DIY Pedicab sound system. Looking for some help!

jacobcammack

Greetings. New to all things audio and been learning a lot I didn't know. That said I still don't feel like I know anything.

I'm a pedicab driver and having a really nice 6-seater built right now. It's a really nice motorized cab and the icing on the cake will be awesome lighting and a sick sound system. Here's a photo of what it will look like:



I bought a set of Polk DB692 6x9s for a good price on craigslist cause they got good reviews. The guy who sold them to me convinced me to buy this Pyle PLMRA410BT amp when I met him but upon getting home I checked out the reviews and it sounds like Pyle is generally a "pile" of you know what.

I've been doing a bunch of research but am feeling a bit lost as to what amp to get. Keep in mind the whole system will be running off of 12V battery. Probably gonna pick up a big ole 80ah battery as I need the system to last all day.

So far I understand I need a 4ohm amp as my speaker are 4ohms.
I also understand that 93db is a good sensitivity for speakers.
I am getting lost with continuous rating stuff cause I keep reading conflicting advice. Some people say to have an amp rated higher than your speakers. Others say to have speakers rated higher than your amp. The thing is... I wanna get this right. I want my #$%@ to sound good. Surely it's possible to optimize this stuff, which is why I'm here.

So I have a RMS rating of 150 watts and a peak of 450. I do not plan to use a sub-woofer as again, I am limited on power and I bought these speakers wanting to optimize for them as I've heard they have good bass.

So far I've come up with using the 75/150% rule on my RMS of 150 watts to determine I want an minimum of 112 watts per channel on my amp and a maximum of 225 watts per channel. For all I know this is not how I should be thinking of this. Again... I am rather confused.

The final and super important thing I'm trying to figure out is this "Infinite Baffle" operation. Assuming the photo of my pedicab loaded correctly, I probably need to install these speakers under the front passenger seat (the seat that faces backwards). Does infinite baffle mean I just stick them out in the open or do I need to build boxes or what? Perhaps these speakers won't work. If out in the open, are they water/dust/everything outside proof enough on all sides, or just on the front?

As you can tell... I need some help.

Thanks SO much if you can provide any. Getting a bit lost in all this here and don't wanna do a sloppy job with this. A pedicab is like a fishing lure. The more shiny and fun and awesome it is, the more people want to get it. I wanna get this audio setup right from the beginning. Considering taking it to a professional and also open to spending more and getting better speakers as well. Sounds like the speakers I got are awesome enough but again... I don't know jack.

THANKS!,
Jacob

nooshinjohn

I think it needs a Hemi.

Dennis Gardner

I would have a box built for use under the front seat that faces to the rear. It could also double as a amp rack. Sealed or ported doesn’t really matter in this installation but using a box will result in the best bass response.

jacobcammack

Thanks @Dennis Gardner for your response. Why doesn't it matter whether I use sealed or ported? Is there any reason I couldn't build this myself? I'm hoping that I can just use this pair of speakers for all my sound so I definitely want the best bass response possible.

Any recommendations on how to select the best amp, producing the best sound and taking into account I'm running on a battery if necessary?

jacobcammack

Just purchased two Rockville RS6x9BL 6x9 Wedge speaker boxes that have been sealed with bedliner ( https://www.amazon.com/gp/product/B01MF85IF2/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1 ). They should fit under the rear facing seats, just will need to secure them nicely.

Guess I just mainly now need to figure out what amp to use. Want it to sound crisp and clean and pair nicely with my speakers but not be overkill on my battery. Any suggestions?

Still open to buying better speakers, etc, and doing a more professional install. Any constructive criticism in my currently design is most appreciated. Want to get this right.

Clipdat

Seems like something around this price point would work fine: https://www.sonicelectronix.com/item_94237_Kicker-PXA200.2-Compact-2-Channel-Amplifier-42PXA2002.html

What is your source?

jacobcammack

@nooshinjohn What is a Hemi?

jacobcammack

@Clipdat I forgot to mention that. I plan to use spotify on my iphone. So ideally I was hoping to use Bluetooth (good Bluetooth).

