PDX-5 vs. XR-5S vs. ?

No problem. And for the record, I pulled the verification certificate on my MRX-V60 and it tested at an impressive 107 RMS x 4 + 373 RMS to the sub (@ 2ohms/14.4V.) This is compared to the 75/300 at which Alpine specs it. Roughly 40% and 25% higher on the full range and sub channels respectively!

 

The amp gain knob is to match the output of your head unit, not a volume or power.

Think of it like this - your head unit has a linear (or somewhat) output, based on volume. As you turn the volume up, the low level voltage to the amp increases.

The best way to think of the gain on the amp is in voltage as well. Most will have something like 4v on the far left, turning up to .5v or lower on the far right. You are basically setting up where the amp will reach its max clean output. If you have a deck that has 4v outs (at max volume) and you set it to 4v, you will only get full output from the amp when the head unit is turned up to that point.

So to answer your question about it mattering if the gains are in different points, or if you are affecting them in a non-linear manner - the increase is as linear as the head unit designer made the outputs in relation to the volume - AKA, dont worry about it.

I was just working with a pioneer with the sub output. I do not have enough time with one to be 100%, but I know Alpine uses the "max" as a 0db level, and you can only turn it down from that point. Not like cranking the gains on the amp, but like bringing the sub outputs to be the same as the other outputs.

I would guess that the Pioneer is the same, but I would test it out to be sure. I would probably set it at +1 or +2, adjust the gains, and then have a moderate amount of room to turn it up, and the ability to turn it down as well. Not a tuning issue or problem, something you definitely need to use


Last up, while "loud" is generally ignored in systems, it can definitely serve a purpose at lower volumes. It is basically an volume based EQ that will boost the lower and higher frequencies at low volumes, though it should go away as volume is increased. This may solve the low volume flat sound you are dealing with, but if you are using an EQ it can wreak havoc.

 

Thanks for the input, good stuff.

On the gains setting delta, this helps out, thanks. As for the sub output setting, I set the HU sub setting at 0db for the DDM max. So right now I am using a +3 setting for low volumes and cutting that to 0 if I want to get after it. So pretty much following what you've said.

As for the loudness setting, I used to use it, but what I found on my Pioneer HU anyway is that the boosting never went away at high volumes. If I turn the volume up high and turn the loudness on and off I can hear definite boosts at both ends. Would very much like to use a "true" loudness, but my Pioneers don't seem to implement it well.

End of the day, you may very well be right that a higher power amp is not going to help much, I may just have too high an expectation that I can have a "set it and forget it" car audio system. From what I've been hearing, seems that many are adjusting settings based on volume, not just on music type or recording quality.

 

Thanks for posting that. My problem with the V60 is that the sub output at 4ohm is only rated at 180W. Since my sub is a DVC 2ohm, presenting a 4 ohm load to the V60 the output will actual (probably) be a bit lower then it is with my RF, even if I take a higher rating from a verification cert. But, do appreciate the data.

 

That makes sense. Since I was purchasing my sub and amp at the same time I was able to get more for my money by purchasing a DVC 4ohm sub and the V60 at the same time. In your case, the XR-5s looks like a very good option.

 

Reviving my own thread here. I went ahead and pulled the trigger on an XR-5S, should be on my doorstep Friday. I still have a couple questions concerning how I should set the sub gains to get the maximum out of my Arc Sub. As a reminder, the XR has a 350W sub channel, while my Arc sub is rated at 250W (both RMS ratings).

I'd like to set the sub to the maximum possible out of it, then balance the front Focal components to the sub. From an earlier post, from Matt I think, setting the gains via DDM from a 50Hz test tone for 250W may not allow for the max sub power due to the transient nature of music itself. Given this, is there a rule of thumb or advice on how, or if, I should add some gain past the 50Hz tone's 250W reading? And no, my DMM does not have a max, or history, capability.

Comments, advice?

 

My first thought is to set the power via dmm around 350w. Then adjust as needed to match with the front stage.

 

That much higher, interesting. Thanks for the input.

