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Monday, November 11, 2013

Another Energy 22 option

A follow up to my post from Saturday here is another drop in replacement.

JBL 033 Tweeter: From JBL L40 or L110. Faceplate is 5 3/8" crossover was 1800hz. I believe these were made by Audax and found in Infinity speakers also.


Saturday, November 9, 2013

Energy 22 tweeter replacement

The mid generation of Energy 22 speakers are currently finding that a lot of their tweeters have failed. I have an early generation Energy 22 the one with 3 posts for attaching the speaker grill, and a mid generation with the four inverted holes for the speakers grills and the post were mounted on the grill verses on the cabinet. The third generation before the Energy 22.2's saw the tweeter deviate from an aluminum plate to a 1/4 thick plastic plate.

Unfortunately Chris Coote from ABI Tech is no longer rebuilding the tweeters, Vancouver Speaker Clinic can re tinsel the leads going to the voice coil if this is where your failure is. If you have a burnt voice coil then you are out of luck. By the way the guys at Vancouver Speaker clinic do excellent work and I have had them fix a JBL T35i tweeter.

The Energy 22 tweeters that I used for this project the guys at Vancouver Speaker Clinic tried to fix for me and if you look close enough you can see the tinsel leads they tried to use. So these are my guinea pigs.


So owners have scratched their heads on how to solve 2 problems with finding a replacement, one is the 1500hz crossover point and the other is the face plate is 5 3/8 in diameter. Most modern day replacements do not have a face plate that size leading to further modifications.

A few tricks that have been tried including myself is using an EPI or Epicure tweeter, the Epicure tweeters were crossed over at 1800hz and almost fit the front baffle cutout.

Another talked about replacement is using Sound Dynamic tweeters as straight drop ins but from what I have read the Sound Dynamic tweets are a bit hot for the 22's.

The most talked about off the shelf replacement is a Dayton Audio RS28F-4 silk dome or a Vifa Dual Ring Radiator Tweeter. Both would require extensive baffle work to get them to fit.

I was always looking for a solution and finally one popped into my head the Vifa OC25SC65-04 tweeter, although it runs at 4 ohms the rest of the tweeter could work. Below are the specs for the tweeter. Here is the Tymphany PDF.

Specifications: • Power handling: 25 watts RMS/50 watts max • VCdia: 1" • Impedance: 4 ohms • Re: 3.2 ohms • Frequency response: 900-28,000 Hz • Fs: 1,520 Hz • SPL: 90 dB 2.83/1m • Dimensions: Overall diameter: 1.6", Cutout diameter: N/A, Depth: 1".
So I did no mods to the crossover and I am sure there is some shift there upwards in the frequency as the tweeter is 4 ohms and the crossover is designed around a 8 Ohm driver. The Energy has a 3rd order cross with an 18db slope and the Vifa tweeter has a resonance frequency around 1500hz so I figure this could work.

Anyway of on with the walk through, after all that's why you clicked this story.

First up we have the tweeter pulled apart, as above.

Next is sizing up how it is going to look mounted on the back or should I mount it on the front?




Next I had to fill the old screw and lead holes with silicone.




While the silicone was drying I added new connectors to the speaker wire, blue is negative and yellow is positive.


Next I pinched the soldered leads to the post for a better fit for the face plate modification. I decided that I wanted the tweeter mounted on the front and not the back for diffraction issues.



Next was filing the plate to mount the tweeter.


Tweeter now fits in.




Next I added silicone to glue them in and seal any gaps.


I bought some 1/8" closed cell foam similar to the original foam on the plates and added a felt ring around the tweeter to help cosmetically.


I have them installed and I am really enjoying my Energy 22's again. I have A/B them against my other Energy 22's that are stock and the modded pair are have a bit more energy in the highs but they sound fantastic and image great. No they don't sound like the originals but they do sound close.


Email me if you have any questions.
 

Monday, November 4, 2013

Mission 700S update


The Mission 700S have found a spot in with the Mission 770 Freedom IV and the Dual CL390's. The Philips tweeter works really well and I prefer it over the Vifa D19-TD in which is stock in this model.

I re-foamed a friends pair of Mission 707's awhile back on the premise I get to listen to them for a few weeks. I found the Vifa tweeter very open at first but after an hour listening I found the Vifa fatiguing. I ended returning the 707's early.

These 700's are a great sounding little speaker.


Saturday, October 19, 2013

Mission 700S refinished

The Mission 700S got a completed overhaul and I am enjoying these fine speakers. No wonder they were rated as a best buy back in the early 80's. These speakers do everything that Mission made name for themselves.

I re foamed the woofers, re capped the crossover and sanded out the scratches in the cabinets and re stained them.

The original Vifa D19 TD tweeters have been replaced with Philips AD 11410 dome tweeters which I find to be better than the original Vifa's. I always found the Vifa D19 TD tweeters to be a bit shrill and fatiguing after awhile. The Philips tweeters were glued to the original round faceplate of the Vifa tweeters.

These were great speakers back when I first bought them and they are great today. They have been playing all day and I have yet to tire of them.

Woofers:


Crossover:


Tweeter:

Cabinets:


Mission 700S beside Mission770 Freedom's:


Wednesday, October 16, 2013

Mission 700S

I just picked up a pair of Mission 700S, the first speakers I bought when I started my journey down the audiophile path. These speakers will probably need to be re foamed, re capped and re finished as there are some water stains on the real walnut veneer.

These speakers were well regarded in the early 80's as an budget audiophile speaker. There is a 8" woofer over top of a Vifa TD 19 tweeter and ported at the bottom. The covers are permanently attached.


Sunday, September 22, 2013

Realistic System Seven

I finally put together the stereo that I always wanted as a kid a Realistic System Seven.

The Realistic STA-7 was designed to work with the Minimus 7 speakers. A nice sleek unit rated at 10 watts per channel.

I picked up this unit and had to replace the dial bulbs and the stereo bulb. I also found the screw speaker terminals to be a pain so I installed proper banana plug terminals. The pots all needed a cleaning to get the scratch out of the controls.

I changed out the Minimus 7 speakers from a 2nd order crossover on the tweeter and the natural roll off of the woofer to a 1st order on both drivers. I like the sound of the Minimus 7's this way.

Click here for the Realistic catalog from 1980 go to page 18.


Thursday, September 5, 2013

More Mini Speakers : Minimus 7's

I keep stumbling across mini speakers with a pair of version 1 of  this famous little Radio Shack speaker, the one made in Japan with the metal baffle plate on the tweeter. By most accounts these are the best of the models.

They are pretty simple little speakers with a 2nd order crossover for the tweeter of which I replaced the 4.7uf cap with a film cap.

The woofer rolls off with no crossover, which most people think in the Achilles heel of this speaker. There is plenty of information on the net in regards to rebuilding the crossover of which I might try.

They are much brighter than the Transonic mini's that I featured earlier and side by side I tend to listen to the Transonics more than the Minimus 7's. Stack the two sound pretty good together.

I also have a pair of Koss Dyna-mite 65's that are waiting a re foam and will be featured then. All this will eventually lead to a mini speaker challenge.