obselete mission tweeter drivers ?

[admin_exported]

first thanks for taking time to read this . i apologise if this post in the wrong place . i need some help quite badly i'm looking for a tweeter for a mission 753 (not freedom) tower im quite confident that its the driver and crossover that have gone pop . the crossover is still available from mission but the tweeter is no longer stocked do you know anywhere i could ether get mine repaired or obtain a new one from ? .i understand from mission that the tweeter was also fitted in there 752 speaker range if anyone has a knackerd pair of these with a working tweeter perhaps we could arrane a deal once again thanks for your help guys [😀]

 

[John Duncan]

Does it have a model number?

 

[Dougal1331]

Bad news Doc.

The 753 (model number 53-HFDOM) tweeters are rare as rocking horse droppings. I gave up looking after 18 months and stuffed a pair of Vifa ring-radiators into mine instead. This was a good move, as they look great and sound incredible, way better than the original units, IMHO.

I've seen them on eBay once- a pristine pair went for £145.

Best of luck in the hunt. If you would like more info on perhaps trying different tweeters, I'd be happy to help.

Jon

 

[Dougal1331]

Also bear in mind that the 751s used an 8ohm tweeter (model 51-HFDOM) whereas the 753 unit is 4ohms. Not sure about the 752!

Getting the impedance wrong will shift the crossover frequency and alter the balance of the speakers- almost certainly for the worse.

 

[Anonymous]

thanks guys, your right about the rocking horse droppings , im considering buying a pair of decent 4ohms tweeters and having a piece of stainless cut to alow them to fit into the orginal mounting plate slot . any recommendations on a good 4ohm set for say sub £50 being as times are hard . i was thinking something like these

http://www.impactaudio.co.uk/product.asp?ref=594&session=41e89ac28f499ad697aca96b4996f8a5

or
https://www.madisound.com/store/product_info.php?products_id=1679

 

[Dougal1331]

Hi Doc, sorry for the delayed response!

The tweeters I used were Vifa
XT25SC90-04. They are neodymium magnet designs and therefore much smaller than units with conventional magnets. The cut-out in the cabinets is fairly small, so these save any woodwork.

Wilmslow used to have them, but no longer seem to, so Madisound is a good bet. Expect to pay another tenner when they come through UK customs though...

You will need to make a mounting plate, and they will also need balancing, as they are of higher sensitivity than the original units. I found a -2dB drop to be about right, and this does require a soldering iron. It involves a couple of ceramic resistors- one across the terminals of the tweeter and one in series on the positive terminal.

If you decide to go this way, I can give you the correct values for the resistors and help you through the installation if necessary.

All the best

Jon.

 

[Dougal1331]

Just checked the links you supplied...

The madisound link is for the same Vifa tweeters I used, as mentioned in my previous post.

I would choose to ignore the Visaton units though- the crossover frequency of the Missions is 2.5kHz, but they only go down to 3kHz. The Vifas will be the best bet, albeit at a higher cost. Believe me, it is money well spent!

 

[Anonymous]

hi there thanks for the info the madisound rimfires are on there way from the states as we speak they should in the country by now could you please post the correct values and wattage ratings for the resistors you mention'd please also which goes in series and which goes in parallel whit the tweeter . getting a couple of pieces of alley lazer cut to mount the speakers on is what i have in mind and i dont mind taking a file or similar to the cabs to allow fitment of the tweeters .

p.s a couple of days after ordering the tweeters i found a post for a guy breaking a pair of 753 on ebay with good tweeters !!! its always the same isnt it lol

 

[Dougal1331]

Hi Doc,

the values I used (for approximate 2dB attenuation) are:

0.82ohms series (on positive terminal)- also called R82

15ohms parallel- also called 15R. They are both 10W axial ceramic resistors.

I purchased them from- and can recommend highly- Audio-components.co.uk, who were very helpful, and about the only place I could find the correct values! The direct link to the page you need is thus: http://www.audio-components.co.uk/store/SubSubCategoryList.asp?SubSubCategoryID=114

You won't need to do any woodwork- the holes are plenty big enough to accomodate the tweeters.

Let me know how you get on!

regards,

Jon.

 

[Anonymous]

wow quick reply thanks fella . the .82 is a strange resistance ( ive done a bit of electronics in the past ) still waiting for the parts to arrive from the states at the moment so ill order the resistors a bit later today . then its a simple job of running around doncaster trying to find some one who can machine me the alley plate to match the original holes if i knew how post a photo of it them online i would once there back up and running properly again

 

[Anonymous]

hi ya just a quick update finally got one of the rim-fires bolted back into the cabinet . to my ear there isnt much difference between them and the missions ( i havnt sorted the attenuation resistors out yet) but then i have spent the last 15years on loud machinery and spent a couple of years working on fast jets so my hearing might not be all that its suposed to be . ill get the other cabinet modded over then weekend and let them bed in for a bit and see how i go . eutythmics there must be an angel and muse undisclosed desires sound awesome now the sound is nearley balanced once again . thanks a million for all your help and advice

 

[Dougal1331]

Good to see you're making progress.

I hope your hearing isn't too bad, but mine were so toppy without the attenuation, that they were unlistenable!

Remember that the performance will smooth up a touch as the new parts break in, expect the odd sharp edge for a few weeks. Best of luck with the rest of the work, let us know what you think when you're done!

Jon

 

[Anonymous]

I have rescued a pair of 753's from the graveyard. They do not have any tweeters at all in t cabs. I have 2 options purchase the replacement units suggested above although I do have 2 mission 780 argonaut tweeters that I have just replaced the tweeter diaphragms on. Would they be suitable given that they are 4 ohms?

Regards

Richard

 

[Sliced Bread]

I tried to get some 78 series drivers a few years ago (the original clay ones), but they informed me that mission went out of business a few years ago and were purchsed by another firm.
Name and some of the staff are the same they are now a different company to the one they used to be.

 

[Oranoco]

By any stroke of luck do yu still have the tweeters from the Argonaut 780? I own a pair and a tweeter went last weekend 🙁