I got an amp from a friend, it's a memphis CA300-4.
it's a 4 channel, 300 watt amp... What I need to know is I'm running two audiobahn 12"'s, which have the dual voice coils, and they're 400 watts a piece... I need to know how to wire them, bridge them, or whatever I have to do to make it sound good... Thanks in advance.
Replies (13)
TheErnie on 11/23/2004 00:55:39
oh, I also want to make sure how it's wired won't burn the amp up. I had a four channel amp before, and had it bridged with these speakers, and it burned up. another reason why I'm asking.
uochronos on 11/23/2004 01:52:09
need to know exact model number for those subs or we cant help much here...
Chronos
TheErnie on 11/23/2004 08:08:06
AW1251T, thats the model...
swez on 11/23/2004 09:20:18
These are 4+4 DVC subs. You will have to wire each sub in series (8 ohms) and run 1 sub per bridged channel to that amp. That's the only safe way to wire these subs to your 4 channel amp when bridged.
FYI: DO NOT ATTEMPT TO RUN A BRIDGED CHANNEL AMP AT 2 OHMS... IT WILL FRY THE AMP!
Swez
PS Why the VERY QUICK? That's causes communication errors as it leaves out key details. ;-)
Victor on 11/23/2004 14:31:27
Well.. i dont think that wud be advisable.. cause that amp wud give 150wrms per bridged channel@4ohms.. with increase in impedence your subs will draw almost half of that power. thats something like 75-80rwms..
and those subs are rated at 400wrms.. that wud be like feeding grass to a lion..lol...
what do u say swez?? aint that really underpowering the subs??
is that advisable???
comments...??
Victor...
uochronos on 11/23/2004 14:47:48
i could not find specs for this specific ampliofier. however if its 150watts rms bridged at 4 ohm thne it is only going to be 75watts rms at 8 ohm. so the best this amp can do
why not get a 1ohm stable mono amp or a bridgable 2 channel amp with proper power?
this amp well work the way swez listed just going to be grossly under powering them and if you well be tempted to turn the gain and bass boost up this well cause clipping and damage the subs..
if your set on useing this amp for now i suggest setting the gain properly and not turning bass boost up at all.
Chronos
ttocs on 11/23/2004 15:38:46
why not run each coil to one channel?
Victor on 11/23/2004 15:55:57
I doubt he can do that..( this is gonna be a long reply..)
it all depends on wht he feeds the amp..
if he wants to use ch 1& 2 and 3&4 as bridged channel A & B( suppose)
then both A & B shall be mono signals.. but A shall be the mono of the front channel and B shall be of the rear.. in case both the front and the rear channels give different signals then the VC shall be damaged.. in order to run each coil on different channel or power each coil with different amps it is a necessity to feed the same input to both the channels(amps) so that both the VC of the sub gets the same signal..
what he can do here is use RCA splits to use only either the rear or the front channel to feed all four channels of the amp so that when ch 1&2 and ch 3&4 are bridged the consecutive ch A & B shall give similar mono signals to both the VC of the sub..
but even in this case he will be able to use only one sub.. i dont see any chance that he can use both the subs..
comments...??
Victor...
Victor on 11/23/2004 16:00:20
I think i may have got u wrong scott.. but here if u are suggesting that he does not use the amp in bridged mode...
and run the two VC of sub 1 on ch 1&2 respectively even then both the VC shall be getting different signals which can be very very harmful to the sub..
the same problem with sub 2 on ch 3&4...
even here he can do it only if he uses the RCA splits and feeds all the channels on the amp with the same mono signal..
comments...??
Victor...
swez on 11/23/2004 19:15:04
It's obvious that this amp is not well suited to the subs mentioned. Anyway we slice it, 300 watts is not even close to what these subs can handle.
