My 777 Modification

Well I've done it at last! I've put new speakers into my 777. The pictures explain what I've have done but I'll try to articulate the change in sound.

The two centre speakers are Skytronic 16mm Kevlar speakers, very cheap and very effective. They are 8 Ohms so there is power loss but I am still pleased for two reasons. Firstly, the speakers are a lot more sensitive to bass than the originals by a mile. Secondly, speaker impedance is variable at different frequencies. It tends to be higher for midrange and lower for bass, on some units as low as 2ohms for bass and 8ohms for mids in a 4ohm speaker. The effect on mine is that I now get a warm low bass of between 30 and 80Hz, which for a boombox is impressive and suites the music I play to a tee.

The original bass speakers responded more to mids than bass, say from about 100Hz, making it sound 'boxy'. The new speakers make the unit sound more like a car stereo now. More on this later.

The two outer speakers are Kenwood car speakers and are 4ohms. They are a little more sensitive than the originals and are a lot less prone to distortion. The tweeters sound crisp too.

In Summary

All in all, I have lost sensitvity in the centre speakers because they no longer give any mid range, but I have gained on the outer speakers because the mids there are less muddy and I have a properly functioning tweeter. This means that the box now sounds much more like a Hi-Fi and for the music I play I am really pleased.

One observation though is that if you play 80s hip Hop, disco or Rock, the original configuration is better because of the prominence of the 100k to 500k frequencies (you get more of a hit than a boom).

I'd like you guys' opinions in regard to the speaker colour. Should I:-

a. Leave the colour is it is.
b. Spray the centre speakers to match the outer.
c. Spray them all black and get a couple of Chrome disks for the centre speakers to make it look original.

The wife things I should leave it as it is because it adds a modern twist to an obviously old unit. I am really looking forward to hearing your views.

Here are the pics

Your wife is right, leave it as-is.

The color they are now looks very "new" and updates a classic very nicely. The whole box looks new...especially without the mesh.

I love it as it is!

Sounds like a great modification.... Its one complaint Ive always had with mine, too muddy sounding for my tastes.

Excellent!

Leave it as is. If you were obsessing about originality, you wouldn't have made the speaker swaps in the first place. Form before function is not your cup of tea, so stick with your java. As for painting black with chrome center caps, forget it. Painting it will add mass to the speaker cones possibly changing the specs and chrome caps are impossible to find. I've looked and looked and never found any. If you have a source, please share it.

It looks great. I wouldn't hesitate to do that to my GF-777 in a second.

GLD.........THATS NOW A TASTY LOOKIN BOX......I SEE YOU HAVE CHANGED THE OUTERS SINCE YOUR PICCYS WITH BENDYCAT AT THE BMX RALLY...DID YOU HAVE ANY MUSIC PLAYING AT THE RALLY ..?????AND HAVE YOU GOT THE PART NUMBERS AND THE RETAILER COS I MAY DO THIS TO MY OTHER 777.....THANKS......DAVE....SUNNY BLACKPOOL

Davebush,

I did have music playing but it wasn't as loud as it could go because my MP3 player needs a Boostaroo to drive the boombox to its potential.

The inner woofers are Skytronics Kevlar 16cm drives (Part no. 902.423). Remember that these are 8 ohms. The outer speakers are Kenwood KFC-1777 car speakers and these are 4 ohms.

There are some Pro TL 6.5" speakers on Parts express that are 4ohms and a wacking 94db 1W/1 Meter
(SPL). The Syktronics are 90db 1W/1Meter. To put this into perspective 3db apparently represents a doubling of audible loudness!

I got the bass speakers locally in an electronics shop and I got the outer speakers in a general electrics store in Hackney. These stockists are obviously no good to you but at least you can look the units up on the internet if you wish.

You definately can get better speakers for the 777 but most of them are available in the US and not here.

The Skytronics units have magnets that are 30 grams each so it adds a lot of weight!

When you compare the build of the original inner speakers and the new ones you can see how louspeaker technology has changed over the years.

Remember, my mods have not made the unit louder, they have made it sound like a Hi-Fi. I prefer quality over loudness.

I'd imaging that this could never take out an M90 but the bass extension and the clear tops make me a very happy man right now.

thanks G

Thank you very much for the inspiration! I'm in the process of overhauling my GF-777 and I decided to follow your example and upgrade my speakers. You were so right, the difference is startling. With bass down to 40hz and fully functioning tweeters, my house is rockin' (so don't come knockin'!)

That's good to hear Kenpat. Hope you put some pics up when you have finished.

Finished the first phase of my gf-777z restoration. This included the speaker mod as per your inspiration, gld.

I used Pioneers for the outer two-ways in my setup, and MCM Electronics woofers to replace the inner "subwoofers" ( ).

My outers are 4 ohm, like yours, but my inners (while they only go down to 40Hz) are 6 ohms so I am probably sacrificing a little bass for a little power...
But not much either way! Like you, my lows are noticibly lower AND warmer while the extra tweeters realy crisp up the highs.
...And my pride & joy STILL pumps up the volume!

I really can't thank you enough!

The modifications look great. BTW Dont' thank me. I think Autobot was the first to do this type of mod on S2G.

Love both boxes!! Great Great MODS!!!!!

gret job, guys, your boxes are looking much better and i am sure, they sound much better to!Love that blue/shampagne-yellow contrast.

Thats definitely in the horizon once my speakers give up ...And maybe before that...