XD600/6 or PDX-5?

[Budge]

Before we start on a "which is better" thread (which really isn't the purpose of my question), let me explain what my situation is.

I have the basic 8 speaker "hifi" system with 2 way components in the front, 2 way coaxials in the rear, and the two underseat midbase woofers. I have replaced the stock amp with an MS-8 and the underseat woofers with a pair of Kicker SSMB8s. At this time, I have no plans to add a dedicated sub in the trunk.

So I am considering replacing the front components with a set of Rainbow SLX 4" components. Ideally, I would like to use the xd600/6 or the PDX-5 to power the components (separately using the MS-8's crossovers) and the Kickers. The xd600/6 can give me 75 watts per channel x 6 (including the woofers) and let me keep the woofers in stereo. The PDX-5 can give me 75 watts per channel x 4 and 300 watts x 1 mono channel to be separated by the two woofers. With the PDX-5, I assume the actual power to the woofers would be 150 Watts each and 2 ohms instead of 4 if I wire them in parallel (true?).

Will the Kickers work better in stereo or with more power? Or should I buy the upgraded crossovers from Rainbow and bridge the extra two channels of the XD600/6 to the woofers in stereo? Options, options....

[808MGuy]

Here is some maybe not so helpful insight as I recently changed from running the SWS-8 at 2 ohms bridged to running them at 4 ohm stereo. They definitely had more output at 2 ohms bridged because my Zapco DC650.6 puts out 500W at 2 ohms bridged on the sub channels. I recently switched to running them at 4 ohms stereo which steps the power down to 100W each. I have been able to compensate for the loss of overall output with the DSP available in the amp so I'm having no problems with volume and the system response is fairly linear so I don't have to crank it to hear any bass. I never noticed a difference SQ wise running them in stereo or mono. Most of the difference was just volume. I would have liked to leave them running bridged but the issue in that configuration was heat. I have no idea how efficient or inefficient the Kickers are compared to the SWS but the SWS are pretty inefficient.

That said, I also have experience with a 600/6 as I installed one in my brother's vette running a set of Zapco competition components active and a single JL 10W1 sub. I felt that the JL sub was a bit underpowered by the bridged channels of the 600/6. You really have to crank it to get it going which is usually the case in an underpowered system. It seems that a class D amp like the JL xd doesn't have the same kind of balls that a class AB amp like the Zapco has so in your case, I would opt for more power and go with the PDX-5. I wouldn't recommend getting the passive crossovers for the Rainbows as you will be defeating the purpose of having the processing power available in the MS-8.

[Budge]

Thanks for the response. After reading your post, I had another idea. What if I used the XD600/6 to run bridged power to each underseat woofer, used the extra two channels to power the rainbow mids, and let the MS-8 handle the tweeters? That way, I get to keep 150 watts to each underseat woofer in stereo. I just don't know how much power the Rainbow tweeters need. I think the MS-8 will give them 28 watts RMS.

[kmarei]

from my personal experience, the built in amp in the MS-8 sucks
would rather get a small 2 channel amp to power the tweeters

[Budge]

Originally Posted by kmarei

from my personal experience, the built in amp in the MS-8 sucks
would rather get a small 2 channel amp to power the tweeters

So would you go with the XD600 in stereo or the PDX-5 in mono for the Kickers?

[kmarei]

Originally Posted by Budge

So would you go with the XD600 in stereo or the PDX-5 in mono for the Kickers?

depends on your crossover points for the kickers
if it's around 150hz, i'd run them stereo
if it's closer to 80hz, like mine
then which ever options puts out more power

[808MGuy]

Originally Posted by kmarei

depends on your crossover points for the kickers
if it's around 150hz, i'd run them stereo
if it's closer to 80hz, like mine
then which ever options puts out more power

Ran my SWS to 140Hz mono for awhile. Still couldn't really pick up the difference when I switched over to stereo. I used to run them at 80Hz like you but have since raised the crossover to 140Hz and running my a/d/s 344is to 160hz. With some EQ adjustments, you can actually get it to sound pretty good. Much better midbass response but you lose a little on the low end.

