Starting a new thread now that I have the AKG "subwoofer"

Pictures attached with measurements.

This is far from what I would call a subwoofer.

It's a tiny 6x9 woofer. The cone feels like it's a paper cone. The entire depth of the speaker is about 3 inches and the magnet feels very light. I'm guessing the excursion is maybe 1 cm at best.

Voice coil reads 3 ohm impedance and it's a single voice coil. Not going to be easy to find an exact direction replacement. Maybe the factory amp will be able to handle a 2 ohm load?

I don't have a audiometer to test the response curve but looking at the speaker, I have a hard time believing this would extend much below 60-80 Hz.

There's also not much room in the existing space to mount much more than an 8 inch round woofer which may not be that much different than a quality 6x9. Maybe if I get really ambitious, I'll cut the right rear interior panel to make room for a larger 10-12 inch subwoofer and fiber glass it in. It would definitely stick out into the cargo area a few inches. I don't have the time or motivation to do it anytime soon. I may just buy higher quality 6x9 with a stronger magnet and better excursion to see if it is adequate.

The Bose systems in the CTS at least had two of these in the rear deck...but I still had to supplement these with dual 10's in my CTS-V. If anyone has easier ideas to intrusively add the low end back into the Lyriq, chime in!

Thank you for doing all this legwork! Assuming you find a suitable replacement, does it seem easy enough to extract the existing speaker from that housing? Looks like it’s wrapped up in there pretty good.

 

The enclosure is the speaker mount and basket so there's going to have to be some cutting. The driver can be fully exposed by removing 4 T-20 screws but the surrounds sandwiched and glued to both sides of the enclosure. Because of this, the standard 6x9 speaker assembly probably isn't going to fit since the mounting points will be outside of the opening of the driver. Just in case I'm wrong, anyone have a spare 6x9 I could use for a fit test? Any 6x9 will do since this is just for sizing

 

it's a 6x9! Whomp! Whomp! Whomp!
How very disappointing. This and an amp would probably be a better idea.

 

it's a 6x9! Whomp! Whomp! Whomp!
How very disappointing. This and an amp would probably be a better idea.

View attachment 653655

Lol I'm looking for unobtrusive.

I might see if I can utilize half the underfloor rear storage area for a compact fiberglass sealed enclosure and amp.

The one part I'm not sure about is how the Lyriq charges the 12v battery when driving. Is it like an ICE that charges it continuously or does it completely switch over to the high voltage battery when the car is on? If the latter, I wouldn't be able to just directly power the amp from the 12v battery like I would on an ICE vehicle. Anyone know?

 

Looks like 3 ohms is the DC resistance (DCR), which is usually lower than the rated impedance (an AC measurement), so it might be 4 ohms impedance. Even just a little more power at the low end would be nice.

There are free or low cost apps with audio spectrum analyzers. I use The KRK audio tools app on iPhone for a low end spectrum display.

 

Starting a new thread now that I have the AKG "subwoofer"

Pictures attached with measurements.

This is far from what I would call a subwoofer.

It's a tiny 6x9 woofer. The cone feels like it's a paper cone. The entire depth of the speaker is about 3 inches and the magnet feels very light. I'm guessing the excursion is maybe 1 cm at best.

I'm trying to figure out your point regarding the AKG subwoofer, did it not come installed in your vehicle, and you're adding it? Are you concerned about its performance? I have the AKG OEM factory system and I think its performance is awesome, with a very deep and rich base to the point my base level is turned down to -4, and it still sounds great on the low end; I don’t believe anyone can max out the volume on a sustained basis without suffering some form of hearing loss. My ears tell me the frequency does drop below 80hz.

 

I have the AKG system. The low end sucks. Therefore, I want to find a way to add it in without making the interior look horrible or cause electrical Gremlins.

