Possible to cheaply improve Minimus 7 speakers?

[N8Nagel]

Picked up some 40-2030Cs in thrift this morning - they are filthy but other than that fine

after doing some research though it appears that the "good" ones are 40-2030, -2030A and -2030B and that these are inferior.

Is there a cheap and cheerful way to bring these up to the level of the earlier ones, or should I just get what I can out of them and move on?

thanks!

 

[Ohighway]

Not quite sure I understood your sentence about which numbers were superior, and which inferior.

 

[N8Nagel]

Apparently the C suffix was when the advertised bass response went from 50 Hz to 100 Hz...

 

[RJolly87]

As I understand it, it was the earlier tweeters were more desirable. Keep in mind however, these are comments made by those who have heard one over the other, done side by side comparisons, etc. Someone who is just coming in to them may not see them the same way that others do.

I also seem to recall the Minimus simply being a fairly inexpensive speaker of the time that was able to withstand quite a lot of abuse, and punch way above its price class.

You can try recapping them, and refoaming them if they have foam surrounds (I think they used rubber however). There are also plenty of mods documented everywhere that I have seen that can change the way they sound.

I think I am up to 3-4 pairs myself, and plan to grab more as I see them.

I also recall a Realistic branded amp that actually has an equalizer switch spec'd for the Minimus speakers to give them that little extra kick. I have one of them too, and it really plays in to their strengths.

I like to think of them as mainstream cars of old. They may not have been the best around, but many people either had one, or knew of one in their life. There was so stinking many of them made, many have been touched by them over some point in their life.

 

[N8Nagel]

the ones I have have rubber surrounds and work OK

I was thinking of flogging them to a coworker along with a powered sub and a low powered Rotel receiver as an entry into good sound for cheap but I know there's some rabid Minimus 7 fans so I wanted to know if I was missing something that wouldn't cost too much to bring these things up.

 

[Justgotohm]

I have installed this crossover in several pairs of Minimus 7's from different periods. It is a night and day diffrence and is extremely satisfying.
http://audiokarma.org/forums/index.php?threads/minimus-7-loudspeakers-measurements.199790/

 

[ra.ra]

Ditto, I'd like to hear your summary of the differences among these variations. I've got pairs of both A's and C's, and while I've never performed a critical comparison, they both sound very good to me and look virtually identical with the grilles off - - the driver part numbers may be slightly different, too.

RJ87 gives good advice - - might due well to re-cap, and yes, the Realistic electronics make a nice inexpensive mate for the Min-7's, see below.

 

[onwardjames]

Get a pound of modeling clay, and line the cabs. Did this with my Minimus 77's (bigger brother) and the deadening that provided was IMMENSE.

And yeah, recap if you're cheap, build a proper crossover if you're not.

 

[Justgotohm]

I have two pairs in walnut, one pair made in Japan very nice veneer, the other pair made in Singapore, not as nice, you can tell the subtle differences in the detail and quality. I have the crossovers built and ready to go in. I had planned to stack them tweeter to tweeter just for fun. I'll do a side by side comparison for any obvious differences. If you just recap them it's a 4.7uf and at least use a metal poly cap. The full crossover is the way to go. The .4mh shunt coil in the upgraded crossover schematic is already on the stock crossover in the speakers.

 

[Tom Brennan]

The best modification for those speakers is to clip the wires leading from the input terminal to the crossover.

 

[jlovda]

The best modification for those speakers is to clip the wires leading from the input terminal to the crossover.

I tried that. It affected the treble as well as the bass. Maybe I cut the wires too close to the input terminals.

 

[rkgren1]

Oh come on Tom! It's fun to play with the gear of modest specification!
Regardless, that was hilarious.

 

[valvenator]

Oh come on Tom! It's fun to play with the gear of modest specification!
Regardless, that was hilarious.

I agree, on both points.

 

[Ohighway]

Not sure of any numbers or which is earlier or later, etc. However the only difference of note in the pairs I messed with is the tweeters. The ones -without- the concentric circle pattern around the tweeter dome sounded better to me. Like the ones shown in the wood speakers below. Just my opinion mind you.



The not as good sounding tweeters had the concentric pattern shown below,

 

[xero-D-hero]

RE: Min7 tweeter situation,I've been meaning to post this for reference so might as well do it here & now.

FYI: The "good/early" tweeters from the wood cabinet min7w are different than the ones in any of the metal cabinet min7.
So note that the early (good) tweeters from the wood cabinets are not a direct fit in any of the metal cabinets.

If one looks at pics of both,you can see the top side of the "good" tweeters from the wood cabinets are less sharply rounded and thus ever-so-slightly taller.
That is what keeps them from fitting in the metal cabinets,so that direct swap is a no-go.
Also the "early/good" metal cab tweeters are cut straight/flat across the bottom edge so they wont overlap the woofers.
So the early/good tweeters from a min7w will ONLY be a direcf fit in those early min7w cabinets.
But any tweeter from a metal cab will fit in the early min7w cabinets that originally came with the "good" tweeters,as the mounting holes are the same pattern.
This includes the later tweeters (w/concentric rings) from the metal cabinets.

vvvv Here vvvv is a pic of a metal cabinet concentric ring tweeter (LH) and an early/good min7w tweeter (RH).

