Decent monoblock amp for sub?

[BLindsay]

So i was thinking i have my Alpine type R 12" (new design) in very nice box i built for it and i was thinking of taking it out of my car and bringing it inside. If i did that i would need a single channel (or an amp that can be bridged) to drive it, its rated for 500rms (currently i have a 600wrms alpine amp driving it)

basically i was thinking either

A: use the Type R and spend $400ish on an amp to drive it

B: buy the eD A2-300

[Big Daddy]

I like option 1. Building a subwoofer is much more fun than buying one. Take it out of the car, modify it, and use it.

External Amplifiers for Passive Subwoofers:
http://www.parts-express.com/pe/show...number=300-812
http://www.parts-express.com/pe/psho...TOKEN=50414889
http://www.amazon.com/Audiosource-AM...8465481&sr=8-5
http://www.amazon.com/Boston-Acousti...8465645&sr=8-4
http://www.amazon.com/TBI-200-su-Sub...8465645&sr=8-5
http://www.polkaudio.com/homeaudio/p...ifiers/swa500/

Also go to the Upgrading & Building Subwoofers thread and look at the pictures of the subwoofers that I build and the external amplifiers. There are a lot useful links in Post #2.

[BLindsay]

Originally Posted by Big Daddy

I like option 1. Building a subwoofer is much more fun than buying one. Take it out of the car, modify it, and use it.

External Amplifiers for Passive Subwoofers:
http://www.parts-express.com/pe/show...number=300-812
http://www.parts-express.com/pe/psho...TOKEN=50414889
http://www.amazon.com/Audiosource-AM...8465481&sr=8-5
http://www.amazon.com/Boston-Acousti...8465645&sr=8-4
http://www.amazon.com/TBI-200-su-Sub...8465645&sr=8-5
http://www.polkaudio.com/homeaudio/p...ifiers/swa500/

Also go to the Upgrading & Building Subwoofers thread and look at the pictures of the subwoofers that I build and the external amplifiers. There are a lot useful links in Post #2.

that second one you listed, it does 512rms at 8 ohms, you think thats a good amp to go with? i could wire my sub up for 8 ohms

i liked that polk one too but it does its peak power at 4 ohms which my sub can only be wired for 2 or 8 ohms

[Big Daddy]

Originally Posted by BLindsay

that second one you listed, it does 512rms at 8 ohms, you think thats a good amp to go with? i could wire my sub up for 8 ohms

i liked that polk one too but it does its peak power at 4 ohms which my sub can only be wired for 2 or 8 ohms

Parts Express is a reputable place. Don't be afraid to call them and ask them. I have ordered many things from them with absolutely no problem. Their amps perform well and are reasonably priced.

The Polk amp is a good one, but a bit overpriced. You have to call Polk and ask them about the specifications. I don't have any experience with that amp.

[Blu-Dog]

Originally Posted by BLindsay

So i was thinking i have my Alpine type R 12" (new design) in very nice box i built for it and i was thinking of taking it out of my car and bringing it inside. If i did that i would need a single channel (or an amp that can be bridged) to drive it, its rated for 500rms (currently i have a 600wrms alpine amp driving it)

basically i was thinking either

A: use the Type R and spend $400ish on an amp to drive it

B: buy the eD A2-300

If you have a place to hide it (it does have fan noise) take a look at QSC's website. I have two of their amps - the 1450 and 2450 - but the 850 would do the trick for a single sub. Hooked up as a single channel, it drives 850 very, very clean watts RMS.

http://www.guitarcenter.com/QSC-RMX-...40-i1145670.gc

[BLindsay]

my sub is dual 4 ohm voice coil so it needs to be around 500rms at either 8 ohms or 2 ohms (currently its wired for 2 ohms)

the polk one looked nice but it was @ 4 ohms, i just am not famliar with some of the brands so im just a bit hesitant having never heard them. and the first one is only like 150w

[mdabb]

You could wire the dual voice coils in a series at 8 ohms or find a two channel 4 ohm stable amp.

[BLindsay]

Originally Posted by mdabb

You could wire the dual voice coils in a series at 8 ohms or find a two channel 4 ohm stable amp.

i thought it was a bad idea to run a 2 channel amp on a dual voice coil sub (ie 1 channel per coil) for the risk that if the channels werent perfectly matched power wise it could cause dmg buy putting more power to 1 coil over the other

[mdabb]

Originally Posted by BLindsay

i thought it was a bad idea to run a 2 channel amp on a dual voice coil sub (ie 1 channel per coil) for the risk that if the channels werent perfectly matched power wise it could cause dmg buy putting more power to 1 coil over the other

Nope, it's called independent wiring. One voice coil per channel sharing the same signal and powered by an equal amount of wattage (matched gain). "DO NOT" wire the voice coils out of phase.

You get uneven loading on a subwoofer to subwoofer connection in a series. Multiple subwoofers connected in series, the speakers can modulate each other causing distortion.

Technically if you want, you can hook up only one of the voice coils if need be. However it changes the parameters of the sub and a -3 db in volume.

DVC subs offer more wiring flexibility which is why they are used in car audio applications, as it is more common to use bridgeable amps and/or amps that can handle loads ranging from 8 ohms down to half an ohm.

[Blu-Dog]

Originally Posted by BLindsay

my sub is dual 4 ohm voice coil so it needs to be around 500rms at either 8 ohms or 2 ohms (currently its wired for 2 ohms)

the polk one looked nice but it was @ 4 ohms, i just am not famliar with some of the brands so im just a bit hesitant having never heard them. and the first one is only like 150w

Bridged, the QSC is about 850W. But a word on power ratings for car subs: Don't believe the hype. Car amps aren't anywhere near as linear in power output as line-powered amps (hence the use of caps to keep the output high), and a good line amp will fry the coils on the average car sub at sustained levels.

