go all out and get an RE XXX with something like 54mm XMax and more XMech... lol
  Reply With Quote
Old 23rd October 2013, 07:41 PM   #8
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by wBorchers View Post
Hi GM
"With such a high compression ratio"<

im new in the "tappedhorn business" ^^, can you tell me were you see how high the compression ratio is and why thats a reason for the horn to play with high distortion at high power levels.

my last 18Sound Tapped Horn is Keystone folded and has 408 Liters. This Horn is smaller and plays lower.
Throat area 181/1210 cone area is a compression ratio of 6.68/1, sounds like too much pressure even for a heavy duty cone.
The Keystone has less than 3/1 compression ratio using about the same mms (304.5).

The smaller horn sim drops off at about twice the rate of the Keystone.

What type of amp would you use for the 1.4 ohm load this speaker presents?

Art
Attached Images
File Type: png Fi BL18.png (408.7 KB, 95 views)
  Reply With Quote
Old 23rd October 2013, 08:18 PM   #9
diyAudio Member
 
Join Date: Jul 2013
So my 18Sound Keystone folded horn got 1134 / 600, that makles 1,89 CR and that seems to be okay.

the Fi Bl18 is able to play with a S2 of 403cm, but linearity and sensitivy is worse than before.

Its a Dual 2 Ohm Voice coil, ill bridge to 4 Ohm and use my Crown Ce2000 in bridge mode if i will built something like this in the future. This Fi Bl18 Horn is just a thought, and i learned something new :-).

btw. which programm did you use in your screenshot on tzhe right side?
  Reply With Quote
Old 24th October 2013, 03:38 PM   #10
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by wBorchers View Post
So my 18Sound Keystone folded horn got 1134 / 600, that makles 1,89 CR and that seems to be okay.

btw. which programm did you use in your screenshot on tzhe right side?
I think you are overestimating the cross sectional area of the Keystone a bit, S1 starts at only 73.9mm.

The screenshot is Smaart V6, to copy the screen on a Mac computer just requires holding down "command" "shift" and "4", selecting the desired area with mouse/trackpad, then release, and paste in with the DIY attachment browser.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
what driver for tapped horn? vadi Subwoofers 11 12th April 2010 07:22 PM
Tapped Horn and Driver resonance Freq. Bent Subwoofers 44 17th April 2009 11:05 AM
Double Driver Tapped Horn MaVo Subwoofers 28 23rd January 2009 05:38 PM


New To Site? Need Help?

All times are GMT. The time now is 01:32 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2