Bridging and Stability question.

[BloodBlight]

Ok, I am in the final stages of overhauling my sound, and have an amp question.

The sub I got today (it was given to me), it is an MTX 10”. I don’t have the papers with me, but it was the middle of what they offer (220 RMS 450 peek). It has dual 4 Ohm inputs.

I also have two 6” JLs in the sails. What I am looking to do, is to take a four channel amp, put two of the channels to the JLs (planning to keeps the amp at 4 Ohm and about 75 watt – the JLs happy point), and the other side is the question.

It was suggested (before I was given this sub) that I bridge the other two outputs (for power) and get a 4 Ohm sub. Well, now I am being told by another guy to put the sub inputs in chain, and run it at 2 Ohm. But I don’t see many amps that have a rating for bridged 2 Ohm. And I seem to remember some amps listing a “Stable @ 2 Ohms” status.

So I have three ways to wire this.
1. Sub in par @ 2 Ohms, amp bridged.
2. Sub in Ser @ 8 Ohm, amp bridged.
3. 1 Coil to 1 channel on the amp.

Will I have problems running a lower end amp (or one just not rated for) at 2 Ohms in bridged mode? Should I run one channel to each end of the sub....

I have not purchased an amp for the subs yet, so my options are open. But I have already spent too much. ^__^ I still need a stealth box.

Should I do a nicer 2 channel? I don't know...

Speaking of amps. What are your folks preferred brands? Got a good used one for sale? A stealth?

[Nikos95]

Re: Bridging and Stability question.

Your third option there 1 channel to each coil, NEVER do that on a DVC sub. Reason being each channel will never be exactly the same and you will eat the coils out of it, and it will sound horrible!

As far as how to wire the sub, what amplifier do you have? Make model?
Some amps are even .5ohm stable bridged and some will only do 4ohm, some wont even bridge! As far as anything else goes, bridgeing a 4-channel on one set to run a sub isn't bad at all, I generally wouldn't do it because I like heavily overpowering my subs to keep them clean and tight at high volume without the amps having to work. But it does work and just fine, just depends on what kind of amp you are running. You might be familiar with some of JL's and a few Pheonix Gold amps, and some others amps that will put out 400 watts at anything between 1-4 ohms so it doesn't matter how you wire it.

Personally I use alot of JL, MB Quart, Kicker, Crossfire, Denon, PPI, Orion, older Rockford Power or Type RF, Kove, Polk, Eclipse or Pheonix Gold amps. I know thats quite the list, but I do alot of Custom and High end systems in cars, its one of the things I do. But as long as you stick with a big dog company that has a good rep for high quality you get yourself your worth 99% of the time, if high end is what you want.

[BloodBlight]

Re: Bridging and Stability question.

I don't have an amp yet, glad I don't. :)

Ok, first, THANKS for the grate response and the tip on running multiple channels. That makes a lot of sense, and could have gotten me into major trouble!

I am new to the game of amps, and there are too many brands to count today. From what I have already been told, I was able to find an older RF for my drivers, but have not been able to find a good one for the sub (in that category). And when I looked for newer RF stuff, I was like “HOLLOY CRAP!” If there is THAT much referb on the market, I KNOW I don’t want it.

I have seen a lot of Phoenix Gold, but was wary because the prices looked a little TOO good. I checked crutchfield real quick and it lists their Phoenix Gold as 4 Omh Bridged Stable... Looked for a manual to one, also listed that.

JLs where just, OUCH.

Found a couple that look good:
MBQ RAA2400 - - About $220 /w SH
Crossfire VR402 - - About $210 /w SH
Orion Orion-4002 - - About $140 /w SH! (Lists as being stable at 1 Ohm)

What is your opinion on these? I realize I won’t be over driving the 10”, but again, not planning on shaking the neighbors house. ^__^

The Orion is really tempting because of both the price, and that it was the only one listed as being stable at 1 Ohm (even though I will be running 2 Ohm on both sides).

[BloodBlight]

Re: Bridging and Stability question.

On closer inspection, it appears the Orion is last years model, and they have a whole new look now. I assume these are close-out units.

[nda0602v6]

Re: Bridging and Stability question.

The Orion is really tempting because of both the price, and that it was the only one listed as being stable at 1 Ohm (even though I will be running 2 Ohm on both sides).

No thats not correct. If you wire the coils on the sub you have in Parallel, its going to create a grand total of 2-ohms (not on both sides). If wired like this, any amp you use will be running at 2-ohms. Weather or not the amp can safely handle the 2-ohm load bridged all depends on the amp itself. Like others have stated, find an amp that can operate at lower ohms while bridged. The Orion you mentioned that can go all the way to 1-ohm bridged would work fine.

[nda0602v6]

Re: Bridging and Stability question.

Some other amps you may want to look at are Hifonics. They have been recommended here before. I found this one on Ebay...stable down to 1-ohm:

http://cgi.ebay.com/HIFONICS-TITAN-T...QQcmdZViewItem

Your best bet would prob be ebay...Do a search for mono amps. Crutchfield is awesome but they are pricey.

[Nikos95]

Re: Bridging and Stability question.

Those are all 2 channel amps, erm the Crossfire might be a 4 I don't remember too well. Those amps are nice but not one you would want to use.

http://www.hifisoundconnection.com/S..._by/sell_price

Here is a link to a Refurb Kicker Sub amp, its a good powerful amp puts out
400x1 at 2ohms, so your sub would get 400 watts solid. They have good strong crossovers, now they arn't as good as thier older counterparts. But Kicker is still a very large, in demand, and heavy hitter in autosound and competetions, I have bought amps and speakers from this company before, always happy to do business with them, and they are authorized by Kicker to sell thier product so you WILL get a warranty still. Just an idea..