Ttocs makes a good recommendation, assuming the incoming amp signals are all sub outs from the HU. That plan (1 coil to each channel) does make sense). This assumes the HU has a sub channel that automatically combines channels A&B to form a MONO sub output. Channels C&D are generally identical to A&B, unless the HU is setup for THX or 4.1/5.1 surround sound. Not many HU's out there, that have that feature now. (that I am aware of)
FYI: Speakers can deal pretty well with very complex wave forms that change quickly. In bass notes, we don't have just 1 long tone. The frequency moves constantly, not to mention the rich harmonics that comprise a bass audio track. (bass, kick drum, synth and low piano notes) In short, a pretty complex set of wave forms are constantly being fed to the sub. The biggest issue, is to avoid cancellations.
On a final note, if we are concerned about L&R channels not having the same signals, one can alway change the RCA wiring so that A&B amp channels are getting FR & RR signals, channels C&D or getting FL & LR. Now we have continuity between each channel output.
What say others?
Swez
Victor on 11/23/2004 22:26:09
Agreed.... but in all the cases the signal going to both the VC's of the same sub shud be the same.. ( thats the only issue i am concerned about)
if we can do that by proper wiring and channel mixing then this can be done..
lets have a look at the head unit we have here..TheErnie please give us the model number.. specs and a link on the HU u got...
Also even if we do as scott and swez have suggested.. each VC will be getting 75wrms.. where as it can easily handle 200wrms( at which its performance is optimum)... so we are no where near the optimum performance yet..
Of-course it will play...but not at its best..
what ya say guys??
comments..???
Victor...
ttocs on 11/24/2004 10:33:51
bass is normally mono, if you use splitters then channel 1 and 2 would have the same signal, and could then go to vc 1 and 2 on the same sub..............
swez on 11/24/2004 18:07:58
Agreed... bass is usually mixed equally on both stereo tracks. But on some very enhanced recordings, drum kits can be panned L-R & R-L to provide a roving audio effect.. This practice is most often used on midrange and highs... not so much on lows as these are onmidirectional signals.
It should work, but don't expect full preformance from your subs off this amplifier. The best part here, is that your subs are very efficient. It does not take huge watts to get some decent bass from them.
Swez
it's a 4 channel, 300 watt amp... What I need to know is I'm running two audiobahn 12"'s, which have the dual voice coils, and they're 400 watts a piece... I need to know how to wire them, bridge them, or whatever I have to do to make it sound good... Thanks in advance.
Replies (13)
TheErnie on 11/23/2004 00:55:39
oh, I also want to make sure how it's wired won't burn the amp up. I had a four channel amp before, and had it bridged with these speakers, and it burned up. another reason why I'm asking.
uochronos on 11/23/2004 01:52:09
need to know exact model number for those subs or we cant help much here...
Chronos
TheErnie on 11/23/2004 08:08:06
AW1251T, thats the model...
swez on 11/23/2004 09:20:18
These are 4+4 DVC subs. You will have to wire each sub in series (8 ohms) and run 1 sub per bridged channel to that amp. That's the only safe way to wire these subs to your 4 channel amp when bridged.
FYI: DO NOT ATTEMPT TO RUN A BRIDGED CHANNEL AMP AT 2 OHMS... IT WILL FRY THE AMP!
Swez
PS Why the VERY QUICK? That's causes communication errors as it leaves out key details. ;-)
Victor on 11/23/2004 14:31:27
Well.. i dont think that wud be advisable.. cause that amp wud give 150wrms per bridged channel@4ohms.. with increase in impedence your subs will draw almost half of that power. thats something like 75-80rwms..
and those subs are rated at 400wrms.. that wud be like feeding grass to a lion..lol...
what do u say swez?? aint that really underpowering the subs??
is that advisable???
comments...??
Victor...
uochronos on 11/23/2004 14:47:48
i could not find specs for this specific ampliofier. however if its 150watts rms bridged at 4 ohm thne it is only going to be 75watts rms at 8 ohm. so the best this amp can do
why not get a 1ohm stable mono amp or a bridgable 2 channel amp with proper power?
this amp well work the way swez listed just going to be grossly under powering them and if you well be tempted to turn the gain and bass boost up this well cause clipping and damage the subs..
if your set on useing this amp for now i suggest setting the gain properly and not turning bass boost up at all.