That amp you recommended. Help me understand... my speakers are rated at 4ohms with 150W RMS. At 4ohms that amp puts out 25W per channel RMS. Isn't this too low? Or will my 4ohm speaker handle 1ohm from the amp at the rated 100W RMS? I heard you never want the speaker to have less ohms than the amp, so in this case the reverse is true so I'm wondering if that's okay.

For all I know, none of this matters, but that's why I'm trying to learn. Thanks for making a suggestion.

jacobcammack

@Clipdat Also, the Kicker amp you mentioned says it is optimized for being able to be heard over a loud motor:

"The sound output is undeniably KICKER. PXA Amps take into account real-world, open-air listening in powersports applications, smartly directing precious power where it succeeds - in the 40-to-250-hertz frequency range where a biker or rider can truly hear and feel it in the open air. It also contains a differential audio circuit that reduces engine noise in the audio system for low T.H.D. (total harmonic distortion) and superb clarity at high volumes"

Other than the wind occasionally, or a busy city street, my pedicab doesn't really make any noise so wouldn't this then be inappropriate.

Again.. I have no idea. Just figuring this out. Thanks!

jacobcammack

This one keeps coming up in my searches:
https://www.amazon.com/Kenwood-1177524-Automotive-Amplifier-Kac-M1824BT/dp/B00UTXQL74/ref=sr_1_2?crid=1P8QFL7XL2RL4&keywords=marine+amp+4+channel&qid=1553661805&s=gateway&sprefix=marine+amp,aps,172&sr=8-2

Says it's "bridgable" which sounds like it doubles the RMS from 45 to 90W per channel.

Thought on this amp? Again... for all I know I'm way off base here.

jacobcammack

This Alpine MRV-F300 4-Channel Car Amplifier, 50 Watts RMS x 4 looks pretty awesome and at a great price on Amazon ($135 - https://www.amazon.com/dp/B00BLQA9BM/ref=as_li_ss_tl?ie=UTF8&linkCode=sl1&tag=azbuka09-20&linkId=abca6cde20bac49d9b83c92e35631404 )

but my worry is... this won't be good outdoors will it? Was reading it shouldn't get too hot and I'll sometimes be in pretty hot conditions. Too bad if that's the case cause it sounds like Alpine amps are super awesome.

motorstereo

Since you're on pedal power I'm thinking keeping the weight down is more than likely a good idea. Perhaps a t amp with a small battery and some small speakers to see how the people like it? I know I wouldn't want to draw attention to myself riding in an open setting like that with music blasting.
I'm also wondering what part of the world you're from if you don't mind me asking?

K_M

All this for a bike? (even a deluxe bike such as this)

Why not greatly reduce the weight and cost and get a decent battery powered bluetooth speaker?

What are your goals, where are you using this at?
Seems weight and size would be the enemies.
An auto sound system on a bike seems counter-intuitive.

Is the under seat area not for passengers to put their feet or stow packages etc?

codycatalist

https://www.crutchfield.com/p_108P6002AM/Infinity-Primus-6002A.html

And

https://www.crutchfield.com/S-0kDTuVWsYXf/p_13691126/JL-Audio-MBT-RX.html?XVINQ=GLX&awkw=79438365495&awat=pla&awnw=g&awcr=65372638345&awdv=m&awug=9030033&gclid=CjwKCAjwvuzkBRAhEiwA9E3FUmZkr5JemETAsuABK0vkB8Rpd7M7kU7WCp571jASs_07FnWd9f3c4BoCGlwQAvD_BwE

tonyb

Must say, I'm a bit curious too as to your location. Why ?

Because that's got to be the biggest pile of bird **** I've ever seen on the pavement there.

Question....how do you propose to power everything ? How do you propose to keep it dry as well ? Secure....so no one steals your goods.

A battery isn't going to last long if you can't recharge by pedal power.

