Absolute noobs experiment with upgrade woofer on aiwa speakers

alitech

Member
2019-12-12 10:22 am
Hi guys

I have just started in this community because I want to explore DIY. Never done it before and from the experiences I have read and seen on youtube, there is a lot to be gained by going DIY.

Firstly, I want to see if I can upgrade my old Aiwa speakers with new woofers as the lows are pretty pathetic. Its not a deep speaker so I need to know what creativity is needed to get the lows to an acceptable state. They are vintage and I picked them up from ebay. The highs are awesome and mids are ok, I like more high and low anway. They are 100w speakers made in Japan.

I am in the UK and would like to see if I can get one of those tang bang paper sub woofers to replace the current woofer in there. I was also thinking about stuffing the woofer with loft insulation foam without blocking the port. Let me know if I am talking crap.

The size of the woofer end to end without the metal surrounds is 5.71 inches.

I think I might be trying to polish a turd, but please humour me if there are gains to be made here.

Here are pics
[IMGDEAD]http://www.thenaqvis.com/ebay/aiwa1.jpg[/IMGDEAD]
[IMGDEAD]http://www.thenaqvis.com/ebay/aiwa2.jpg[/IMGDEAD]
[IMGDEAD]http://www.thenaqvis.com/ebay/aiwa3.jpg[/IMGDEAD]
[IMGDEAD]http://www.thenaqvis.com/ebay/aiwa4.jpg[/IMGDEAD]
[IMGDEAD]http://www.thenaqvis.com/ebay/aiwa5.jpg[/IMGDEAD]
 
Just take out the "woofer" and you'll discover that
1) the woofer is driven full range, i.e. there is no lowpass filter
2) the tweeter will have a tiny 2.2 uF cap for high-pass filtering
3) the little thing aside the tweeter is a) fake; b) is a piezo paralleled to the tweeter

The value of that thing is about 5 £ new.
 
You can’t polish a turd but you can roll it in glitter. :D

If you insist on this madness, mainly in the sense that any money spent on this would be better spent building something from scratch, then start by measuring the internal volume of the speaker box to ge a figure you can put into some speaker box design software and see what easily and cheaply available woofer might show reasonable bass response in that box.

The “porting” is an utter joke, looking like it’s just two holes in the box rather than having ports and so it might be best to just seal them up and treat it as an sealer box for... ahem sound quality reasons.

In the unlikely event that they have a crossover then make some measurements with a multimeter and a signal generator to get an idea of crossover slopes.

If it doesn’t have a crossover then buy the woofers with a crossover in mind.

The kids look like they could have been given away in a happy meal in some dystopian post apocalyptic future but you could measure them and source some replacements to fit in with the woofer and crossover you have in mind.

Given you say you like the sound of the tweeters then by ou could try them with the above or find a good reviewed cheap pair to try for the sake experiment as well.

After you have done all of that I would be tempted to then build another speaker box for all the bits you have already bought to maximise their potential as the box really makes thy s difference in getting the best performance from any given set of components.

Or, in the alternative buy a kit and put together something that will sound good straight off the bat for less money than the above... :D
 
Good man, you know it makes sense. :)

I don’t know anything about that set up in your link but I’m sure it’ll sound pretty good.

Grab a copy of WinISD and have a play with the design of various ported and sealed boxes for the woofer given in that video.

See if you can arrive at the design rationale behind the speaker in the video as a learning exercise to be going on with.

I started In DIY building subwoofers, building full range speakers came out of that for me.

I’ve fancied an active build for a while too, keep us posted.
 
The first speaker i build was an old Aiwa speaker, where i took the drivers out and build a new better box (including crossover) for it. Someone designed it for me and it did sound a lot better than the original. The only thing i did have to buy was mdf and the cutting wich was done at the woodshop. I glued it toghetter and used it for about 10 years. That speaker is still in use by a friend with very small budget who needed decent speakers (i sold the pair to him for 20€ 7 years ago).

I think in your case, that will also be a better scenario than just replace the woofer. It's even possible that the existing woofer is decent, and that it's just the box that is wrong. Or you could add an other woofer to the rest of the drivers. In any case, you will need someone who can design speakers to help you to get a good result.
 

Galu

Member
2018-04-17 6:50 pm
The “porting” is an utter joke, looking like it’s just two holes in the box rather than having ports...
It looks like the porting arrangement is provided by the silver plastic moulding situated below the black speaker grill.

Removing the plastic moulding will alter the tuning of the box in a way unlikely to improve the bass response.

Personally, I would look for an old British made speaker like the Wharfedale Denton.

It has a solidly built box which provides a suitable foundation for experiment using alternative drivers etc.
 

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It looks like the porting arrangement is provided by the silver plastic moulding situated below the black speaker grill.

Removing the plastic moulding will alter the tuning of the box in a way unlikely to improve the bass response.

Yeah, I was to say that the plastic mould ( which plant's production for the mould takes most of the design costs, IMO ) also often exhibits a short horn around the woofer.

PS I wonder why they didn't even ever thought of making a karlsonesque enclosure:p
PPSS A chinese new entry brand did some nice looking "TL" speakers with a little fullrange in a big waveguide . Something like "ba-jooou" but I'm not so sure :D
 

Xoc1

Member
2008-11-08 8:25 pm
Devon UK
The Aiwa speakers are so budget that changing the drivers would not be cost effective. The main compromise will likely be the box.
If you want to improve the speakers I would start by looking at bracing the panels and panel dampening by lining with carpet tile or similar. This can make a surprising difference to the overall performance. Internal stuffing is best added in small amounts, Too much will reduce bass. I tend to add small amounts and listen. When the stuffing is adequate any boxy hollow effects will be reduced and stereo focus should improve.
Any thin wiring to the woofer could be replaced with whatever chunky copper you have handy.
Further improvements would probably require some sort of measurement to evaluate porting and crossover performance. This would probably result in diminishing returns given the basic nature of the speakers, it may be worthwhile if the point of the exercise is to learn, but probably best to move on to a better project.