Chronos
ttocs on 11/23/2004 15:38:46
why not run each coil to one channel?
Victor on 11/23/2004 15:55:57
I doubt he can do that..( this is gonna be a long reply..)
it all depends on wht he feeds the amp..
if he wants to use ch 1& 2 and 3&4 as bridged channel A & B( suppose)
then both A & B shall be mono signals.. but A shall be the mono of the front channel and B shall be of the rear.. in case both the front and the rear channels give different signals then the VC shall be damaged.. in order to run each coil on different channel or power each coil with different amps it is a necessity to feed the same input to both the channels(amps) so that both the VC of the sub gets the same signal..
what he can do here is use RCA splits to use only either the rear or the front channel to feed all four channels of the amp so that when ch 1&2 and ch 3&4 are bridged the consecutive ch A & B shall give similar mono signals to both the VC of the sub..
but even in this case he will be able to use only one sub.. i dont see any chance that he can use both the subs..
comments...??
Victor...
Victor on 11/23/2004 16:00:20
I think i may have got u wrong scott.. but here if u are suggesting that he does not use the amp in bridged mode...
and run the two VC of sub 1 on ch 1&2 respectively even then both the VC shall be getting different signals which can be very very harmful to the sub..
the same problem with sub 2 on ch 3&4...
even here he can do it only if he uses the RCA splits and feeds all the channels on the amp with the same mono signal..
comments...??
Victor...
swez on 11/23/2004 19:15:04
It's obvious that this amp is not well suited to the subs mentioned. Anyway we slice it, 300 watts is not even close to what these subs can handle.
Ttocs makes a good recommendation, assuming the incoming amp signals are all sub outs from the HU. That plan (1 coil to each channel) does make sense). This assumes the HU has a sub channel that automatically combines channels A&B to form a MONO sub output. Channels C&D are generally identical to A&B, unless the HU is setup for THX or 4.1/5.1 surround sound. Not many HU's out there, that have that feature now. (that I am aware of)
FYI: Speakers can deal pretty well with very complex wave forms that change quickly. In bass notes, we don't have just 1 long tone. The frequency moves constantly, not to mention the rich harmonics that comprise a bass audio track. (bass, kick drum, synth and low piano notes) In short, a pretty complex set of wave forms are constantly being fed to the sub. The biggest issue, is to avoid cancellations.
On a final note, if we are concerned about L&R channels not having the same signals, one can alway change the RCA wiring so that A&B amp channels are getting FR & RR signals, channels C&D or getting FL & LR. Now we have continuity between each channel output.
What say others?
Swez
Victor on 11/23/2004 22:26:09
Agreed.... but in all the cases the signal going to both the VC's of the same sub shud be the same.. ( thats the only issue i am concerned about)
if we can do that by proper wiring and channel mixing then this can be done..
lets have a look at the head unit we have here..TheErnie please give us the model number.. specs and a link on the HU u got...
Also even if we do as scott and swez have suggested.. each VC will be getting 75wrms.. where as it can easily handle 200wrms( at which its performance is optimum)... so we are no where near the optimum performance yet..
Of-course it will play...but not at its best..
what ya say guys??
comments..???
Victor...
ttocs on 11/24/2004 10:33:51
bass is normally mono, if you use splitters then channel 1 and 2 would have the same signal, and could then go to vc 1 and 2 on the same sub..............
swez on 11/24/2004 18:07:58
Agreed... bass is usually mixed equally on both stereo tracks. But on some very enhanced recordings, drum kits can be panned L-R & R-L to provide a roving audio effect.. This practice is most often used on midrange and highs... not so much on lows as these are onmidirectional signals.
It should work, but don't expect full preformance from your subs off this amplifier. The best part here, is that your subs are very efficient. It does not take huge watts to get some decent bass from them.
Swez
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