I hate cars

I only learned because I did the same thing when I was new lol. Good luck with the sale.

tquint14

Does "high level input" mean it wont accept a bal signal

NIGHTEHAWK

Thanks for looking out, I dont want to get on their bad side.

Trunk Monkey

iTrader: (1)

You sure that accepts balanced?

I might know where you can get a Kenwood XR-4s for cheap if you wanted to go that route.

Most JL amps do. Fastest way would be to just call them. I'll take their word over a forum

KJ TL-S

iTrader: (9)

I'm not sure at all, in fact, I'm guessing it doesn't. But I'm considering looking for a processor of some sort. It seems that not only will that free up my amp options, it should also make everything sound better as well. Would you agree? I'm thinking of the audio control matrix or something else that I might be able to find used. Processor and used amp might be about the same price as a new amp anyway.

That being said, any opinions on that Kenwood line? I can't use the one you mentioned unfortunately, it's only 4 ohm stable bridged. This damn w6 sure would be easier to work with if I could wire it to 4 ohms.

jda123

A matrix is not a processor. They are talking about MS8, Bitone.1, 360, etc.

Trunk Monkey

iTrader: (1)

The Matrix acts as an LOC w/ level adjustment AND will convert our pre-amp signal to unbalanced.

A processor (3sixty.2, MS-8, Bit.1/Bit.10, Alpine's, etc) will do quite a bit more along with what the Matrix does. These include:

Time Alignment
EQ (usually 1/3 octaves and L/R independent)
User Adjutable x-overs/slopes
Auto-tune
Logic7
etc etc

But beware, a processor can make thing quite a bit worse than just using passives if you want to dig into it without knowing what you're doing. By all means, you could just set up the x-over/slope for your speakers..maybe do the TA if you wanted and call it quits. But me personally, I'd rather save $100+, not worry about TA and just do the Matrix if you're not "that" into audio

I hate cars

I remember back when life was simple. I wish I had never heard of anything besides passive crossovers.

KJ TL-S

iTrader: (9)

Haha, I can definitely see how that can happen all too easily. And I'm not wanting to fall down that rabbit hole, but I might be willing to peak over the edge to see what it looks like.

Another "processor" I considered was the arc audio SRI after I got an email back from brad at arc audio. Any thoughts on that? I think it is made to integrate aftermarket systems with the factory head unit. Not sure how much else it does tho. Anyone know?

jda123

Just get a good quality used/reman/refurb amp that accepts the balanced signal. The fosgate power line are the only current amp that I know of that will accept balanced and is 2 ohm stable bridged. Something like a JL 450/4 will do rated power at 8 ohms bridged (IIRC), so that could work with the JL sub. Either of these are better amps that most of what has been discussed on this thread.

Here is a copy of the birthsheet that came with my fosgate T400-4. It is a pretty powerful little bugger. It is hard to read, but it says 246w at 4 ohms bridged. You can usually double when you go to 2 ohms:

jda123

Also, amps that are 1 ohms stable are usually made better and will last longer when you use them at 2 ohms or even 4 ohms - basically, they are made to handle double what you are throwing at them. That is what I call engineering headroom. Not always, but generally. Some doods are still pounding with their .25 ohm stable MTX, Fosgate, etc. amps from the 1990s.

tquint14

man! this fosgate t400-4 is starting to catch my attention.
correct me if im wrong JDA123..but say i used the chn 1/2 to power my front stage @ 4ohms i can still bridge channels 3&4 n get approx 250+watts.

jda123

Yes, or you can get a 2 ohm sub and push closer to 500w. Make sure you get a newer one that accepts the balanced signal - a good seller should be able to help you to verify.

KJ TL-S

iTrader: (9)

So that amp can run the fronts at 4 ohms and the sub at 2 ohms?

niebur3

Okay, I would like to just say, I am confirmed this with many of the finest installers in car audio.....

