Sonusthree said:
R teh roond stikas spalt bidly? Ithorwyse wyh wud I be intaristd??
Glad to hear your Chakras are perfectly aligned, one of mine hangs a bit lower on the left! 😉
Well I started my purchases, and in the wrong order... I was looking for caps for the third amplifyer and I ended up buying the lot.
Just ordered a set of Nichicon Muse KZ caps for the bas and mid sections. For the 10uf bipolar I ordered a Muse ES cap. The Muse were quite a bit cheaper than going for Black Gate, yet I beleive they are pretty good caps anyway. It means I am spending about £40 on the upgrade rather than £80 upwards. I have to draw a line somewhere....
I will order the sonicaps and the vishays in a few days.
Just ordered a set of Nichicon Muse KZ caps for the bas and mid sections. For the 10uf bipolar I ordered a Muse ES cap. The Muse were quite a bit cheaper than going for Black Gate, yet I beleive they are pretty good caps anyway. It means I am spending about £40 on the upgrade rather than £80 upwards. I have to draw a line somewhere....
I will order the sonicaps and the vishays in a few days.
Hi jb,
I would check other websites also for tweaks,
but you prob. are in the right path.
Check this by Mission loudspeaker designer Peter C.
(don't forget to register in their forum)
also their parts 'page
http://wduk.worldomain.net/acatalog/Components.html
this was for another forum member with bad tweeters or 'splashy' high frequencies...
Note: use only (make always sure) non inductive resistors, so they don't change treble curve.
I would check other websites also for tweaks,
but you prob. are in the right path.
Check this by Mission loudspeaker designer Peter C.
(don't forget to register in their forum)
http://www.wduk.worldomain.net/forum/showthread.php?t=786&highlight=MISSION
also their parts 'page
http://wduk.worldomain.net/acatalog/Components.html
this was for another forum member with bad tweeters or 'splashy' high frequencies...
Have fun
Note: use only (make always sure) non inductive resistors, so they don't change treble curve.
Hi Inductor...
Your googling skills are excellent... I had not seen that post before and I have searched and searched.
I dont think I have a problem with bad tweeters anymore. Removing the grills from the non freedom 753's sorts out the tizz. However I tried bypassing the caps on the tweeters with .22 and 00.22 poly caps I had and while I did get some extra smoothness on the top end, I also have intoduced some sibilance. I think it may be the quality on the .22 caps. They were an ebay purchase and probably not the best quality. I bought them for power supply bypass origionally.
I have alos searched for speaker tweeks on other websites. That was where the nomore nails mod came from. I have to say that the more I listen the more I like this mod. The extra definition in the lower mid and bass ranges is delightful.
Regarding the inductors... I have been looking at cheap inductance meters on e-bay. They measure up to 20H. are the inductors in a crossover likely to exceed this figure? I'm kinda tempted to invest.
Other mods I am considering.
Rubber (high mass) backed carpet tiles on the insides of the cabinate. I priced up dynamat... Too expensive though I may buy some for further damping of the speaker baskets.
I plan to add mass to the plastic plate that the tweeter is mounted in. I also plan to glue the tweeter onto the plate with no more nails Its held in with plastic clips at the moment.
I also intend experimenting with felt surrounds on the tweeter and possibly the front baffle.
Rewire.
And finally... Gulp
Removing the dust caps.
Though I am still searching the web for an aswer to this question.
Is it a bad idea to remove the dust caps on a sealed enclosure mounted speaker? Logic tells me that the enclosure will no longer be sealed, am I right?
I am not sure about removing the dust caps. I have heard of advantages in doing so in terms of flatter responses bit not with mission speakers.
I will keep researching this mod and try and talk myself out of it...
I may give it a whirl on my mission 760's as an experiment first!
Your googling skills are excellent... I had not seen that post before and I have searched and searched.
I dont think I have a problem with bad tweeters anymore. Removing the grills from the non freedom 753's sorts out the tizz. However I tried bypassing the caps on the tweeters with .22 and 00.22 poly caps I had and while I did get some extra smoothness on the top end, I also have intoduced some sibilance. I think it may be the quality on the .22 caps. They were an ebay purchase and probably not the best quality. I bought them for power supply bypass origionally.
I have alos searched for speaker tweeks on other websites. That was where the nomore nails mod came from. I have to say that the more I listen the more I like this mod. The extra definition in the lower mid and bass ranges is delightful.
