(2) 6.5 inch subwoofer under dash install questions

  • I just purchased a 2016.5 Slingshot. Previous owner installed the 6 1/2 inch sub enclosure under the glove box. In it are 2 Memphis 6 1/2 inch subwoofers. Here are the specs according to their page 300 watt max dual 2 ohm power reference PRX6D2 . However there is no wiring or amp. Does anyone have a DIY on installing that set up and what size amp is required and wiring that is involved. Thanks in advance for any help.

  • I just purchased a 2016.5 Slingshot. Previous owner installed the 6 1/2 inch sub enclosure under the glove box. In it are 2 Memphis 6 1/2 inch subwoofers. Here are the specs according to their page 300 watt max dual 2 ohm power reference PRX6D2 . However there is no wiring or amp. Does anyone have a DIY on installing that set up and what size amp is required and wiring that is involved. Thanks in advance for any help.

    Does it look like this -


    https://www.slingmods.com/pola…glass-subwoofer-enclosure




    If it looks like that, it is from Jack at Underground Audio in Florida. On the Slingmods website it shows that they offer it with an amplifier. You can reach Jack at Underground at


    https://www.undergroundautostyling.com/


    941-706-4000


    As Kyle D mentioned, Mitch up at Rev Dynamics does a lot of stereo installs also and could help you out - https://revdynamics.net/ 574-933-2269


    Hope that helps,

    Dave

  • Thanks for the info. After talking underground audio I figured out the size amp I need wiring and how to connect to the factory radio. Parts on order hopefully installing this weekend. See how it goes

    Hey Mike is it possible you can pm me or post that info here? I am asking because this is the same sub box setup im planning on getting. Thanks

  • So I have everything installed and it’s not working properly. My two 6 1/2 inch subs have both negatives jump together and positives jump together to the side of the enclosure where I have speaker wire connected to the red and black. They run back to the amp to the positive and negative amp output terminals. I have the amp wired with 12 V from the battery and a good ground. I have the remote wire run from the amp to the accessory port in the glove box to trigger 12v ignition. lastly I have RCA cables running from the input right and left on the amp into a line output converter which is spliced into the red and black wires on the factory speaker pod lower speaker for a signal. When I turn on the radio the subs do move slightly with music but there is no thump to them. What should I check?

  • The way you have your speakers wired effectively reduces their impedance to half of what they normally are. Assuming each speaker is 4 ohm impedance, they are presenting a 2 ohm load to the amp. Is your amp rated for 2 ohm operation? If the amp is NOT rated for 2 ohm operation, there is a chance that the amp broke due to the unexpectedly low impedance, but hopefully it didn't damage itself.

    Here's a good loink on wiring speakers - https://hometoys.com/series-parallel-speaker-wiring-2/.

  • Mike,

    I have heard several of those under the dash 6.5's and none of them had any noticeable bass what so ever.

    BKL is correct to a degree, you actually drop those puppies down to 1 ohms when you ran the wires like that so that is the first thing to check. Assuming you have a mono channel amp (based on your description) I would just remove one of the sets of wiring and ensure you have the Low pass set to filter out any highs from those Jl's and give it a whirl.

    You will know in a few seconds if that was the issue. If not you may have popped the AMP as suggested due to the power draw.

    Good luck brother.

  • Slopoke, has a point. If you have 2 ohm speakers in parallel, the total impedance the amp sees is only 1 ohm and may cause problems with your amp's output. Most modern amps are designed to handle 2 or 4 ohm speakers, so wiring 2 x 2 ohm speakers in series will look like 4 ohms to the amp or 2 x 4 ohm speakers in parallel will look like 2 ohms to the amp. Use whichever combination matches your amp's power output specs.

    Another option for more sound is to swap your current subs for higher Sensitivity subs. The subs you have are rated 82 dB Sensitivity. If you can find some subs with high Sensitivity ratings (that will fit in your enclosure), each 3 dB increase in Sensitivity will sound noticeably louder at the same power output level.

    To sum up - Higher Sensitivity subs wired to match your amp's impedance design, either 2 or 4 ohm impedance will produce the best combination of sound output.

  • The way you have your speakers wired effectively reduces their impedance to half of what they normally are. Assuming each speaker is 4 ohm impedance, they are presenting a 2 ohm load to the amp. Is your amp rated for 2 ohm operation? If the amp is NOT rated for 2 ohm operation, there is a chance that the amp broke due to the unexpectedly low impedance, but hopefully it didn't damage itself.

    Here's a good loink on wiring speakers - https://hometoys.com/series-parallel-speaker-wiring-2/.

    thank you for the info. I Purchased the slingshot with the sub enclosure already installed and the Memphis speakers wired in it. All other components were missing. I was told this would be the correct amplifier to match the Memphis speakers. I pulled them out of the enclosure just to see how they were wired and I guess thats you’re what you’re referring to as parallel? I only ran one set of speaker wires from that box back to the amp and put them on the positive and negative terminals seen on the bottom right of the amp picture. It comes with a remote knob To control the signal which did nothing when adjusting it. However I did not touch the switch in the upper amp pic on the right. Is there another way to wire the speakers to have them be more powerful with this setup. Is it possible that I reversed the wires +/- ? I believe the power specs are right with the speakers being 2 ohms and the amp

    Able to power 4 ohms for the pair. Thanks in advance

  • Mike,

    I have heard several of those under the dash 6.5's and none of them had any noticeable bass what so ever.

