Need recommendation for Sub/Amp/Speaker - Page 7

ticconi · 02-06-2009, 08:02 PM

Quote:

Originally Posted by SirGCal

Sorry.

for an amp like that, there are tons.. pretty much depends on what your ears like. You could get a 4-ohm single coil sub and run it direct (cheapest option) or a DVC 4-ohm sub and run it 2-ohms.

For example, an MTX Thunder4500 T4510-04 or
Infinity Reference 1050w or MTX JackHammer JH4510-04 or (the list really does go on and on and on...) or JL Audio 10W1v2-4 would run just fine. Any 4-ohm 200-300W RMS sub. Or 4-ohm DVC, again huge list...

can you explain in laymens terms why someone would buy dvc over svc and the whole 2 ohm and 4 ohm thing. I dont understand the pros cons of each. This would releave some of the mystery for me thanks

spife7980 · 02-06-2009, 09:09 PM

you buy a dual voice coil because it can allow for more wiring options to reach the impedance you desire.

say you have a DVC 4 ohm you can wire the coils in parallel to get the impedance down to 2 ohm or in a series for a load of 8 ohms. with a dvc 2 ohm you can wire in parallel down to one ohm or series up to 4 ohms. so parallel = 1/2 the impedance and series is double.

if you take 2 4 ohm svc subs you can wire both of the coils together like you would on a dvc for either a 2 or 8 ohm load.

but if you have 2 4 ohm dvc you can wire each speaker down to 2 ohms and then both of them together to lower it to one ohm or back to 4 ohms.

basically each time you wire something in parallel you split the load in half. and series you double it. to get to what ever load you want, such as on your amp to get the most out of it you would want it at 2 ohms so you get the full 300 watts it is capable of, and the different coil and ohm configurations are a way to get there.

from the 12volt.com (shows you how it results in differences in power as the load changes. just general because it depends on the technology in the amp. such as your infinity or some alpines where it doesnt double but rather steps up in increments not like most)

An amplifier rated at an output of 100 watts per channel into a 4 ohm load will produce 50 watts per channel into an 8 ohm load, and only 25 watts into a 16 ohm load. The same amplifier will also produce 200 watts per channel into a 2 ohm load if the amplifier is capable of full output at a 2 ohm load. The crossover not only separates the frequency ranges for the different loudspeakers in a speaker system, but also separates these frequency ranges and impedance (resistance) ranges for the amplifier.

An Amplifier Rated at 100 Watts per Channel at 4 ohms which is Capable of Full Output at a 1 Ohm Load per Channel
Load Watts per Channel % of Power at 4 ohms dB change
1 ohm 400 400% +6
2 ohms 200 200% +3
4 ohms 100 100% 0
8 ohms 50 down 50% -3
16 ohms 25 down 75% -6
32 ohms 12.5 down 87.5% -9
64 ohms 6.25 down 93.75% -12
128 ohms 3.125 down 96.875% -15
256 ohms 1.5625 down 98.4475% -18
512 ohms 0.78125 down 99.21875% -21

hopefully i made this clear and not just alot of muck.

ticconi · 02-06-2009, 09:30 PM

Quote:

Originally Posted by spife7980

you buy a dual voice coil because it can allow for more wiring options to reach the impedance you desire.

say you have a DVC 4 ohm you can wire the coils in parallel to get the impedance down to 2 ohm or in a series for a load of 8 ohms. with a dvc 2 ohm you can wire in parallel down to one ohm or series up to 4 ohms. so parallel = 1/2 the impedance and series is double.

if you take 2 4 ohm svc subs you can wire both of the coils together like you would on a dvc for either a 2 or 8 ohm load.

but if you have 2 4 ohm dvc you can wire each speaker down to 2 ohms and then both of them together to lower it to one ohm or back to 4 ohms.

basically each time you wire something in parallel you split the load in half. and series you double it. to get to what ever load you want, such as on your amp to get the most out of it you would want it at 2 ohms so you get the full 300 watts it is capable of, and the different coil and ohm configurations are a way to get there.

from the 12volt.com (shows you how it results in differences in power as the load changes. just general because it depends on the technology in the amp. such as your infinity or some alpines where it doesnt double but rather steps up in increments not like most)

An amplifier rated at an output of 100 watts per channel into a 4 ohm load will produce 50 watts per channel into an 8 ohm load, and only 25 watts into a 16 ohm load. The same amplifier will also produce 200 watts per channel into a 2 ohm load if the amplifier is capable of full output at a 2 ohm load. The crossover not only separates the frequency ranges for the different loudspeakers in a speaker system, but also separates these frequency ranges and impedance (resistance) ranges for the amplifier.

An Amplifier Rated at 100 Watts per Channel at 4 ohms which is Capable of Full Output at a 1 Ohm Load per Channel
Load Watts per Channel % of Power at 4 ohms dB change
1 ohm 400 400% +6
2 ohms 200 200% +3
4 ohms 100 100% 0
8 ohms 50 down 50% -3
16 ohms 25 down 75% -6
32 ohms 12.5 down 87.5% -9
64 ohms 6.25 down 93.75% -12
128 ohms 3.125 down 96.875% -15
256 ohms 1.5625 down 98.4475% -18
512 ohms 0.78125 down 99.21875% -21

hopefully i made this clear and not just alot of muck.

ok cool man much appreciated. So I would rather overpower the speaker by 75 watts then underpower it by 25? RMS on the sub is 225.

