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Mach Two problems

bre's dad

bre's dad

I drank what?!?
I picked up a near mint set of Mach 2's a few weeks ago. These are not the balanced, open sounding Mach 2's I remembered from a few years ago when I last had a set. The highs are very muffled, almost like someone stuffed a jockstrap in the tweeter. Both speakers sound like that and sound the same, but I know that's not how they are supposed to sound. I yanked the tweeter out of one and hooked it up against another tweeter with similar specs. Out of the Mach 2 cabinet it came to life, singing about like the other as it should. I put the compare tweeter in the Mach 2 cabinet and sure enough, it sounded flat & muffled as well. I've cleaned the pots on the Mach 2's and no difference. Next step is to rebuild the crossovers & recap them. Anyone have any other suggestions?
 
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bre's dad said:
I picked up a near mint set of Mach 2's a few weeks ago. These are not the balanced, open sounding Mach 2's I remembered from a few years ago when I last had a set. The highs are very muffled, almost like someone stuffed a jockstrap in the tweeter. Both speakers sound like that and sound the same, but I know that's not how they are supposed to sound. I yanked the tweeter out of one and hooked it up against another tweeter with similar specs. Out of the Mach 2 cabinet it came to life, singing about like the other as it should. I put the compare tweeter in the Mach 2 cabinet and sure enough, it sounded flat & muffled as well. I've cleaned the pots on the Mach 2's and no difference. Next step is to rebuild the crossovers & recap them. Anyone have any other suggestions?
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Pots are the biggest issue. Have a stubborn pair of JBL L88's that just don't want to function correctly from min to max. Had similar issues with other speakers including Mach One's and Two'. Do the pots really good. Caps may not be as urgent but I'd do them anyway. Did my One's and Two's though the One's showed the most improvement. Now however the mids and tweets are now begging for attention.
 
I had a set of JBL 100's that the mid & tweeter were dead on one... dirty pots. I soaked the Mach 2 pots pretty good a few times with DeOxit and while they did turn smoother, it really didn't make any difference on the sound. I'm going to replace a resistor on the Crossover tonight and see if that helps. Caps will be ordered later this week. They need (and deserve) to be rebuilt anyway.
 
bre's dad said:
I had a set of JBL 100's that the mid & tweeter were dead on one... dirty pots. I soaked the Mach 2 pots pretty good a few times with DeOxit and while they did turn smoother, it really didn't make any difference on the sound. I'm going to replace a resistor on the Crossover tonight and see if that helps. Caps will be ordered later this week. They need (and deserve) to be rebuilt anyway.
Click to expand...
I'm sorry I let mine go and wouldn't hesitate to buy another pair, for the right price.
 
After cleaning pots to fix silent drivers, step 2 is always crossover caps. Particularly when the tweeter sounds like it has a jock strap stuffed in it. Deffly worn out caps. :yes: I don't think I've replaced a resistor in a crossover yet.
 
Yap the pots are an Big Issue in general but especially with the mach two.
I have had similar problems with the midrange.
The pots were totally out of range, and needes a three days cleaning orgy for being "neutralized":D

Which ones do you own?

The one withe the visaton ribbon tweeter?
I have got these and they are really well engineered Speakers.


Take your time to rebuild them it#ll be worth it. :thmbsp:

Cheers Dan
 
Are those an aftermarket retrofit? I've never seen those before or saw them in any catalog (I have Rat Shack catalogs up through about 1991.) I did see a set that had a ribbon tweeter though (his installed his own after one f the radial horns quit working). They sounded alright but were crossed over too low for the tweeter. I have the standard issue version with the radial horn tweeter.

I used a whole can of deoxit (small lighter sized mini-can) on the pots on one. I have a large can somewhere I'll spray more on later. I won't use the term spray orgy around my wife... she's mad enough at me as it is :D
 
bre's dad said:
Are those an aftermarket retrofit? I've never seen those before or saw them in any catalog (I have Rat Shack catalogs up through about 1991.) I did see a set that had a ribbon tweeter though (his installed his own after one f the radial horns quit working). They sounded alright but were crossed over too low for the tweeter. I have the standard issue version with the radial horn tweeter.

I used a whole can of deoxit (small lighter sized mini-can) on the pots on one. I have a large can somewhere I'll spray more on later. I won't use the term spray orgy around my wife... she's mad enough at me as it is :D
Click to expand...

As far as i know these are regular, and were manufactured in germany for Tandy Corp. (says the badge on the back)
The Ribbon tweeter is a Visaton (so the Midrange is) which was very popular by the end of 70's and was also sold for DIY but much too expensive for me at that time.

Perhaps they were only availible in germany at tandy, but i remember i saw them in the catalogue around 1981-82 for about 279,95$/piece.
Which was a real Bargain in my Opinion.

I was very lucky getting two pairs of these, at a garage Flea market in 1996.
And they will never leave again:music:
cheers Dan
 
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