 

Do you have a Lyriq? If so what stereo did you opt for (8 or 19)? This stereo is not lacking in bass and does not distort, shakes all mirrors (incl. rear view), and can't be listened to for any extended period without causing some type of hearing malady. You have measurements on the "sub", what about the amp? Are you adding a separate unit or just dropping something in place? You are going to have to forfeit the noise cancelling depending on if dropping something in or adding aftermarket amps. The first time the aftermarket amp does not turn off and causes a battery draw will it be worth the change?

1. stock 19 AKG loud with low distortion
2. no lights flickering inside or out
3. no overheating causing thermal shutdown
4. all speakers hidden or properly housed with no impediments (external sub box).
5. this is an ev, the simple rule of thumb is not to mess with the already sensitive 12 volt battery that is known to go off the rails in literally all ev brands (if adding a separate sub woofer).

I am still curious on how this will play out. I like innovation and different ideas.

 

I have the Sport 3 trim with the AKG 19 speaker system. The system has decent mid bass but really sputters out once you start expecting true bass frequency. This is what I would expect from a system with good woofers and lacking a subwoofer. I only took measurements of the woofer, not the amp...which was my intention and how I titled the thread.

In my mind, best case case scenario, I could do a direct woofer replacement that would match the stock impedance so the stock amp could drive it. Worst case, no space and the amp can't drive a larger woofer, and I would have need to wire a new amp and fabricate an enclosure for a sub. "meh" case, I would need to fabricate a new subwoofer enclosure but could still use the stock amp, avoiding any increase electrical loads.

I'm a big fan of your 4th point which is why, best case, I could use the stock mounts and space. If I need to fabricate an enclosure, I'd probably look first to use the space in the underfloor storage area. This is what I did with my CTS-V (the unused spare tire section under the floor in the trunk).

Lets not confuse shaking panels with a good sound system. A good sound system you can hear and feel in your chest but should have minimal body panel shaking or rattles. Also, I added an amp and subs in my CTS-V and noise cancelling still works flawlessly. It's not necessarily true that you have to get rid of noise cancelling to add an additional amp.

 

I have a 2024 Lux 2. I agree the AKG 19 system is just bla. it is ok at best, but really lacks the proper tuning. Yes if you turn the volume up, you can get decent bass, it would be nice if there was a bass boost to get better response at lower volume.

 

it would be nice if there was a bass boost to get better response at lower volume.

Are you talking about something more than the EQ settings in the Sound screen?

 

Thanks @seasonnet for pointing that out, and to @Jimpilot for the like. There are however more than a few factors that are relevant here. The amount of air that a speaker can move is given by the formula:
[ V_d = S_d \times X_{max} ]
where:

• ( V_d ) is the volume displacement (in cubic centimeters, cc)
• ( S_d ) is the effective cone area (in square centimeters, cm²)
• ( X_{max} ) is the maximum linear excursion (in millimeters, mm)

For example, if a subwoofer has a cone area of 480 cm² and an excursion of 18 mm, the volume displacement would be:
[ V_d = 480 , \text{cm}^2 \times 18 , \text{mm} = 8640 , \text{cc} ]

So a replacement speaker with a significantly greater excursion, can make a difference. The speaker enclosure can also make a difference. My comment regarding trying two opposing speakers in a sealed enclosure needs to be looked at not just from an air movement standpoint, but as a 6th order Butterworh function. See DIY Audio.com article or this in audiojudgement.com if you don't want to go to the original research by Thiele in the Journal of the AES.

Also, you need to consider factors of placement within the vehicle and the fact that the LYRIQ itself is a box of about 105 cubic feet (2975 liters) with a maximum interior dimension under 5 meters, so when considering sound inside the vehicle and frequency wavelength, you are in a near field for pretty much anything under 40 hz or so, which will have a profound effect increasing perceived gain on the lowest frequencies.

Of course, in the system there are also electrical and physical properties to consider including the amount of power delivered cleanly to the woofer, which I just don't know if using the stock leads, the impedence and Qms of the woofer (and Qts for the enclosure).