**SirGCal** · 02-06-2009, 09:36 PM

Quote:

Originally Posted by ticconi

ok cool man much appreciated. So I would rather overpower the speaker by 75 watts then underpower it by 25? RMS on the sub is 225.

Well, ideally you'd run right at the RMS of both. but going a little over or under isn't really going to make any difference. If you run grossly over or under powered, you will potentially damage the speaker either from too much power or inadequate control. Generally from 50-125% of the rated RMS of the speaker is where you want to be. So for a 200W RMS speaker, say 100W - 250W of RMS power.

spife7980 · 02-06-2009, 09:39 PM

but personally i would do the under by 25 on the 4500 just as a comfort factor. make me feel warm inside knowing i dont have to worry about someone riding along and cranking it past its limits. but thats just me and stupid people that i have to drive around.

ticconi · 02-06-2009, 10:59 PM

crap i just figured out how to wire them in parallel to get 2 ohms. I think i'll power it with 300 watts instead of 200. Just have to be careful as all.

spife7980 · 02-06-2009, 11:30 PM

wait. i thought you had one single voice coil 4 ohm sub? the mtx 4500 if so you can only present a 4 ohm load to the amp. if im mistaken in what you actually have then i apologize.

**SirGCal** · 02-06-2009, 11:39 PM

Quote:

Originally Posted by spife7980

wait. i thought you had one single voice coil 4 ohm sub? the mtx 4500 if so you can only present a 4 ohm load to the amp. if im mistaken in what you actually have then i apologize.

Me too, I'm a little confused.

GCool · 02-07-2009, 06:44 AM

Quote:

Originally Posted by SirGCal

And as for competition rigs; saying you won't win sound competitions in a Jeep; poppycock!

http://www.sirgcal.com/2ktj/

God I was fat in this picture... And UGLY! Shesh.. Someone just photochop me out of my own picture would ya?

USACI I see...... I have 4x world Champ in USACI good old Ralph place.... Did you ever go to finals?

**SirGCal** · 02-07-2009, 10:42 AM

Not in many years. I don't have the $ or time anymore. And none of my personal vehicles ever went, only customers vehicles I designed. (and actually most of my vehicles in final were mostly in IASCA and their various SQ classes. I'm a bit newer (ohh, maybe a decade or so) to uSACI and their SQ formats. And never was a DB fan).

So yea, I've been but not for myself. Unfortunately, I never had the budget to make a world champ for myself, I always had to do the work for someone else to reap the reward. I'm I little jealous.

Very cool achievements you've made.

Unfortunately now with my medical condition, I will likely never have the chance again to ever get to enter my own vehicle as I doubt I'll ever be able to build another one to that level. I guess I missed my chances.

I try to make the local shows when I can. Occasionally I get someone who's willing to do the physical work and just wants my guidance. That's about as close as I get to doing installs anymore. I'm going to try one more when/if I ever get a new vehicle. It will likely be my last and will take probably way to long to complete, if I ever can. If that happens, and I build it strong enough for at least the < 600W SQ class, I might try to enter it into the uSACI and see if I can get to finals. Until then, that might be one thing that I personally miss out on. Only time will ever tell.

ticconi · 02-07-2009, 03:13 PM

i don't have the speaker in my posession yet so when i look at it i'll know. I just thought sirgcal said it was a 4ohm dvc model.

spife7980 · 02-07-2009, 04:48 PM

mtx makes both dual and single voice coils in the 4500. but we're pretty certain that the loaded enclosures came with single voice coils. you need to check on that though. should be good to go either way. just have to be a careful when you set it up and tune it etc so that you arent overpowering it

ticconi · 02-07-2009, 05:12 PM

right on i am going to be picking it sub and amp up wed when i get payed. It was in the 40's here today which is beautiful for mich this time of year so I got to take some measurements. This was actually the first time when i went to the self wash the water didn't freeze on the paint lol. I went to buy the 3/4 MDF but they were out should have more this week. And I start my new job on Monday!! So hopefully I can have this done sooner or later. Im gonna post pics of the build although i know it's not anything special hopefully it will help someone.

ticconi · 02-08-2009, 09:13 PM

ok quick question my dimensions for my box HxWxD are: 7.25x24x11 These dimensions it will have 2.5" of clearance for the downfiring sub. It's going to be alot wider than it is longer does anyone see a problem here? I hope not because I want to get started on this!

spife7980 · 02-08-2009, 10:55 PM

are those the internal or external dimensions? if it is external it comes out to .71 ft^3 minus the displacement of the sub according to the rockford link earlier. its a tad smaller than the recommended but if that fits then its no biggie really. if you measured 2x to make sure it will fit i think you could go ahead and start fabbing it up. if it doesnt for some reason its only like $8 in materials around here so no huge loss there besides time but you get some experience and know how.