Can someone explain this odd subwoofer design?

[StrWhtMME]

FYI: Check out who is Harman Kardon, maker of that Sub


Harman International Industries, Incorporated, commonly known as Harman (stylized as HARMAN), is an American audio electronics company.[3] Since 2017, the company has been an independent subsidiary of Samsung Electronics.[4][5]

Headquartered in Stamford, Connecticut, Harman maintains major operations in the Americas, Europe and Asia. Harman markets its products under various brands, including AKG, AMX, Arcam,[6] Bang & Olufsen Automotive, Becker, BSS Audio, Crown, dbx, DigiTech, Harman Kardon, Infinity, JBL, Lexicon, Mark Levinson, Martin, Revel, Soundcraft and Studer.

On November 14, 2016, Harman entered into an agreement to be acquired by Samsung.[7] The sale was completed on March 10, 2017.[8] Harman now functions as an independent subsidiary.[9][10]

Sponsored

 

[kdryden99]

FYI: Check out who is Harman Kardon, maker of that Sub


Harman International Industries, Incorporated, commonly known as Harman (stylized as HARMAN), is an American audio electronics company.[3] Since 2017, the company has been an independent subsidiary of Samsung Electronics.[4][5]

Headquartered in Stamford, Connecticut, Harman maintains major operations in the Americas, Europe and Asia. Harman markets its products under various brands, including AKG, AMX, Arcam,[6] Bang & Olufsen Automotive, Becker, BSS Audio, Crown, dbx, DigiTech, Harman Kardon, Infinity, JBL, Lexicon, Mark Levinson, Martin, Revel, Soundcraft and Studer.

On November 14, 2016, Harman entered into an agreement to be acquired by Samsung.[7] The sale was completed on March 10, 2017.[8] Harman now functions as an independent subsidiary.[9][10]

We are aware it was already discussed

 

[markboris]

Mark, Could you also post some pics for the 12V battery connection, and routing to the back and the OEM sub wires for the audio signal? Thanks!

Joe, I only took some photos under the front trunk. Running the wire from inside under the dash, down the left driver side kick panel, along the front and rear kick plates then into the rear cargo area is was very simple. Lots of room under the kick panels to run the wire. I used 8 gauge wire which is sufficient for the amp I am using and not too thick to run to the rear. I did not take photos of the sub connection but I just spliced into the wires that were going to the sub and using those for the audio input signal. This is what I have done for the last two B&O sub replacement/upgrades. The ground wire I grabbed from the ground wire bolt on the right side close to the OEM sub that the B&O amp is using.

I woke up this morning not even thinking of the sub in my car and ended up running the wires and gettin it ready for the JL sub I ordered. I would have eventually done this anyway as my F150 and GT500 both have JL subs and going from them to the Mach-E is a disappointment in quality deep bass. I said this before, I am not interested in very loud "Rap" type bass. I just want good quality low end bass and that is what I will have on Friday. I am satisfied with the sound in the car after I set the EQ the way I like it and won't be changing the speakers or amp (for now) but I need better sounding bass. The mid-bass that the system has is abundant with no low end.

 

[markboris]

There's room under there? It's that deep? Very interesting.

Yes, if you want a huge 12 or 15 or two 10's, you still have room as long as you keep the cargo floor in the upper position. I want to be able to use the cargo floor as intended in either the upper or lower position so I went with a single 10 with a built in amp. Will be plenty of room.

 

[phidauex]

Funny enough it's not the first time I've seen this. If you ever used software for box design for very small subwoofers an infinite baffle is recommended which is impossible but in this case if you ported outside, it would be possible. If you ever watched the west coast custom series they actually do this for one of the clients.

Yep, that is what this is - an infinite baffle subwoofer. IB subwoofers are great because they are more power efficient and reduce distortion compared to sealed or ported enclosures.

Sealed enclosures are a lot less efficient because they have a powerful air spring behind the driver (the air in the box). This limits excursion (good to avoid killing your driver), and prevents distortion from group delay (signals arriving at different times), so is good for high accuracy applications where you have plenty of power and big drivers.

