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Discussion Starter · #1 ·
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:

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).


Also, what does "non-clipped" mean?


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


Any help would be greatly appreciated.

 

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Try to get the exact replacement tweeter. You should be able to order them. Drives are 99% not interchangeable. You have impedance, sensitivity, physical size, recommended crossover frequency (replacement has to match the crossover), out-of-band issues, etc. I don't imagine that tweeter would cost much.


"Clipping" is distortion from an amplifier that, when viewed on an oscilliscope, looks like the top of the signal is being clipped off. When an amp is driven beyond what it can do, the output stage goes into clipping, which damages tweeters.


Short version.
 

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Discussion Starter · #3 ·
Thx for your prompt response & feedback...bump...I was hoping with this mishap to have an opportunity of getting better tweeters (Sony doesn't produce great quality - even the 2 woofers don't sound great)...


Ok, so worst case scenario: if I can't get replacements, what next? I found 8 ohms tweeters (most of them have a 3-20kHz range), but I'm not sure what power I should use?...I'm still confused over the 130W specs, and how much power the tweeters need be (so far, I've found matching tweeters for 25W, 30W, 45W, 60W, 75W & 100W)


Thx again for your time
 

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Quote:
Originally Posted by rockblock /forum/post/15518875


Thx for your prompt response & feedback...bump...I was hoping with this mishap to have an opportunity of getting better tweeters (Sony doesn't produce great quality - even the 2 woofers don't sound great)...


Ok, so worst case scenario: if I can't get replacements, what next? I found 8 ohms tweeters (most of them have a 3-20kHz range), but I'm not sure what power I should use?...I'm still confused over the 130W specs, and how much power the tweeters need be (so far, I've found matching tweeters for 25W, 30W, 45W, 60W, 75W & 100W)


Thx again for your time

The power rating on the back of the speaker is an overall rating for the entire speaker. Most of that power ends up in the woofers with only a small portion in the tweeter.


For an experienced DIY'er it's an easy matter to switch to a different tweeter. It does require some software most of which is available for free download these days and some understanding of how to use that software plus some related equipment.


The crossovers in low-end mass market systems are not typically designed correctly for the original tweeter anyway so sometimes an arbitrary replacement is no worse off than the original. Still, if you do get an off the shelf tweeter, getting the optimum results will require some effort that will likely require redesigning and replacing the crossover. With educated guesses your odds of getting comparable or better results than the original are still pretty good. Personally, with over 30 years of speaker building I've found it's actually difficult to build something that sounds as bad as most of this mass market stuff. You simply can't find low quality enough drivers to do it.


I would find something from Parts Express or Madisound that physically fits with an efficiency around 87 ~ 90 dB (give or take) that's rated 8 ohms and a recommended crossover of 2.5 KHz or lower. If what ever you get is too bright you can tone them down with resistors. If they are not bright enough then you need to choose something else with a higher efficiency rating. If you don't damage them both Parts Express and Madisound will let you exchange for something else.


This arbitrary approach isn't the best solution but it will most likely work out better than you think. Another option would be to search the DIY forums and web sites, Parts Express projects pages etc and find an existing DIY design with a similar cabinet volume and driver configuration. Then toss all the drivers and crossover and replace everything based on the DIY design.


Monte
 

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Discussion Starter · #6 ·
Ok, thx for all your great feedback...I guess my final question would be, 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 again !
 

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Quote:
Originally Posted by rockblock /forum/post/15520682


Ok, thx for all your great feedback...I guess my final question would be, 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 again !

I don't know of any good cone tweeters so I would stay with a dome.


Your estimate of the power distribution is probably not too far off. It all depends on where the crossover is set. The lower the suggested crossover for the tweeter the better. The power rating is based on this. If you choose a tweeter that can be crossed over as low as 1500 Hz for example and if that tweeter is rated 25 watts based on that crossover then it will be able to handle more with a higher frequency crossover.


