Sub Replacement Question

[xford]

Maybe a good ? for 1Loud.

First off 2006 LS with THX system

I bought a pair of CDT Audio HD-690CF.2's that I found a great deal on. They are 2 ohm, 89db Sensitivity, and 125 WRMS. Do you think the stock dedicated sub amp will drive these adequately? Secondly, when I pulled out the factory speakers (from the top as others have suggested - very easy with small 6mm ratchet!) the speaker grills had thin foam covering them from the inside that due to age were falling apart. Should I replace this thin foam - is it just to keep dust out or does it serve some other purpose like limiting rattles around the grill? There is a thin plastic liner that holds the foam in place that goes around the periphery of the inside of the grill - I assume I would remove that as well if not replacing the foam?

 

[1LoudLS]

I wouldn't worry about replacing the foam.

as far as the amp, those speakers have a lot higher powering handling than the OEMs did and are heavier duty, because of this, I would expect them to no be quite as loud as the OEMs were, but I think it would probably sound fine. but to drive them to their fullest, you may need a larger amp.

 

[xford]

Thanks 1Loud - install done - sounds like I will need a larger amp. Do you have a 2ohm Amp you would recommend for this application and how tough of an install?. Also question on polarity as the factory speakers had no indication of +/-.Left side (facing forward) Grey/Orange stripe & White/Green stripe. Right side Grey/Purple stripe and White/Blue stripe - I used the Grey's to positive and Whites to negative -am I good?

Comparison stock vs. CDT

Installed

I took the CDT logo off the speaker grill and added to the stock

 

[joegr]

... I used the Grey's to positive and Whites to negative -am I good?...

Not so much. Gray/Violet and Gray/Orange are negative, and White/blue and White/green are positive. This according to the factory wiring diagrams.

 

[1LoudLS]

Thanks 1Loud - install done - sounds like I will need a larger amp. Do you have a 2ohm Amp you would recommend for this application

well hese is the thing, since they are 2 ohm speakers (each), you will either need a mono amp that can do 1ohm stable (wired in parallel) or just run any mono amp at 4 ohm (wired in series) which would be running most amps at half power.

how tough of an install?.

super easy, get power right from a battery, and then if you get an amp that has auto turn on, you can just run the OEM amp's outputs into the new amp's inputs and you don't have to find a turn on wire, you could also remove the OEM amp, solder RCAs on to the OEM signal wires, and then find a turn on signal (tricky to get a signal with RAP)

 

[xford]

Thanks Joe! - I just double checked and that is the way I have it - I got it backwards above: whites to + and grey's to -

 

[xford]

Thanks 1Loud - understanding this is not audiophile setup do you have an Amp that you recommend that offers good bang for the buck? As far as the options above on 1ohm vs. 4ohm I would defer to your suggestion.

 

[04_Sport_LS]

I wouldn't get too volume happy until you get a different amp for the subs. Considering the low efficiency, (89db), low resistance, (2 ohm), and high power rating, (125w) ... it would be very easy to push the factory sub amp into "clipping",,, and blow your new subs. It's just as easy to blow speakers by under powering them,,, as it is by over powering them. Been there...done that.

 

[Alax7]

Nice subs.

I almost pulled the trigger on similar on older CDTs. Post on update on how they sound once you get a new amp. I was debating between these or maybe some 8" shallow mount subs with a custom enclosure but mounted like factory.

 

[Alax7]

Nice subs.

I almost pulled the trigger on similar on older CDTs. Post on update on how they sound once you get a new amp. I was debating between these or maybe some 8" or 10" shallow mount subs with a custom enclosure but mounted like factory.