The point of all of this geeking out is that there are many factors to consider, and it's difficult to change one without affecting others. A significantly better sub driver, even of the same size could have close to double the excursion. Modification of the space around the woofer can lead to additional gains, but short of placing the woofer elsewhere or cutting into a second cavity, you're either looking at something not hidden or a rather extreme modification.

The final factor (I'm a wiseass) is a variable function involving the amount of T$ you wish to expend, where T is time and $ is money. I'm willing to toss under $2K into this particular problem because I want a minimalist solution. If a proper driver can be found, I'm guessing that it will be roughly a grand, Mods to mount it and labor another grand.

 

There are however more than a few factors that are relevant here...

That is awesome to have such a deep understanding base going in... I was massively simplifying, since not many people are as knowledgeable as you. (I am a EE who studied Audio Engineering and built very high-end car audio systems years ago.)

I assumed that the current driver in the car is long throw, given its application, and that any replacement would likely be similar. That is why I simplified down to just cone size. Assuming that you can replace the driver with something capable of more output, the next biggest problem is probably power. And the only way to beat that is either speaker efficiency or external amp. One of the best ways to improve efficiency is through a tuned port enclosure, which means volume. Sealed port enclosures are more accurate but far less efficient.

That's why I am skeptical of a driver replacement in that constrained space. You can only marginally increase driver and enclosure size, but you will need amplification to put it all together. If my guess is correct that the AKG system is only allocating 100 W or less to the bass driver, then a new driver won't make much difference. Go big or go home!

As a point of reference, the AKG Stuido system in the Escalade has a 10.5" subwoofer in a proper enclosure. I have not found amp specs on that system, but my guess is that they have at least 300 W for the sub.

 

@Pennstac, there might be another factor to consider in automatic noise cancellation if you have a Lux/Sport 2 or 3, otherwise not a factor. Not saying a subwoofer upgrade cannot work with ANC, just another variable to factor in.

 

Yes @Luxiondrive, that’s one of the reasons that I want to try an improved direct replacement first. I don’t want to lose any existing ANC, and I do have a Luxury 3. Another reason that mods are such a friggin’ nightmare.

@seasonnet - I learned and learned where to look years ago when I had a friend who was a grad student in Acoustic Engineering at Penn State. He also sang barbershop, played theater organ and was close friends with design engineers from Dynaco and Electrovoice. I also was in publishing services and had publications folks from SEMPTE, and the Society for Acoustic Engineering as clients.

I wish that there would be an Android Automotive global PEQ (Parametric EQ) program available. That way you can at least tune to get the most out of what we have.

You’re correct that power would probably need to be addressed on a high end solution. The AKG subwoofer is only OK, and from the cost differential of the premium sound system, you know it can’t be near TOTL. Sooner or later, one of the big boys may introduce an improved replacement. You can see that there is room for improvement both in throw and in the magnet design. Other than that, you need room for a proper enclosure (the current location isn’t).

 

I don’t want to lose any existing ANC, and I do have a Luxury 3. Another reason that mods are such a friggin’ nightmare.

I think I read in one of the threads that ANC is only in the headrest speakers. So in theory, you could do about anything to the rest of the speakers without affecting ANC.

 

Maybe @Pennstac can shed some light on how the ANC reacts to enhanced low frequencies from an improved sub. I have a JL amplified sub in it's own box that I could try someday, however as far as I can tell from diagnostics so far, my ANC seems to be always off. With all of the reported problems, not in any hurry to try to get ANC back online. My cabin seems reasonably quiet, so I suppose my ANC might come on when moving, not sure TBD.

 

I'm no expert on ANC. Have been trying to locate an aftermarket installer that really understands this stuff, but I'm limited in my location. Not a large urban area. I don't see the point of ANC (Vehicle ANC, not something like earbuds) when not moving, so I would imagine it's tied to velocity. In fact, I doubt you would want ANC when going slowly - like you should do in say, a parking garage.