Clipdat

jacobcammack wrote: »

@Clipdat Also, the Kicker amp you mentioned says it is optimized for being able to be heard over a loud motor:

"The sound output is undeniably KICKER. PXA Amps take into account real-world, open-air listening in powersports applications, smartly directing precious power where it succeeds - in the 40-to-250-hertz frequency range where a biker or rider can truly hear and feel it in the open air. It also contains a differential audio circuit that reduces engine noise in the audio system for low T.H.D. (total harmonic distortion) and superb clarity at high volumes"

Other than the wind occasionally, or a busy city street, my pedicab doesn't really make any noise so wouldn't this then be inappropriate.

Again.. I have no idea. Just figuring this out. Thanks!

Marketing speak. You might be surprised at how loud 25wpc is. The Alpine you linked is also a good option. Really any marine rated class-d will be, along with that BT adapter that Cody linked.

codycatalist

tonyb wrote: »

Must say, I'm a bit curious too as to your location. Why ?

Because that's got to be the biggest pile of bird **** I've ever seen on the pavement there.

Question....how do you propose to power everything ? How do you propose to keep it dry as well ? Secure....so no one steals your goods.

A battery isn't going to last long if you can't recharge by pedal power.

Yeah but if you recharge it daily it should last most of the day since he isn't pulling in a sub which really draws the power. I would say to keep it dry put it in an acrylic box that has holes for each wire with grommets to keep the water out. Where there is a will there is a way...even if it isn't "worth it" for the most part.

For simplicity I would go with a decent Bluetooth speaker as well but since they already bought some stuff itll work.

To keep the battery dry put that sucker in a lunch cooler and seal er up. I have built plenty of "Party boxes" out of drink coolers, car batteries and car amps. We used to float on the salt river for 6 hours at a time. Haven't had issues thus far.

jacobcammack

Thank everyone for jumping in on the discussion. @tonyb and @motorstereo I'm in Austin, Texas, but will be riding this bike all over the country.

To clarify, this is a motorized 6 seater pedicab. I'll be carrying at any given time, two 48v 33ah LiFePo4 batteries (Lithium Iron Phosphate). They're big powerful honkers.

On that note, I'm leaning heavily now towards buying a good 48 to 12v converter and powering my audio system that way. @Clipdat , Your point that I might be surprised at how loud 25wpc is timely, as from what I've been reading it seems I'm worrying too much about the power draw from my speakers. Been too worried about these big numbers, but it sounds like things are loud enough at smaller numbers. Very curious about this whole sensitivity thing. For instance, my speakers are rated at 93dB (1W@1M), so to get to 102dB(which is pretty darn loud) I only need 8W. Perhaps this is irrelevant, but it seems pertinent.

So given all this I'm pretty sure I'm gonna get a class D amp as anything else is overkill and inappropriate for this setup. A friend told me about this simple one here that's used in kits:

https://www.parts-express.com/tps3116d2-class-d-21-bluetooth-40-amplifier-board-2-x-50w-100w-with-filter-and-volume-con--320-635

It has bluetooth, good reviews and plenty of power for what I'm doing. I would of course put it in a waterproof container. Appreciate the recommendations @codycatalist. Is that a class D? Had trouble finding that spec on it.

@K_M and @codycatalist , a Bluetooth speaker is a good suggestion. Many pedicabbers go that direction. There's others though, who have leaned towards keeping it lean, and putting in speakers with a simple little board of an amp. I guess I also am enjoying learning about all things sound. Have seen some great systems where everything is really dialed in and installed all snappy and sounds great. It's also to my advantage to use these big expensive batteries I've got to pull the bike for my sound system as well.

@motorstereo I've been pedicabbing for awhile and the music thing depends on where you're cabbing and when. I personally like the silence of many rides and good conversations. As night time descends, folks come out to party downtown, or at a festival, and many groups very much enjoy bumping to the tunes while taking a fun little roller-coaster of a ride with me to their destination. For many late night customers, the music is like a magnet.

