Radio Shack Optimus 7 Speakers..

[Steve Smiley]

Trying my new “toy”, looking not vintage as previous bullet tweeters.

Is there anyone experience this kind of tweeter before? Please be advised

Hello Pointed, those are Optimus Linaeum dipole tweeters. Lots of info on AK about them. Many have used them with good success. I have several pair of RS speakers that use that tweeter (or design) to play around with but mine are not dipole. I haven't had much listening time on them to give you a personal evaluation. I am in the middle of modding a pair of Optimus LX-4, using the Blacjk Dahlia mods. I am giving them to my brother in law as a gift. Read up on them and them might help in your use of them as a supertweeter. I recall one AK member using them as supertweeters with an open baffle design. I'm sorry I can't give you any feedback on how they mate with your Optimus 7.

https://www.blackdahlia.com/tipindex/Tip__3/tip__3.html

Hook 'em up and let us know what you think!

Smiley

 

[woofercooker]

Hey! to all you Optimus 7 fans... I decided to change out the motor run oil caps for some Audyn-Cap Plus caps and a Jantzen Standard Z. I still will have one pair with the motor run caps. I don't really need two. If anyone wants these motor run caps, let me know..You can have them for free..Try them out and if you don't like them you can always go back to what you have or want. Here is a pic of the crossover and caps...I flat out love these Audyn-Cap Plus capacitors for these speakers...

 

[woofercooker]

Notice how much larger the 22uf Audyn Plus Cap is compared to a still sort of big 22uf Jantzen standard Z.

 

[Jim Pearce]

Confused! Regarding the cloth surrounds ...
I have googled and read myself to complete confusion. I thought it would be a simple answer- I was wrong. I have read no less than 400 post of 20+ different concoctions on what to use on resealing the 44 year old cloth surrounds. latex paint, elmers, plasti-dip, permatex, white glue, pba, rubber cement, rtv, pva, paint, caulk, silicone, gasket coat, fabric glue, butyl, plastic/rubber revitalizer, and combinations thereof. Simply Speakers sells 1 oz bottle of white pva but there is a 50/50 split on good vs bad. VintageAR does not sell anything. Isn't there a product made specifically for cloth surrounds. I don't want to use something that may hurt the sound and value of my woofers.

Never, never use anything besides solubleized butyl.

Nothing like PVA, for cloth surrounds only.

Roy c classic speakerpages.org formula now only available through vintage AR on the bay.

Ask me about rebuilding back to factory specifications the 3/4-in paper mache tweeters on acoustic research 3A or 2ax, they are the same except 2 ax is 8 ohm and 3a is 4 ohm.
By the way the red ones are interchangeable with no mods to the crossover.

 

[Jim Pearce]

I will always buy any Optimus 7 components but you should keep any extra ones you have. You never know when you need them. I recently purchased two more "Extra" CR tweeters from ebay. They are off white like the others drivers in the Opt 7. They also fit perfectly in the cabs. They also have Alinico magnets, too. They test at 6.8 ohms. The original Optimus 7 tweeter tested at 6.2 ohms and I was watching my tech do the testing. If anything I would love to find some crossovers like you did. Then I could change them out and decide which work best for me. I did buy another TRIO midrange from ebay so I can have an extra in case one of those fails. Those are the mids I'm using in the Optimus 7s I got from you. I did get my magnets a few days ago. I ended up getting the same ones you bought. The guy said it would be a whlie before they were to manufacture the bigger ones with china new year coming. I just put them in tonight. Its difficult to tell if there are any improvements because I had also resealed the crossover and the woofers with AR woofer seal gaskets. These speakers are tight as a drum. And the bass is pitch stable. Sounds very good and tight. I'm happy for you having a tube amp. I use mine at lot. Helps warm up the living room during the winter.

I need ONE tweeter for these speakers.

 

[Jim Pearce]

Thats good info as I have decided to replace the cheap-o caps that I had installed in the first pair of Optimus 7 with Audyn plus caps.... They actally cost more than the Mundorfs EVO Oil in Aluminum. I'll ask my tech guy and see or hear his opinion on the bypassing of bass switch, Good to know you are using your Optimus 7s, Amante! More people need to hear these speakers.

I need replacement tweeters for these model 7s or a recommendation on an upgrade to easily available tweeters, I have tried Simply Speakers, Madisound, Midwest Speaker and a couple of others.
I've been tearing my hair out trying to find these, apparently these speakers go for somewhere between $500 and $800 and I'm trying to get them back into shape, I bought a pair of them for a song and I'm wondering if they are really that good.

