13017
From: BYND, [px1nr.wp.shawcable.net]
Subject: What Amp ??
|
Ok I Have 2 12' Rf Punch XLC subs they are 4 ohm and 200-400 watts I know nothing about amps so any help?? I was lookin at a sony amp that is bridgable at 380 watts and someone was saying i could still run both of them off it at 190watts each ? But dont i need at least 200 ? Im confused I have not much money left after the subs so Lots of help needed thanx alot , My icq is 46683459 or email is Grifty_mcgrift@hotmail.com Please reply quick I need tha amp in 13 days |
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[13030] [13018] [13033] [13037] [13092] [13101] [13039] [13102] [13053] [13035] [13054] [13066]
13030
From: Nate, [pavilion]
Subject: Re: What Amp ??
| Don't sweat it! Audibly there won't be a diff between 190 watts & 200 watts. Go for it. |
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None
13018
From: BYND, [px1nr.wp.shawcable.net]
Subject: Re: What Amp ??
| Also im gonna get 2 sets of mids , and if that guy was correct is there a way i could make get an amp that is bridgable at 300 wtts @4ohms and split that by 4 ? and give each mid 75 watts ? plus I was gonna hook the powere from the deck to tha mids as well. Also how would i be able to bridge this amp to feed 4 diff mids and how would i be able to bridge the other one to feed the 2 subs ??? Please reply soon |
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[13033] [13037] [13092] [13101] [13039] [13102] [13053] [13035] [13054] [13066]
13033
From: Jason U., [spider-tm051.proxy.aol.com]
Subject: Re: What Amp ??
|
------------------------------------------------------ Also im gonna get 2 sets of mids , and if that guy was correct is there a way i could make get an amp that is bridgable at 300 wtts @4ohms and split that by 4 ? and give each mid 75 watts ? plus I was gonna hook the powere from the deck to tha mids as well. Also how would i be able to bridge this amp to feed 4 diff mids and how would i be able to bridge the other one to feed the 2 subs ??? Please reply soon ------------------------------------------------------ What do you mean split 300 Watts @ 4ohm into 4. You can't really split 300 watts into 4 or 75 watts. You can use series but each midrange will be out of phase of each other by 60 degrees, 120 degrees, 180 degrees, etc.. You will soon notice when you first play one note of music. To use series connection I suggest you use with a dual voice woofer. This makes your subwoofer have two seperate outputs. One output will be in-phase with the front and 60 degrees out of phase with the surround or rear speakers. Another thing, midranges or mids are a little louder because our ears are most sensitive in that area. You can use a 4 X 50 watt or 4 channels 50 watt amplifier and still it will be loud enough. For the subs I suggest you buy a seperate amplifier around 200 watts or over. You said your subs or woofers power rating is 200 watts - 400 watts. If all amps clip buying a over rated amplifier for the subs will decrease clipping thereby decrease the chance of burn out of the voice coil. Clipping is when a amp excedes its ratings by pushing more watts but with added distortion into the audio. |
Responses:
[13037] [13092] [13101] [13039] [13102] [13053] [13035] [13054] [13066]
13037
From: Brian, [webmaster]
Subject: Re: What Amp ??
|
>You can use series but each midrange will be out of >phase of each other by 60 degrees, 120 degrees, 180 >degrees, etc.. Whut? I'd like to see your reasoning for that. >To use series connection I suggest you use with a >dual voice woofer. This makes your subwoofer have two >seperate outputs. One output will be in-phase with >the front and 60 degrees out of phase with the >surround or rear speakers. I'd like to see your reasoning for that as well. The CORRECT answer to his question is: Yes, it is possible to wire 4 speakers to a 300x1 bridged amplifier so that they get 75 Watts each. For example, you can split the drivers into two pairs, then either (1) wire the drivers in each pair in parallel, then wire the pairs together in series, or (2) wire each pair in series, then wire the pairs them together in parallel. However, I wou not suggest doing either, as the drivers we are talking about here are MIDRANGE drivers, which usually means that you want to use them to obtain a stereo image, not a mono image. As the amplifier in question is bridgeable to 300Wx1, it can be assumed that it will driver 150Wx2 into 2 ohms. In that case, split the drivers into two pairs as before, then wire the drivers in each pair in parallel, then connect each pair to a separate channel on the amplifier. Brian |
13092
From: Ted McConnell, [cvg-29-17-105.cinci.rr.com]
Subject: mono vs stereo.