 

[1LoudLS]

well if it were me, there are two ways I would go, the power handeling of the speakers is a little odd so its going to be hard to find a perfect match



A: you can find a small 2ch amp, which you would be running full power (2 x 2ohms)

a good option for this is this Rockford with 150w RMS X2 at @ 2 ohm
Rockford Fosgate PBR300X2 Punch Series 2-Channel Boosted Rail Amplifier



B: you can get a small mono amp and run it at half power with the pair of speakers wired in series (1 x 4ohm)

some of the best options for this are an Alpine, Rockford, and a Pioneer. they are all 300w x1 @ 4 OHM. of the three, the Alpine is probably the best amp, but both of the other two are a little cheaper and include a bass knob (the alpine has an optional one that needs to be purchased separately)

Alpine MRV-M500 V-Power 500W Class-D Digital Monoblock Amplifier

Rockford Fosgate R500X1D 500W RMS Prime Series Class D Monoblock Amplifier

https://www.sonicelectronix.com/item_63976_Pioneer-GM-D8601.html


if it were me, one thing would make my decision for me...

if I knew that those 6x9s were going to be enough for me (and I can already tell you that it wouldn't!) and I would never want more, then I would go with the 2ch Rockford because it is a super small compact amp that is easy to hide, can even be put next to or where the OEM amp is. However, if I ever though I might upgrade, then I would likely go with the Alpine cause its a really good small amp that when ran at full power @ 2ohm it kicks out over 500w RMS with is enough to drive most really good single 12"s.

 

[04_Sport_LS]

and include a bass knob (the alpine has an optional one that needs to be purchased separately)

Yeah,,, I was going to, (but didn't), suggest an amp with an on board gain control. That way you can dial in the subs to the rest of your system,,, then just use the bass contol on the head unit.

All of the Alpine pieces/parts I have used in the past has been quality stuff.

 

[xford]

Thanks - A couple of final questions:

First off I will be happy with these subs and dont plan to upgrade (have a replacement for my Vette on the way that will be a money pit ).

#1 Does the PBR300x2 have the "auto on" that would meet your comments from above on install:

"super easy, gray power right from a battery, and then if you get an amp that has auto turn on, you can just run the OEM amp's outputs into the new amp's inputs and you don't have to find a turn on wire, you could also remove the OEM amp, solder RCAs on to the OEM signal wires, and then find a turn on signal (tricky to get a signal with RAP)"

#2 I assume it also has the "On board gain control"? And are there specific install items you would recommend I purchase?

I looked at the link/specs but its not totally clear to me as I am no stereo expert...

 

[1LoudLS]

#1 Does the PBR300x2 have the "auto on" that would meet your comments from above on install:

yes, as long as you use "high level inputs" (the speaker wire coming OUT of the factory amp) the amp has auto turn on.

#2 I assume it also has the "On board gain control"?

all amps have their gain knobs mounted "onboard" of the amp, this amp also has a port that you can use a remote bass knob (so you can change the level from a seperate knob mounted where you can reach it from the driver's seat)

are there specific install items you would recommend I purchase?

yes, if you would like a remote bass knob, you will want to get this too

Rockford Fosgate Punch PEQ Wired Remote Punch Bass/Treble Equalization Control for select 2007 and Newer Rockford Fosgate Amplifiers.

and you will also need some wiring for the amp. since you will integrating into a OEM sound system, you wont need a complete amp kit, best bet is to get an 8 gauge power only kit since it wont come with RCA cables that you wont need but does come with power, ground wires and a fuse kit. with having the amp and the battery both mounted into the trunk, I tend to do the install a little differently than most cars, first I wouldn't used the ground wire and ground to the body like normal, instead I would cut the power wire in half (protip: wrap black tape or shrink wrap on both ends of the piece of wire that DOES NOT have the fuse to note which piece of wire to use for the ground) then run both the power and ground wires from the amp right to the battery itself. then you may or may not need a little speaker wire to go from the OEM amp to the new amp and from the new amp to the speakers.

 

[xford]

Thank you - very helpful!

 

[xford]

1Loud - Love this little amp and thanks again for the recommendation!! Seems very well made and has some heft for its small size

Just to confirm I will be using the speaker wires OUT of the stock amp to the inputs displayed below (White +/- Left and Grey +/- Right. Should the Blue "Adjust" be set at 4V or 6V or in between ? Any recomended starting point for Gain and Freq settings?