But try to look for a Mono Amp that gives you around or slightly above the rated power of the sub at 2ohms.

Hifonics, isn't a bad group of amps, I don't have alot of expierience with them, but they make a fairly decent amp for thier price.

Ohh and just for the FYI on the amp prices being too low, don't worry about too low generally when you are buying from non-licensed retailers, that MB Quart amp you qouted Retails for around $500-$600. On average markup on mobile audio/video equipment can get as high as 100-150% and more on amps and speakers.

[Nikos95]

Re: Bridging and Stability question.

No thats not correct. If you wire the coils on the sub you have in Parallel, its going to create a grand total of 2-ohms (not on both sides). If wired like this, any amp you use will be running at 2-ohms. Weather or not the amp can safely handle the 2-ohm load bridged all depends on the amp itself. Like others have stated, find an amp that can operate at lower ohms while bridged. The Orion you mentioned that can go all the way to 1-ohm bridged would work fine.

The Orion 4002 ratings are as follows

100x2 4ohm stereo
200x2 2ohm stereo
400x1 4ohm mono

That amp IS NOT 1ohm stable. You need to really watch who you buy these amps from, alot of no-body companies list incorrect numbers, and some of these will be impossible to find real ratings on.

The way you want to wire your sub is both voice coils together to start, positive to positive and negative to negative, that will wire it in Parralel, and give you a 2ohm load, then wire one of the coils to the amp. Don't put each coil on a channel thats what I was saying before.

[nda0602v6]

Re: Bridging and Stability question.

The Orion 4002 ratings are as follows

100x2 4ohm stereo
200x2 2ohm stereo
400x1 4ohm mono

That amp IS NOT 1ohm stable. You need to really watch who you buy these amps from, alot of no-body companies list incorrect numbers, and some of these will be impossible to find real ratings on.

Sorry, my mistake about the Orion. He posted earlier that "The Orion is really tempting because of both the price, and that it was the only one listed as being stable at 1 Ohm" I didn't bother to look up the specs on that Orion Amp before I posted....thanks for catching that.

[BloodBlight]

Re: Bridging and Stability question.

Sorry guys, I didn't say what I was doing clearly.

I plan get a two channel because I will have a total of three subs (along with my 4 drivers on another amp). Two are two low power JLs (4 Ohm) and one dual coil MTX (two 4 Ohm). So I will run the JLs in parallel on one channel (so those will be at 2 Ohms on one channel) and the two MTX coils in parallel on the other (also at 2 Ohm). I am doing it this way rather than buying a bigger mono amp so I can control their levels. I have two sub output on my head. I plan on putting some of the mid on the JLs and most of the low on the MTX.

Sound right? I was thinking this would be the best bang vs. performance...

[BloodBlight]

Re: Bridging and Stability question.

I am in the works to get a nice Memphis PR300 for like $140 (used, but in pristine condition). It’s used, but I have heard good things about the brand. It will push like 250 ish in the config I have planned…

You thoughts?

[Nikos95]

Re: Bridging and Stability question.

Okay you shouldn't actually put the different subs on different channels like that either, you can't really control the output of each sub that way. In that case you are going to want to run either a BIG 4-channel because on one set you will run your JL's stereo and wired by themselves. And on the other set you are going to run your MTX wired into most likely 8ohm unless you find a 2ohm mono 4channel amp..

Personaly I would get a smaller set of Sub amps, don't worry being you arn't pushing a ton of power, but I would deffinetly run 2 small sub amps, one to the set of JLs and one to the MTX. Plan on spending even online around 100-150 each..

The only way to control output on a 2channel the way you are thinking unless you want to buy another set of $100 boxes, is to balance it with your deck, but that would make your main speakers sound like CRAP because they will follow.

What JL's and what size are they?
What is the model number of the MTX?

[BloodBlight]

Re: Bridging and Stability question.

I'm not at home right now, but the JLs are 6w0's 6", 4 Ohm, Optimal power is said to be about 100 Watts per unit.

The MTX I think is a Thunder 4500. It is a 10", Dual 4 Ohm, RMS of something like 225 Watts.

So, to go into more detail, my head has a total of 10 outputs. 4 Amped (FL, FR, RL, RR), and 6 Pre-amp (FL, FR, RL, RR, SUB1, SUB2). So I would not be running a single lead from the HU and splitting at the amp. I have two independent sub channels that I control at the HU (HPS Level & LPF Level). The controls do NOT have a level select in the HU if I recall though. Now that I think about it, I would not be able to adjust the volume for the subs independently.

Lemme re-think this, I'll post agian later.

[BloodBlight]

Re: Bridging and Stability question.

Ok, I DO have a control that will let me adjust the volume to the second sub output.

However, now that I am looking at some mono amps, I see some prices that aren’t too bad… How are the Pioneer Premier amps? I have a PP head and am VERY happy with it, so it caught my eye.

How about the HiFonics Zeus series?

[Nikos95]

Re: Bridging and Stability question.

Both of those are decent amps, by all means.

2 sets of subwoofer outputs? as in 4 RCA jacks? Because a standard sub out from a Pioneer deck is Left/Right sub outputs, which basically means it has a lowpass crossover in the deck itself, and it doesn't fade. Which would mean you cannot control each sub off the deck either, only as a set...

But if you go with 2 mono's I think you would be very happy.

Just something to think about-

You might want a seperate crossover for the Jl's because you don't want midrange comming from them and you don't want bass notes under about 100hz going to them. So you are going to want something they call a Bandpass crossover set somewhere I would guess around 100hz-300hz would be good. That will keep them good and clean sounding.