Droid Turbo 2 Speaker Mod

[pwrdbykyank]

 

[darkSSide]

Cool if you have access to a laser cutter..lol

 

[FoxKat]

It's an interesting modification but I'd bet the rectangular area facing the back cover, and through which those slits are allowing sound into from the front speaker are actually part of a more highly engineered acoustic suspension design to enhance the bass response of the speaker and/or assist in providing a more flat frequency response, as well as to reduce distortion due to out of phase sounds (front facing waves versus rearward), from muddying up the sound.

In vintage audio equipment you would most often find the speaker(s) mounted in an open air configuration where the back of the speaker(s) is/are simply free to resonate through the back of the cabinet, usually through a series of ventilation holes like would be found on large console TVs or speaker cabinets of guitar amplifiers. Around the late 1950s is when manufacturers began to fully enclosed their speakers to capture and minimize that out of phase distortion and to enhance the bass response.

Just like the large ovalized compartment or open area shown in the front of the phone where the moderator shows the slots, any sealed or semi-sealed compartment in these phones which sits behind or along side the speaker transducer and is essentially connected via an air coupling channel is almost certainly intended to increase volume, reduce distortion and/or enhance audio quality.

By "modding" the back cover to allow the sound waves, which are normally otherwise trapped and reflected or reverberated back to the rear of the speaker transducer to instead "escape" out the back cover, it will most definitely have an impact on frequency response, audio quality and volume coming from the front.

I'll leave mine as is for now, thank you... But it is interesting to see what some people can and will do given the need, desire, ingenuity and access to high tech equipment such as a laser cutting apparatus.

Sent from my XT1585 using Tapatalk

 

[pwrdbykyank]

It's an interesting modification but I'd bet the rectangular area facing the back cover, and through which those slits are allowing sound into from the front speaker are actually part of a more highly engineered acoustic suspension design to enhance the bass response of the speaker and/or assist in providing a more flat frequency response, as well as to reduce distortion due to out of phase sounds (front facing waves versus rearward), from muddying up the sound.

In vintage audio equipment you would most often find the speaker(s) mounted in an open air configuration where the back of the speaker(s) is/are simply free to resonate through the back of the cabinet, usually through a series of ventilation holes like would be found on large console TVs or speaker cabinets of guitar amplifiers. Around the late 1950s is when manufacturers began to fully enclosed their speakers to capture and minimize that out of phase distortion and to enhance the bass response.

Just like the large ovalized compartment or open area shown in the front of the phone where the moderator shows the slots, any sealed or semi-sealed compartment in these phones which sits behind or along side the speaker transducer and is essentially connected via an air coupling channel is almost certainly intended to increase volume, reduce distortion and/or enhance audio quality.

By "modding" the back cover to allow the sound waves, which are normally otherwise trapped and reflected or reverberated back to the rear of the speaker transducer to instead "escape" out the back cover, it will most definitely have an impact on frequency response, audio quality and volume coming from the front.

I'll leave mine as is for now, thank you... But it is interesting to see what some people can and will do given the need, desire, ingenuity and access to high tech equipment such as a laser cutting apparatus.

Sent from my XT1585 using Tapatalk

I agree with what your saying. I did consider the fact that it might be there to help with certain sound effects or pitches etc. Opening the back has made the sound more sharp now and differs from what a regular one is. It is louder and a bit sharper so at times I tend to lower the volume down a bit since it can be a bit loud at times. For certain songs for example, some very high pitched noises sometimes sound very loud and overcome much of the bass in the background so I need to lower the volume one or two notches to have a more unified sound. However for the most part for those who want a dual facing speaker/sound, or just even slightly sharper and louder, this would be a good mod. But for those who just want the best quality sound and dont care much for it to be any louder at the slight expense of losing a bit of quality at times in the sound, it would be best to just stick to what it is. It is possible though to add a second speaker to the left so you would have sound coming out of both front openings, however it would require a lot of modification and also skills in modifying the power output from the board to be able to give additional power to an extra speaker in which I don't know how to do. Also there is the chance of interference with the microphone unless one was to reroute where the sound would come into the mic from.

