Question about hooking a 2 subs to a box (Car Audio)

[mulester7]

......Buck, I continue to like you to the point I may soon ask you to adopt me....ABSOLUTELY....try anything with speakers....keep feeling the amp....or, time how long you get before thermal cutout....it might be long enough to satisfy you for the morning before you have to go feed the chickens and milk cows....Clint, heard you were sleeping in the lean-to-shed out back as directed by your better half....heard you were relieving yourself a little close to the house and the chickens were trackin' it in....Clint, somebody said outhouses.com was worth a looksee....(hint).....

 

[zumbo]

Actually Zumbo, the amp "sees" a 2 ohm mono load. It cannot make 2 ohms 1 ohm. 2 ohms mono is the equivalent to 1 ohm stereo for a 2 channel amplifier. Just as 4 ohms mono is like 2 ohms stereo. Check power specs on most amps and you will find this to be correct.

No sir. See if you can follow me on this one.
Two 4ohm subs.
Tie those subs + & - together and you have a 2ohm load.
Now, bridge that 2ohm load & the amp sees 1ohm. Who cares if you call it 1ohm stereo or mono. The amp still has to be 1ohm stable.

His little amp can't take that. The only one that can is a mono-block, or my modified Linear 2202. And it's not for sale.

I re-read your statement. Even though the amp doesn't make it 1ohm, it still has to be 1ohm stable. I am not as technical, but I knew his amp couldn't drive two 4ohm subs parallel and bridged.

 

[zumbo]

I hooked it up to one sub and it freakin pounds! you've been all very helpful, especially zumbo. ONE more question. What's the CHEAPEST amp I can get that can handle both subs? Is there a specific one thats on sale that you can recommend? thanks. American/Canadian only please.

Your best bet is to run two amps bridged @ 2ohms as you have done with the first amp. The cost of an amp that will drive a 1ohm load is too high. Plus, it will kill your alternator. Also, the cost of an amp that will drive those 4ohm subs in stereo will also be costly.

I do have one option for you. This is a bad little amp. Two of these will rock those subs just fine. Look here.

One MB Quart amp will give you 200w to each sub in stereo. Two amps will give you 400w bridged on each sub. It's worth the extra money if you have it.

 

[zumbo]

These look to be a better value!

Phoenix Gold 1ohm stable amps. here.

Mono-block. Meaning the power remains the same whether @ 4ohm, 2ohm, or 1ohm.

Just Google for "1ohm stable amps".

 

[mulester7]

......Zumbo, I feel your assertion that the laws of paralleling apply on the other side of the terminal posts is right on....I'm going to post a portion of an IM earlier with Bob....I haven't asked him if he minds, but he won't on this subject....I have to use mulester360 with aol when I changed to cable....which has changed to SWB DSL....remember as you read, "on and off the voice coil more quickly".....


Mulester360: question....does strapping a stereo amp follow the laws of paralleling and increase the ohm load presented to the amp to double?....like 4 to 2?
Spkrart: It doubles circuit distortion
Mulester360: but if still inaudible who cares?
Mulester360: screw the scopes
Spkrart: cuts your damping in half
Mulester360: to what result?
Spkrart: never sounds as clean as single mono

 

[zumbo]

If you bridge one 4ohm sub on a 2-channel amp, it sees a 2ohm load.

So, certainly, if you run two 4ohm subs in parallel(making them amp see them as one 2-ohm speaker) and then bridge them on that amp it sees a 1ohm load. It' really pretty simple.

I don't know how Annunaki missed this. He is certainly more learned than I.

He didn't miss it. He is just being technical. The amp may not see a 1ohm load, but it acts like it. So it has to be 1ohm stable.

 

[mulester7]

.....Zumbo, as far as I'm concerned, so let it be written....you strap speakers on one side of the speaker terminal posts, and strap amp sections on the other for the same result per ohm load....why not?....other daughter coming over here in about 30 minutes and bringing her boyfriend....gotta' scoot....Clint, I've had a terrible time today trying to access windows at this site....did we blow an amp?....is anyong experiencing the same thing or is it just my computer?.....boys, may your fences be horse-high, pig-tight, and bull-strong....ladders.....

 

[zumbo]

Found this.

 

[Buckeyefan 1]

Last year I bought and returned a Power Acoustik amp that drove two 10" Kenwood subs to unreal levels. It was nowhere near what the amp below is. I think I paid $105 for it and I loved it, but Bazooka agreed to credit an old amp I owned of theirs and upgrade me to their top of the line class D amp. I couldn't pass up that opportunity. My current set up could make me go deaf if I didn't have some self control, but I'm in my mid 30's and know better now. Anyhow, if I were to purchase one amp to drive two subs, no matter what the impedence, for the money, you'd be hard pressed to beat these two SOB's. Do some research and read the reviews. Although they're huge, it's what you want driving two subs. I've been putting systems in cars for 19 years. You don't need to spend $500 for a subwoofer amp for two subs unless you are competing (then I'd recommend one for each sub).

Here's my amp (at an unreal price - it retailed for $499 last year at Circuit City) and will cook most subs if you're not careful:

http://www.bazooka.com/productAutoAmplifiersRS.asp?id=201

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=18797&item=5768591642&rd=1&tc=photo

Here's a monster that's not quite a as powerful, but will still overpower most subs on the market:

www.poweracoustik.com/gothicseries.html

http://store.yahoo.com/csexpo/ovpowaccaram4.html

 

[mulester7]

What would you like broken down? That only applies to two channel bridgeable amplifiers. One 2 ohm speaker with the amp bridged (mono) is like having one 1 ohm speaker on each channel...