The TL does put out a balanced signal, but not a true balanced by nature. A true balanced has 3 wires: Positive, Negative and Ground. Ours only has a Positive and Negative, so it is a Differential Balanced. Now with that said, our factory HU puts out maybe 1/2 volt max, so it is not a big deal. Meaning you can solder RCA ends directly on to the signal wires before the amp and run a RCA from those to ANY amp. Now, it will be very low voltage, so a line driver would be a smart move to help noise. I would would personally tap the signal before the amp, run through a quality line driver and buy any amp that performs the job best for my application and not stress about the whole balanced signal thing!

niebur3

Also, don't get caught up in 400 vs 500 watts for a sub. Unless you are blasting the system, it will be running well below that most of the time. Same thing with midrange/midbass and tweeters. Tweeters at max will most likely only draw maybe 30 watts from the amp, no matter how much you have available. The speaker will pull the max it needs to reproduce the note accurately up to the max of the amp. Lower frequencies will require more power to reproduce than higher frequencies. Music is dynamic, unlike a sign wave. 600 watts is only 3dB louder than 300 watts. So, 500 watts is less than a dB louder than 400 watts (turning the volume knob up a notch or two will make up the difference).

The most important thing in a amp (IMO) is that it reproduces the information without coloration, has a good reliability rating and gives you a good match in power to drive your speakers (meaning it produces 400 watts at 2 ohm and you actually can wire your particular speaker to 2 ohm). If you have a 4ohm final load sub, it doesn't matter what the amp does at 2ohm or 1ohm because you aren't able to take advantage of it.

Boosting the input voltage gives you many advantages. So, budget for a line driver even if that means you have to buy a slightly less powered amp. You can really drive the input voltage and end up realizing more real world wattage vs a higher watt amp with no line driver.

Also, don't give tips while tipsy because you can't proof read them to make sure all your advice makes sense to the average person....lol!

I hate cars

This is great info. I've connected amps that did not use balanced inputs to the HU and never had issues. I think the signal was a little cleaner with less noise and all, but I never had bad results with any amp I hooked to the factory HU balanced or not. On DIYMA, one poster seems to think you will fry components by running balanced with unbalanced.

It seems like the whole you must run an amp with balanced input is fairly new, like 6 months or so. I didn't hear much about it in the old days. So what I'm getting from your post is that it's a good idea to run balanced but not necessary. Is this right?

Also, I had to run a line driver with the MS8. It would always say signal low when run straight from the HU. I could bypass the line leveling and it would work but it could use more power.

Originally I ran the line driver in the trunk, next to the MS8. I later moved it to the stock amp location behind the kick panel and it cleaned the signal up a bit. What little noise I had was completely gone. I crossed power and signal a couple times on it's run to the trunk by not planning ahead and the extra power over that run seems to have solved all noise issues. I was also using very cheap Radio Shack RCAs. Now I run slightly more expensive and shielded Knu cables. I'm actually a believer in a line driver when it's implemented correctly.

Trunk Monkey

iTrader: (1)

That 400-4 is powerful, but why no love for the p900.4? The fosgate line has more wiring options & will accept balanced though..so I get your point. I tried to find a 800-4, but all used were too expensive for my build.

Bench tested from PASMAG
150x4@4
235x2@2
477x2@4


Jerry, I knew that our signal wasnt a "proper" balanced setup, but still ventured to guess that noise would be introduced. Wouldn't you just be amplifying the noise too??

tquint14

niebur3 by line driver u mean a reg LOC?
this being case and going back to the original topic of this thread $500 budget, im almost tempted to go alpine amp/type R sub and JBL GTO comps since i could get all this at BB have them install it and use my $600 gift cards.

KJ TL-S

iTrader: (9)

That T400-4 looks really tempting to me. A powerful, four channel that is 2 ohm stable bridged. Can anyone explain to me how the amp knows to do 4 ohm or 2 ohm? If I hooked up 4 ohm components to the front channels and bridged the rear channels, would it know to give my sub 2 ohms? Sorry if thats a stupid question, I'm just trying to understand as much as possible about all this.