Regarding the inductors... I have been looking at cheap inductance meters on e-bay. They measure up to 20H. are the inductors in a crossover likely to exceed this figure? I'm kinda tempted to invest.
Other mods I am considering.
Rubber (high mass) backed carpet tiles on the insides of the cabinate. I priced up dynamat... Too expensive though I may buy some for further damping of the speaker baskets.
I plan to add mass to the plastic plate that the tweeter is mounted in. I also plan to glue the tweeter onto the plate with no more nails Its held in with plastic clips at the moment.
I also intend experimenting with felt surrounds on the tweeter and possibly the front baffle.
Rewire.
And finally... Gulp
Removing the dust caps.
Though I am still searching the web for an aswer to this question.
Is it a bad idea to remove the dust caps on a sealed enclosure mounted speaker? Logic tells me that the enclosure will no longer be sealed, am I right?
I am not sure about removing the dust caps. I have heard of advantages in doing so in terms of flatter responses bit not with mission speakers.
I will keep researching this mod and try and talk myself out of it...
I may give it a whirl on my mission 760's as an experiment first!
justblair said:
Hi, I'll keep this short and simple ... do not go there ... , 🙂sreten.
(I've done it for yuk alloy shiny dustcaps, anything else, leave it...)
sreten said:
Yeah, unless you own a factory and (have) plenty of them to destroy...
(... Mission 753 has at least 8 speakers)
I would spend the money in measuring equipment, as somebody already said...
Hmmm, I'm even more scared now!!
I will have a go at the other mods and see how I feel about it. I have a set of almost redundant 760i's that I can afford to lose. I may give the mod a go with them first and see how easy it is, and what difference it makes. The construction of the drivers looks similar so it should be a reasonable comparison
Then I will make a decision as to the surgery on the 753's. I have to say the challenge is kinda gnawing at me. I am way to ambitious for my abiliites I think. But then again I pull off some unlikely feats most of the time.
Your comments certainly involk caution in me. Thanks
Noone stepped in to answer the question about the lcr meter. The cheap ones can't measure above 20H. Is it likely that the inductors in my crossover are going to have a higher value than this?
Regards
Blair
I will have a go at the other mods and see how I feel about it. I have a set of almost redundant 760i's that I can afford to lose. I may give the mod a go with them first and see how easy it is, and what difference it makes. The construction of the drivers looks similar so it should be a reasonable comparison
Then I will make a decision as to the surgery on the 753's. I have to say the challenge is kinda gnawing at me. I am way to ambitious for my abiliites I think. But then again I pull off some unlikely feats most of the time.
Your comments certainly involk caution in me. Thanks
Noone stepped in to answer the question about the lcr meter. The cheap ones can't measure above 20H. Is it likely that the inductors in my crossover are going to have a higher value than this?
Regards
Blair
sreten said:
Thanks sreten, I think I shall invest, I can get one for about £25 which measures capacitance as well. I will no doubt get some use out of it over the long term.
I always think to myself when I invest in a tool I wont use that much that it may be a waste of money, but when I choose not to invest, invariably several more occasions arise in quick succession when I think "Damn, I could have done with a <insert tool here>!
Thanks
Blair
If you are a pro or you became one then you can spend more money in an expensive one (tool). I don't know what's the doubt since you are interested in mods. The next step would be to know what kind of speakers you have on your hands. You know, some people say those x-overs are garbage. I don't know, but if I know their specs (drivers) I can design a new xover from scratch, or check if it's true or not.
Inductor said:
I dont see me becoming a pro, but I would like to think I can become a competent amateur. I ordered the LCR meter the other night. I will measure the inductors and either buy some replacements... Or roll my own... I need to see what the values are and then make a decision.
In the meanwhile. I recieved some caps today from Minisemi. I must thank Luc for the super quick service. I ordered on the 19th, the postman tried to deliver it on the 27th. In fact I tried to change my order a few hours later only to find out that it had been dispatched! The parcel was very well wrapped (overkill).
So it was time to start some more mods!
First up was to replace the pair of 1000uf caps on the Bass drivers crossover.
What was in there was a pair of elecon 1000uf. The Muse KX were quite a bit bigger...
You can see the location of the big caps on the crossover.