REALLY appreciate everyone's insights. Worried that that little class D amp I listed above won't be loud enough at 12v. Guess I'm still trying to understand what "is" loud wattage wise, how my sensitivity factors in (as stated above... apparently I only need 8W to hit 102dB), etc. Will that little amp draw enough power to bump the bass on my Polk DB692 3 way 6x9's? I don't know.

codycatalist

jacobcammack wrote: »

It has bluetooth, good reviews and plenty of power for what I'm doing. I would of course put it in a waterproof container. Appreciate the recommendations @codycatalist. Is that a class D? Had trouble finding that spec on it.

Yup!

Class-D Full Range 4-Ohm Stable 2-Channel Amplifier

Although I wouldn't consider Class A/B to be "overkill" just not "needed" for the application you choose. While having generally better sonic qualities they do get hot and are usually bigger in size. Almost everything you get that is a compact style amp will be class D or T. I mean if the amp gets hot as it stands then just wire a computer fan to the top and wire it into the ground, remote and 12V.

codycatalist

Btw I've owned those DB models before. They are plenty efficient and with the boxes you purchased should give you enough bass within reason.

If you want to have some fun get a 4 channel connected to the DBs and get two rockers mounted under the seat for some pseudo bass effects.

codycatalist

For reference here is my car stereo (only Polk is the sub) but my speakers only run 65/70 watts up front and 45 in the rear.

https://youtu.be/qkF-4KmCK5o

jacobcammack

@codycatalist Super helpful to hear from someone who has owned the DB speakers I'm going to use before. The class D amp module I was going to buy was sold out so I just ordered this Kenwood Class D on Amazon:

https://www.amazon.com/gp/product/B00UTXQL74/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Consistently kept coming up as a best buy. Any reason I should cancel my order? Literally just ordered it.

(Warning... About to do a lot of rambling math.)

If that all looks good the last thing I need to understand/order is a 48 to 12v converter to step down my voltage from my batteries to my system. My 48v 33ah batteries have a max continuous discharge of 50a and max peak of 100a. Apparently I need to set aside about 30a for my pedicab motor so that leaves me with 20a for my led lights and audio setup (50a minus 30a). Here's where I'm not sure my calculations are correct. My amp puts out 45w RMS so, times two speakers, is 90w. 90w divided by 12v = 7.5a so clearly my RMS is well in the clear of 20a. FURTHER... really... I get a lot more amps to play with because when my amp/speakers ask for power from my battery, they go through my 48v-12v convertor... so it'll be taking 48v power down to 12v power which will x4 my amps. so really by these calculations I can take those 7.5a and divide them by 4 to get 1.9a that will consistently be asked for from the battery.

So even if.... for some crazy reason... I hit the peak power of the speakers of 450W... that calculates down as follows. 450W is 37.5A @ 12v which converts down to 9.3A @ 48v x 2 speakers (right?) for a total of 18.6A peaks. Honestly not sure if that peak rating is for one speaker or two.

Probably did something wrong here but (long story short) want to make sure I'm not asking for more power for my motor, amp, speakers, and lights than it can handle. Mainly just worried about this peak stuff, but I guess... I didn't factor in the 100A peak of the battery so... I guess I probably just need to make sure and get a high enough Amp-Hour 48-12v converter and I'll be fine.

codycatalist

jacobcammack wrote: »

@codycatalist Super helpful to hear from someone who has owned the DB speakers I'm going to use before. The class D amp module I was going to buy was sold out so I just ordered this Kenwood Class D on Amazon:

https://www.amazon.com/gp/product/B00UTXQL74/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Consistently kept coming up as a best buy. Any reason I should cancel my order? Literally just ordered it.

(Warning... About to do a lot of rambling math.)

