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Replacement Tweeters worth it? JBL 2800

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Seanduffy32

New Member
I picked up some JBL 2800s at a local Goodwill for the 'why-not' price of $12. I got them home, hooked them up, and both tweeters are blown. I know these speakers aren't worth much or very highly regarded, but I would like to have them fully operational. The plan is for them to replace my KLH 911Bs that I've been using for my modest turntable only set-up for years (Dual 1229 and Sansui 5000a if that matters). Currently I have both sets of speakers hooked up and I definitely notice a more full sound with much more detail in the lows. This makes sense, but I'm wondering if it would improve the sound if I installed some new tweeters in the JBLs and just used those. I've never done any kind of speaker work so I'd like to get some that are plug and play. I'm fine with making the mounting hole larger (it's right around 2" now) and changing out the wire connectors, but I don't want to have to change anything on the crossovers. I mainly listen to 60s-70s folk and a little classic rock with the occasional modern folk/americana record thrown in and I don't ever push it past 1/2 volume in my small space.

Specs of JBLs and two possible replacement tweeters below:

JBL 2800:
Crossover - 2.5 kHz
Impedance - 8 Ohms
Frequency Response - 40 Hz to 23 kHz
Sensitivity - 89 dB

Option # 1: Visaton SC5-8 1/2" Tweeter
Impedance - 8 Ohms
Frequency Response - 1.5 kHz to 22 kHz
Resonant Frequency - 2 kHz
Sensitivity - 90 dB
Power Handling - 60 Watts
Cutout Diameter - 1.89"

Option #2: Polk Audio SL5500 Tweeter
Impedance - 8 Ohms
Frequency Response - 2.5 kHz to 25 kHz
Resonant Frequency - unable to find
Sensitivity - 90 dB
Power Handling - 45 Watts
Cutout Diameter - 3"
 
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Actually, those 2800's and their cousin the 2600 are pretty good speakers. They aren't TOTL by any stretch, but they are better than most of the crap at Goodwill.

Are you sure the tweeters are blown? If you have a multimeter I would remove the tweeters and check for continuity, setting the meter on the lowest ohm setting (mine is 200). If they are 8 ohm tweeters you should get a reading of about 6 or 7 ohms.
 
I don't have a multimeter. Although, I may as well get one since I've needed one a couple other times. I do know I can't hear anything from either Tweeter and when I hook up the KLHs in addition to the JBLs I can hear the highs again. I'll see if my local ACE has any multimeters and get one if they do. I'll post the findings once I check them.
 
Seanduffy32 said:
I'll see if my local ACE has any multimeters and get one if they do. I'll post the findings once I check them.
Click to expand...

Great! It's a handy tool to have around.

It may be that the tweeters are fine but there's another problem somewhere. Checking a seemingly blown driver with a multimeter has helped me multiple times.
 
Walmart has multi meters. Under $10.
Good enough for this project. And many others.
 
I like Polk tweeters, (having owned different polks) I can say I have never read anyone complain about them.

This is the reason I bought a new set to replace the Planer tweeters in my Sansui

Is there something better, probably. Do they do anything bad, no.


IMG_2439.JPG

IMG_2440.JPG
 
You can also check the tweeters by setting your amp at low volume and temporarily connecting the speaker wire to the terminals on the backs of the tweeters. Make sure it's loud enough that you'd hear something through the speakers so you know you're doing a valid test. Once you hear something, disconnect right away. Tweeters aren't designed to handle much power, especially at lower frequencies.
 
So I got a multimeter and tested the tweeters. As I suspected, no signal.

Now the question is, which of the two tweeters are a better replacement? I like the idea of not having to modify anything in the existing cabinet, but I am leaning towards the Polk tweeters because they have a higher frequency response. Would the SL5500 tweeters pair well with these speakers? My only concern is the crossover frequency is the lowest frequency these tweeters can reach. Should I get tweeters that can "go lower" than the the crossover of 2.5 kHz, or will the SL5500s work just as well, or better than, the Visatons?

Thanks for all the help so far!
 
