Returning to an old Passion - Stereo Audio

Rediscovering the Joy of Good Audio

 I am renovating a pair of Sansui SSL-1F speakers I bought in Brazil around 1995. They badly needed repair so I left them with a nearby speaker repair service. Turns out the product name was definitely Sansui, as found in an ad by Sansui, but the speakers were "Made In Brazil." Haven't figured out what part of them was actually a Sansui product, except for the tag on the front.

From a 1994 Sansui Catalog 

Anyway the floor-standing speakers (Four Bravox components each - a 10" woofer, 4.5" mid-range, and two small tweeters) still work fine, but I will replace the woofers for now and have a new pair of JBL Selenium 10", 200 WRMS speakers on the way. The bass only kicked in on the old woofers at around 60Hz and I chose the new woofers to do about the same. They cost around $65 US each.

Guess it was a little nostalgia that led me to spend $400 US on fixing them up. Here in Brazil, a new pair of JBL A180's would run close to $800 US, or for a 2.1 setup,  JBL A130 + A100p subwoofer cost about $1000 US.

Find as I might, I cannot determine exactly what speakers, JBL brand or other, are inside the A180s and A130s. I'd love to install the same in my towers. I never imagined my Sansui speakers would have Brazilian brand components.

Very damaged Sansui SSL-1F speaker cabinets

Original Bravox components - No description on them at all, except the name Bravox

New cabinets built  - old one on the right, and not the worse one.

Finished cabinets

I will post a pic of the new speakers without the grill in a few days. I should have my babies back home by then. I am not expecting much change in sound quality, but I'll be glad to have some newish attractive speakers in the house.

Just received my replacement woofers... 

JBL Selenium 10pw Pro 200Watts RMS.  Nice huh?

I'd rather get some Dayton Audio speakers but they are unavailable here. These have a frequency response of 60 - 20,000 Hz. Similar to what I could hear coming from the old Bravox drivers.

I will take them to the cabinet maker tomorrow and hopefully have my speakers at home by Friday.

Received my new woofers Monday, installed them on Wednesday

Tested them with sound files I found on YouTube and they sound great. Good work for a local service. But I'll only trust him with speaker cabinets in the future. He has no idea what "ohms" are and uses no multi-meter.

Just not too happy with the impedance of the new JBL woofers. Should be 8 Ω but measured them at 5.8 Ω. 

My amplifier, a rather inexpensive Panasonic SC-AKX100, outputs at 6Ω though so we're ok. But it does make me wonder if my speakers are false.... Comparing them to  to pics I found online they look legit.

July 03, 2023

Listening to music and movies on my street bought $5 headphones, I could hear deep base notes that were missing on my renovated stereo speakers. So I have decided to add a subwoofer to my setup. 

After days researching 8" subwoofers on the internet, I purchased a DBX 8" Dual Coil, 4+4 ohm, 250W RMS speaker for R$200 (about $45 USD). Dual coil gives me three configurations for three different amplifier resistances: Single coil connection gives 4 ohms, dual coil in parallel gives me 2 ohms, and dual coil in series, 8 ohms. My cabinet maker hooked up a single coil.

I am having a cabinet built for it today and will have pics tomorrow, and results of my listening experience with the new subwoofer.

Cheers!

Aug 27, 2023

A cabinet has been made for the DBX 8" subwoofer driver and it looks pretty good with it sitting in it's new home..

       

DBX PRO 8", home made cabinet             Passive speaker connections (old school)

Have to say though the "deep" base I was hoping to hear did not materialize. Specs on this 8" speaker say 30-350 Hz, but I can hear  only a little at 50 Hz, good bass at 60 Hz, and strong at 70 Hz. Much like the bass speakers in my rebuilt pair above. I have been powering this one with a Sony MHC-GTZ2 2,0 audio receiver, supposedly putting out 200 RMS watts per channel, but no subwoofer channel, so I get plenty of  volume but no deep bass frequencies.  (Updated story below).

So, still looking around the online local Marketplace I found a used Samsung Subwoofer, from a home theater system for about $8. Yes, $8. Couldn't pass it up. The UBER to pick it up cost a few dollars more. 

  

Samsung subwoofer from model J355 system

I have seen Samsung subwoofers berated when they are in home theaters, but this 5" subwoofer sounds great in my L-shaped living area, giving me a clean and loud 40 Hz in some online audio files that go that low. (See my playlist for relaxing, deep base music on YouTube - https://tinyurl.com/5frfedjt)

Newer Samsung sound-bar systems only have blue-tooth subwoofers... and there are complaints about connecting them wirelessly with the sound bar. Glad this one is old school.