    BKL is correct to a degree, you actually drop those puppies down to 1 ohms when you ran the wires like that so that is the first thing to check. Assuming you have a mono channel amp (based on your description) I would just remove one of the sets of wiring and ensure you have the Low pass set to filter out any highs from those Jl's and give it a whirl.

    You will know in a few seconds if that was the issue. If not you may have popped the AMP as suggested due to the power draw.

    Good luck brother.

    I just updated the post with some more info responding to BKL. I’m very mechanically inclined and have plenty of electrical experience however have never dabbled with stereo so this is all new to me. Appreciate any input you can provide. Thanks

  • Thanks Mike,

    I assumed you had the JL speakers that came in the boxes (at least the 3 I have seen had).

    Did you try to only connect one speaker and see how that worked? From what I am seeing your speakers are 2 ohm each so bridged they will overdraw your amp.


    At this point, from what I can tell you have a few of options.

    1) Buy a 2 Channel 2 ohm marine amp.

    2) Replace those speakers with 150 Watt 4 ohm units so bridged they are 2 ohm.

    3) Buy my new in the box (Factory taped) 10 Inch JL audio stealthbox for $600 and sell those under the dash units

    3a)

    Offer: Brand new (Still factory sealed) JL Audio Stealthbox Sub Enclosure with 10" Marine Subwoofer *REDUCED PRICE Item done

    I have a brand new in the box (Still factory sealed) JL Audio Sub enclosure for the Drivers side.
    There is nothing wrong with this unit, I just decided I wanted the 2 ohm version not the 4 so it's up for sale.
    I am happy to help install for free in the…
    $600 Delivered $550 pickup in GA


    Happy hunting sir.

  • Just to clarify what BKL explained earlier, two 2 ohm speakers can be wired in series to create 4 ohms of resistance. To do this, run a wire from the positive speaker output on the amp the positive terminal of the 1st speaker. Run another wire from the negative terminal of the 1st speaker to the positive terminal of the 2nd speaker, then run the final wire from the negative terminal of the 2nd speaker to the negative speaker terminal on the amp.

    Remember folks - this isn't a rehearsal, it's The Show!8)

  • Just to clarify what BKL explained earlier, two 2 ohm speakers can be wired in series to create 4 ohms of resistance. To do this, run a wire from the positive speaker output on the amp the positive terminal of the 1st speaker. Run another wire from the negative terminal of the 1st speaker to the positive terminal of the 2nd speaker, then run the final wire from the negative terminal of the 2nd speaker to the negative speaker terminal on the amp.

    Agreed, but his AMP would not be able to push those speakers well if at all in that configuration as that amp only pumps out a max of 190 watts at 4 ohms plus I'm trying to pimp hardware over here, sheesh.. 8o

  • Agreed, but his AMP would not be able to push those speakers well if at all in that configuration as that amp only pumps out a max of 190 watts at 4 ohms plus I'm trying to pimp hardware over here, sheesh.. 8o

    Roger that. I was not addressing the amp or it's compatibility, just the wiring and resistance of the speakers.

    Remember folks - this isn't a rehearsal, it's The Show!8)

  • Mike,

    Here's a picture to show what SlingLow was writing about:


    By running them in Parallel, you are essentially halving the Ohm (Resistance); in Series you double it.


    Since you have a 4 Ohm Amp, and the speakers are supposed to be 2 Ohm, you need to wire in Series as shown on the right side above (exactly what SlingLow said).


    Presuming the amp is still good, and you see (or feel) movement in the speakers, they are working.


    HOWEVER, let's put some caveats in there: You are running 6.5" subwoofers (Really, just mids with the input frequency turned down) in an open cockpit with the speaker location facing away from your listening position - four strikes against getting good bass. You are NOT going to get great thump. You're not going to feel it in your stomach. You will hear some bass guitar and drums when at a stop light and the engine is idling, but that's it.


    If you're wanting to really feel some thump, you will need to put 10" (or 12") subwoofers in a proper enclosure right behind your seat facing your back. And keep the stereo turned up and the engine rpm turned down. (Mind you, I am not telling you to do this - I am merely suggesting a realignment of expectations of what these speakers can do.)

  • I appreciate the offer on trying to sell me your unit but these already came with it and I like the fact that it’s pretty much concealed under the glove box and doesn’t take up any storage space. After just talking with the tech support at Memphis, it seems my only issue is the way the subs are wired in the box. Original owner wired them in parallel had them run in parallel...the tech tells me if I run each speaker in series (each sub has 2 sets of +/- one on either side...jump one + on one side to one - on opposite side of same sub to create a 4 ohm situation then run the remaining +/- back to the amp and do this for both subs) they will go from 2 ohm to 4 ohm because of the jumper and then run them parallel to the amp it will power at 300W at 2 ohms. Doesn’t make sense to me but I’m going to try it

  • Does what I just said in the above post makes sense?? Going to try it later but I wanna make sure I’m understanding it right. I agree with you on having the larger sub but I do not want to take up the area behind the seats were the storage compartments are. Just looking for a little bit of extra because the subs were already there and the factory sound system is very tinty sounding to me. All highs with no bass