Tri-Mode Amp

[jtm311]

Hello Guys,



I'm looking to hook up my amp as shown in the attached photo. Can someone tell me, do I need crossovers or can someone recommend what wire coil and what 100v non-poplar capacitors which I could use?

Thanks,
John

[mitch_04]

You can generally buy the filters from car audio suppliers, the high end ones are called Bass Blockers IIRC. However, I would recommend against this setup. I'm assuming the amplifier is relatively low wattage, probably 50X4 RMS, which when spread out over 6 speakers will not be enough to make the subwoofer sound good at all. Subwoofers tend to have large magnets, even the small ones, and under powering them hardly creates any sound at all. My recommendation is purchasing a 5 channel amplifier that has crossovers built into it. Generally, using capacitors for filters isn't always the best idea because they can't handle much power. They are OK for high end, but low end needs more juice than they can handle.

If you still want to continue, I'd google building your own crossovers, you should find a calculator that will tell you what to build. I have a book somehwere that describes the process, but I couldn't begin to tell you where it is. If you sold the amp you have an invested in a 5 channel, I think you'd be much happier. After all, comparing it to the cost of the car overall, it's hardly anything.

[jtm311]

You can generally buy the filters from car audio suppliers, the high end ones are called Bass Blockers IIRC. However, I would recommend against this setup. I'm assuming the amplifier is relatively low wattage, probably 50X4 RMS, which when spread out over 6 speakers will not be enough to make the subwoofer sound good at all. Subwoofers tend to have large magnets, even the small ones, and under powering them hardly creates any sound at all. My recommendation is purchasing a 5 channel amplifier that has crossovers built into it. Generally, using capacitors for filters isn't always the best idea because they can't handle much power. They are OK for high end, but low end needs more juice than they can handle.

If you still want to continue, I'd google building your own crossovers, you should find a calculator that will tell you what to build. I have a book somehwere that describes the process, but I couldn't begin to tell you where it is. If you sold the amp you have an invested in a 5 channel, I think you'd be much happier. After all, comparing it to the cost of the car overall, it's hardly anything.

Thanks I should have given more info,
RMS Power:

• 150 Watt x 4 Channel @ 4 Ohm
• 190 Watt x 4 Channel @ 2 Ohm
• 380 Watt x 2 Channel @ 4 Ohm Bridged

1800 Watt Max
and the subs are only 10" 600watt 4 ohms I would like to just connect my (2) 6x 9 to the amp as well.
John

[PT Sportwagon]

I would run the subs off the rear channel mono and the 6x9s stereo off the other channel. I have ran an amp three channel. while It worked you have no control over settings and sound quility. For the best sound I would run your 4 channel for front and rear full range and add another amp for the subs.

BTW: Your amp may say 1800 watts but I guess that it has a 20 amp fuse. there is no way it is 1800 watts. that is a marketing ploy it maybe 1800w test bench but not in the real world.

Tim

[jtm311]

Thanks for the help.
John

[UNBROKEN]

That absolutely will not work. Sorry.
You're gonna have to eliminate some speakers or buy a 2nd amp for the subs.

[jtm311]

That absolutely will not work. Sorry.
You're gonna have to eliminate some speakers or buy a 2nd amp for the subs.

I've changed based on the comments, however, I wonder why you say it would not work? the above is how a standard Crossover works, correct?


Thanks
John

[UNBROKEN]

Well....depending on what the amp is stable to and where you come up with the filter for the sub it can work. What is the amp stable to?

[makoshark]

What is proposed in the diagram will not work at all. You cannot bridge an amp to run a subwoofer and then run stereo speakers off of the same channels. You must use an amp designed to be bridged and you cannot run drivers off of that bridged channel in stereo. Use the proper equipment for the a proper installation. If you don't, then you will end up spending more money than you would have doing it the right way from the get-go

[UNBROKEN]

Tri mode can work....I think it's more work than I'm interested in and there's not likely a filter for the sub...may have to make your own. Again...more hassle than it's worth. get a small mono amp for the subs and go for it.

[mitch_04]

Well, I wouldn't say it can't work, I would say it's not ideal. It is stated to have an 8 ohm minimum subwoofer, and 4-8 ohm speakers. Your speaker resistance wouldn't be the problem. The problem would be adjusting for sound quality.

You should post the model number and brand of your amp, we can tell you more about it that way. If it is 2 ohm stable in stereo, the using 2 channels for high end and 2 for low isn't the worst idea.

Never go by "max" ratings of subwoofers or amplifiers, always go by the RMS (continuous) rating. It is what the amp will run on most of the time, other than a few big bass hits or volume cranks.

Unless the amplifier is, IIRC, CEA-2006 compliant there is no way to know whether the power ratings are correct. CEA-2006 compliancy, which is voluntary, means the manufacturer sent their product in to be tested by an independent facility, paying for it themselves, to have their power claims verified. Just because it DOESN'T have this does not mean it won't be an accurate rating, but if it DOES have CEA-2006 you know the power is correct. More often than not, ones without CEA compliancy are not accurate.