[kmarei]

Originally Posted by 808MGuy

Ran my SWS to 140Hz mono for awhile. Still couldn't really pick up the difference when I switched over to stereo. I used to run them at 80Hz like you but have since raised the crossover to 140Hz and running my a/d/s 344is to 160hz. With some EQ adjustments, you can actually get it to sound pretty good. Much better midbass response but you lose a little on the low end.

My issue is anything higher than 100hz and I can hear the bass coming from underneath me. Below 80, and I feel the bass coming from the door speakers.
But I run my BSW 4" mid down to 80hz as well, except I'm only giving them 45w rms
All 18db/octave
I'd love to give them more than 120w each, but my current amp puts out 240 at 1ohm, so I'd have to add an amp. And I can't be bothered to find a spot, along with my ms8 And my 5 channel amp.
Was thinking today of disconnecting the right sub, and giving the left one 240 (my amp puts out the same power into 2ohm as 1ohm) to see how it sounds with more power

[kaigoss69]

I have the MS-8's internal amp powering 14 speakers (7 mids and 7 tweeters) and it does it with ease and it sounds very very good (and I have pretty high standards). Granted, the speakers are L7 2ohm so you may have different results with 4ohm aftermarket speakers. OP, I believe your idea of using the MS-8 to power the front tweeters is a good one, as well as utilizing the XD600/6 amp in 4-channel mode to power the front mids and underseat woofers. That's how I would do it. L7 does not assign the side and/or rear speakers very much volume at all [edit: when set to "driver", "passenger" or "front"], so the MS-8 amp is ok for that purpose as well.

[808MGuy]

Originally Posted by kmarei

My issue is anything higher than 100hz and I can hear the bass coming from underneath me. Below 80, and I feel the bass coming from the door speakers.
But I run my BSW 4" mid down to 80hz as well, except I'm only giving them 45w rms
All 18db/octave
I'd love to give them more than 120w each, but my current amp puts out 240 at 1ohm, so I'd have to add an amp. And I can't be bothered to find a spot, along with my ms8 And my 5 channel amp.
Was thinking today of disconnecting the right sub, and giving the left one 240 (my amp puts out the same power into 2ohm as 1ohm) to see how it sounds with more power

I had the same issue. But seeing that Technic and VP run their systems with similar xover points I decided to just keep going higher and eventually I did find a sweet spot. I still feel like the bass is coming from in front and not under my butt. I does require a bit of adjustment with your EQ to get the transition between the under seats and the mids just right but once you find it, you'll be surprised how much of an improvement it is.

I think my settings are as follows (I will double check when I get to my laptop at home):

Tweeters: HP 5kHz, -6dB/oct
Mids: HP 160Hz, -12db/oct, LP 4kHz, -12db/oct
Woofers: LP 140Hz, -24dB/oct

[Budge]

Originally Posted by kaigoss69

L7 does not assign the side and/or rear speakers very much volume at all [edit: when set to "driver", "passenger" or "front"], so the MS-8 amp is ok for that purpose as well.

That brings up a good point. I use the "all" setting most of the time, since I have an E90 and my kids are with me a lot. I wonder if that makes a difference. Either way, the MS-8 will still control all of the channels.

[Budge]

Right now, I'm considering getting the XD600/6 with the assumption that it gives me more options with that 6th channel than the PDX-5. Right now, I'm running my HP at 200Hz in stereo. With the XD600/6, I can run the front mids off of CH 1 and 2, then bridge CH 3 and 4, 5 and 6 for the Kickers. Or I can use CH 1 and 2 for the tweeters, 3 and 4 for the mids, and 5 and 6 for the Kickers. The XD600/6 does not have as much power in 6 channel mode at the PDX-5 does, but it does let me keep the stereo option.

On a side note, I was reading the manual for the XD600/6, and came across something I didn't understand. It states:

"Rated Power at 14.4V with less than 1% THD+Noise (20Hz - 20 kHz)
Stereo, all channels driven:
75W RMS x 6 @ 4 ohms, 100W RMS x 6 @ 2 ohms
Bridged, all channels driven:
150W RMS x 3 @ 8 ohms, 200W RMS x 3 @ 4 ohms
Rated Power @ 12.5V with less than 1% THD + Noise (20Hz - 20 kHz)
Stereo, all channels driven:
60W RMS x 6 @ 4 ohms, 90W RMS x 6 @ 2 ohms
Rated Power Bridged, all channels driven:
120W RMS x 3 @ 8 ohms, 180W RMS x 3 @ 4 ohms"

Where are they getting the 14.4 and 12.5 voltage ratings? Isn't the system 12 volts from the battery?

