Those aluminum mini speakers

[Cal Weldon]

I have a set of Sound Barrier: Concord speakers that need new drivers.

Here is the tweeter section. It measures 3" X 2" on the bolt pattern.

 

[Cal Weldon]

and here is the woofer section. It is 4 1/2" on the bolts. It also has the rounded square basket. It seems like an OK little project.

Cabinets have an internal of 1.7 litres.

Are there replacement parts worth considering?

Am I just looking too hard for something to do in the DIY deparment?

Cal

 

[HiggityHank]

Those look a LOT like Realistic Minimus 7's. Very similar cabinet, and measurements. I know there was some talk a while ago about refurbing a set of Minimus's's's's's''' but I don't know if we ever actually got past spray painting the cabinets...

Either way, it's something worth looking for.

 

[Cal Weldon]

Those look a LOT like Realistic Minimus 7's.

Hi HiggityHank,

That's what I was thinking. When I was younger, these were one of the 7's competition. These didn't sound quite as good. I would like them to sound even better than the 7's.
Anyone have ideas? I be quite happy to make these a great little set of speakers. ie: come up with some decent coin, if the cabinets are worth it.

Any help is good help,

Cal

 

[Cal Weldon]

The shape of the driver is like the first link.
frame shape
This driver looks OK but my box is 1.7 litres or just over 100 cubic inches.
4 1/2 woofer
What else is out there?
I wouldn't mind some good drivers in an ugly box. you know, for the surprise factor.

Cal

 

[Illusus]

why don't you try something from Tang Band?, something like these http://www.tb-speaker.com/detail/1208_03/w4-616s.asp

 

[Cal Weldon]

Thanks Bartek,
That looks pretty good. Will that give me some decent bass in such a small box?
Cal

 

[Illusus]

You're welcome.

It should, it's about the same size as an elf1.5 from css which use a pair of similiar TB drivers, they have a good reputation. Also you can make a plate to cover up the tweeter hole and run that driver full range as it's meant to. Should image great. If those cabs don't work out that well you'll still have a pair of great, inexpensive drivers to play with in DIY cabinets. Good luck.

 

[Cal Weldon]

Re: You're welcome.

Also you can make a plate to cover up the tweeter hole and run that driver full range as it's meant to.

Thanks Bartek,

I was actually thinking of using the tweeter plate with the hole from where the the dome was and adding a small port, approx 1" inside diameter.

A wee little ported full range.

Are there other drivers that might fit the bill and handle a little more power I wonder? I wouldn't mind seeing these things handle some real gusto, but first and foremost I would like them to sound good in such a small enclosure. Full range or two way. In fact I might just use the XO in the cabinet with a full range to attenuate the mids if needed.

Cal

 

[Illusus]

The port is a good idea. It would give you a little more low end you're looking for. Try modelling this set up in win isd...maybe I'll get to it first, watching a flick with wife right now.

 

[Cal Weldon]

I tell you what Bartek, if you do the calculations on the, I'll do the PE order thing and grab those drivers...Maybe.

I would like to know if I could do a real kiss @ss little system or should I just put the Tangband full rangers in them.

Cal

 

[Illusus]

Well, after playing around with the modelling proggy, it came up with=> 1.7L cab, 1.6" dia port 6" long = -3db at 110Hz...that's about the best you can do in this driver/cab arrangement. With some stuffing the driver will see a larger box and the -3db point should be lower, then you may have to play with port length to optimize, I estimate you can get <90Hz @ -3db. To get the ports (as calculated by win isd) to fit you can use two 3/4" ports 3.25" long. These modelling programs are only a guide, I've yet to hear a driver that sounds like a graph. I bet this combo would sound surprisingly good. I don't think you could do too much better in the bass department from a cabinet this small and I bet you can't get better imaging from a two way set up.
I'm guessing you really want to shock people with the huge sound coming from such a small box, IMHO good imaging impresses more than huge bass, most non-audiophile people never heard a speaker produce a believable soundstage, besides, I think this fullrange arrangement will produce more bass than expected to come from such a tiny box. Laff, I think I'm starting to sound like a salesman. This was the first driver to pop into my mind and I do not want you to be disappointed, let's keep hunting, maybe we can find something a bit better. Give it a couple of days.

