XR5 speaker surround repair gone wrong

[Styles B]

Hi everyone. New guy here looking for some advice. I’m putting together a 70s system which includes a pair of XR5 speakers powered by a Mac 1900. The speakers actually sound great and I’ve got an MQ 107 en route to improve bass response.

My issue is that I picked up the XR5s for a good price mainly because a previous owner replaced the surrounds in a sloppy amateurish way. The mids are the worst. It almost looks like he got his five year old to do it. Any expert advice on how to approach making cosmetic improvements? As I say, they sound good but I’m not sure if there will be problems in the future. I don’t know what glue was used but it’s cloudy, thick and hard. I’ve attached photos.

 

[pleeson]

Looks like Elmer's glue was used liberally....
You could attempt to remove the center dust caps and replace them with new ones and the proper glue from places such as Midwest Speaker or Simply Speakers.
Considerable risk of damage if not done very carefully.
The foam surrounds will be a little easier.
If they sound OK, you might not want to bother, and watch for replacements that come up for auction occasionally.
The exact part numbers are available on Roger Russell's site.
http://www.roger-russell.com/drivers.htm

 

[Styles B]

Thanks, Phil That's really helpful, as I had not considered that it was something like white glue (was thinking epoxy or hot glue gun or something I'm not aware of. Wondering if heat might be best for removing the glue, but as you note there is considerable risk of damage. I expect the worst area of concern is damaging the cone? I've seen several tutorials on removing foam surrounds and dust caps that are professionally glued and it does not seem difficult, but this is another story.

In the time that I've posted about the speakers at first I decided to do an a/b sound test with another set of speakers (Dahlquist Prelude System). Admittedly very different speakers, but the XR5s are pretty muddy in comparison. Lots of strong highs and lows but muddy in the middle. Not sure if it's these poorly done mids or if it's just how these speakers sound.

 

[pleeson]

The mids might not even be working.
McIntosh speakers are an acquired taste, they remind us oldsters of the 70’s, think AR, Advent, etc.
BTW, they sound best up against the wall if you’re going to use them.

 

[act1292]

Have you tuned the speakers with the MQ107?

 

[jdwk]

The mids might not even be working.
McIntosh speakers are an acquired taste, they remind us oldsters of the 70’s, think AR, Advent, etc.
BTW, they sound best up against the wall if you’re going to use them.

they sound much better than those speakers.

 

[Styles B]

Have you tuned the speakers with the MQ107?

Yes! I finally hooked up the 107 and then spent a while trying to figure out how to use the damn thing. There is so little information available on how to use the 107!

I'm happy to say that the addition of the MQ 107 made a world of difference to the low frequency response of the XR5s. It just wasn't possible to get that deep bass without it. As Roger Russell's site notes, the 101 or 102 was "required" for flat low frequency response. The 107 provides that compensation and more, so it's really worth the investment. Plus, I just can't bring myself to pony up what guys are asking for the 101, no matter how nice it looks. Someone near me is asking CAD950 for one! I picked up a 107 for CAD350, but have to source some missing capacitors.

After getting the 107 going and dialling in some of the settings, the speakers are sounding really, really nice. However, I'm still not totally happy with how the mid range is performing. It's really not as active as it should be. The question is, did some glue get inside during the messy re-glue or are they losing their performance due to age? Someone commented on a recent XR7 post that the mids are known to fade over time. Can anyone confirm this and, if so, how I can test and (hopefully) repair?

Thanks again for the helpful comments. Great community here.

 

[Styles B]

A few updates on this issue.

• I can confirm that Phil's suggestion that the glue is Elmer's or some similar white glue is correct, as it softens somewhat when I apply vinegar. Unfortunately, there is just so much that using vinegar to clean everything up just wouldn't be a reasonable task. It would require soaking the cone too and I expect that would damage them - likely beyond repair. Any other suggestions are welcome.
• I pulled out one of the 8" mids to try to understand why it's so quiet. First, I discovered they're from the later production batch made by Rola-Jensen (036-031) and they're supposed to be quite reliable (correct me if I'm wrong). The cone doesn't rub when I push it and when I hook the leads up directly to an amp, it is loud and very active. So why are the mids so subtle when in the cabinet? Is this how they were designed? I noticed basically the same question from last year being asked here, but there's no real answer.
• As I say, I've been toying with the MQ107 to dial in the speakers nicely and it's surprising how much better they sound. Does anyone have tips on what what frequency boosts or cuts work best for the XR5 speakers? Anyone happen to have a scan of the MQ107 user manual, as that may help. i can't seem to find one anywhere online.

 

[VintageMac]

I have an owner's manual for the MQ107 in PDF form. PM me your e-mail address and I'll send it along.

Larry

 

[gizzyman47]

You'd think that the original owner could have afforded to have those speakers professionally re-foamed. If he did do that hack job!

 

[act1292]

To dial in the sound using the MQ107 you need an audio analyzer. I used a Phonic PAA3 with the assistance of fellow AK members here to get my XR7s dialed in.

 

[Styles B]

To dial in the sound using the MQ107 you need an audio analyzer. I used a Phonic PAA3 with the assistance of fellow AK members here to get my XR7s dialed in.

Thanks for the tip. I’ve been looking at using something like EQ Wizard but I assume I’m limited by the sensitivity of the mic I use. I assume you didn’t buy the PAA3, given the price and the fact that you really only need to use it once…

 

[act1292]

I assume you didn’t buy the PAA3, given the price and the fact that you really only need to use it once…

You are correct. I borrowed it from my brother.