Tony Sestito
Tony Sestito UltimaDork
3/11/24 1:00 p.m.

I'm 3.5 years into my 2020 Kia Forte GT ownership adventure, and I'm suspecting that one of my stereo speakers is blown. The driver's side front door speaker has been getting wonky lately, and now I have to basically cut all the bass otherwise it sounds like the cone is going to leave the speaker enclosure. I am not quite sure that it's blown, and it very well could be a door panel rattle, but I started shopping around to see if there are any upgrades I can do. 

The car has the optional Harman/Kardon stereo, and from what I understand, that means 2-ohm speakers. I am almost certain these are set up like component speakers, with a midrange woofer and a separate tweeter. I'm a car audio veteran from way back, and I remember that with other systems, you basically had three options when coming across 2-ohm stuff:

-Replace with stock parts
-Gut the whole car, rewire everything, and get a new head unit
-Get a flaky step-down adapter and but 4-ohm stuff

I had to do Option 2 once with an old Nissan Maxima equipped with the Bose stereo, but with today's modern OEM head units, this is not an option anymore. 

I was hoping that someone made a drop-in replacement 2-ohm 6.5" speaker so I could upgrade, rather than kick the can down the road and deal with the same thing inevitably again with a factory replacement, but I'm not finding much out there. Any ideas? 

Again, I could be barking up the wrong tree, but I'm looking for some options. 

bmw88rider
bmw88rider GRM+ Memberand UberDork
3/11/24 1:05 p.m.

Infinity Kappa 62IX series are 2.7 Ohm. That would be a good choice for you in the 6.5" size.

JBL GTO 629 are 3 Ohm and the stadium 620 version are 2.5 Ohm.

There is a really good conversation on 2 ohm speakers here for something to think about. 

https://www.diymobileaudio.com/threads/2-ohm-6-5-speakers.76878/

thewheelman
thewheelman Reader
3/11/24 1:13 p.m.

Crutchfield is also a good resource. They have quite a few 2-ohm options. While their prices are higher than most, but their customer service is top notch. 

You can also always search the part numbers you find on Crutchfield on Amazon or Sonic Electronix for lower prices. 

Peabody
Peabody MegaDork
3/11/24 1:51 p.m.

It may not matter. The impedance rating is nominal and could be anywhere from somewhere under 2 to over 2. Many of the the 4 ohm speakers will be in the range of 3 and the only negative to using that in it's place is the possibility of slightly reduced output, but without knowing the sensitivity of both drivers you won't know. The crossover will be active so it's unaffected by impedance, and a higher resistive load will actually be easier on the amplifier.
The long and short of it is, it probably doesn't matter. 

QuasiMofo (John Brown)
QuasiMofo (John Brown) GRM+ Memberand MegaDork
3/11/24 2:34 p.m.

If I may add one suggestion, buy these: 

CT Sounds Meso

and a pair of these:

CT Sounds Meso Tweeter

And wire them together to make a 2ohm load making certain to add the resistor in line before the tweeter. 

Your amp sees 4 ohm, you get a very dynamic sounding set of speakers and you spend about $150.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
3/11/24 5:37 p.m.

I'm in a similar boat with the JBL system in my Mark VIII.

Just be aware that Harmon Kardon really kinda has you in a pinch.  The whole thing was designed to work together, and just replacing the drivers might sound fine or might sound awful.  They have done a million dollars in tweaks and R&D so that they could make a decent sound with cheap paper cones, small magnets, and the cheapest amplification.

It's that reason that has prevented me from replacing the trashed drivers in my Mark.  I will someday, but I'll have to be careful to gently install them so they remain returnable in case they suck.

You can always go higher impedance, but lower is tricky.  The 2-ohm nominal is an average across the frequency range.  There is usually a strong peak in the resistance near the free-range resonance, so your 2-ohm drivers might test 1.7 on a bench.  The downside to higher resistance speakers is that they draw less current from the amp, which means the amps won't be generating the same wattage as before.... TL;DR, quieter sound.