 

It wont hurt the amp, and in a sealed box of appropriate size, it should not harm the sub - your sub should be easily able to shed the extra heat that 100w will generate, since you wont be listening to test tones for a long period of time.

This will also give you a theoretical max - you can turn it down from there using your head unit or a remote gain knob to get it to blend with the other channels, so it sounds good at your normal listening. Always easier to go down, than try to go up without incurring problems.

I have always been surprised at the lack of power needed for a good install with a solid midbass install.

You can also put in a bass heavy song, and (while this is much easier with a DMM that has a peak hold and averaging function)watch the voltage to get an idea of actual output during those peaks. Brief periods of extended high power will not be an issue, so if you see peaks well over 250w do not be concerned.

If you see continued voltage indicating higher output, it may be time to consider a ported box, more subs, or one with higher sensitivity/more power handling with more power to get the output you want.

 

Thanks again, appreciate the advice!

Although I think that your assumption that I don't listen to test tones for long periods of time may be flawed. I tend to listen to 50Hz test tones on long road trips, I love the monotony

 

Oh, in that case you might want to work on tuning the resonant freqency of the majority of the panels in your truck to 50hz. You could get away with less power and get a great sense of space by turning the whole truck into a speaker!

 

Just an update, I bought the XR-5S a few weeks ago and just got it installed this last weekend. I DMM tuned the sub output to 350W and the front component output to 75W. Given the Focal comp's output, I had to turn the comp's gain down to about a 50-60W max to get a good balance with the sub.

The sub output at the 350W gain setting is just about right. The extra 125W over my Rockford amp setup made a world of difference. I can now get a good sub thump with the components. I did need to do some equalizer mods to get a better balance and the sub channel is not turned up or down on the HU, still at 0db.

Matt mentioned the lack of need for a high-powered sub if you have a good mid-bass setup. Starting to wonder if my Focal components aren't giving me a good mid bass as I can easily get way too much high from the tweets when at loud volumes. I've had to turn the 8 & 10K HZ equalizer settings down a couple dbs to gain some balance, but still feels like something is missing.

 

New PDX5 should be hitting stores next month, which means two things.... older PDX5 amps on clearance, and I believe I read somewhere that the new PDX5 was going to have more power (I think I saw that on the Alpine CES2012 page).

Also, I'm about 80% sure I'm gonna spring for a MRX-V60 (this missing 20% being the cash to do so) - I saw it in a local store last weekend for $280 down from $400... Might be a little small on the power size for ya, but still a great buy at that price.

 

You are running passive components up front, not a processor and active, right?

If so, play with the EQ, but I dont know if you can get rid of the Focal tweet harshness. Some love em, some like em, some find em too harsh. A limited EQ will take some work, but you can do it!

Also, remember that a passive install, no matter the door treatment, will be a slight detriment. The passive is not designed to give the less efficient driver (midbass) more power, and due to the passive design it also waste's a little power. This means, in most cases, that you are a bit bright on the tweet, and need to make some adjustments.

Dont be afraid to boost on the left side of the EQ, and cut on the right (bass and treble, respectively), as you are getting it set up for your taste.

 

Passive, yes. Thanks for the comments, good timing as I landed on just this solution by trial and error (along with an iPad RTA and some pink noise). On the equalizer (7 band on my pioneer 4300) I have a 2-4db bass boost at 40 and 80HZ, then I cut all the rest of the eq by 2db across the mid-high range. Sounds reasonable but can still be on the harsh side depending on the tune. As a reminder, sub gains are set for max ouput - 350W, with the component channels set to about 50-60W. If I turn the comp gains down any more, mid-bass suffers too much, just like you've said.

I have considered going active, but not sure if I want to take the $$$ and time to get there. I have also considered trying to bi-amp the components off of the xr5s since I am not using the rear channels right now (rear coaxs are coming off of the HU). I could use the gains and hpf's on the amp to control level and cutoff, but it would all be by ear. But again, not sure how much time I want to expend.

Thanks again.