 

[sreten]

IMO sealed all the way unless you want them farting on low bass.

I've rebuilt a similar pair of speakers using a mylar dome similar to :

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=275-065

The mounting holes need to be extended.

And a tandy bass unit that just dropped in as the chassis was the same.

This could be reflexed, 80Hz port, also Q=0.6 sealed :

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=299-432

Using a series resistor for the tweeter for level matching.

Crossover depends on if you want to include BSC, and if
so how much, the more you include the more attenuation
the tweeter needs, and the more you get a surprising
"killer" sound.

Due to size BS will very high.

I'd suggest around 1.3mH for the woofer.

Around 3Khz for the tweeter series capacitor, value
depends on the added attenuatiing resistor.

Sealed or reflexed will be a lot better than a full range.

sreten.

 

[sreten]

done a quick check, 70Hz is a better tuning frequency,
still I'd recommend sealed or use 1000uF non-polar
electrolytic series capacitance for the reflex.

Port is 0.8" internal dia x 4" long.

sreten.

 

[Cal Weldon]

Hi sreten,

Thanks for the reply. If you look at post #5, you'll see that the woofer frame shape is pincushion and the diameter of the Vifa frame won't fit. The tweeter looks like a good match though.

As far as farting, it's such a small driver that it will probably add to the sound rather than take away. No?

If there is a woofer out there that might work, please bring it on.

What are the thoughts on this one. I believe I could modify it to fit.

1vifa woof

Not having much luck with the link today, can't rename it for some reason

Cal

 

[sreten]

The plastic frame is nothing 15 minutes with a plane couldn't sort out .


I was also looking at the other driver, but its nearly 3 times the price.

It is a perfect match for the box for a sealed alignment.

It also needs a trap circuit for the top end.

sreten.

 

[sreten]

This looks like it could fit well :

http://www.apexjr.com/speakerstuff.html

with a series resistor for padding it could work well
with the VIFA / INFINITY ALUMINUM MIDBASS 8 OHM

first order series crossover + trap on the vifa infiniity.

sreten.

 

[Cal Weldon]

OK if you think the aluminum mid bass unit is OK then that's the way I'll go.
Now, about the tweeter. The Dayton mylar one looks OK. Is it likely to be a bit beamy? I"ve always thought the mylar to be a little flat and plasticky sounding. Is this a decent unit?

Cal

 

[sreten]

OK if you think the aluminum mid bass unit is OK then that's the way I'll go.
Now, about the tweeter. The Dayton mylar one looks OK. Is it likely to be a bit beamy? I"ve always thought the mylar to be a little flat and plasticky sounding. Is this a decent unit?

Cal

the aluminum unit looks good but not easy to use,
at it really takes off above 10KHz.

The Audax equivalents I've used of the Dayton have been fine,
though in this case if it fits I'd go for the Sonance, looks easy
to remove the front and spray it another colour if thats a concern.

The bass unit needs hardly any BSC if any at all.

Note both tweeters need to lowered in level ~ 8dB.

The crossovers I'm thinking parallel 2nd order Linkwitz riley,
at 3kHz + trap circuit for the bass unit may get back to you
on this.

sreten.

 

[Cal Weldon]

the aluminum unit looks good but not easy to use,
at it really takes off above 10KHz.

The Audax equivalents I've used of the Dayton have been fine,
though in this case if it fits I'd go for the Sonance, looks easy
to remove the front and spray it another colour if thats a concern.

The bass unit needs hardly any BSC if any at all.
sreten.

Using the existing crossover:

I will be cutting off the aluminum woofer at about 3000 Hz (6dB)
Do you think that is OK?
Is the Sonace tweeter available from PE? I would like to order from them. The speed crossing the border is not bad. Approx 2 weeks, through Canada customs.

Cal