 

[premiumplus]

I've owned four of these great speakers since 1973, and I blew the original tweeters in the first year I owned them...I just replaced them with a good quality tweeter that Radio Shack carried at the time and they've been fine ever since.
I'd just suggest getting a nice 8 ohm replacement tweeter and pop it in. They're easy to change and the crossover sets their operating frequency, so dive in and try one that will physically fit and you should be fine. I'd get one that can handle whatever power you're going to throw at them; I ran mine for years on a Pioneer SX-1010. Right now they're on a rebuilt SX-1250 and sound awesome.

 

[Jim Pearce]

I've owned four of these great speakers since 1973, and I blew the original tweeters in the first year I owned them...I just replaced them with a good quality tweeter that Radio Shack carried at the time and they've been fine ever since.
I'd just suggest getting a nice 8 ohm replacement tweeter and pop it in. They're easy to change and the crossover sets their operating frequency, so dive in and try one that will physically fit and you should be fine. I'd get one that can handle whatever power you're going to throw at them; I ran mine for years on a Pioneer SX-1010. Right now they're on a rebuilt SX-1250 and sound awesome.

Thanks, I get it man.
I'm looking for this particular tweeter or a suitable replacement.
If you know any make or model numbers that would be appropriate please let me know.

 

[markshan]

I need replacement tweeters for these model 7s or a recommendation on an upgrade to easily available tweeters, I have tried Simply Speakers, Madisound, Midwest Speaker and a couple of others.
I've been tearing my hair out trying to find these, apparently these speakers go for somewhere between $500 and $800 and I'm trying to get them back into shape, I bought a pair of them for a song and I'm wondering if they are really that good.

I'm virtually certain those aren't the original tweeters. First off, they have a Rat Shack catalog number on them. That means they were for individual sale, not for use in a pre made speaker cabinet. Second, if you Google image search Optimus 7 speaker you see several different tweeters (as mentioned above, the tweeters are delicate) but the most common one has a round frame without square trim. Google phenolic tweeter and match mounting hole sizes to get a good match. Make sure it's 8 ohms if you don't have the skills to mod the xover.

 

[ukfan4sure!]

Stopping back by again, and I see a lot of talk about tweeter replacement. I never could find a replacement for one of mine that was blown, so I tried several different ones as replacements. The one that sounded the clearest and cleanest was one with a phenolic ring from parts express. They are touted as a replacement for vintage AR4 speakers along with others. The stock number is 270-252 and the model number is PRT-8. I disagree with some who said to use any tweeter with the correct physical and electrical ratings. I tried 4 different ones, including a couple that were triple the cost of this one.

 

[colehager]

@ukfan4sure! – thanks for the above post, which I know is several years old at this point. I acquired some Optimus 7 recently and am blown away. I currently have the Nova 8B (VL-mod) and a set of Optimus 9 I restored myself, but these absolutely give both a run for their money.

The one bummer is my pair has had its tweeters replaced with Cerwin Vegas, which are fine but not to my taste. (Too bright and then some.) I am holding out hope for sourcing originals, but I recognize that could take years. (I actually found one, but it arrived from the auction site with a tear in the paper cone. Tragic!)

Hopefully one day someone will be parting out a pair and I'll get lucky. Until then, I might take a look at the part you've noted above. I appreciate all the research you've done for this relatively rare speaker!

 

[Steve Smiley]

@ukfan4sure! – thanks for the above post, which I know is several years old at this point. I acquired some Optimus 7 recently and am blown away. I currently have the Nova 8B (VL-mod) and a set of Optimus 9 I restored myself, but these absolutely give both a run for their money.

The one bummer is my pair has had its tweeters replaced with Cerwin Vegas, which are fine but not to my taste. (Too bright and then some.) I am holding out hope for sourcing originals, but I recognize that could take years. (I actually found one, but it arrived from the auction site with a tear in the paper cone. Tragic!)

Hopefully one day someone will be parting out a pair and I'll get lucky. Until then, I might take a look at the part you've noted above. I appreciate all the research you've done for this relatively rare speaker!

I would second the use of the phenolic ring tweeter that @ukfan4sure! identified above. At least for why you wait for an original to show up. I used that Parts Express tweeter in a rebuild of the Optimus T-100 and it was really quite nice.

 

[Randy_P]

Before swapping the tweeter for good, I’d probably check more than just the driver itself - things like the L-pad, switches, and old crossover caps are definitely worth looking at too. With vintage speakers, “dull” highs or a top end that’s way too bright isn’t always the tweeter itself - sometimes the real culprit is somewhere else in the crossover.