If that all looks good the last thing I need to understand/order is a 48 to 12v converter to step down my voltage from my batteries to my system. My 48v 33ah batteries have a max continuous discharge of 50a and max peak of 100a. Apparently I need to set aside about 30a for my pedicab motor so that leaves me with 20a for my led lights and audio setup (50a minus 30a). Here's where I'm not sure my calculations are correct. My amp puts out 45w RMS so, times two speakers, is 90w. 90w divided by 12v = 7.5a so clearly my RMS is well in the clear of 20a. FURTHER... really... I get a lot more amps to play with because when my amp/speakers ask for power from my battery, they go through my 48v-12v convertor... so it'll be taking 48v power down to 12v power which will x4 my amps. so really by these calculations I can take those 7.5a and divide them by 4 to get 1.9a that will consistently be asked for from the battery.

So even if.... for some crazy reason... I hit the peak power of the speakers of 450W... that calculates down as follows. 450W is 37.5A @ 12v which converts down to 9.3A @ 48v x 2 speakers (right?) for a total of 18.6A peaks. Honestly not sure if that peak rating is for one speaker or two.

Probably did something wrong here but (long story short) want to make sure I'm not asking for more power for my motor, amp, speakers, and lights than it can handle. Mainly just worried about this peak stuff, but I guess... I didn't factor in the 100A peak of the battery so... I guess I probably just need to make sure and get a high enough Amp-Hour 48-12v converter and I'll be fine.

I personally wouldn't want it tied to the lifeblood of your job (pedal car battery). That's just me though, I would worry about a sudden rush of power possibly damaging something. I would go with a separate car battery to run this stuff but that's just me.

Can't help you on the math, I ain't no math wizard.

codycatalist

Also I like Kenwood, they have a full sound and built well.


Just looked at the amp, it's not bad but I would worry about everything integrated together. If something fails the whole thing is junk. I'm a believer in stand alone amplifiers as they are usually built to last... And outlast the Bluetooth portion it will.

jacobcammack

@codycatalist Agreed on not having things integrated. Just out of all the options this one kept coming up as the best buy. I'm assuming you are referring to the bluetooth portion in particular. Anything else you think shouldn't be integrated?

Clipdat

jacobcammack wrote: »

@codycatalist Super helpful to hear from someone who has owned the DB speakers I'm going to use before. The class D amp module I was going to buy was sold out so I just ordered this Kenwood Class D on Amazon:

https://www.amazon.com/gp/product/B00UTXQL74/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Consistently kept coming up as a best buy. Any reason I should cancel my order? Literally just ordered it.

Nice looking amp, cool that it has BT built in.

codycatalist

jacobcammack wrote: »

@codycatalist Agreed on not having things integrated. Just out of all the options this one kept coming up as the best buy. I'm assuming you are referring to the bluetooth portion in particular. Anything else you think shouldn't be integrated?

Just because I feel that way doesn't mean you should return yours. We have different views, mindsets and experiences being brought into our stance. In a good way though! I just think in terms of what will last in a CAR enclosed safely running on a native 12vDC line. I plan an amp on lasting me at least 10ish years.

I think that amp would work well with your plans. In your situation I don't think longevity will be on as big of a scale as in my situation.

Plus having 4 channels you can add those under the seat rockers!

Dayton Audio TT25-8 Puck Tactile Transducer Mini Bass Shaker 8 Ohm https://www.amazon.com/dp/B009RGJ47S/ref=cm_sw_r_cp_apa_i_sydNCbNFBK6G7

According to the manual it can be wired in parallel into 4 ohm.

jacobcammack

Totally on the same page. I like to learn and understand but certainly not going to go with something just cause someone said to. In this case I just asked cause I'm curious.

Yeah... saw that about wiring it in parallel. Guess I need to do some testing with how loud it is with just two channels and how much draw that has on my battery vs going in parallel. For all I know all my worries about that will turn out to be overkill.

Would be pretty sick to add under the seat rockers.

jacobcammack

Might be buying a separate battery to power this whole system. Anyone got any recommendations on where to get the best prices on a 12v 80AH sealed lead acid battery?

lightman1

Autozone

nooshinjohn

Any chance your license plate reads "UBUYGAS"?