.....ok, ok, I see your logic....I don't understand how I missed this post, Annunaki, so sorry to seem to not respond at all....when I reread a thread, I try to listen one more time to what others have said....good for birthing thoughts....you are saying the two strapped amp sections are handling 2 ohms of resistance, which you might as well say each half is handling one....I totally agree....win-win situation, Zumbo.....to bed....

 

[zumbo]

The Poweracoustic amps are not 1ohm stable. The Bazooka amps are though.

 

[zumbo]

What would you like broken down? That only applies to two channel bridgeable amplifiers. One 2 ohm speaker with the amp bridged (mono) is like having one 1 ohm speaker on each channel...

I missed this one too. This is why he needs a 1ohm stable amp. I updated some earlier post to agree to this terminoligy.

 

[cbraver]

MB Quart:

http://www.mbquart.com/2003/en_US/products/prod_detail_amplifiers.asp?isArchive=&cat=auto&series=reference series amplifiers&strt=1&model=RAA1000

I use both the Reference and their Q-line amps at work and in my dads Hummer. They are simply fantastic.... the Reference line is the less expensive, but still very good. Q-line is great if you have a little more cash to spair.

-Chad

 

[zumbo]

Oh my. 1000 watts. I love MB Quart!

 

[Buckeyefan 1]

The Poweracoustic amps are not 1ohm stable. The Bazooka amps are though.

I agree, but I couldn't hear the difference at 2 ohms. At those levels, who cares. You need ear protection.

Bazooka RSA800.1D
Power @ 2 OHM 924 watts (RMS) x 1
What does that calculate out to driving 2 10" dual voice coiled subs at 1 ohm? And this thing does not overheat. The beauty of class D. IMO, perfect for a bass amp.

 

[zumbo]

I agree, but I couldn't hear the difference at 2 ohms. At those levels, who cares. You need ear protection.

Bazooka RSA800.1D
Power @ 2 OHM 924 watts (RMS) x 1
What does that calculate out to driving 2 10" dual voice coiled subs at 1 ohm? And this thing does not overheat. The beauty of class D. IMO, perfect for a bass amp.

He cares. He HAS to have a 1ohm stable amp to drive two 4ohm subs parallel & bridged.

How do you have those DVC's wired? My guess is, the subs are getting about 600 watts each. Depends on how you wired the coils. If the retailer did the install, chances are you are not getting that due to warranty issues. There are many things you can do with DVC's, but I prefer SVC's due to the fact there is less mass to move.

 

[RecLodossWar]

Final answer. Connect the two speakers in series for an 8 ohm load as shown in your little diagram and bridge your amp which would act like it is seeing a 4 ohm load and should be happy as a clam at high tide.. Actually, I this would be the way I would go. While the power will be a little low for seismic lows, you'll have something to live with and it won't cause any damage.:

Are you saying I should change it to the 8ohm load diagram I showed you instead of just hooking only one sub up like I did? Which one will sound better? ALSO, what's seismic lows mean? I like my bass to be DEEEP...

 

[zumbo]

Are you saying I should change it to the 8ohm load diagram I showed you instead of just hooking only one sub up like I did? Which one will sound better? ALSO, what's seismic lows mean? I like my bass to be DEEEP...

That will give you a WHOPPING 30watts for each. WOW!

The way you have it, you are getting 120watts to one. I think the food is ready.

Specs again

 

[annunaki]

No sir. See if you can follow me on this one.
Two 4ohm subs.
Tie those subs + & - together and you have a 2ohm load.
Now, bridge that 2ohm load & the amp sees 1ohm. Who cares if you call it 1ohm stereo or mono. The amp still has to be 1ohm stable.

His little amp can't take that. The only one that can is a mono-block, or my modified Linear 2202. And it's not for sale.

I re-read your statement. Even though the amp doesn't make it 1ohm, it still has to be 1ohm stable. I am not as technical, but I knew his amp couldn't drive two 4ohm subs parallel and bridged.

WRONG!
The amp must be stable to 2 ohms MONO. Tell me how the amp changes 2 ohms to 1. It is NOT possible. All you are doing is internally summing the voltage from the left and right channels.

Of course his amp cannot drive both speakers in parallel. The amp is only stable to 4 ohms mono not 2 ohms mono.

An amplifier that is stable to 2 ohms stereo (if bridgeable) is almost always only stable to 4 ohms mono.
An amplifier stable to 1 ohm stereo (which is very rare) is again, almost always stable to 2 ohms mono.
I think we are on the same track just looking at it from different angles. If using a bridgeable amplifier he would nned to look for one stable to 1 ohm stereo. If using a mono amplifier he would need one stable to 2 ohms.

What he really needs is a 500 watt rms class D mono amplifier stable to 2 ohms (which most if not all are).

 

[annunaki]

These look to be a better value!

Phoenix Gold 1ohm stable amps. here.

Mono-block. Meaning the power remains the same whether @ 4ohm, 2ohm, or 1ohm.

Just Google for "1ohm stable amps".

Wrong on that too!
A good mono amplifier will typically double (or nearly double) it's output from 4 to 2 to 1 ohm (if it is 1 ohm stable).

Unless, the amplifier has impedance regulation circuitry built in, like JL Audios "Slash" series amps.

Mono block means 1 channel. Not 1 wattage.