The top board was unscrewed, the caps desoldered with my desolder pump and the Muse caps inserted. I left the leads long so that i can rebuild the crossover using point to point some time in the near future.
The result
I then reassembled and did a comparison between the unmodded and modded speaker. I have to say that it was difficult to tell the difference.
You can see in the schematic that the 1000uf's are not in the signal path.
So I routed through my music collection for music with lots of low down bass. It actually suprises me how little these speakers get worked.
I did manage to hear some small differences on some tracks. However its obvious that this is not an area where huge gains can be made. Small gains though all add up!
Next up I deassembled and replaced the two 470uf caps in the mid range drivers crossover. As well as the 10uf.
After.
Again nothing here has been nailed down, and leads were left untrimmed. I will rebuild properly after when I have settled on all of the mods. I even left the origional caps glued in in case I wanted to reverse the mod.
This time I fired up the speaker for a comparison to the unmodded one. I put on Norah Jones to start with. It sounded poor. I was horified to realise the tweeter looked like it had barely survived a round with a 5 year old! A bit of speaker snogging later things were better. But still the mod had little effect, I could hear little difference.
Fortunately moving away from "Norah" and onto "The Muse" things started looking up. Well at least I could here a difference. Male vocals in the modded speaker had more "life" to them and percussion had more drive and purpose. I at this point hauled my flatmate through and used him to do a blind test. He reported the same as I had noted, and without prompting.
I have since listened to a few more pieces of music. My favourite so far has been Renauld Garcia Fons, the double bass maestro. On the album Arcoluz, The timbre from the double bass and classical guitars is more pronounced. The instruments have gained some life about them and I find it enjoyable to listen to. Switching back to unmodded, The high end seems more pronounced certainly, but the rest of the sound seems thinner. My first thought was that I had lost some detail in the mod, but thats not the case.
Drums on Arcoluz seem more engaging. The percussionist plays traditional arabic drums which punch the mid range. They seem to have more presence.
I am tempted to go ahead and mod the second speaker, but I am not going to just yet. I want to give the Muse caps some playing time to loosen up. My Flatmate also has some high quality mics, so I was going to shove some white noise through the speakers for a by thumb examination of the difference the mod has made. My guess is that there was a whole at the mid/tweeter crossover point that has been filled. The existing caps after all are lytics that have done 10 years of service.
I also have ordered the soncap 6.8uf caps from sonicapeurpe. Fabio has been an excellent communicator and has promised me a couple of stickers. 😉 I'm getting some bypass caps as well. If Fabios delivery is as good as his communication they will be here yesterday! Again I hope to have some measurements made for before and after with these.
So progress has been made. Looking forward to hopefully more improvements.
Blair
It will be interesting to know how the caps will measure comparing to their face value (when they are 10 or more years old).
Also, probably I would use better caps for the mid section not electrolytics (MKT or MKP). This doesn't mean they don't sound good, you do the test. Maybe on the mid high range you can benefit.
For the high frequencies you can bet I would spend my money here (again MKP only).
Also, probably I would use better caps for the mid section not electrolytics (MKT or MKP). This doesn't mean they don't sound good, you do the test. Maybe on the mid high range you can benefit.
For the high frequencies you can bet I would spend my money here (again MKP only).
Inductor said:
I would have used MKP for the mid section, however the value required was just so damned high. Two 470uf back to back makes 235uf. I may try a mix of caps on these to make up the value in the future. I also will try bypassing with a vishay mkp some time soon.
The 10uf I could have gone for a poly on, but my thinking was that as it is not in the signal path, the improvements may have been minimal compared to cost. I may be wrong here, if so please correct me, I may be willing to experiment if opinion is that it will yield results.
My advice so far is that if you have a set of these speakers, spending two or three pounds on "no more nails" to strengthen/dampen the baskets makes more of a diffeerence than changing the lytics.
The LCR meter I have ordered will let me test the values on the old caps, so I will report in on what they are when it comes.
I was playing tonight with a further mod on the tweeters. I made a ring of some thin foam that fits in to the tweeter enclosure. The initial results may be good on this one, but cutting the ring is difficult. The metal grill was fixed in a groove between the tweeter and the plastic baffle/fitting. Its removal left of course this groove. Gaps as far as I can tell from my research are bad for the sound, so this mod closes the gap. using foam should also remove reflections back on to the dome.