Ported enclosures attempt to improve efficiency by recovering some of the energy from the back of the driver by directing it through the port. The problem is that it only boosts energy at the ports tuning frequency, and the fact that you now have signals arriving from two places at two different times increases group delay distortion. It is easy to design a ported enclosure that is LOUD, but hard to design one that sounds GOOD. Big boomy blurry bass is typical for simple ported designs.

Infinite baffle tries to solve both problems - it is energy efficient because the driver doesn't fight an air spring - the outdoor air isn't being compressed, so the driver can move at full excursion easily. You avoid group delay because you still only have one source. You do need to carefully EQ so you don't over-extend the driver.

I think they are gaining popularity in cars, but they've been used for a long time in home theater - the simple implementations put the driver up in the attic or down in the crawl space, and use a rectangular box to connect it to a hole in the ceiling with a heater vent over it. No big box, no big drivers visible, but lots of big omnidirectional bass that is easy to tune the room around.

 

[markboris]

Sam, that was a great explanation of the different types of sub enclosures. I generally prefer sealed enclosures as I like a more quality, tighter bass over full on volume. Since the B&O system in the Mach-E hardly has concert volume I’ll be ok with a sealed box and 400 watt amp.

it’s nothing new for me to completely revamp an audio system and spend usually between $5000-$8000. I am very partial to Focal speakers (French), Mosconi amps (Italian) and JLAudio for the sub and sub Amp (American). As of right now, this car is just getting a sub upgrade. Down the road, you never know what I might do. ?

 

[americanflannel]

Yep, that is what this is - an infinite baffle subwoofer. IB subwoofers are great because they are more power efficient and reduce distortion compared to sealed or ported enclosures.

Sealed enclosures are a lot less efficient because they have a powerful air spring behind the driver (the air in the box). This limits excursion (good to avoid killing your driver), and prevents distortion from group delay (signals arriving at different times), so is good for high accuracy applications where you have plenty of power and big drivers.

Ported enclosures attempt to improve efficiency by recovering some of the energy from the back of the driver by directing it through the port. The problem is that it only boosts energy at the ports tuning frequency, and the fact that you now have signals arriving from two places at two different times increases group delay distortion. It is easy to design a ported enclosure that is LOUD, but hard to design one that sounds GOOD. Big boomy blurry bass is typical for simple ported designs.

Infinite baffle tries to solve both problems - it is energy efficient because the driver doesn't fight an air spring - the outdoor air isn't being compressed, so the driver can move at full excursion easily. You avoid group delay because you still only have one source. You do need to carefully EQ so you don't over-extend the driver.

I think they are gaining popularity in cars, but they've been used for a long time in home theater - the simple implementations put the driver up in the attic or down in the crawl space, and use a rectangular box to connect it to a hole in the ceiling with a heater vent over it. No big box, no big drivers visible, but lots of big omnidirectional bass that is easy to tune the room around.

Do you have a link to home theater use? that sounds interesting and I would like to know more.

 

[macchiaz-o]

Do you have a link to home theater use? that sounds interesting and I would like to know more.

Start here:

https://www.bing.com/search?q=infin...-25&sk=&cvid=416D449B235048A8AEE3C6BAAD124531

 

[macchiaz-o]

Yep, that is what this is - an infinite baffle subwoofer.

Excellent info, thank you.

I've really been enjoying the B&O IBS (??) in my Infinite Blue SUV, even with its mildly-Irritating But Safer pedestrian sounders.

 

[sockmeister]

That rectangular hole I show in one of the above photos goes OUTSIDE. If I were to take off the fiber wheel well liner behind the right rear tire, you will see that whole and can look straight up into the woofer enclosure through the port. If you want, I can take a photo of that too from the outside behind the fiber liner.

That is really strange. But it could be to allow air pressure to equalize as the sub moves about while thumpin'. My best guess. Still, gotta be part of the design. I hope water doesn't end up somehow getting in there.