Did you disconnect at least one terminal when you tested them?
Seems like otherwise you'd be reading the whole tweeter circuit, caps and all.
As swschler mentioned, you can hook them up directly to an amp or receiver, using caution with volume. And don't let the wires short out.
Do the JBLs have fuses or circuit breakers? Have you checked them?

I just like to try all the cheap and easy things before I spend money, but that's just me.
 
goodolpg said:
Did you disconnect at least one terminal when you tested them?
Seems like otherwise you'd be reading the whole tweeter circuit, caps and all.
As swschler mentioned, you can hook them up directly to an amp or receiver, using caution with volume. And don't let the wires short out.
Do the JBLs have fuses or circuit breakers? Have you checked them?

I just like to try all the cheap and easy things before I spend money, but that's just me.
Click to expand...

I disconnected both terminals, tested the tweeter by itself, and didn't get a signal with the multimeter. For good measure, I removed one of the KLH tweeters and hooked it up to one of the JBL speakers and I could hear music through the tweeters. So, the tweeter circuit itself is getting power and works fine, it's just the original (JBL) tweeter itself that doesn't work in each speaker.
 
If that's the same JBL that I think it is- I have managed to take the faceplate off of a Goldwood GT302 mylar tweeter- and install it on the faceplate from the original JBL tweeter. It sounded pretty much identical to the original one.

Regards,
Gordon.
 
swechsler said:
I personally am not a fan of polycarbonate tweeters; they sound OK but there are better options when you're buying replacements. How about this soft dome?
Click to expand...

I looked at that one. My only concern with that soft dome would be that it's frequency response starts at 3,000 Hz and the crossover is 2,500 Hz. Would this impact performance? I can't/don't want to have to alter anything. Just looking for something plug and play.
 
GordonW said:
If that's the same JBL that I think it is- I have managed to take the faceplate off of a Goldwood GT302 mylar tweeter- and install it on the faceplate from the original JBL tweeter. It sounded pretty much identical to the original one.

Regards,
Gordon.
Click to expand...
If you're correct, then this is easily the cheapest replacement option! Again, my only concern is the crossover frequency. The GT302 has a frequency response begining at 4,000 Hz where as the crossover for this speaker is at 2,500 Hz. Would this impact performance?
 
What I look at, is the construction of the tweeter.

The Goldwood has the same voice coil diameter, same overall diaphragm diameter, same magnet size (within a small margin), and same materials of construction, as the original JBL tweeter.

I suspect that JBL has tweaked the crossover in there- whereas it may be a nominal 2500Hz crossover point- I'd bet that the tweeter not getting significant power below 4KHz...

I have done this swap in a couple JBL speakers, over the last few years- and so far, no one has had a repeat problem...

Regards,
Gordon.
 
GordonW said:
What I look at, is the construction of the tweeter.

The Goldwood has the same voice coil diameter, same overall diaphragm diameter, same magnet size (within a small margin), and same materials of construction, as the original JBL tweeter.

I suspect that JBL has tweaked the crossover in there- whereas it may be a nominal 2500Hz crossover point- I'd bet that the tweeter not getting significant power below 4KHz...

I have done this swap in a couple JBL speakers, over the last few years- and so far, no one has had a repeat problem...

Regards,
Gordon.
Click to expand...

Well, I like the sound of that, and you brought up some great points. If you've done it before and not noticed a difference I don't see why I shouldn't give a shot. Thanks for the input!
 
Hey all, after some more thought and research I called parts express to go over a few options. They suggested that I get tweeters with a resonant frequency that was half of the crossover or less. In this case that means a resonant frequency of 1,250 Hz or less. I found 3 tweeters that met this qualification in my preferred price range. After discussing those 3 options with the staff at Parts Express, I decided to go with the cheapest option to keep cost down as much as possible, the GRS 1TD1-8. Link: https://www.parts-express.com/GRS-1TD1-8-1-Dome-Tweeter-8-Ohm-292-462

Thank you for all of your help! I'll report back once I have them hooked up.
 
I got the tweeters yesterday and just finished installing them! I had to widen the cutouts, but other than that they were plug and play. At first listen they sound fantastic! Overall, very happy with this decision.
 

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