Pa1200.1 @ 1 ohm w/ 2 mm1240dvc's??

IrishChamp

I'd like some input on whether I should go with two dvc subs and run them at 1 ohm (1200 rms) or go with svc subs and give them 2 ohms. (800 rms)
My thinking is this : more power and less gains is always good but I would still be technically overdriving the subs and pushing the amp to its limits (I've not found much into at all on how this amp does at one ohm). Also sound quality is a big concern of mine. On this front people seem to argue night and day, some can hear a difference, some can't.

So what to some of you veteran audio folks suggest?

On a side note, I figure some of you guys must have some experience with the new pa d1000.1. I've tentatively decided against it based on some input from another member in another thread based on the subsonic filter not being detestable. Is it up to par with the older pa stuff?

IrishChamp

Bump, I know someone must have first hand experience here.....

IrishChamp

Afternoon bump, I want to get my stuff ordered.

Another side note: anyone know what standard style mesh grills fit the mm1240's?

IrishChamp

I decided I didn't want to go any lower than 2 ohms so I went ahead and purchased two svc subs, so now it's either the 1200.1 or another sq amp at 4 or 2 ohms.
I'd still like some input however.

pentoncm

There is really no difference in SQ between 4, 2, or 1 ohm. The theoretical difference is that as the impedance rises the damping increases. The issue is that past a point, extra damping doesn't mean anything.

For instance, the polk amplifiers all have a damping factor around 150. Ok, then if you were to go and look at damping factors, the alpine mrx and pdx amps run at 1000, does this mean that alpine amps will sound 6-7 times better? No it doesn't. There is no problem running things down to 1ohm as long as the amp says that it is stable down there.

For all those people that say they heard a difference, I really doubt that they did double blind tests. Most people aren't scientific about these things at all. People don't control for different power levels, different amps, different drivers.

IrishChamp

Well I no longer have the option of running at 1 ohm so I will be getting a pa 1200.1 and feeding them 400 each at 2 ohms or if I can find something that makes 1000 or so at 2 ohms that would be great. Maybe if I come across a powerhouse a/b 2 channel amp I'll try running them at 4 ohms as well.
I've read about the great subwoofer debate far too much now, I just needed to pull the trigger so I can get the install started. 2 os seems like a nice middle ground especially considering I can't find much info on how the Pa1200.1 does at 1 ohm, one thread where the guy was troubleshooting something dying after running 1 ohm, no resolution posted.

pentoncm

Most people out there on forums don't actually know what SQ is. Honestly, you will never hear the true potential of your sub if you never properly EQ your car. A kick drum doesn't just compose the sub range (20 to 60Hz), those are only the fundamental notes. There are harmonics made by the drum that reach all the way up to 2kHz.

Too many people get stuck on specs and technologies when in the end if you aren't going to get a processor for you car, the bass is going to sound similarly amp to amp, and sub to sub. The major things that make a difference even w/o a processor are getting the placement right in the trunk and getting the phase correct. I'd be willing to bet that reversed phase will sound better in your car. Also, probably 90% of people have xover points that are way too high. Anything higher than 60Hz and you will start to hear pulling to the trunk as well as too much midbass bloat that kills your bottom end.

IrishChamp

Pentoncm,
I've been experimenting with the PEQ on my deck for some time now trying to get that sound that's so purely enjoyable, my vehicle is a single cab truck and it's proving harder to achieve satisfactory audio reproduction over my last vehicle (4 door sedan). I have a few install areas to put more work into and I'd like to actually play and measure tones to see where the problem areas are.
I've always enjoyed my sub x over point in the 60hz range, 80+ just ends up giving me a headache.
I'm currently running a 3 way full active front stage (sr6500 woofers and sr5250 woofers and tweeters), when I install the new subs I might try going with just the 5250's, we'll see.
Thanks again

pentoncm

Are you running passive xovers or are you active? 24db filters sound much cleaner than 12db filters (in a car). If you are ever up to it you may consider a bit one.

IrishChamp

Full active. My hu is a drz 9255 and it only has 18db x overs. I know many achieve fantastic sound with it though.

pentoncm

What are your EQ settings?

IrishChamp

Sub 63hz
Lows 50-250hz
Mids 200hz-6.3khz
Tweeters 6.3khz
All 18 db slopes
Phase what ever sounds best.
Peq 50hz -1.5 everything else flat.

pentoncm

Okay lets play around with your EQ settings.

