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XRT20 Speaker System Restoration (and questions)

w1jim said:
My guess is that if the tweeters are weak that one or more of the groups have an open tweeter.
I doubt the cable is at fault.
I presume you’ve seen this regarding the XRT18:

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Wow !
I`ve had my purchased demo showroom used from my local Mc. dealer since 1992, and other than first having their woofers surrounds replaced in the early 2000s, and then the mid ranges around 10 yrs. ago, I`ve had zero issues of any sort, and they sound wonderful.
The tweeter banks are separately fused from the main cabinet`s input fuse, so one would wonder, if at some time in the past, that the OP`s 18s were "spanked abusively" and the HF fuses were super stupidly replaced with a higher value to "cure" the fuse popping annoyance, and then amplifier overdriven again resulting in damaging some of the tweeter groups, or it`s capacitors !

Or the crossover or it`s wiring was disturbed in some way when unhooking/reconnecting the woofer`s wiring for the re-foaming, as those speakers have a pretty complicated crossover, especially with the tweeter banks wiring ?

My XRT-18s reside in my bedroom and are driven every day as soon as I wake up, and during cold weather here, I run that system 24/7/365 until the outside temperatures rise playing WAV. ripped music all day, to help provide some heat in the bedroom, as I`m currently doing at the moment.

My 18s seem to respond very well, to the (2) 2006 purchased Mc. MC-1201 mono blocks, driving them in there, and zero chance of sending amplifier clipped music to them, no matter how loud I would sanely crank up the system.

I`m very grateful that the dealer called me back then in 1992 to enquire if I would be interested in the attractively priced purchasing offer of them with the optional matching tweeter line array stands, and drove them out to my house and set them up where I requested in my bedroom.
 
Some re-foam shops applied a subtance on the woofer and midrange foam surround to extend the life of the repair. The only problem is that reduces the efficency of the woofer and midrange if applied by 3 to 5 db. So don't do it. Mac changed the type of foam with their later speakers to get a longer life. That foam may be acceptable for older woofers and mids. Call MAC or Audio Classics to find out. You can read about it on Roger Russells website about the different Mcintosh speakers he designed for Mcintosh. He also had the tweeters treated to remove any high frequency resonant oscillations.
 
Bill Ferris said:
Wow !
I`ve had my purchased demo showroom used from my local Mc. dealer since 1992, and other than first having their woofers surrounds replaced in the early 2000s, and then the mid ranges around 10 yrs. ago, I`ve had zero issues of any sort, and they sound wonderful.
The tweeter banks are separately fused from the main cabinet`s input fuse, so one would wonder, if at some time in the past, that the OP`s 18s were "spanked abusively" and the HF fuses were super stupidly replaced with a higher value to "cure" the fuse popping annoyance, and then amplifier overdriven again resulting in damaging some of the tweeter groups, or it`s capacitors !

Or the crossover or it`s wiring was disturbed in some way when unhooking/reconnecting the woofer`s wiring for the re-foaming, as those speakers have a pretty complicated crossover, especially with the tweeter banks wiring ?

My XRT-18s reside in my bedroom and are driven every day as soon as I wake up, and during cold weather here, I run that system 24/7/365 until the outside temperatures rise playing WAV. ripped music all day, to help provide some heat in the bedroom, as I`m currently doing at the moment.

My 18s seem to respond very well, to the (2) 2006 purchased Mc. MC-1201 mono blocks, driving them in there, and zero chance of sending amplifier clipped music to them, no matter how loud I would sanely crank up the system.

I`m very grateful that the dealer called me back then in 1992 to enquire if I would be interested in the attractively priced purchasing offer of them with the optional matching tweeter line array stands, and drove them out to my house and set them up where I requested in my bedroom.
Click to expand...
I don't know that they were abused as I got them from an estate sale years ago; perhaps more likely the fact that they did not get exercised regularly (read: were in storage unused) may have more to do with it. I'm anxious to get my multimeter on them.
 
good news, bad news. cable didn't help, but all the tweeters have continuity and are firing. To be honest, I haven't really opened them up with much juice yet, so it could just be a perception issue, ie low energy in the higher registers. Definitely need to feed them some more power to see if the same phenomenon is happening at higher volumes. I was somewhat loathe to pull out all the stuffing to check connections and oxidation; kind of a pain that the crossover isn't accessible without pulling the big woofer and stuffing out but guess that is the next step if a higher volume test confirms an imbalance. Maybe it's my hearing!
 
mrichards said:
good news, bad news. cable didn't help, but all the tweeters have continuity and are firing. To be honest, I haven't really opened them up with much juice yet, so it could just be a perception issue, ie low energy in the higher registers. Definitely need to feed them some more power to see if the same phenomenon is happening at higher volumes. I was somewhat loathe to pull out all the stuffing to check connections and oxidation; kind of a pain that the crossover isn't accessible without pulling the big woofer and stuffing out but guess that is the next step if a higher volume test confirms an imbalance. Maybe it's my hearing!
Click to expand...
Perhaps you`re not used to their presentation, as those type Mc. tweeter arrays HF delivery are normally very airy sounding, and don`t come off in your face presentation (not shouty) like some point source speakers sometimes do.

At least that`s been my perception, of first owning my 1990 purchased new Mc. XRT-22s, then the purchased used in 1992 18s, and now the purchased new in late 2003, and currently still in use tri-amplified XRT-30s.