Also, the XD600/6 has an input sensitivity dial for each pair of channels. How are these supposed to be calibrated when using the MS-8?

[kmarei]

Originally Posted by Budge

Where are they getting the 14.4 and 12.5 voltage ratings? Isn't the system 12 volts from the battery?

Also, the XD600/6 has an input sensitivity dial for each pair of channels. How are these supposed to be calibrated when using the MS-8?

i believe 12.5 is with engine off, 14.4 with engine on

have you thought of the JL Audio XD700/5?
give same power on the 4 main channels as 600/6, but the sub channel (mono) puts out 400 watts into 2ohm, so you can wire both your kickers and run them so they each get 200w

if money is no object, how about a 600/6 to power tweeters, mids, rears and a 400/4 bridged to run the kickers

levels i started by keeping them all at half way on my amp
any differences will be automatically adjusted by the MS-8 when you calibrate
ideally you set the gain as low as possible to keep the noise floor low
BUT high enough to get max power without having to have the head unit volume on max, as it begins to distort 7 or 8 clicks from max

[JerryK73]

I just bought an XD600/6 and an XD600/1. I prefer JL amps over Alpine since traditionally Japanese companies have never been very good at making amplifiers..........head units are a different story.

[Budge]

I decided to go with the XD600/6. Since I don't have a dedicated sub, and all my mids are 4", I have my mid/woofer crossovers set to 200 Hz. At that frequency, I'd really like to keep the underseat woofers in stereo.

The question now is...how am I supposed to tune the MS-8 with the XD600/6? It seems like I could set the XD600/6's input sensitivity to almost any level I want, and the MS-8 is still going to adjust it's output.

How do you adjust a second amp when using the MS-8?

[kaigoss69]

Originally Posted by Budge

I decided to go with the XD600/6. Since I don't have a dedicated sub, and all my mids are 4", I have my mid/woofer crossovers set to 200 Hz. At that frequency, I'd really like to keep the underseat woofers in stereo.

The question now is...how am I supposed to tune the MS-8 with the XD600/6? It seems like I could set the XD600/6's input sensitivity to almost any level I want, and the MS-8 is still going to adjust it's output.

How do you adjust a second amp when using the MS-8?

JBL recommends an initial amp input sensitivity setting of 2V.

[Budge]

Originally Posted by kaigoss69

JBL recommends an initial amp input sensitivity setting of 2V.

Are you saying that the MS-8 should be set to put out 2 volts per channel to the secondary amp?

[Technic]

Originally Posted by Budge

Are you saying that the MS-8 should be set to put out 2 volts per channel to the secondary amp?

The amp gains should be set to 2V sensitivity while the MS-8 acoustic calibration is run.

[Budge]

Originally Posted by Technic

The amp gains should be set to 2V sensitivity while the MS-8 acoustic calibration is run.

So I need to adjust the input sensitivity of the XD600 so that it is only putting out 2v per channel while running the acoustic calibration? Is that correct? I just reread the manual. Where did y'all find that?

[Technic]

Originally Posted by Budge

So I need to adjust the input sensitivity of the XD600 so that it is only putting out 2v per channel while running the acoustic calibration? Is that correct? I just reread the manual. Where did y'all find that?

You got the amp gains function wrong... a 2V sensitivity does not means that the amp will be outputting 2V. It means that the amp input stage will be level matched to an input level of 2V max.

The JBL MS-8 project manager suggested that amp gain setting in the DIYMobile forum. Use it as a guide.

[Budge]

OK, then how do I set the input sensitivity on the XD amp to 2v? It has a turn dial with no numbers.

[Technic]

Originally Posted by Budge

OK, then how do I set the input sensitivity on the XD amp to 2v? It has a turn dial with no numbers.

Minimum is 4V RMS, max is 100mv... just set it in the middle and listen to the results. You can always adjust it more after calibration.