You can get away with much lower power levels, and it will be cleaner, with a typical line amp. Even the QSC 850 in non-bridged mode has plenty of power for your purposes.

The R12 line are power hogs - but they are very clean, so once you get past the minimal power level (I'd guess 50 to 75 watts), they're going to deliver for home theater just fine. Peaks probably shouldn't exceed 300 watts for more than a few seconds. You could get another R12 and really make some noise if you wanted.

Think it over - it's a bit of work, but it would definitely pay off in the right sealed box. I have two Infinity DVC 10" in my pickup - 4 ohm setup - and they are very, very, very clean, driven by a 300 watt amp.

[BLindsay]

Originally Posted by Blu-Dog

Bridged, the QSC is about 850W. But a word on power ratings for car subs: Don't believe the hype. Car amps aren't anywhere near as linear in power output as line-powered amps (hence the use of caps to keep the output high), and a good line amp will fry the coils on the average car sub at sustained levels.

You can get away with much lower power levels, and it will be cleaner, with a typical line amp. Even the QSC 850 in non-bridged mode has plenty of power for your purposes.

The R12 line are power hogs - but they are very clean, so once you get past the minimal power level (I'd guess 50 to 75 watts), they're going to deliver for home theater just fine. Peaks probably shouldn't exceed 300 watts for more than a few seconds. You could get another R12 and really make some noise if you wanted.

Think it over - it's a bit of work, but it would definitely pay off in the right sealed box. I have two Infinity DVC 10" in my pickup - 4 ohm setup - and they are very, very, very clean, driven by a 300 watt amp.

Arent caps more so for a bandaid for crappy power systems in cars, i have a 140amp alternator in my car and a battery the size of a small boat lol. i use to have a JL 1000/1 and id stake that against most home audio amps.

it would be nice to find an amp that has a low pass filter built in so i dont have to grab an external crossover of the sorts, but if i have to i have to.

Yeah i like my type r12 alot for the money. My question though, as a driver how does it compare to the raw driver in the a2-300? if i do end up getting a good amp to drive my r12 is it gonna be better then the a2-300?

sealed box? i have a nice ported box built very soild to alpine specs, should i really switch to sealed, arent alot of home theater subs ported anyways?

[Blu-Dog]

Originally Posted by BLindsay

Arent caps more so for a bandaid for crappy power systems in cars, i have a 140amp alternator in my car and a battery the size of a small boat lol. i use to have a JL 1000/1 and id stake that against most home audio amps.

Caps are a pain in the neck, and a fire hazard in my opinion.

That JL powers a 13W7 with no pain; what an amp!

Originally Posted by BLindsay

it would be nice to find an amp that has a low pass filter built in so i dont have to grab an external crossover of the sorts, but if i have to i have to.

I have filters in my QSC, but I don't use them. The pre-out for the receiver handles that chore; I just run them full range, it plays what it gets. You probably don't need it.

The filter is 50hz, which is lower than I like, but it works.

Originally Posted by BLindsay

Yeah i like my type r12 alot for the money. My question though, as a driver how does it compare to the raw driver in the a2-300? if i do end up getting a good amp to drive my r12 is it gonna be better then the a2-300?

It's a tossup, as the A2-300 is mated to the box and built in amp. The R12 is a more robust driver, no question; but only in comparison to the driver in the R12. As a complete unit? Depends on the box and amp, but I think if correctly powered, the R12 would spank the A2-300 in a heartbeat.

The specs tell the tale:

Alpine R12:

http://vault.alpine-usa.com/products..._SWR-1242D.PDF

Elemental designs e3.12 (I think this is the right driver):

http://www.edesignaudio.com/product_...roducts_id=782

The Alpine has more power handling, longer xmax, etc. etc. Ironically, the ED has lower free air resonance; but at the price of power handling.

But that's not the full story. The A2-300 is a high-quality unit, within it's parameters. Owners rave about the performance per dollar - and I believe them. The usual limitations - tuned port frequency limitations, and all that - appear to have been solved by the ED team.

You will spend more setting up the R12 with the right power, correctly tuned sealed size, and all that; and you would wind up with a more robust sub - but you get what you pay for. I'm a do it yourselfer guy, so if you want to see this happen, use the R12.

Originally Posted by BLindsay

Sealed box? i have a nice ported box built very soild to alpine specs, should i really switch to sealed, arent alot of home theater subs ported anyways?

If you have the ported box, use it. I prefer sealed for sound quality (SQ) subs, for various reasons, but that's because I listen to a lot of music at various volumes. I also have bags of power, a luxury that costs money. Ported subs have a big cost savings; some folks equate sound volume with value, and ported subs are louder for the bucks.

With the SQ of the Alpine, along with its ability to handle power, I'd go with sealed. Depends on your room size, what you listen to, all that. If it's home theater, ported is fine; I use ported and sealed subs. But for music, sealed is better (again, my opinion) since there is no dropoff at frequencies outside the port's tuning range.

Depends on what you're going listen to most, I guess.

[daily jobs]

monoblocks are specifically designed to handle those low frequency outputs <100hz. It really depends on what your budget is. You will still get decent bass out of bridging two channels, e.g. I can get bass just as loud and clear from bridging 2 of my 4 channel amp as my mate can out of his mono Alpine. Ideally, you'd have a seperate monoblock for your subs but on a budget, bridging two channels will do the job just fine.