Also, to IHC, the dimensions of the amp are 13-5/8"W x 2-1/4"H x 9-5/8"D. All but the width seem like they would be ok for going under the driver's side seat. Based off your experience, do you think that would cause a problem? I would put the floor mat over any amount that I had to, but I just dont want 4 inches of amp sticking out past the seat.

niebur3

From my sources and experience, because our HU only puts out 1/2 volt or less, it won't damage anything. Typically a true balanced signal is WWWWAAAAYYYY higher in voltage then unbalanced.....hence why it could damage the amp by overdriving the input/pre-amp section. Ours is super low voltage, so it shouldn't make a difference. I haven't heard of any noise issues doing this.

When I mean a line driver, I am not talking about a LOC (line out converter). Those are 2 different things. The LOC takes speaker leads from a HU and turns it in to usable signal, required for any after amp install in our cars. A line driver accepts a RCA in, boosts voltage, and sends the signal back out through a RCA. This is good for pretty much any system....it make makes sure your actually giving your amp enough voltage to produce the power it is actually rated at. The signal boosting also helps to reject noise.

And FWIW, aftermarket HU's even need a line driver. Even if the HU says "4 volt RCA outs" it is probably driving 1-1.5 volts continuously.

Hey Matt (I hate cars)....I have some really nice RCA's on the way I'll have to send you some info on. Huge discount on them and some of the best quality you can get.

niebur3

When you connect the speakers, the impedance of the speakers and how they are connected determines how much power the amp will deliver. Look up Ohms law. So, if you connect 4ohm speakers to the front channels, the amp will produce power up to what it is rated at for 4ohms. If it is rated for 100 watts at 4ohms, it will max at 100 watts (maybe running in the 30-40 watt range most of the time). As long as you never drop below the minimum impedance an amp can run at, you will be just fine.

djtsmith007

iTrader: (1)

Pretty much exactly what i wrote on another forum post. Good job!

niebur3

I really can't see this amp producing anywhere close to 500w on the rear 2 channels. Rule of thumb is one thing, but this amp will be limited by the internal power supply, and since Rockford doesn't show a rating at 2ohm Bridged (even though they say it is stable) I doubt it produces anything extra and may actually produce less.

For example....The ARC Audio KS 1200.1 is rated at: 1200x1 @ 2ohm but only 1000x1 @ 1ohm.

If this amp really did produce more, Rockford would plaster it everywhere!

KJ TL-S

iTrader: (9)

Man...just when I think I'm getting close a decision, more information comes into play.

By the way, what type of line driver is necessary for this application. As I said before I'm looking to amp the fronts and a sub. Have an example of one that would work?

Trunk Monkey

iTrader: (1)

Also would like to know some of the better line drivers. Never looked at this aspect of car audio.

Hell..I might pick one up, drop the 3sixty.2 & run passives again.

niebur3

There are many good line drivers.
ARC makes 2 good options....the ALD or the SRI
Tru Makes very high end 8-channel line drivers....Line-8 (8i and 8is)
Audio Control and Phoenix Gold make good ones you can usually find used
Sinfoni make one that retails for almost $2,000. (I have one on my demo board)

Trunk Monkey

iTrader: (1)

I'll just pick up that Sinfoni then..

Seriously though, in my case, I only use the front L/R and that signal is given to every other channel (sub, center, front, rear) for my processor. Is there something like this that will just take our Front L/R pre-amp signals and channel sum them?? Is that what the Matrix does or will this not be possible w/o a processor??

Like I said, I wouldn't mind just running the passives again and getting rid of the 3sixty.2. So...

Front L/R (pre-amp) ---> line driver ---> One set of RCA's to sub amp and 2 sets of RCA's to p900.4

The p900.4 can be run active, though only on 12db slopes. I'm wondering know if a line driver is what I need. When I set my gains using a DMM back before I sold all my gear, I had to crank the gains to get the voltage I calculated/needed. I thought the 3sixty.2 was supposed to put out like 4-5V, but I guess not.

I hate cars

Does the 3sixty have at least 6 channels? Let me know before you put it on the market.

