www.justblair.co.uk

  • Increase font size
  • Default font size
  • Decrease font size

Mission 753 Tweeter Mod

E-mail

The Mission 753 is a favourite speaker of mine.  It was supplied in two versions. The standard, and then later on a revised edition described as the Freedom model

At the beginning of the series the tweeter supplied with the Mission 753 was a metal dome tweeter.  This gave a very crisp top end to the speakers voice.  However also detectable was a slight tizz in the top end that masks some of the detail.  Worse than that, in time the top end tizz or sharpness begins to get a little wearing on the listener.

Mission received criticism for the overly sharp top end, and when they wished to revitalise sales in the speaker they replaced the metal dome tweeter with a  softer sounding silk dome tweeter,much to the delight of the critics.This freedom model was considered an improvement.

Now my opinion.  I loved the Mission 753 when it came out.  I was a Hi Fi Salesman at the time, and there was something about the taughtness of the bass in the 753 that I just loved. Its competition at the time were transmission line speakers, and they never quite had the punch or the looks of the Mission.  they also were bigger.

The freedoms on the other hand i disliked when I heard them.  Though the top end was cleaner, the softness of it was not to my taste.  Fair enough when married with the sharp as glass top end of the Marantz CD63Mk2 (loved by What Hi Fi) the silk domes certainly tamed the CD player.  But i didn't like the CD63, I was using a DACMagic as my source.

Years later I read about a simple tweak to perform on the original Mission 753 tweeter, and I had to give it a go.  I have lost the original forum posting, so If this is your mod I am describing, please get in touch with the original posting and i will be delighted to give credit where it is due.

Basically a lot of the high end tizz from the Mission 753 came not from the tweeter domes  themselves, but from a wire mesh grill that covers them for cosmetic reasons.  Remover the grill, improve the sound!  



  1. Remove the four retaining bolts to the speaker, found on the front of the Mission 753.  With a little prising the tweeter and its casing should pop out.

 

 



2.  Carefully prise open the four retaining clips that fix the plastic bezel to the metal tweeter assembly.  At this point be very wary.  The plastic bezel also clips the tweeter dome to the magnet assembly.  You need to remove the magnet at the same time as the front bezel.
You should now have a magnet assembly..
And separate to this the front bezel.

Step 3.  Turning the bezel over you will see that the mesh grill is not permanently attached to the plastic bezel,

 

 

it should easily pop out to leave just the bezel.  


  Step 4.  Reverse steps 2 and 1 to reassemble the tweeter and screw it back into the Mission 753 cabinet.  You should be left with a plain metal dome protruding from the cavity.

 

 



Now repeat for the second speaker, find some nice music and enjoy your new smoother cleaner sound. 
Comments
Add New Search
+/-
Write comment
Name:
Email:
 
Website:
Title:
UBBCode:
[b] [i] [u] [url] [quote] [code] [img] 
 
 
:angry::0:confused::cheer:B):evil::silly::dry::lol::kiss::D:pinch:
:(:shock::X:side::):P:unsure::woohoo::huh::whistle:;):s
:!::?::idea::arrow:
 
Please input the anti-spam code that you can read in the image.
Mike  - 753 Mission |29-08-2008 02:01:03
Nice article, I still have a pair of these in good condition. Must give it try.
Also is there a low cost valve amp you would recommend for these speakers?
Admin |05-09-2008 00:48:04
I dont know of a valve amp, I have never tried valves.



I am currently using them with a homemade lm3875 bi-amp setup and I love this
sound.



Next stop is going to be a 10 channel Tripah amp setup with active crossovers.
More major project, but you can see the components of it starting to appear
here. ie. Sure TA2024 amps, and PedjaRogic Buffers will be in the case.
matt  - tweeter 753 |25-07-2009 14:07:48
Hi,I'm looking for a 753's tweeter because one of my pair doesn't works no
more.

So do you know a dealer who sells it on the internet?
Justblair  - I have seen something that came close |04-08-2009 16:38:11
Matt, apologies I missed your comment somehow.



I have not seen anyone selling these specifically, but there are a couple of
options.



Look out for second hand 75 series speakers (freedom or otherwise) perhaps with
damaged cases. The same tweeter appears on several of the models in the range.




Alternately I once participated in a thread on diyaudio a while back where
someone used a spare part from a Peerless tweeter that they bought from
madisound. You can read bout it here.



http://www.diyaudio.com/forums/showthread.php?s=c8
d05d7b47052c36a92996a52e19b4c0&threadid=107658&per page=25&pagenumber=1
Pete(r)  - Many thanks! |04-08-2009 15:54:28
Many thanks for this excellent guide. With it even this audio DIY newbie could
remove the tweeter grill from his Mission 753's (non Freedoms).

I can't say I can hear a night and day difference (although I haven't listened
long enough to verify they are less wearing) but I think a little of the
harshness I'm trying to remedy is gone.

I've got them driven by a Pioneer A300R Precision. Source is a PC sound card,
although I recently auditioned the DacMagic but I couldn't hear any difference.
If you have any idea's on toning down their brightness (preferably without
soldering!) I'm all ears.

Do you also find them a little muddled on complex (electronic) pieces?
Justblair  - Thanks |04-08-2009 16:29:46
Hi there. I am glad that you have managed to reduce some of the tiz.



To reducing the brightness is a little more difficult, it is part of the tone of
the speaker.



The 753 is not a particularly bass heavy speaker, it goes down to about 50hz
despite its 4 bass drivers.



Improving the clarity and smoothness of the speaker can be achieved though
(within reason).



A small improvement can be made by replacing the capacitor in the crossover.



http://www.justblair.co.uk/mission-753-crossover-c apacitor-swap.html



The pictures don't show it, but the description gives details.



As for the muddled sound on complex pieces. This can be tamed a little with
another technique that I have not yet written up. I will try and find the
photos and write this up.



Basically one source of the muddiness is the baskets of the speakers. A small
improvement can be made t...
Pete(r)  - Spikes or biwiring? |04-08-2009 20:42:47
Do you have any idea how much spikes or biwiring would help me?

I don't really know of a way I can use spikes as they're on a parquet floor,
which while not expensive I don't really want to put holes in it.

Also my amp only has one set of speaker posts, so I'm not sure getting another
set of speaker cables in would make much difference, especially if I haven't
upgraded the B05 crossover.
matt |22-08-2009 21:16:32
Thanks for the several solutions. Maybe i can ask mission if they sell spare
parts

!joomlacomment 4.0 Copyright (C) 2009 Compojoom.com . All rights reserved."

 
Browse this website in:

Content Menu

Home
Welcome
Blog
CD Players
DAC's
DIY Pre-Amplifiers
Class D Amplifiers
Gain Clones
Tube Amplifier
Discrete Amplifiers
Speakers
Media PCs
Tools
Online Calculators
Want to Contribute?

toolbar powered by www.mit3xxx.de