 

[sockmeister]

Joe, I only took some photos under the front trunk. Running the wire from inside under the dash, down the left driver side kick panel, along the front and rear kick plates then into the rear cargo area is was very simple. Lots of room under the kick panels to run the wire. I used 8 gauge wire which is sufficient for the amp I am using and not too thick to run to the rear. I did not take photos of the sub connection but I just spliced into the wires that were going to the sub and using those for the audio input signal. This is what I have done for the last two B&O sub replacement/upgrades. The ground wire I grabbed from the ground wire bolt on the right side close to the OEM sub that the B&O amp is using.

I woke up this morning not even thinking of the sub in my car and ended up running the wires and gettin it ready for the JL sub I ordered. I would have eventually done this anyway as my F150 and GT500 both have JL subs and going from them to the Mach-E is a disappointment in quality deep bass. I said this before, I am not interested in very loud "Rap" type bass. I just want good quality low end bass and that is what I will have on Friday. I am satisfied with the sound in the car after I set the EQ the way I like it and won't be changing the speakers or amp (for now) but I need better sounding bass. The mid-bass that the system has is abundant with no low end.

Nice, neat work running the cable. I like the grommet on the factory firewall large grommet you punched through. Before I've just left it open when running cable.

You are quite possibly the first person to do this mod to the mach-E. I am definitely interested in seeing the finished setup and maybe a write-up and sticky is in order.

 

[sockmeister]

Start here:

https://www.bing.com/search?q=infin...-25&sk=&cvid=416D449B235048A8AEE3C6BAAD124531

BING!? Preposterous.

 

[markboris]

That is really strange. But it could be to allow air pressure to equalize as the sub moves about while thumpin'. My best guess. Still, gotta be part of the design. I hope water doesn't end up somehow getting in there.

As Sam mentioned earlier, this is an infinite baffle design. I was chuckling at your comment on "allow air pressure to equalize as the sub moves about while thumping'". This is a cheap 6x9 speaker that has a 1" voice coil and the foam suspension around the edge of the paper cone is barely 1/4" wide. This thing does not move much I can tell you that.

Water would only get into the speaker if the fiber liner in the wheel well was removed.

 

[markboris]

Nice, neat work running the cable. I like the grommet on the factory firewall large grommet you punched through. Before I've just left it open when running cable.

You are quite possibly the first person to do this mod to the mach-E. I am definitely interested in seeing the finished setup and maybe a write-up and sticky is in order.

Yes there was an unused closed grommet as if it was intended for wiring at some point. I made a little x cut in the rubber and ran the 8 gauge wire through. Had to do the same thing on the inside as it was closed there too. There was a little circle on the inside which was opposite the grommet on the outside. Made a cut in there and the wire came the rest of the way through. I attached the fuse to the negative cable wire with a tie strap. Wanted to be able to access that fuse if needed to with only taking the one panel off so that is why I attached it there.

Not sure if I am the first person to add a sub to the Mach-E but maybe the first one posting it here. Like I said before this was not even on my list of projects for this car but I had all the panels removed under the front truck because of other projects I am working on so figured, why not run a wire to the back for future sub. I did not take any more photos than the ones I posted earlier but have had some requests for what it looks like behind the trim panel where the OEM sub is so might pull that apart again and take a photo. I will write something up when I am finished tomorrow after the sub (hopefully) comes in.

 

[sockmeister]

As Sam mentioned earlier, this is an infinite baffle design. I was chuckling at your comment on "allow air pressure to equalize as the sub moves about while thumping'". This is a cheap 6x9 speaker that has a 1" voice coil and the foam suspension around the edge of the paper cone is barely 1/4" wide. This thing does not move much I can tell you that.

Water would only get into the speaker if the fiber liner in the wheel well was removed.

Lol. And yeah, I did see those comments later. So that infinite baffle design is the reason.
Looking forward to hearing your take on the improvements. I'm guessing you're going to disconnect those OEM subs, or are you going to leave them in place?

Sponsored