Modifying RX-CT900 speakers has made an incredibly deep bass (from 40 Hz)

[Reelcassette]

Installed are:
Layer of pwc foam, layer of cotton ,
Cross wooden brace , calculated bass reflex
and thick black/red wiring.
Original tweeters were replaced with sensitive high output piezo tweeters.
Decorative polished chrome rings added to finish bass reflex ports' edges.
Wire organizers were gently released and saved along with original wires
You can always put them back originally with original screws.

 

[neanderthal]

That is nice!

 

[Reelcassette]

I know what you mean..
But if you have that wide range bass -
you don't need to have it loud -
it sounds more detailed at low volume..

 

[Reli]

Cool!
What's the black spots in the cotton?

 

[Superduper]

Cool. Looks as good from the backside as from the front now.

Oh wait, you removed the wire organizer and cut holes into them?

 

[Reelcassette]

Black spots are drops of liquid rubber.
They came thru layers of cotton like stitches to prevent moving.

Yes,i've made holes,BUT
original wire organizers can be installed back with 2 original screws
to make it looking original again if needed.

1988 magazine photo and my RX-CT900 today.

Tapes are separately - let me know if you like them





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[Reli]

Black spots are drops of liquid rubber.
They came thru layers of cotton like stitches to prevent moving.

You purchased the cotton like that, or did you add the rubber somehow?

 

[Reelcassette]

Cotton was purchased in farmacy, but
you need to stitch it to make layers.
You can use any flexible glue for this.
Any shoe glue is ok.
When you're done with cotton layers -
just drip glue all over the layers and
it'll kinda penetrates thru the layers
and freeze them for good.
https://sites.google.com/view/reelcassettetapes/home

 

[Reelcassette]

Please, check this Modifying RX-CT980 as well!
http://boomboxery.com/forum/index.php/topic/30008-modifying-rx-ct980-made-a-portable-hi-fi/

 

[floyd]

Honesty if you have a large woofer in a small cabinet a ported box is the way to go. If you have a small woofer in a small to medium box then sealed is the way to go that is if the cabinet resonance can be brought under control through bracing and poly fill , the poly fill breaks up the standing sound waves trapped inside the cabinet because of the group delay which is sound waves inside a cabinet fighting for space , those sound waves produced bounce around and interfere with new sound waves in short.

 

[Reelcassette]

The key thing is - it's not a woofer.
This is a very sensitive /2.7 Ohms/ full range speaker .
It doesn't bounce like a regular rubber suspension woofer..

 

[Superduper]

Personally, I think that if you tried it, and it sounds good to you, produces the sound quality you like, then it's all good.

BTW, I like those cassette tapes you make. How much would you charge for some shipped to USA?

 

[Reelcassette]

Trackable shipping to US is $8,50 for package of 1-2 tapes.
Usually arrives within 7 business days.
https://sites.google.com/view/reelcassettetapes/home

https://www.youtube.com/watch?v=pKVj-Ib_f4k

 

[Reelcassette]

Why have i modified my RX-CT900 Speakers?
As a flagman of Panasonic's boomboxes in 1989 and till January of 1991,
RX-CT900 has a quite decent amp. / 2x30W PMPO /.
I've connected a pair of Technics SB-CS60 ( 8Ohm ) instead or
original 2.7 Ohm speakers and that was a very solid sound with a plenty of trebles ,
mids and bass without noticeable output power loss and distortions were way lower !
Then i've connected them serially along with original speakers and guess what happened?
Sound was even better WITHOUT POWER LOSS AGAIN ! AT 8+2.7 = 10,7 Ohm !
This Amp drives 10 speakers without any problems with less distortions at higher impedance !
This is how i've figured to modify my original speakers for maximum efficiency .
So before you start to modify your boombox speakers , make sure you check it with some
other speakers to see if there's a point to do that.
Some boomboxes have amps designed to work with original speakers only and
any spontaneous modification can affect their good original sound
(I don't mean original tweeters - see my further posts about them )

Happy listening to eveybody!
https://sites.google.com/view/reelcassettetapes/home

 

[martins44]

Hello. What is the size of bass tube? Leight coud be 10cm, not more but what is diameter inner?