We don't know what the crossover frequency is and we don't know what the slope is but most likely on a system like this, it isn't that low. If I were to venture to guess, I would estimate around 2500 Hz or higher and -12 dB/octave. Again, that's just a guess. I wouldn't worry too much about the tweeter's power rating, unless you get something just really cheap and with way too high a resonance frequency you shouldn't have any issues there. The resonance frequency should be lower than the crossover frequency. You can get a pretty cheap tweeter with a resonance frequency plenty low. Just don't get something that's intended to be crossed over at 3 or 4 KHz.


I don't know if this will physically fit, you will need to check the dimensions but at www.partsexpress.com search part number 275-070. This is a very popular DIY tweeter for low cost projects and is exceptional for the money. It would probably work well.


mk
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by Montekay /forum/post/15521218


I don't know of any good cone tweeters so I would stay with a dome.


Your estimate of the power distribution is probably not too far off. It all depends on where the crossover is set. The lower the suggested crossover for the tweeter the better. The power rating is based on this. If you choose a tweeter that can be crossed over as low as 1500 Hz for example and if that tweeter is rated 25 watts based on that crossover then it will be able to handle more with a higher frequency crossover.


We don't know what the crossover frequency is and we don't know what the slope is but most likely on a system like this, it isn't that low. If I were to venture to guess, I would estimate around 2500 Hz or higher and -12 dB/octave. Again, that's just a guess. I wouldn't worry too much about the tweeter's power rating, unless you get something just really cheap and with way too high a resonance frequency you shouldn't have any issues there. The resonance frequency should be lower than the crossover frequency. You can get a pretty cheap tweeter with a resonance frequency plenty low. Just don't get something that's intended to be crossed over at 3 or 4 KHz.


I don't know if this will physically fit, you will need to check the dimensions but at www.partsexpress.com search part number 275-070. This is a very popular DIY tweeter for low cost projects and is exceptional for the money. It would probably work well.


mk

Thx for your advise and direction...I was looking @ your recommended part but unfortunately the cutout diameter is too big (I need 2") ...but I got the picture and will do some research to see what I can come up with.


Thx again for your most valuable feedback.
 

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Discussion Starter · #10 ·

Quote:
Originally Posted by maxcooper /forum/post/15522983


For the money, these may be worse than randomly picking something, but...
http://www.partstore.com/Part/Sony/S...90011/New.aspx


I have never bought anything from that store, but I was googling for a good deal on the whole speaker to present that as a viable choice, and found the replacement tweeters instead.


-Max

Yes, thx Max, I stumbled over that link also...I was thinking, given the fact that Sony doesn't produce great speakers, this may be a good opportunity to upgrade in a cost-effective manner. The only problem is that I don't have all the specs (I guess crossover being most important) to make a sound decision for a replacement (I've seen great tweeters at Parts Express for $20 and I'm sure that the sound better than the Sonys)...I've asked Sony for specs info, but don't have too high hopes in a positive resolution. For now, I'll keep the link in my back-pocket as last resort. Thx for your help.
 

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Your fastest road to a trustworthy answer is probably to reverse-engineer the existing crossover. Figure out the circuit, read the markings on the components, and measure anything that doesn't have enough markings to identify the component values (like inductors, for instance, probably don't have markings to tell you their specs). Note that if you need to measure the inductors, you'll need to buy a meter similar to this one . Then post the info you have gathered and see what experienced folks like Montekay recommend.


However, if I were you, I would just order the original replacement tweeters. It will be cheaper and much easier.


Or not order them and move on to other speakers. Perhaps a DIY kit or some inexpensive-and-moddable Insignia NS-B2111 speakers if you have the DIY bug.


-Max
 

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Discussion Starter · #12 ·

Quote:
Originally Posted by maxcooper /forum/post/15525858


However, if I were you, I would just order the original replacement tweeters. It will be cheaper and much easier.