 

[xford]

Also - The "Power Only" wiring kit I purchased Power cable is 17 ft long - w/o doing the measurements I assume cutting in half will leave adequate length to accomplish your suggestion:

"I tend to do the install a little differently than most cars, first I wouldn't used the ground wire and ground to the body like normal, instead I would cut the power wire in half (protip: wrap black tape or shrink wrap on both ends of the piece of wire that DOES NOT have the fuse to note which piece of wire to use for the ground) then run both the power and ground wires from the amp right to the battery itself."

 

[1LoudLS]

1Loud - Love this little amp and thanks again for the recommendation!! Seems very well made and has some heft for its small size

yeah its a pretty darn good amp for such a tiny footprint. I've used it a couple of times on Harleys cause it can fit under the faring pretty easy.

Just to confirm I will be using the speaker wires OUT of the stock amp to the inputs displayed below (White +/- Left and Grey +/- Right.

correct.

Should the Blue "Adjust" be set at 4V or 6V or in between ? Any recomended starting point for Gain and Freq settings?

I'd probably start with it turnedall the way to 6v. since the amp has a little more power than the speakers can handle it will give you a little extra safety room. I'd also set the X-over to "LP" and set the freq to 125hz to start and probably lower it a bit once starting to listen to it, but depending on where the mid bass is cut for the door speakers (it cant be too low with how small the woofer is) it might even go up a little bit. all depends on how those drivers sound and what they like. as far as the gain goes, I would start with it turned all the way down, since it is getting signal from a factory sub amp, its probably going to be one of the strongest signals the amp would ever be designed for, especially compared to a factory radio's output or even a set of preouts from an aftermarket deck. with the radio up about mid way(make sure the new amp and subs are not playing unusually loud), I'd take a listen and see if it needs to be turned up at all. if it does, it really shouldn't be much at all. often when installing these micro/brick amps on factory radios I leave the gain all the way down, 10%-15% tops.

 

[xford]

Completed the install over the weekend. Still playing with the settings & have the gain set all the way down to min. In the instructions it said to turn Gain all the way down to where you hear nothing from the radio then roll it up to where you can hear minimal distortion - even all the way to min I can still hear the radio...The Adjust was set to 6v and no pop from the amp at start up so I have not tweaked it further. Additionally, I have experimented with both the All Pass and Low Pass settings. Since I am using the high level outputs out of the factory sub amp I wonder if the DSP is already sending the Low Pass frequencies since I don't seem to hear a big difference between All Pass and Low Pass. Unsurprisingly, the bass is powerful and can easily overpower the rest of the sound system. Thus far the best result, for my listening taste, has been to use the "Bass Reducer" setting on my iPod.

Thanks again for the advice

dd

 

[joegr]

Yes, only the lows are sent to the sub amp.

I'd plug the open battery vent on the left side of the battery, otherwise hydrogen can still vent into the trunk and interior.

 

[xford]

Yes, only the lows are sent to the sub amp.

I'd plug the open battery vent on the left side of the battery, otherwise hydrogen can still vent into the trunk and interior.

Never caught that one before - It may be that it is already internally capped in some way since I would think I checked on install...but IDK. I will need to see if I can get a look w/o pulling it out - maybe with a light and mirror - if open any suggestions on a good method of capping since its kind of a tight fit and odd shape? Thanks Joe!

 

[embe]

Nice. I still can't believe how small they make Amps nowadays compared to the real estate the older ones took up.

Minor suggestion: on the red power wire going through the metal seatback, you might want to throw a grommet or something on there. Over time the vibrations can cause the metal edge to chafe through the wire insulation.

 

[joegr]

... if open any suggestions on a good method of capping since its kind of a tight fit and odd shape? Thanks Joe!

Maybe a short piece of hose with something plugged the end of it?

I think that group 65 batteries have the single vent connection that we need, and group 66 batteries have two. The battery for my BWM had two, but the car only had one vent hose (like the LS). The battery came with a plug to put into the unused vent connection.

 

[xford]

Minor suggestion: on the red power wire going through the metal seatback, you might want to throw a grommet or something on there. Over time the vibrations can cause the metal edge to chafe through the wire insulation.

Good idea - I will do that

 

[xford]

Followed RollinLS 's "How To Article" on modifying the Stock 2-way speakers - pretty easy and noticed an improvement in the sound quality.