Before
And after
You can see the roughness of the job, I need to work on how to cut this stuff more accurately.
The foam is some stuff that came in a box of mouse mats delivered to my work, its off cuts from the factory, just the right depth for my purposes. Its slightly squidgy. If you depress it it takes a minute or so for the mark to disapear. Its also hard to cut accurately. But I will find a way. My Gf has access to surgical scalpels, this might be what I need.
I should at this point give a quick tutorial on removing the tweeter grill for anyone who has these speakers.
Here goes...
First remove the four bolts that hold the plastic tweeter housing to the front baffle. The tweeter should pop out, if not gently prise it out.
The tweeter is held onto the plastic with four clips, Gently unprise these with a small screwdriver. You will find that when you get two undone the tweeter may release suddenly. Make sure you have a hold of it. Note also that the metal dome is only held in place by the plastic grill. Be carefull it does not wrench out awkwardly. You could damage the coil.
The plastic housing can then be removed.
The metal grill is easy now to remove, just pop it out with a finger.
Then reassemble the tweeter carefully. You will hear four clicks as you push it together.
Done...
While I had the tweeter apart I also took some time to look at the magnet.
You can see that it has a cavity behind the tweeter that has a dense foam plug. This is just held in by its own expansion. A pair of tweezers can be used to remove it.
I reckon that there may be some small improvement to be had from experimenting with the fill in this plug. I have seen on David Ralphs Speaker pages this tutorial
David Ralph's tutorial
He uses lambswool as sound deadening in a number of tweeters to good effect. I am thinking about trying the same on the missions.
Any other suggestions on tweeter mods?
First, ... I would check with Peter Comeau (Administrator - http://www.wduk.worldomain.net/forum/forumdisplay.php?f=20) Mission Loudspeaker Designer, did you checked with him?
Second, the mod you are doing propably will give you the high frequencies more bright. The net his there to make the speaker curve more even. You may have to play with a new L-pad for the tweeter if it is to loud or a new type of screen.
The 7W resistor (2.2Ohm) may not be enough. Check if it gets (too) hot (compression/distortion). (It) Is not of a problem if you don't get more than 7W/10W from the woofer, I guess. (See, we have to check everything, when designing/making/mod. it). The 4.7Ohm is not of a big problem because is dividing power with the drivers.
(my 10 cents)
Second, the mod you are doing propably will give you the high frequencies more bright. The net his there to make the speaker curve more even. You may have to play with a new L-pad for the tweeter if it is to loud or a new type of screen.
The 7W resistor (2.2Ohm) may not be enough. Check if it gets (too) hot (compression/distortion). (It) Is not of a problem if you don't get more than 7W/10W from the woofer, I guess. (See, we have to check everything, when designing/making/mod. it). The 4.7Ohm is not of a big problem because is dividing power with the drivers.
(my 10 cents)
Inductor said:
I have not checked wth Peter as yet, though I know I should start a thread there.
The mod you say will make the frequencies bright. Is this the removal of the grill you mean or the changing of the foam in the cavity behind the speaker?
Removing the grill most certainly improves the sound. i did this ages ago, I just included it for any other mission 75 owners who stumble on the thread. Those grills are dreadfull. The only thing they do for the sound is add a high end tizz when they react with the dome. The tone does not change on their removal, but the clarity does.
Or do you thinkn that playing with the foam damper in the cavity will cause the brightness. I dont know myself how this will work out, but its an easy experiment to reverse if it does not work out. For a couple of pounds in lambswool, I can live with it if it does not work.
Hi JB,
Is the ferrofluid still in place? Do you reckon it might have dried out?
I'm just interested,
Martin.🙂
Is the ferrofluid still in place? Do you reckon it might have dried out?
I'm just interested,
Martin.🙂
I cant really see inside, but there is a small amount of redish residue on the inside of the coil former. I think that is is ok. I'll have a close look the next time I have the things apart. I didn't really want to touch it to see if its damp for obvious reasons.
Tonight i think I will replace the internal wiring. for both speakers. I have done this mod before on the 760is that I own, so I know it can produce some good results. I'm planning on using 14swg (2mm solid copper) magnet wire as the capbling. I use this already as my speaker cable from the amp to the crossover and like the sound better than any of the comercial speaker cables I have tried. Its a bit stiff, but once its in its in. I also have had the modded XO speaker burning in its new caps. So I will have another listen to it tonight and see is the sound has imroved.