-Max

Unfortunately, based on the info I received so far, it appears to be the best solution...darn, I was hoping to make those speakers come alive with superior tweeters...if I ever get the specs back from Sony, I'll run them by you folks for any additional feedback


Thx again for your time, your help is greatly appreciated !
 

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Quote:
Originally Posted by loopguru /forum/post/15519014


If you can't find two more of the original tweeters, replace the speakers entirely would generally be the advice.

or he could get some dome tweeters from partsexpress seince sony uses similar drivers in thier speakers, no need to replace an entire speaker over one little bad, inexpensive, part, no wonder America can't go green we still have a throwaway mentality.
 

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Quote:
I would find something from Parts Express or Madisound that physically fits with an efficiency around 87 ~ 90 dB (give or take) that's rated 8 ohms and a recommended crossover of 2.5 KHz or lower. If what ever you get is too bright you can tone them down with resistors. If they are not bright enough then you need to choose something else with a higher efficiency rating. If you don't damage them both Parts Express and Madisound will let you exchange for something else.

Monte's advice is spot on imho.


Obtaining original replacement tweeters is of course the best solution but one must balance effort and cost vs. the end result. The fact is that these speakers even in brand new form are not very good performers and really don't warrant the level of details discussed here. A +/-2db change in tweeter response behavior to these speakers is not going to destroy their output quality relative to brand new performance.


I have only two slight modifications to Monte's suggestion:


1.) Check and make sure the high frequency crossovers are still intact. That is, hook another tweeter (of any type) up and make sure the crossovers are still functioning. Sometimes if the speakers have been abused to the point of frying the tweeters, the crossover can go along with it, or vice versa.


If the crossovers are bad as well, then imho it's no longer cost effective to service these speakers unless you are truly interested in a DIY project and would like to take advantage of the cabinets while using all new drivers and crossover networks. There would be some argument that the crossovers themselves could be repaired inexpensively, but my assumption is that if you are looking for advice about what tweeters to use then crossover repair/building is outside of your comfort range. I apologize if this is not the case.


2.) If the crossovers are ok, then my 2nd suggestion is that I would use an even cheaper tweeter, the cheapest one I could find that has about ~90db sensitivity, is 8ohms nominal, and can support a 2.5kHz crossover point. I say this because the Dayton tweeter's mentioned earlier will run about $50 shipped for a pair, and that's about the fair market value of the Sony's even if they were functioning at 100%.


I'd bet my left one that these two tweeters below would be a decent match and are likely still of higher quality than the originals.

http://www.parts-express.com/pe/show...number=270-058
http://www.parts-express.com/pe/show...number=270-182


PE is a great vendor.
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by Slare /forum/post/15535250


Monte's advice is spot on imho.


Obtaining original replacement tweeters is of course the best solution but one must balance effort and cost vs. the end result. The fact is that these speakers even in brand new form are not very good performers and really don't warrant the level of details discussed here. A +/-2db change in tweeter response behavior to these speakers is not going to destroy their output quality relative to brand new performance.


I have only two slight modifications to Monte's suggestion:


1.) Check and make sure the high frequency crossovers are still intact. That is, hook another tweeter (of any type) up and make sure the crossovers are still functioning. Sometimes if the speakers have been abused to the point of frying the tweeters, the crossover can go along with it, or vice versa.


If the crossovers are bad as well, then imho it's no longer cost effective to service these speakers unless you are truly interested in a DIY project and would like to take advantage of the cabinets while using all new drivers and crossover networks. There would be some argument that the crossovers themselves could be repaired inexpensively, but my assumption is that if you are looking for advice about what tweeters to use then crossover repair/building is outside of your comfort range. I apologize if this is not the case.


2.) If the crossovers are ok, then my 2nd suggestion is that I would use an even cheaper tweeter, the cheapest one I could find that has about ~90db sensitivity, is 8ohms nominal, and can support a 2.5kHz crossover point. I say this because the Dayton tweeter's mentioned earlier will run about $50 shipped for a pair, and that's about the fair market value of the Sony's even if they were functioning at 100%.