Tony Sestito
Tony Sestito UltimaDork
3/11/24 7:01 p.m.

Great info so far, as always! 

I wouldn't want to replace drivers with 4-ohm ones; as some have said, that will reduce volume and fidelity. If I am going in there, I am going to do an upgrade rather than a downgrade, whether they are components or just drivers.

Last time I did a full swap in my old Maxima, I had to modify the stock speaker enclosures to make it all work, so I know what I am getting into. The result was the best sounding system I've had in any car, but that's also because I was able to swap out the head unit for one of the best Alpines available back then. That's not an option these days with cars like mine. 

The thing is, I am really not sure if the speaker is actually blown! I had a hunch it may have something to do with streaming fidelity, and I may be onto something. I had been noticing this most with streaming from Spotify, and decided to try and play some higher quality MP3s directly from my phone. The result was a cleaner signal and no blown warbling sounds. I can crank the volume and add more bass to the mix as well. Now, I am hearing other parts of the interior rattle when I do that, but that is another issue. 

Hmm....

flat4_5spd
flat4_5spd Reader
3/11/24 7:22 p.m.

To expand a little on what Curtis is saying, putting the impedence issue aside, the head unit or amps may have large amounts of fixed EQ built in to compensate for the non-ideal frequency response of the OEM speaker drivers. (I once installed aftermarket speakers in an Acura with a Bose system and they were IIRC insanely  bright, waay too much treble...it was just about passable with drastic adjustments to the user tone controls, but definitely not the highest of fi. I would try to figure out the failure mode of the existing driver. Pull it out and take a look. for a 2020, it seems unlikely that the foam surround on the speaker has already perished (if it is indeed a foam surround)  unless you live in an area with a ton of sun and or ozone. Water leaks warping the cone or some debris in there rattling around seem possible. You could have just cooked the voice coil by rocking it too hard. 

spandak
spandak Dork
3/11/24 7:32 p.m.

I've noticed weird issues with Spotify as well. Try downloading the playlist if you haven't done that already. 

triumph7
triumph7 Dork
3/11/24 8:06 p.m.

Tony, it seems like almost all of the car systems now use a separate amplifier.  Crutchfield may be able to set you up with something plug and play as far as a 4 ohm amp and speakers.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
3/11/24 8:42 p.m.

Crutchfield is amazing.  I try to search for cheaper prices on Parts-Express or Woofersetc, and Crutchfield is always within a couple bucks.  Their reps are not on commission, and they will literally sit and talk with you an hour about options.

The only time I have ever bought from another place is if I'm looking for a brand they don't carry.  They will likely answer all of your questions in one phone call, then they'll email you a quote with everything you talked about.

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
3/11/24 8:49 p.m.
Tony Sestito said:

The thing is, I am really not sure if the speaker is actually blown!

Same here with my JBL... although mine is a 1997 and I doubt the old man I bought it from listened to anything but NPR, so I strongly suspect speakers.  Just need to pull the door apart to check.

You can check them with a multimeter.  If they are supposed to be 2 ohm, you're looking for 1-2 ohms.  If they are above 2 ohms, they're likely toast or on the way to being toast.  If there is less than 1 ohm, toast.  If there is no continuity at all, some wire broke inside and it's toast, but it also wouldn't make any noise when played.  Basically, anywhere between 1 and 2 ohms should be kosher.  Test the other speakers for a comparison.

Tony Sestito
Tony Sestito UltimaDork
3/11/24 9:07 p.m.

Crutchfield is awesome. I have spent a lot of money with them in the past, so I know what they are all about. 

If I do end up pulling them out, I'll be sure to test them as well. 

Definitely investigating the audio format issues though. Will definitely try downloading the offending album in question (it's the new Judas Priest album Invincible Shield, BTW) and see if that changes things. 

Peabody
Peabody MegaDork
3/11/24 9:07 p.m.
Curtis73 (Forum Supporter) said:

 free-range resonance

Haha. They're not chickens. 
 

Free air resonance 

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