|
Brian, I'm curious about your POV on stereo image for low end. Some people I respect swear by it, but the complexity in the room of two sources - even if they are mono - seems destined to erode my precious phase linearity. Also, btw, I had much trouble posting messages to this forum 6 months ago - server errors maybe, so I just gave up. Was I perhaps locked out for having a narrow point of view.:). |
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[13101]
13101
From: Brian, [webmaster]
Subject: Re: mono vs stereo.
|
>Brian, I'm curious about your POV on stereo image for >low end. In my view there is no such thing as a "stereo image" for anything below 80 Hz (or even slightly higher than that). Some people I respect swear by it, but the complexity in the room of two sources - even if they are mono - seems destined to erode my precious phase linearity. |
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13039
From: Jason U., [spider-wq042.proxy.aol.com]
Subject: Re: What Amp ??
|
If a resistor increases the Q of the driver and a driver has its own resistance. All four drivers are connected in series or one after another. The first driver will be in phase while the other will have an increase Q. The high Q driver will react slower to the signal although it is the same driver. I don't have phase meter to measure my subwoofer's phase. I have looked into dolby surround sound and it shows that the surround channels have a phase of 60 degrees but inverted. This is why I came up with that conclusion. Using 4 midrange drivers in parallel will have a impedance of 2 ohms or 1 ohm. A bridge amp will see 0.5 ohms. This is not good even on very high quality amplifiers. The devices will over heat and break down. It might even catch on fire. This is not good for car environments. You can do this but I suggest liquid nitrogen. |
13102
From: Brian, [webmaster]
Subject: Re: What Amp ??
|
>If a resistor increases the Q of the driver and a >driver has its own resistance. All four drivers are >connected in series or one after another. The first >driver will be in phase while the other will have an >increase Q. This implies a basic misunderstanding of what goes on when you wire two or more components with identical impedance characteristics in series. >I have looked into dolby surround sound and it shows >that the surround channels have a phase of 60 degrees >but inverted. "Dolby Surround" has nothing to do with what's going on here. "Dolby Surround" reproduction involves a decoding process that produces more than two channels of sound from an encoded source. >Using 4 midrange drivers in parallel will have a >impedance of 2 ohms or 1 ohm. Please demonstrate how 4 midrange drivers of 4 ohms each can be wired to produce a total impedance of two ohms. If an amplifier is rated to be able to drive a load of 4 ohms when bridged, it is usually safe to assume that it can also drive a load of 2 ohms on either channel instead. |
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13053
From: Ron E, [zdialup162.mpls.uswest.net]
Subject: Re: What Amp ??
| When drivers are in series they share the same current. The phase angle of the current does not change. Each driver has the same impedance at all frequencies (ideally) and each will see the same voltage drop across it. They act like a voltage divider with four equal value resistors. |
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13035
From: BYND, [px1nr.wp.shawcable.net]
Subject: Re: What Amp ??
| Oh alright So My Deck (sony) is 52x4 So that should be enough to power the mids hey ? Then i just need an amp for the subs and i should be good right ? |
13054
From: Ron E, [zdialup162.mpls.uswest.net]
Subject: Re: What Amp ??
|
52x4 will probably be enough power for your mids (I assume these also have tweeters or are you going to build a passive crossover?). You are correct that you could then just get an amp for your subs. Don't try to connect your woofers and mids to the same amp (or more than one amp channel to any voice coil), ok? I don't want to see your amps break... |
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[13066]
13066
From: mark, [sydney2.au.ibm.com]
Subject: Re: What Amp ??
| When you say 4x50W output from the deck, I think that those are mox output figures and not RMS. If you check the RMS specs, it is more likely that the deck will give 4x25W RMS will high THD. I would run the rear mids off the deck (for noise) ... but run your front speakers off a seperate amp. I suggest getting BostonAccoustic splits. |
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