FWIW, the line driver can be used to stop any noise that's being picked up between the HU and amp in the trunk. Just get it physically as close to the HU and with a much higher voltage being sent to the amps and the amps having to amplify less, less noise will make it's way into the system along the wire runs. It won't help noise that's there from the HU but it will help anything else.

Also, the RF BLD is a great 2 channel line driver that you can switch between balanced and unbalanced along with level and clipping indicators for only $70.

niebur3

^^^What he just said!!!

Signal summing is a whole different story. You will need something that will specifically sums the signal, which a line driver by itself won't do. The ARC SRI does. JL makes one that does and otherwise, you need a processor. The matrix will not signal sum.

And if you didn't see before....MATT....I have some sick RCA's coming my way. You want these for you car

Trunk Monkey

iTrader: (1)

Yeah, it's 6-channel outut. Supposed to be 5v out too....bullshit. Essentially the processor is a line driver, but I'm still not sure why I had to really crank the gains on my amps (Sundown 100.4 specifically) to reach the voltage needed for the cx62 comps. I understand music is dynamic, but still...I figured it'd be nice to do it with a DMM and see if I was way high or way low. After my calculations, I set the amp using the DMM and the mids were LOOOUD. I could hear tons of noise from them and they were loud as hell by about volume 5 on the knob lol

= sqrt (voltage x ohms) ----> voltage at amp output


http://www.sonicelectronix.com/item_...687322953.html

KJ TL-S

iTrader: (9)

I know there has been a lot of talk about the Phantom 900.4....but there is also this. Not sure when Sonic will have it in stock tho or what the price will be.

http://www.precisionpower.com/html-v...ps/P900-5.html

tquint14

So?? to sum it up, our systems will require a line driver no matter which amp(jl,fosgate etc) is used even if the amp itself accepts a bal signal..correct? This being due to our HU only puts out 1/2 volt

jda123

My HU put out .9 volts - tested in my car. No line drivers for me. My fosgate, JL, Audison and Zapco amps all work just fine with 900 milli volts.

Monkey, you need a large resistor and a o scope to dial in you amps like that. Not easy. I borrowed an o scope from a juco here in town when I was doing my IB experiment. Punch amps are fine, but I kind hold them in the same regard as other middle level amps - I would rather spend a few more bucks for a nice one. On some brands there is not much difference in cost.

niebur3

So you measured it at .9 volts at full volume??

tquint14

Jda123 so u r not running any line drivers,LOC or processors? And r u going pre amp?

Man! So much for a $500 budget lol. I was looking into going all polk from best buy since got $600 in gift cards and all their polk line is on sale

I hate cars

Due to the "loudness" eq of the stock HU, I like to set mine where I never have to turn it up past 20 and the majority of the listening can be done at 10 or lower on the HU. Otherwise your highs and lows can get kind of thin at high volume. The line driver is needed for this. I don't like to run any component at full power.

During the setup of the MS8, on the screen where you're setting the level, with the HU at 40 the MS8 says the signal is dirty and won't accept it.

Trunk Monkey

iTrader: (1)

40

Didn't know about factory "loudness". Where'd you hear that?? I have mine set to never go past 25ish

Hopefully mine will sound even louder and cleaner once I deaden the actual door panel. Has anyone tried 8's in our doors?? I've always wanted to try. Random thought

DiamondJoeQuimby

iTrader: (2)

Completely off topic, kinda, but do you know if the 1st gen TSX has the same diff balanced output? I have read all sorts of conflicting info on that car. I'm getting ready to a system in the wife's car and am trying to decide what to do with the input signal.

I hate cars

There's an older post on DIYMA about that with RTA of the stock HU. It's basically a built in loudness function. Bass and treble boosted when the volume is low and it gets flatter as the volume is raised. It's not on or off, pretty linear.

I've tried it to see if I can hear a difference with just my ears. I'll turn the volume on the MS8 way down so I have to crank the HU and compare it to the volume on the MS8 almost maxed and the bass does seem to hit harder with the MS8 turned up and the HU volume down with overall SPL being at about the same level.

An RTA would be the only true way to find out though.