Help needed with bad tweeters (1 Viewer)

[rockblock]

Hi Folks, I'm quite new to this, so any help would be greatly appreciated.

I just got a pair of used Sony tower speakers SS-AV55 (130W) that each have 2 woofers (6" each)+ 1" dome tweeter.

The problem is that I think tweeters are busted, as only the woofers can be heard. I took out the tweeters and checked them each individually...they produce barely any sound...with my ear against them and slowly turning up the volume, I can barely hear anything...upon taking the tweeter out, through the hole I can see that internally, all 3 drivers feed into some sort of circuit board with capacitors & coils (I guess it's the crossover board). On the other side of the board are the 2 speaker connections.

The tweeter has no specs on them, just some numbers stamped on the magnet. The only specs that I see are on the back of the cabinets:

SONY MODEL SS-AV55
SPEAKER SYSTEM
RATED IMPEDANCE: 8 ohms
MAX INPUT POWER: 130W (non-clipped)

So, does this mean that each of the 3 drivers drivers has an impedance of 8 ohms? Same for power: does the 130W mean that each driver can handle 130W, or is that the combined power? How do I know what wattage I should be looking at for when choosing a suitable tweeter (I've seen them go from 25W->100W).

It's interesting how both tweeters react the same way...

Any help would be greatly appreciated.
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[David Willow]

What did you play to test the speakers? What amp/source?

You need either full range sound or a high frequency sweep to really test them. Just playing music may not reveal anything meaningful.

 

[rockblock]

I simply disconnected the speakers and connected the tweeter driver to my yamaha 5x100w amp output...the result was the same. With my other (good) speakers, I can clearly hear the tweeters...

 

[rockblock]

I do have one more question : what power should I be looking for the tweeter to handle? Between the 3 drivers (2 woofers + 1 tweeter), I assume that the power is not distributed evenly amongst the 3...so, what ratio should I be using?...would it be a good guess to say that 40% + 40% + 20% (tweeter)? If so, would that mean I would be looking at something like this:

- 8 ohms
- 25-35W
- 87-92dB

PS. Does it matter if I replace them with cones, or should I stick to domes?

Thx

 

[Robert_J]

Not smart to feed a full range signal into a tweeter without a crossover in place.

Check Parts Express for replacement tweeters. Normally I wouldn't recommend this because it could impact the sound in a negative way. But they are Sony speakers. How much worse could they sound?

-Robert

 

[David Willow]

Ouch! If they did work, they probably don't now.

I second parts express. There is probably no way you will ever know exactly what was in the original.

 

[rockblock]

Thx for all your advise.

I guess I'll be looking for a dome tweeter @ 8 ohms, with a crossover frequency somewhere around the 2kHz, that will be able to handle power somewhere in the range of 30-50W...is that about right?

 

[Brett DiMichele]

That is the nice thing about buying better speakers, replacement parts!

When I fried my tweeters (don't ask, it was a Pro Sound piece of equipment that did the deed) I was able to order two brandie spankin new tweets at the paultry sum of $130.

Here you go:

http://www.partstore.com/Model/Sony/...20&%20Speakers

And no, I can NOT vouch for them...

 

[rockblock]

Thx for the link, I was thinking because Sony doesn't produce great speakers, that this may be a good opportunity, as you say, to upgrade (cost-effective that is)...the problem is I don't have too much specs (I guess I'm missing the crossover portion most of all)...I've also sent a request for specs to Sony, but, due to past experience with them, I don't expect to hear back from them with a positive resolution. But I'll keep the link in my backpocket as a last resort. Thx for your help

 

[Brett DiMichele]

It's not worth upgrading. You just can not arbitrarily throw in a different tweeter and expect it to work right. Speaker design is very complicated and crossover slopes and frequencies plus baffle step compensation all go into the design of the passive crossover network. Just buy the OEM replacement tweeters for $44 and call it a day.

 

[rockblock]

darn...thought it would be easier...but I get your point...thx

 

[rockblock]

I've managed to get a hold of the manual that provides some additional info on the speakers (not sure if this can provide any additional help for the tweeters though):

Speaker specs:

Woofers: 6.5" cones x 2
Tweeter: 1" dome
Freq. response: 30-20kHz
Impedance: 8 ohms
Sensitivity: 91 dB SPL , 1W measured @ 1m
Power handling: 130W

I'm not sure if the sensitivity gives us more insight, but I thought I'd share

Thx

 

[Robert_J]

To properly match tweeters with an aftermarket model, you would need frequency response graphs, impendance by frequency graphs, dispersion graphs (both horizontal and vertical).

-Robert