posted
Ok, I'm considering running 3 RF power bd 1000a1's to 3 JL Audio 10w7's. Basically one amp to one sub. Now I posted this question in a local Houston forum, and I got a response that worries me.
"go one big amp or two amps straped(one slave and one master amp) you most likely won't get three amps to run the same...hence you will have cancelation."
How much truth is there to this? Can anyone help explain this?
Posts: 101 | From: Houston, TX | Registered: Feb 2003
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posted
There is no truth in that statement if you properly match the outputs of all amps.
C'mon now, how many competitors run multiple amps(not strapped) on quad coil subs? At 170 dB, it doesn't seem cancellation is an issue.
Posts: 768 | From: Ottawa, On, Canada | Registered: May 2000
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Hmm..checked it out...I'd steer clear If I were you. Sounds like a bunch of high school idiots.
Well the guy who said that was a former installer at Tweeter. I'm starting to 2nd guess on what I'm doing now. This feeling sucks. Where in houston did you take your ride? I need help Posts: 101 | From: Houston, TX | Registered: Feb 2003
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posted
cancellation?? why would you have any cancellation if all the subs are getting the same signal and playing the same notes at the same time moving the same air in the same direction? I have heard alot of salesmen say some weird things but dood.. come on..
dont worry bout all that stuff that them doods say on ICCH .. they may know bout performance but the only one ive seen a couple of doods that knows their stuff bout car audio is Dak4.7...
I dunno much bout the tweeter installer.. Ive read his old posts.. sorta seems he sorta knows and sometimes doesnt... I've never heard of this master slave thing.. nor have i ever heard an issue of cancellation in what you propose.. he may have run into an issue but that is on the fault of the installer.. not the equipment..
Posts: 1 | From: Houston, TX | Registered: Mar 2003
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quote:Originally posted by NisAznMonk: Well the guy who said that was a former installer at Tweeter. I'm starting to 2nd guess on what I'm doing now. This feeling sucks. Where in houston did you take your ride? I need help
I took it about 5 inches from my garage..lol If I were you I would do the same..do it yourself.
But....if your gonna go anywhere I would say either River Oaks Car Stereo, Custom Car audio or last ditch; the Car Toys on Westheimer.
-------------------- Andrew Kemendo Team Pro Creations FAA Pilot #2718765 Oderint dum metuant
quote:Originally posted by NisAznMonk: Well the guy who said that was a former installer at Tweeter. I'm starting to 2nd guess on what I'm doing now. This feeling sucks. Where in houston did you take your ride? I need help
I took it about 5 inches from my garage..lol If I were you I would do the same..do it yourself.
But....if your gonna go anywhere I would say either River Oaks Car Stereo, Custom Car audio or last ditch; the Car Toys on Westheimer.
Man, I wish I had your skill. I can't cut wood or anything. The only thing I know how to do is wiring. This really sucks Posts: 101 | From: Houston, TX | Registered: Feb 2003
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quote:Originally posted by NisAznMonk: Man, I wish I had your skill. I can't cut wood or anything. The only thing I know how to do is wiring. This really sucks
Screw that nonsense, go buy yourself some MDF and tools and start learnin...
-------------------- Andrew Kemendo Team Pro Creations FAA Pilot #2718765 Oderint dum metuant
posted
Hey, I would like to point out that you probably need to consider different amplifiers for your application. The 10W7 comes in only a single 3 ohm voice coil configuration. When you put that in a box, you will get a rise in the impedance from the box. This should put the effective impedance "seen" by the box to over 4 ohm per driver. A bd1000a1 will only do around 500 watts into a 4 ohm load. You are paying for 3000 watts, but only getting 1500 out of them. I would go with either 1 amp total (wire all subs in parallel to 1 ohm), or a pair of amps strapped together into one load (still wire all subs in parallel).
A lot of people make this mistake with W7s and get an amp that is not designed to make power at the impedance that they need to operate at. I believe this is why a lot of people say that the W7 is crap, as they are hearing the distortion of their amp driving to put out more power than it can (even if its only 500 watts).
-------------------- Team Shedluv Team Sweep Team Kicker Team JBL
quote:Originally posted by Shedluv: Hey, I would like to point out that you probably need to consider different amplifiers for your application. The 10W7 comes in only a single 3 ohm voice coil configuration. When you put that in a box, you will get a rise in the impedance from the box. This should put the effective impedance "seen" by the box to over 4 ohm per driver. A bd1000a1 will only do around 500 watts into a 4 ohm load. You are paying for 3000 watts, but only getting 1500 out of them. I would go with either 1 amp total (wire all subs in parallel to 1 ohm), or a pair of amps strapped together into one load (still wire all subs in parallel).
A lot of people make this mistake with W7s and get an amp that is not designed to make power at the impedance that they need to operate at. I believe this is why a lot of people say that the W7 is crap, as they are hearing the distortion of their amp driving to put out more power than it can (even if its only 500 watts).
I'm new at this, and I am aware that I don't know as much as you do on this....but I've never heard of this fact. Is there anything on the web that would back this up? I just want to do more research. I have been considering the Orion Pro XTR 2400.