Tonight i think I will replace the internal wiring. for both speakers. I have done this mod before on the 760is that I own, so I know it can produce some good results. I'm planning on using 14swg (2mm solid copper) magnet wire as the capbling. I use this already as my speaker cable from the amp to the crossover and like the sound better than any of the comercial speaker cables I have tried. Its a bit stiff, but once its in its in. I also have had the modded XO speaker burning in its new caps. So I will have another listen to it tonight and see is the sound has imroved.
I didn't have time for a proper listen, but I did tidy up the foam insert for the speakers. I bought a compass cutter from maplins. This makes a much better cut in the foam. With a bit of practice I might just get it perfect....
With the foam in the tweeter seems better behaved. More like a single point source. However I have to really do a comparison once the pair of speakers is equalised and with foam in, foam out.
I checked the fluid in the tweeter. Its looking healthy enough. Plenty there and its wet.
Maplins were oos on the 14swg mag wire... So that is a mod that will have to wait for another day.
With the foam in the tweeter seems better behaved. More like a single point source. However I have to really do a comparison once the pair of speakers is equalised and with foam in, foam out.
I checked the fluid in the tweeter. Its looking healthy enough. Plenty there and its wet.
Maplins were oos on the 14swg mag wire... So that is a mod that will have to wait for another day.
justblair said:
I was refering to this, yes.
So, if the patient does not complain the surgery should be fine.
It would be interesting if they can give you old measurements (tests) of the tweeter with net/grille and with out to compare (the frequency output).
I have to admit that I am pretty clueless when it comes to measurements. But I am getting to the point where I must learn if I am going to advance this project meaningfully.
The mods to the grill is completely reversable. In fact the pictures I took were done last night some months after doing the origional mod.
I cant remember where I found the tweak (it was by accident) but the poster on whatever forum it was had mailed the mission Factory. The advice they gave was that the grill is cosmetic.
Its clear to me this is the case. Its so flimsy, it protects nothing and removing it appears to my ears at least not to add or detract from the detail. Except of course you can now hear more of it as it is no longer masked by the resonance of the grill metal.
Tests or no tests, any owners of the origional 75 series with this grill are doing themselves a diservice if they dont try this mod.
The rubber foam that I have added I think is also recommended, but I will report on this more once I have had a chance to do some proper comparison. My intial impression is that the imaging improves and the top end is smoothed further.
My theory (and all mods have to have a pet theory) is that the foam does several things.
1 It fills in the recessed groove in the plastic housing that is there to hold the grill in place. Reducing unwanted resonance
2. That the foam ring adds gentle pressure between the face plate the dome surround and the magnet behind. Reducing unwanted vibration.
3. Rarefaction may be removed to some degree or another.
My origional plan was to use wool felt for this (others have used plasticine or blue tak to fill the recess and have reported it to make improvements, but the foam stuff literally fell into my lap when I opened the box of new mouse mats that I use in my classrooms. The depth is just right.
The mods to the grill is completely reversable. In fact the pictures I took were done last night some months after doing the origional mod.
I cant remember where I found the tweak (it was by accident) but the poster on whatever forum it was had mailed the mission Factory. The advice they gave was that the grill is cosmetic.
Its clear to me this is the case. Its so flimsy, it protects nothing and removing it appears to my ears at least not to add or detract from the detail. Except of course you can now hear more of it as it is no longer masked by the resonance of the grill metal.
Tests or no tests, any owners of the origional 75 series with this grill are doing themselves a diservice if they dont try this mod.
The rubber foam that I have added I think is also recommended, but I will report on this more once I have had a chance to do some proper comparison. My intial impression is that the imaging improves and the top end is smoothed further.
My theory (and all mods have to have a pet theory) is that the foam does several things.
1 It fills in the recessed groove in the plastic housing that is there to hold the grill in place. Reducing unwanted resonance
2. That the foam ring adds gentle pressure between the face plate the dome surround and the magnet behind. Reducing unwanted vibration.
3. Rarefaction may be removed to some degree or another.
My origional plan was to use wool felt for this (others have used plasticine or blue tak to fill the recess and have reported it to make improvements, but the foam stuff literally fell into my lap when I opened the box of new mouse mats that I use in my classrooms. The depth is just right.