Just speculating, but I think the idea of a sub in its own box might cause a bit of wonkiness in ANC, but one can't be certain. An alternative I'm considering would be a sub in its own box - or two subs, perhaps under seats. I don't expect there to have been a lot of real theory on the effect of the curved closed volume of an SUV on perception of bass in the vehicle. In a rectangular room, there is a lot of research done on how bass propagates, and on standing waves. I hear this in my office, where moving 8 inches in one direction or another can affect what I hear - I have one sub. Two subs improves more (I assume it would also in a vehicle), and more does even better (look up DEBRA and SWARM subwoofer systems, which use multiples and arrays).

Still, you all should know that despite having a good background, I'm asking more questions than answering, and the specifics of what I'd like to accomplish - including budget under $2500, proper integration, and minimal intrusion into the cabin may not be easily done. Or may not be exactly what you're looking for.

 

I guess for most of us the key take-away is we need to wait for some self-sacrificing forum member to try a solution and report awesome results 😀.

 

Somebody did: Finally replaced stock subwoofer

 

I think three or four projects have been posted now, including with new amplifiers. More projects, and more analysis would still be good, particularly for those upgrading the sub with ANC (I think there has been at least one with ANC where phase was discussed).

 

I guess I've been hoping for a return to the good old days where you could unscrew a 6x9 and replace it with a better one. I'm amazed at the selfless nature of those who have posted incredibly detailed procedures, which unfortunately are far beyond my limited capabilities.

 

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unfortunately are far beyond my limited capabilities.

Not so! You're a Cadillac owner. Just throw money at it.

 

JMO, but this AKG sound system is just nasty/cheap sounding. There's no deep base at all, and even the mid base sounds muddy. It's really unbefitting any Cadillac. They should be ashamed of the "effort". Thankfully, I normally drive with a car's system either off or on Mute, so it won't affect me...but my wife will be subjected to it, and that just sucks.

 

This is legit and one of the things I am watching for in the next gen Lyriq... My guess is that the AKG Studio system is around 400W total power. That is in line with the base systems in competitive luxury brands. Their premium systems are 600W - 800W total power and have multiple bass drivers, not just a simple, low power 6x9 speaker. The Lyriq's version of AKG Studio is a level below the same named version in the Escalade. I am hoping that the next version for the Lyriq has a variation of the Studio Reference system in the Escalade. That is a lot more like the premium systems in other cars.

 

OK so far a good discussion, let’s not let it degrade into personal attacks.

 

Hello @seasonnet - I showed in some detail the point you're making in post #24 https://www.cadillacforums.com/posts/18312389/
This probably got covered up as there are some a number of replies, and this forum tends to make you click to see them all. I can tell you that the replacement subwoofer that @Mbai2 and I used does have a longer throw and does make an audible difference.

The classic physics of speakers in a room are modified by the fact that you are inside a closed volume - the car - and that at no point in that volume do you have any distances that are more than a small (under 1/2) fraction of the wavelength of the lower bass frequencies. While a tuned enclosure will make a difference, if that tuning is done by a port, the port itself needs to be a reasonable distance from other surfaces to work properly. In a room, that would be roughly half a foot to over one foot depending on the frequency and amount of air being moved. Lord knows what the physics would say about a dipole source (open speaker) in an irregular cavity loosely covered but not sealed by the plastic panel and then with carpet on top.

Given the above, the AKG speaker, to my somewhat trained ears produced sound that drops off significantly by 60 hz, Below is a chart that may be helpful as to what to listen for:

In the actual case of the replacement 6x9 in the LYRIQ, it does make a difference when listening to EDM, music with kick drums, classicle organ, and other actual lows.

 

Just to state again, since everyone is missing it. The AKG isn't missing the low bass. The 6x9 is in a horrible location........... The bass is there, even when just hooking the stock amp up to my 10" Alpine that's in the storage cubby.

 

Now...if only we could drive the car from the cargo area...with your 10" Alpine connected.

Seriously, though...the reason "everyone is missing it" is that it cannot be heard from the driver's seat. It doesn't matter if the signals are present in the wires coming out of the amp. If they're not making it to the ears (guts?) of the passengers, then "the system" is a failure.