To find out power the formula is P=EI. If you have a charging system putting out 14.7 when the vehicle is running, you have P=14.7I. If you have a 30 amp fuse in your amplifier you know the maximum allowable amperage is 30, so P=14.7 x 30. When we solve, we get 441 watts, assuming 100% efficiency which is not going to happen. If you have an 80% efficient amp, you would have 352.8 watts. Divide this by 4 channels and you have 88.2 watts per channel MAXIMUM. Generally, RMS tends to be 50% of the maximum (rule of thumb) so your are looking at 44.1 watts per channel RMS. This is for a imaginary 4 channel amplifier with a 30 amp fuse and a 80% efficiency. Efficiency can change depending on the class of the amplifier (A/B/BD/D etc etc) so it's just a rough way of figuring out things.

I'd either get a separate subwoofer amplifier or a 5.1 channel amplifier.

[mitch_04]

By the way, quality products tend to overdo. I purchased a couple Rockford Fosgate BD1000.1 amplifiers for my system a few years back. They are rated at 1000 watts in mono at 1 ohm resistance. They come with a "birth sheet" that is an actual test of how much power they put out when they left the factory. One was rated at 16XX watts, the other 17XX. Quality product to say the least. I think they were 150 amp fuses in each amplifier, but I can't remember for sure.

[UNBROKEN]

My Mosconi amps aren't CEA 2006 rated....I think I'm safe on them being true to their word though. lol

[PT Sportwagon]

One of the old school sound quality champions in 0-100 class ran a single PPI pro-mos 50. running 48 speakers IIRC. including 8 ten inch subs. the crossover coil was about 4" x10". The installer said it was a nightmare to tune. Like other have said single amps in tri mode can be done. but takes alot to get right. Plus the right amp to accomplish it.

My old school US amps USA-150a use 2 8 gauge power and grounds. and have 2 40 amp fuses. but only rated at 75x2 @ 4 ohms, 300x1 4ohms mono. but clearly capable of much much more.

Tim

[UNBROKEN]

You can still find amps that make tons of clean power...they're just not cheap and they're damned sure not at Best Buy. lol

Both my Class AB 4 channels take 0/1 power and ground, 10 gauge speaker wire and are fused with 150amp ANL fuses.

As was mentioned earlier...any amp that says it's 1800 watts but has a 40 amp fuse...isn't. It can't be...just not possible. A good rule of thumb for shopping is 10 amps worth of fuse for every 100 watts of output. Anything less is lying.

[instro84]

One of the old school sound quality champions in 0-100 class ran a single PPI pro-mos 50. running 48 speakers IIRC. including 8 ten inch subs. the crossover coil was about 4" x10". The installer said it was a nightmare to tune. Like other have said single amps in tri mode can be done. but takes alot to get right. Plus the right amp to accomplish it.

My old school US amps USA-150a use 2 8 gauge power and grounds. and have 2 40 amp fuses. but only rated at 75x2 @ 4 ohms, 300x1 4ohms mono. but clearly capable of much much more.

Tim

I've ran tri mode with my old schoschool phoenix gold and orion hcca amps and once tuned it sounded well. For everyday listenining thou ir sucked i was destroyin batteries and alternators, they couldnt keep up with the demand and i didnt want to run a trunk loadof batteries and dual alternaters

[mitch_04]

It doesn't get much better than the old Orion HCCA amps. I remember a buddy wondering why the cost so much when they were rated (can't remember exactly) 50X4. He didn't realize they were somewhere near 1/2 ohm stable in stereo. Crazy good quality.

I didn't realized we had so many true car audio enthusiasts here! This section tends to be a little slow... guess pro-touring doesn't really want 4 batteries and 600 lbs of equipment either though!

[UNBROKEN]

I tried no to add too much weight...I kinda failed though I suppose. Tried to keep the system minimal but it still adds up.
I kept the OEM head unit running into a RF 3Sixty.3 DSP. Only run 2 amps...a pair of Mosconi AS 200.4's. a single JL 12W6v3 and a Focal Utopia Be N*7 3 way front stage. Add in deadening and materials and I probably still added well over 200 lbs to the truck. I opted for a 250 amp alternator and 1 XS Power battery though instead of multiple batteries.

Car audio is that one bug I just can't shake....no matter what I build.

FWIW I have 2 Orion 2100 HCCA amps in boxes...circa 1986ish. Big red *******s are still sexy.

[mitch_04]

I love car audio, it will be a true challenge to install a system I appreciate when I build a Pro-touring vehicle. However, my current project is a '85 C10 whose goal is more for looks and cruising, it lays pinchweld on the ground when the air is let out. I have 2 older Rockford 12" T2's receiving over 1500 watts RMS each that will go into a blowthrough box into the cab. Small volume with that much power will have to be fun.

Sorry for the thread hijack, but I hope the OP has a good idea what should happen.

[jtm311]

No problem in the hijacking I love to learn new stuff. So in the end I went with more show then quality, sorry to the true sound guys
I went with this amp just for the subs and will pick up a nice one for the the 6x9.

here is how it turned out.