 

[FoxKat]

Well I certainly want to give you props for taking the plunge, as well as having executed it so well. You may be able to offset some of the harshness you mention by cutting a rectangle of R38 or other high density fiberglass insulation and fitting it in that rectangular spot immediately behind the back cover. It will serve two purposes, by not only reducing harshness but also by filtering dust particles from entering the phone through those holes. These phones are designed to be mostly air tight or at least mostly dust tight. Since sound is the movement of air, the holes on the back will act like a suction port and draw dust in as the sound pushes and pulls. You may even want to cut a nice piece of felt to glue over the holes on the inside of that cover to further protect from dust.

Anyway, thanks for sharing and I hope that the addition of some of my suggestions will get you even closer to a perfect solution.

Sent from my XT1585 using Tapatalk

 

[MJ5150]

Opening the back has made the sound more sharp now and differs from what a regular one is.....

Do you know where I can buy one of those back covers? Not necessarily one like yours with the holes in it, just a stock one.
Mine is a gray/black diamond look that is slippery. I'd like something different, and I don't want to buy a case.
I see a few on eBay from China, but I don't buy much on eBay anymore these days. Maybe I'll need to if I want one of these.

-Mike

 

[FoxKat]

Do you know where I can buy one of those back covers? Not necessarily one like yours with the holes in it, just a stock one.
Mine is a gray/black diamond look that is slippery. I'd like something different, and I don't want to buy a case.
I see a few on eBay from China, but I don't buy much on eBay anymore these days. Maybe I'll need to if I want one of these.

-Mike

Mike, I did a quick Google search and came up with not only the eBay ones you mentioned but also online retailers. The search I used filtered out eBay, specified "Droid Turbo 2" and then refined to just "shopping", and it gave me the following results...

Fixez.com and RepairsUniverse.com, both selling at $29.99.

Let me google that for you

Looks like the eBay option may be your best course in terms of cost as they are only $13.99 from eBay seller "2012cherrychina", but let's see what the OP has to say.

Sent from my XT1585 using Tapatalk

 

[pwrdbykyank]

Thanks for the suggestions FoxKat, Ill look into it. Also for the back covers, yea you can easily find them many places online, and they are listed on ebay as well.

 

[FoxKat]

Thanks for the suggestions FoxKat, Ill look into it. Also for the back covers, yea you can easily find them many places online, and they are listed on ebay as well.

You're quite welcome. I would definitely suggest at least one or the other additional modification to prevent/minimize dust from entering into that port and collecting inside. In fact if you take a look at pretty much every speaker or microphone port on portable devices you'll almost certainly find a dust barrier of thin felt.

Since we place these devices into our pockets where "dust bunnies" collect, and they are also exposed to the outdoors with wind blowing all manner of airborne particles about the risk is significant. There is even the further risk that ferrous (iron metal), particles could find their way into that pathway leading to the speaker/transducer and become magnetically attached to the actual transducer cone (thin clear Mylar type material which makes up the front cone of the speaker - similar to the left of the two images below), thus causing buzzing sounds as they rattle and vibrate to the audio source.

The vibrations would eventually also cause the metal fragments to cut through the cone and that could render the speaker useless.

Sent from my XT1585 using Tapatalk

 

[pwrdbykyank]

Yea the screen/filter or dust barrier I took off an old blackberry speaker and attached it to the back plate where the holes are. Hopefully that will do the trick.

 

[FoxKat]

Yea the screen/filter or dust barrier I took off an old blackberry speaker and attached it to the back plate where the holes are. Hopefully that will do the trick.

Awesome, should work well.

Also upon further inspection it appears that the OEM Droid Turbo 2 speaker is capsulized and has its own filter cover on the sound port. You can see the oval opening at the lower left in the third image below. This is unique versus transducers I've seen in the past (like the one on my earlier post). This means the speaker incorporates is own dust barrier, which is further evidence of the extent in engineering that Motorola goes, often far more rugged than their counterparts.

Front

Back

Front (close-up showing sound port)

Sent from my XT1585 using Tapatalk

 

[pwrdbykyank]

Yea, I guess it already has one over the speaker itself.

 

[FoxKat]

Yea, I guess it already has one over the speaker itself.

Agreed, however the addition of the filter on the inside back cover will keep dust and such out of the innards of the phone so it's still a good mod.

I'd love to hear a comparison between a non-modded phone, one modded like you've done and then one with an insulation baffle to see how effective the fiberglass would be at bringing the sound back closer to its original design yet giving that rearward output you were shooting for.

Anyway, props for a job well done.

Sent from my XT1585 using Tapatalk

 

[pwrdbykyank]

Thanks appreciate it. If I get around to tearing it apart again to mess with it, will try and do a comparison.