So far I have only hooked up the new Fosi amp to a couple of Panasonic bookshelf speakers from a SC-AKX100 stereo system I bought a couple of years ago for about $120 and this Samsung subwoofer. Sounds so good... I have not been in a hurry to hook the new amp to my larger speakers and DBX subwoofer. Keeping that setup in the bag for now, saving it for my son's next visit to share the experience.

Cheers!

September 12, 2023

Getting great bass from both subwoofers now! Hooked up my old, renovated stereo speakers as well.

Update: One problem was that, according to the spec sheet, the Panasonic SA-AKX100 receiver was only outputting 60-16kHz, with 40 watts per channel, i.e. no low, deep base.

I ordered a Fosi BT30D amplifier with Left, Right, and Subwoofer outputs and a 20-20kHz frequency range and now have awesome deep bass music massaging my tinnitus afflicted eardrums.  It's wonderful. 

Anyone listening to old school stereo speaker systems can do themselves a favor by upgrading to a 2.1 audio system just by adding a subwoofer component - passive or active - and 2.1 amplifier. My 2.1 BT30D amp, with blue-tooth tech,  cost only about $75 and a really good active new subwoofer (Elac or Polk) costs less than $200. A good, used passive subwoofer can be found on social media sites for under $100 while new ones cost slightly over $100. Do not get a blue-tooth subwoofer! These come with newer home theater 5.1 systems or 2.1 sound-bars. People are having trouble connecting with blue-tooth to those subs. And if you are upgrading from a 2-speaker stereo system, the Fosi and other similar 2.1 amplifiers easily connect to cell phones and blue-tooth enabled laptops, as well as smart TV's. 

Fosi BT30D link:    https://tinyurl.com/49uckdm8

Fosi website:           https://www.fosiaudio.com/product/

Cheers!

Combining Two Hobbies - 3D and Lunar Imaging

How to Image the Moon in 3D

For years I have been entertaining the idea of imaging the full moon around 6pm then again at 6 am, believing I could create a stereo image (3D) of the moon. Two images 12 hours apart would give me a base of nearly 8000 miles, the diameter of the earth. Surely, I thought, at midnight the moon is almost overhead, so imaging it after sunset and before sunrise would give me slightly different viewpoints of the moon, about 240,000 miles away. Two viewpoints are needed for stereo imaging, their separation in general being about 1/30th the distance to the subject. 8000/240,000 = 1/30.

But, I am a lazy guy, and getting up at just before 5 am, betting on weather has been difficult. Then a thought came to mind, before I make all the effort, maybe I can test my idea with software.

As it happens, I have a program called Virtual Moon Atlas (Link to VMA). At any given date and time it gives me a realistic map of the moon. The idea came to me today to simulate the moon at the different times, make screen caps, then display them side-by-side to create a stereograph or 3D image.

Below are two stereographs - the full moon surface and an image of just the eastern portion. The full moon stereograph doesn't give an obvious 3D view. But the eastern moon stereograph clearly shows a 3D effect. Best viewed in cross-eyed mode.

For those 3D fans who have a pair of anaglyph classes, below are anaglyph, red/green images

I'll still plan on getting up and recording the moon at 5am some day, then 12 hrs later acquiring more video. 

Appreciate any comments... 

Have a nice day and night.

07-03-2023

Update

I figured out that I only need the 8000 miles of separation between two captured moon images for a 3D of the full moon, or 12 hours apart from my location. I can create a 3D image of parts large areas of the moon from images captured a few days apart. 

It works like this. For full moon images I need the 12 hour interval but for parts of the moon I can image it a couple of days apart at the same time. The moon circles the earth in 27.322 days. So relative to my position, it has rotated about 27 degrees (2/27.322 x 360) between two day's exposures. On earth that corresponds to 1760 miles separation.

The description of the moon's rotation about the earth is explained here:

https://tinyurl.com/mppjbjjk

Below are two images of the moon side-by-side taken from Virtual Moon Atlas simulating how the moon appears to someone at my location two days apart. I have done some alignment and cropping processing.  With Cross-eye viewing the 3D effect is obvious.

That's only after two days! 

I'll be working on getting my own telescopic views in the next few days and compare to the simulations. 

Cheers