I'd bet my left one that these two tweeters below would be a decent match and are likely still of higher quality than the originals.

http://www.parts-express.com/pe/show...number=270-058
http://www.parts-express.com/pe/show...number=270-182


PE is a great vendor.

Great advise, thx...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
 

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Quote:
Originally Posted by rockblock /forum/post/15535642



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


The 91 dB is higher than I expected but it may not be real. Still, keep the tweeter choice as close to that as possible. The Frequency response of 30 - 20 KHz is definitely not real.


Slare has a good point. You should verify the crossovers are working. You can get a good idea by, as he said, connect just about any speaker to the tweeter wires and listen. You could probably take one of the 6.5" drivers and connect it to the tweeter wires and tell. Check both speakers tweeter output.


I'm use to seeing wholesale prices so I didn't realize the tweeters I suggested cost nearly $50 pair shipped for regular PE customers. Slare's suggestions are more in the proper price range for this project.


I would say try to verify the working condition of the crossovers and if ok then go with one of Slare's tweeter suggestions. Don't scratch them up or damage them in any way and PE will take them back if it doesn't work out. If the crossovers are ok the odds are good that it will work out fine.


Monte
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by Montekay /forum/post/15537700


The 91 dB is higher than I expected but it may not be real. Still, keep the tweeter choice as close to that as possible. The Frequency response of 30 - 20 KHz is definitely not real.

Will do...just out of curiosity, which don't you believe to be true, the 30Hz or 20KHz?...also, is it typical for vendors to "exaggerate" with their numbers, or is it merely a matter of how the parameters are being measured?


Thx
 

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Quote:
Originally Posted by rockblock /forum/post/15538347


Will do...just out of curiosity, which don't you believe to be true, the 30Hz or 20KHz?...also, is it typical for vendors to "exaggerate" with their numbers, or is it merely a matter of how the parameters are being measured?


Thx

The normal accepted standard is to base frequency response on the - 3dB points. That system is highly unlikely to be capable of 30 Hz based on that test criteria. More likely these are - 3dB in the mid 40's or higher. Since they didn't specify how far down the response would be, they can claim just about anything they want. They just omit the fact that it's -10 dB or worse at the frequency they specify.


Monte
 

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Discussion Starter · #19 ·
OK, it's confirmed, tweeters are busted and crossovers are good...off to "PartsExpress" for a replacement.


So just to recap, I'd be looking for the cheapest driver that meets the following requirements:


freq response: 2k-20kHz

sensitivity: 90-92 dB (the higher the better)

power: 30-60W RMS (the higher the better)


P.S. I've also some provide additional parameters, such as Fs (resonance frequency?) =1,000 Hz...how important is this, given the fact that not all tweeters provide this info? (some have 1,300 Hz, others 1,000 while others 750 Hz)
 

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Quote:
Originally Posted by rockblock /forum/post/15549041


OK, it's confirmed, tweeters are busted and crossovers are good...off to "PartsExpress" for a replacement.


So just to recap, I'd be looking for the cheapest driver that meets the following requirements:


freq response: 2k-20kHz

sensitivity: 90-92 dB (the higher the better)

power: 30-60W RMS (the higher the better)


P.S. I've also some provide additional parameters, such as Fs (resonance frequency?) =1,000 Hz...how important is this, given the fact that not all tweeters provide this info? (some have 1,300 Hz, others 1,000 while others 750 Hz)


Fs is the natural resonance frequency of the tweeter. Usually the lower the better but the main thing is that it be lower than the intended frequency range. If for example you buy a tweeter with an Fs of 2 K Hz and try to use down to 1.5 K Hz you will definitely have problems. Since our assumption is that your crossover is probably 2.5 K Hz or higher then anything with an Fs lower than this should be ok. Since we are only assuming you will be crossed over at 2.5 K Hz then you should give your self some room. I would think any of the ones you mention including the 1,300 Hz one should be ok.


mk
 
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