The tweeter on the left is 2 9/16" vs. 2 13/16" on the right,and trust me that 1/4" difference is crucial.

And to complicate this situation even further yet,the later "concentric ringed" tweeters in the min7w (wood) cabinets changed as well.
They're physically larger (everywhere) than any of the metal cab tweeters.
Also note that the mounting hole pattern for those later min7w is different as well,as it too is bigger.
So the "early/good" min7w tweeters wont be a direct swap into those later min7w cabinets.
So swapping tweeters in the later min7w will likely require tweeters from the same later min7w cabinets.
And those later concentric ring min7w tweeters wont fit in any min7 metal cabs either (nor vice-versa).

Ask me how I know all this,,,LOL...

Pic vvvv here vvvv shows the metal cabinet concentric ring tweeter on the left,and a later min7w concentric ring tweeter on the right.

Sorry no ruler for size reference,still it's fairly obvious (visually) that these two tweeters ^^^^ above ^^^^ are NOT a direct interchange...
Just look at the distance between the rings and the top/bottom of the tweeter,and then look where the mounting holes are relative to that.

Now you ask "why no comparison pics of the good tweeters from an early metal cabinet min7" ???".

Well,I did'nt notice these differences and had'nt come across any reference material pointing all this out.
So like a total DA I bought some min7w speakers whose cabs were rough yet had a nice pair of "early/good" tweeters in 'em.
I did so thinking I could swap those tweeters into my Optimus Pro7AV project speakers.
Well,that did'nt work out like planned,,,DOH !!!

So now I've been on the hunt for some "early/good" tweeters for the metal cabinets of those Pro7AV.

Below are those Optimus Pro7AV project speakers I mentioned.
Main item of note vvvv here vvvv is to look at just how tight the "fit" is for the metal cab tweeters.
Also note that I've swapped out the OE woofers for some kevlar woofers from a Optimus LX4.

Note should be made that these woofers were some NOS/NIB LX4 woofers.
More pics of that Project HERE >>>> http://audiokarma.org/forums/index.php?media/albums/optimus-pro7av-project.484/

Also have done that LX4 woofer swap on my minty pair of early min7w that I had before all this got started.

Note to be made here is that these kevlar woofers were original "pulls" from a pair of trashed out Optimus LX4.
That's because those also differ ever-so-slightly from the NOS/NIB LX4 woofers that were used in the Pro7AV project above.
More pics of that project HERE >>>> http://audiokarma.org/forums/index.php?media/albums/min7w-project.494/

Now of course all this relates to direct drop in fit,if one is inclined to swap out the plates,then that may change things,I honestly dunno.
All I can say 'bout that is I have never done so and as such I cant really say that it would even be adviseable,so swim @ your own risk if going that route.

And yeah,the plan is to do the crossover mods (PZ 2.1 or ???) on both of these,and likely a few others if I'm happy with how these two pairs work out.

HTH

Bret P.

 

[Tom Brennan]

Oh come on Tom! It's fun to play with the gear of modest specification!

Oh yeah, I too had a couple of pair of them.

 

[getone]

Thanks for the info. What are the three bolts closer to the tweeter dome for? Can those be loosened and the tweeters swapped between the mounting plates?

Thanks!

 

[toxcrusadr]

The best modification for those speakers is to clip the wires leading from the input terminal to the crossover.

Here we see the creature in its natural "All Audio, No Class" habitat.

 

[Ramseybella]

Everyone should at least have five or six pairs..
I buy them when I find them, most of the time never use them except in my garage setup.

 

[xero-D-hero]

Thanks for the info. What are the three bolts closer to the tweeter dome for? Can those be loosened and the tweeters swapped between the mounting plates?

Thanks!

More-or-less yes,but I have no idea how swapping the plates would work out.

I hafta assume there are some ins & outs that need to be considered.
For instance I'm not sure if all the various tweeters share that same exact (3) bolt pattern.
Then after pulling them apart I figure they may need to be realigned so the voice coils dont rub.
And I dont know if the various plates/tweeters all use the same alignment methods.
Also I dunno how fragile the leads may be either,so that could possibly be a bit of an issue.

What I'm getting at is I've never done that (pulled 'em apart and swapped 'em),so I dont know how fussy a job it may (or may not) be.
Hence why I said: "swim @ your own risk" if going that route.

But I have given it some thought,and I'm considering trying to do such.
But I figured I'd see if I could scare up a pair of the ones I want first.

Knowing my luck it's a super easy job and I'm just sweating it out over nothing.

LOL

But I could'nt find any info anywhere about doing that either.
I did find a guy's site that showed him swapping in some AMT mini 8 ribbon tweeters though.

FWIW

Bret P.