FE207e and Vofo - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 19th September 2007, 03:51 AM   #1
diyAudio Member
 
Drewaudio's Avatar
 
Join Date: Mar 2006
Location: New Zealand
Unhappy FE207e and Vofo

Hello,

I'm new to this forum and would value you advice.

I've been thinking about building a full range speaker to match my diy triode KT88SE amp. I read a heap of posts in this forum about various speaker designs and have chosen to focus on Martin's virtual project 5 using the FE207e or, FT-1600 using FE167e or, Vofo.

My question relates to the Vofo design which uses the FE206e. What design changes are required to accommodate a FE207e? Is it simply the BSC or are dimensional changes required for the cabinet?

Kind Regards
Andrew Parsons
  Reply With Quote
Old 19th September 2007, 08:29 AM   #2
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
You'd need to change Vb and port CSA, which Ed has tuned carefully to match the 206. Response of the 207 will slump in the bass somewhat as-is.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 19th September 2007, 02:18 PM   #3
diyAudio Member
 
vitalstates's Avatar
 
Join Date: Jan 2006
Location: uk
Hi Andrew

As mentioned previously the cab volume has been reduced for the latest version. This figure was actually by 0.8 ltrs. The first version is probably more suited to the 207 but I would guess that given the paras below you will be hard pressed to tell the difference. To make a pair of mark 1s just add 12mm depth to the cabinet. This can be easily achieved by building the bottom wave guide on 6mm ply instead of the prescribed 18mm.

Is there any reason for using the 207 in preference to the 206??

fwiw I believe Nelson Pass mentioned his preference for the 206 in his paper on matching FR units with transconductance amps, and that was good enough for me.

Regards

Ed
Attached Images
File Type: jpg fostex-comp.jpg (63.0 KB, 472 views)
  Reply With Quote
Old 19th September 2007, 02:30 PM   #4
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
207 is shielded. It'll need less correction in a mass-loaded line as it's got a higher Q. In a TQWT like the Vofo, the 206 would be the better bet IMO. Goes higher than the 207 too.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 19th September 2007, 02:54 PM   #5
diyAudio Member
 
vitalstates's Avatar
 
Join Date: Jan 2006
Location: uk
Sorry Scott, I glibly took spectrum's figures as gospel...does this mean that theres a typo on their page????
Attached Images
File Type: jpg fostex-comp1.jpg (52.4 KB, 431 views)
  Reply With Quote
Old 19th September 2007, 05:40 PM   #6
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Nah, just Fostex PR speak. They claim 20KHz for both, but even using their massively smoothed graphs, compare the efficiencies / SPLs of each at 20KHz. On-axis FE206E = 95db. FE207E = 86db. This 8 - 10 db difference at 20KHz continues off axis as well. The FR207E is only really usable to about 12 - 14KHz; despite the whizzer, it doesn't get up much higher than the FE208ESigma, which is more of a WR than an FR driver. It can probably be EQ'd ~flat though like the Sigma, but it needs some help, either with that or a supertweeter of some description.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 20th September 2007, 12:14 AM   #7
diyAudio Member
 
Drewaudio's Avatar
 
Join Date: Mar 2006
Location: New Zealand
Interesting comments guys!

The main reason for using the 207e is that this project will be my first experience with full range speakers and I thought that the 207e would allow me to try a range of different designs using the same divers.

It seems that it will be too much work to modify the vofo for the 207e. Perhaps I should buy the 206e as that might be a driver that is capable of being used in a range of enclosures. I've read a number of comments about the 206e (rising HF etc) that caused be to consider other options.

Vitalstates: I'm not clear about the vofo mark 2 dimensions. Would you mind giving the dimensions (internal or external) again.

Kind Regards
Andrew Parsons
  Reply With Quote
Old 20th September 2007, 11:19 AM   #8
OzMikeH is offline OzMikeH  Australia
diyAudio Member
 
Join Date: Mar 2007
Quote:
Originally posted by Drewaudio
Interesting comments guys!

The main reason for using the 207e is that this project will be my first experience with full range speakers and I thought that the 207e would allow me to try a range of different designs using the same divers.
I have a pair of 207 and I am about to build my second cabinets, Generally any cabinet that will allow the 207 to really perform well will consume at at least one full 1200 x 2400 sheet of material per speaker. Really big cabinets aren't that great in MDF so you're looking at a cabinet cost about equal to the driver cost.

One thing you must do: put phase plugs in. Don't even bother breaking them in, just make sure they work then void your warranty and cut them up. They do need a good thrashing before they sound any good.

My biggest mistake: making cabinets suited to corner loading without having appropriate corners in the room.
  Reply With Quote
Old 20th September 2007, 11:32 AM   #9
diyAudio Member
 
vitalstates's Avatar
 
Join Date: Jan 2006
Location: uk
Quote:
Originally posted by Drewaudio
Interesting comments guys!


Vitalstates: I'm not clear about the vofo mark 2 dimensions. Would you mind giving the dimensions (internal or external) again.

Kind Regards
Andrew Parsons
Andrew

Are you saying that you don't understand the dimensions on the plan?
  Reply With Quote
Old 20th September 2007, 03:38 PM   #10
GM is online now GM  United States
diyAudio Member
 
GM's Avatar
 
Join Date: Jun 2003
Location: Chamblee, Ga.
Quote:
Originally posted by Drewaudio

The main reason for using the 207e is that this project will be my first experience with full range speakers and I thought that the 207e would allow me to try a range of different designs using the same divers.
Greets!

FYI, the lower the driver's Fs, Qts and the greater its Vas, HF gain, the greater its in-room tuning flexibility with various forms of acoustic and/or electrical EQ, so between the 206/207 the 206 is the 'no-brainer' choice and if you need the shielding, scraps of cold rolled steel (CRS) sheet metal from the local tin-knocker on either side of the TV/monitor solves the problem if you can't find the proper size tin can to fit around the magnets or don't want to pay for bucking magnets if you don't have any old drivers around to scrounge magnets off of.

GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
  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
Fostex fe207e in 36l box quiet fish Swap Meet 0 12th July 2009 05:25 PM
FE207E BSC + BR Questions rjbond3rd Full Range 8 1st May 2008 09:54 PM
GC vs. amp6 w/ FE207E sneakers563 Chip Amps 5 19th February 2008 05:26 PM
FE207E + terminal? Lostcause Full Range 2 24th May 2007 08:31 PM
Metronome for FE207e Kinnja Full Range 1 20th February 2007 07:34 AM


New To Site? Need Help?

All times are GMT. The time now is 12:33 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