Posts: 101 | From: Houston, TX | Registered: Feb 2003
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posted
If you want to run one amp per sub, look for power ratings at 4 ohm impedance.
If you want to run one amp total, look for power ratings at 1 ohm impedance.
Certain mono amps, like the RF bd series, Memphis 1000D, Crossfire 1000D, Directed 1100d (or 1200d), Kicker kx 1200.1, etc. can be strapped together to power a single load. Here's a little more info:
On amp ratings, a lot of time you will see something like this:
150 watts X 2 @ 4 ohm stereo 300 watts X 2 @ 2 ohm stereo 600 watts X 1 @ 4 ohm mono
These ratings tell you how much power the amp puts out at specific loads. You have a 3 ohm load (per sub) which in actuality when you put it in a box and play music through it will be closer to 4 ohm, so you need to look at the 4 ohm mono (bridged) ratings for amps in your selection. That is to run one amp to each sub.
Now if you want to just run one amp total, you can combine all of your subs into one load. When doing this you put all of the +s together and all of the -s together on the speakers. When doing this you end up with a 1 ohm load (3ohms/3speakers). Several amps out there make a lot of power at 1 ohm (bridged). You would just use one amp to power all of the subs in this configuration, so you would need to look at the 1 ohm bridged output power of the amp.
Then given your choices you could make the best selection as to what amp would be best for your budget and power needs. If it were me, I would either run one bd1500 to all of the subs, or 3 XTRPRO2400s, with one on each sub. I would not recommend running one bd1000 to each sub. If you want to run 3 amps, the RF 1050s (I think) would be a better option to run 3 amps if you want to stick with Rockford amps.
-------------------- Team Shedluv Team Sweep Team Kicker Team JBL
quote:Originally posted by Shedluv: Hey, I would like to point out that you probably need to consider different amplifiers for your application. The 10W7 comes in only a single 3 ohm voice coil configuration. When you put that in a box, you will get a rise in the impedance from the box. This should put the effective impedance "seen" by the box to over 4 ohm per driver. A bd1000a1 will only do around 500 watts into a 4 ohm load. You are paying for 3000 watts, but only getting 1500 out of them. I would go with either 1 amp total (wire all subs in parallel to 1 ohm), or a pair of amps strapped together into one load (still wire all subs in parallel).
A lot of people make this mistake with W7s and get an amp that is not designed to make power at the impedance that they need to operate at. I believe this is why a lot of people say that the W7 is crap, as they are hearing the distortion of their amp driving to put out more power than it can (even if its only 500 watts).
You dont know what your talking about..entirely. I want to make sure this guy has the right info not get in your craw.
He is referring to impedance rise as the woofer gets loaded by the compliance of the air in the box.
While it is true that there is a rise, it is not true across the band. Also in most regular situations it is not really relevant.
I am not sure what he is advising when impedance matching, but a good rule of thumb is match Woofer DC resistance with amp impedance. Other than the JL amps which are impedance regulated from; what 1-4ohm(?), there are few if any other amps out there rated at 3 ohm. Only because it is atypical of most woofers.
I would suggest against the W7's for a First project just so you dont mess up a expensive pair of woofers, and for ease of installation. I would pick an amp and stick with that amp. Then match number of woofers so you get everything right; instead of just buying 4 xbrand woofers and 2 xbrand amps. get it?
-A
-------------------- Andrew Kemendo Team Pro Creations FAA Pilot #2718765 Oderint dum metuant
quote:Originally posted by Shedluv: Hey, I would like to point out that you probably need to consider different amplifiers for your application. The 10W7 comes in only a single 3 ohm voice coil configuration. When you put that in a box, you will get a rise in the impedance from the box. This should put the effective impedance "seen" by the box to over 4 ohm per driver. A bd1000a1 will only do around 500 watts into a 4 ohm load. You are paying for 3000 watts, but only getting 1500 out of them. I would go with either 1 amp total (wire all subs in parallel to 1 ohm), or a pair of amps strapped together into one load (still wire all subs in parallel).
A lot of people make this mistake with W7s and get an amp that is not designed to make power at the impedance that they need to operate at. I believe this is why a lot of people say that the W7 is crap, as they are hearing the distortion of their amp driving to put out more power than it can (even if its only 500 watts).
You dont know what your talking about..entirely. I want to make sure this guy has the right info not get in your craw.
He is referring to impedance rise as the woofer gets loaded by the compliance of the air in the box.
While it is true that there is a rise, it is not true across the band. Also in most regular situations it is not really relevant.
I am not sure what he is advising when impedance matching, but a good rule of thumb is match Woofer DC resistance with amp impedance. Other than the JL amps which are impedance regulated from; what 1-4ohm(?), there are few if any other amps out there rated at 3 ohm. Only because it is atypical of most woofers.
I would suggest against the W7's for a First project just so you dont mess up a expensive pair of woofers, and for ease of installation. I would pick an amp and stick with that amp. Then match number of woofers so you get everything right; instead of just buying 4 xbrand woofers and 2 xbrand amps. get it?
-A
Just get whatever you want, I guess I don't know anything at all, its not like I'm a rocket scientist or anything.
-------------------- Team Shedluv Team Sweep Team Kicker Team JBL
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