I`ve learned that from owning all three sets of these speakers that they really love lots of very clean power, for them to sonically disappear, especially if played at any realistic SPLs.

If possible, try running them for a day or so, playing at a moderate level, and see if that has any improvement effect, as I found doing that seem to help revitalize a very long unused pair of purchased used DQ-10s that I currently use in my sunroom.

I didn`t spend anytime critically listening to them at first, I just passed through the sunroom every hr. or so, during the day and night, on my way to the car garage to smoke a cigarette, so it was unlikely that I was "getting used to their sound" by constant exposure to their SQ.
 
Bill Ferris said:
If possible, try running them for a day or so, playing at a moderate level, and see if that has any improvement effect, as I found doing that seem to help revitalize a very long unused pair of purchased used DQ-10s that I currently use in my sunroom.
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that was exactly what I was thinking of doing. thanks for confirming that could be a possibility
 
so for my tin ears I now think they are ok. Besides needing some warm up of old electronics I think the problem was also my fairly small, extremely lively room forced me to keep the volume levels so low that very little energy was being fed to the tweeters. when I had the chance to open them up a little, I could not discern any issues
 
I was very impressed when the XRT 20 came along. Great definition with out the honky horn sound. But the definition didn't go low enought I thought. The XR 290 proved that to be true. I always wanted 290's but they were to large. So When a pair of XRT 28's came along I jumped. XRT 30's took up to much floorspace. There are some tricks in making the 28's really significantly better than 20's if you want increased definition. They have the low distortion Mids and Woofers the 20's and 22's and even the 290's don't have the low distortion mids. That can make quite a difference. You can exchange woofers and mids at Audio Classics. Or you can get the foam surround kits at Midwestern Speaker company and do it your self. I just hope the crossover components are good , but I bet all the caps need to be replaced, too. If you have tweeter issues you are going to have to call the factory or Steve or Ryan at Audio Classics for an answer. Steve had some extra tweeter columns at one time he was thinking about selling or stripping for parts.
 
macman007 said:
My XRT-20's had the 4 woofers and 2 mid-range's replaced by Audio Classics on an exchange basis. Part #'s matched the old one's and the "salad bowls" that were missing were also replaced, resealed with the proper putty and all re-installed.

These are later model 20's with the nice neat crossovers from 1989 IIRC, so I didn't replace the capacitors. Also, my tweeter columns are mounted on the outsides of the credenzas, to the left of the left and right of the right credenza. The mounting posts connecting the cabinets to the tweeter columns are installed and the curved feet on the tweeter columns are also in place. These are possibly the most mint set of XRT 20'S in existence.

My question is, should the tweeter columns be inside or outside the credenzas as I have them? Any modifications or placement suggestions you can offer. I have no set up or installation brochures to refer to and could never find instructions online to read or print out?

:music:

Thanks.

Oh yea, these speakers just love the MC-501's powering them. They love all the power and really take what you give them. I was thinking of adding a Mc 104 or 107 Eq as listed above or the MEN-220 Room Correction System with custom eq and 2 way crossover with built, in microphone and set up the room properly.

Philip
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I personally exchanged emails with Roger Russell and he told me they were designed to be inside . I actually sent him pictures and he corrected me on my placement.
 
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Elamar said:
I personally exchanged emails with Roger Russell and he told me they were designed to be inside. I actually sent him pictures and he corrected me on my placement.
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Welcome to AK!!
Would you share those emails with RR on this thread for posterity?
 
Found it . I have the exchange abut reforming the woofers but not on the placement. I actually called him and he asked me to send pictures which I did. I then called him and exchanged a pleasant chat. Truly a great guy
 
For those of you who haven't seen it, here's my post regrading repair of the XRT20 tweeters:
w1jim

Thread 'McIntosh XRT20 036056 1" Philips Tweeter (and similar) Repair'

When I found my XRT20's back in 2011 they had a couple of blown tweeters.
Each channel of the XRT20's has 24 tweeters arranged in 5 groups of 5 tweeters each arranged in series and then those groups paralleled to give the appropriate impedance. One of those groups has 4 tweeters and an 8 ohm/20 watt resistor in place of the missing 5th tweeter.

Since these tweeters are in series it's very unlikely that more than 1 tweeter would go bad in each "string".

One failure point in these tweeters is that the coil wire looses contact at the rivet where it attaches to the terminal. The other of...

It would be extremely unusual for more than one tweeter to blow in the series string of 5.
The replacement dome is a Philips !" dome.
 
Elamar said:
I personally exchanged emails with Roger Russell and he told me they were designed to be inside . I actually sent him pictures and he corrected me on my placement.
Click to expand...

When I was having problems getting my XRT20s to image properly, no center, Roger told me to move the tweeter columns outside of the LF/MF columns, which made them image properly.

YMMV, it likely depends on your setup, and Roger apparently knew that.
 
I think the confusion stems from the article he wrote where the picture he posted has them on the outside but the same article says on the inside 8 inches from the cabinet and not more than one meter from the center. After talking to him I switched from outside to inside
 
I switched mine from outside to inside and toed in the woofers - much improved.

IMG_9851.jpeg
 
Elamar said:
I think the confusion stems from the article he wrote where the picture he posted has them on the outside but the same article says on the inside 8 inches from the cabinet and not more than one meter from the center. After talking to him I switched from outside to inside
Click to expand...

No confusion here, Roger knew that I had the tweeters inside and directed me to try them outside suggesting that they would image better that way, and they did.
 
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