Try something like this and see how it sounds.

(1) 80Hz -2db
(2) 315Hz -4db
(3) 1kHz -3db
(4) 3.15kHz -2db
(5) 12.5kHZ -2db


Your EQ is parametric so you'll have to play with the Q settings. I would use a narrow Q on 80hz like a 3, use a q of 2 on 315, the others use a q of 1 or 1.5.

IrishChamp

Well it's definayely a nice starting point!! First off much better midbass reproduction, fuller sound through out. I might adjust the gains on the tweeters a little, I had them turned town 6 db. I didn't get much of a chance to listen yet but I'm excited to listen more later.
Impressive!
Thank you!

IrishChamp

Looks like I might have found a arc audio fd1200.1
510x1 @ 4 ohms
1010x1 @ 2 ohms
1100x1 @ 1 ohm
Im thinking it would be a good fit.

pentoncm

Glad to hear its better. Its not going to be perfect but it will help a lot. If you really want to start tweaking you can always shift where those bands are located as well to see what sounds better.

You might move 315 down to 250 but don't move it up to 400, you might have a null at 400-500 and cutting there would make it worse.

1kHz should be good where it is.

You might want to shift 3.15 down to 2.5kHz or up to 4kHz and see how they do.

You might want to try to change your mid/tweeter xover point to 5kHz as well just to see. How are your mids aimed?

IrishChamp

I'll try some of your suggestions, see how it changes the sound. I just recently changed the mid/tweeter x over point so I will definitely try changing it back to 5khz now that the other adjustments are made. Mids are aimed at each other in the doors, no angle at all. Tweeters are both angles in the kicks, the right one faces the left headrest and vise versa, I wish they had a little more angle on them, it sounds best if you were sitting in the center legs dangling off the seat and about 1 ft tall

IrishChamp

Mid/tweet 5khz x over is better. I left everything else the same for now.

pentoncm

You might even try crossing the mids/tweets even lower because the mids aren't angled, try 4kHz. Also if that is correct what you posted before, change your mids so that they don't overlap with the midbass. So shift the mids from 200Hz to 250Hz on the low end.

IrishChamp

I'll check the bottom and try 4khz up top
Again, much thanks!!

IrishChamp

X over point of 4khz on the mids and tweeters seems to have brought up the sound stage a little, I'm going to try both a little but I think I like it. I added 1db to the mids and .5 more to the tweeters. Sounding good!!!
Now I'm really excited about getting some subs running again.

IrishChamp

Just pulled the trigger on a arc audio fd1200.1, 1010 rms @ 2 ohms, should be adequate. Im a little bummed I'm not getting a matching Poll PA amp but they will be under my seat so it really doesn't matter.

IrishChamp

I got a little crazy and bought all new amps, got some smokin' deals though. To keep it consistent I got all Arc Audio FD amps.
I'm wonder though if I should give the mids (sr5250 woofers) or the lows (sr6500 woofers) more power. I have a concervative 80rms x 4 and 100rms x 2 for my front stage.

pentoncm

How did you get your deals on Arc amps? From your dealer? I want to upgrade to the Kar 4 channel but I'd like to get it for cheaper than the $450 online.

IrishChamp

I bought them used. I got 3 amps for less than $450.

IrishChamp

The arc amps really seem to do the sr components and mm subs justice, system is sounding really nice. I was using a JL amp for the tweeters before, arc sparkles MUCH more, sound is more delicate and detailed. Lows and mids are sounding great too, a little fuller, a little punchier. Left right balance is better, sound stage is better, Funny thing is I didn't need to play with the gains, tweeters are not too harsh, everythig blends really well right off. All amps the gains are all the way down except the sub amp, it's up maybe 10% of the way to get low volume bass.

Vital

What are those distro blocks? Knu?
They look really cool.

IrishChamp

Yes and Thanks.

Vital wrote: »

What are those distro blocks? Knu?
They look really cool.

IrishChamp

Can anyone direct me to a straight forward guide to setting gains, phase, TA, and identifying dips, humps and harmonic abnormalities?
I do t have any anylizing equipment.

Edit: I have some test tones, I noticed when playing some of them the left right balance was way off, others sounded balanced.........