Hi,
All,
How the power is shared, between the speakers?
In my case, I have a 350wrms x 4ch @ 2ohms
If I use 3 x 8ohm 100rms speaker and one 4ohm tweeter with a high pass caps on a channel in parallel, how is my power shared and is this ideal for the system?
Thank You
Regards
b_bass59
Replies (9)
swez on 08/14/2006 14:08:23
Are these 8 ohm speakers subs, midbass or midrange?
A make and model # will help and a hyperlink is also good.
What are you trying to accomplish here? From what I see at the moment, if these three, 8 ohm speakers are subs or MB drivers that can go down to 40 Hz., they could make for a nice tri-subwoofer application.
Give us the big picture of what you hope to do in this install. With that and specs on the 8 ohm speakers and your tweet, might have a few ideas for you.
Swez
b_bass59 on 08/15/2006 22:07:36
Hi,
Swez,
The 8ohms speakers are for midrange and they are Alpha 6a.
The problem I have is that, these speaker are 100wrms each and the tweeter is a 100w max it don't have the rms value, on them.
My question is how the power is shared between the speakers,
If the tweeter is 4ohms and its on a high pass cap, with 3x8ohm alpha6a speakers in parallel on 350rms @ 2ohm amp channel.
Thank you
Regards
swez on 08/15/2006 23:52:29
OK, the Alpha 6's in parallel = 2.67 ohms. The tweeter is almost 2 x that number. 2.67 + 4.0 = 6.67 ohms. (Usable, but not efficient)
That means the Mids will get 67% of the power and the tweet will see the rest... 34%, above the passive crossover value. This in a series circuit application.
If the tweeter has a max input value of 100 Watts, (Peak) it's RMS value is somewhere between 25-50 watts RMS.
Mids: 2.67 ohms = That's about 300/3 or 100 watts RMS/speaker off just 1 channel
Tweet: 4.0 ohms = If the tweeter has it's own channel, it will see about 175 watts RMS @ 4 ohms. This power will fry that tweet in a heart beat, w/o an attenuator.
However, if you have three mids and one tweeter off one channel, we have to calculate the coupled resistance in this network. We have 2.67 ohms in the mids, coupled with a 4 ohm tweeter.
We can do this in "Series" to get a net ohmic value in the circuit of 6.67 ohms. Here, that amp channel that delivers 350 watts @ 2 ohms, will now deliver a net wattage of about 105 watts to the network. Remember, the mids will get 66.7 % of that (~70 watts) and the tweeter gets about 33.3%, or ~35 watts. Workable, but not efficient huh?
Now, suppose we wire all this up in parallel. We have a problem Houston... this nets a 1.6 ohm load and the amp will balk at that load for sure.
Questions for you... Who makes Alpha 6's? Is that an Eminence brand model? Is this for Home Theater, Live sound car audio or some other application? Can you bi-amp this suystem if needed?
I ask as this is a rare combination of speakers for car audio. However, it makes sense in HT and live sound applications.
Swez
b_bass59 on 08/16/2006 06:08:02
Hi,
Ok the alpha6a are eminence, but look at this when i check the ohms across the tweeter with the capacitor on it, its reads infinity.
when I check it across the whole network its 2.67 ohms.
this puzzled me, if the tweerer reads infinity how much power does the tweeter get, because i think if the meter reads 2.67 ohms the amp sees 2.67ohms.
Thanks
swez on 08/16/2006 09:36:20
Correct, when a Capacitor is in the circuit and it gets a DC voltage, it will block all DC. Hense, an Infinite reading. (An ohmeter uses DC voltage to measure ohmic values)
AC voltages below the passing frequency of the Cap/tweet load will also be attenuated. Audio signals are AC voltage. Power supply and meter testing voltages are DC.
From what I see here, your best bet is to use a Bi-amp arrangement here. That means, the mids get their own amp channel and the tweeter gets it's own amp channel too.
However, the tweeter only takes 25-50 watts RMS.power here. If you feed it too much w/o a tweeter protection circuit or attenuation, it will fry a delicate tweeter voice coil.
FYI: The other "SAFE" option here, is to wire the mids in parallel, (2.67 ohms) then connect the tweeter/cap in series. You get a net ohmic load of 6.67 ohm. That's safe for your amp and 105 watts RMS to this circuit is enough to drive the mids to good SPL levels. The tweeter will either need a fuse, power bleeding circuit or a vairable attenuator to protect it from excess voltage/wattage that can harm the tweeter.
Do you have links to the mids, tweet and amplifier used here? Seeing that, I may have a few more suggestions for you.
Swez
PS With this tweet, it may be better if you used a 2nd order filter network to block lows. A cap, is a 1st order filter and only filters at a
-6dB/octave slope. (Fair, but may not be adequate) A 2nd order filter has a -12dB/octave slope and will protect the tweeter much better too.
b_bass59 on 08/16/2006 12:26:49
Thanks alot.
What I'll do is to run the tweeter with the HU (pioneer 480mp) and the eminence on the amp, is that a good idea.
Thanks again
Regards
swez on 08/16/2006 19:03:02
Yes, that should work as you'll get about 22 watts RMS of clean power off the HU. Be sure to use at least the filtering cap in series with the tweeter to HU speaker wire.
BTW, this is a Bi-amp configuration we had discussed earlier.
Swez
b_bass59 on 08/16/2006 20:08:12
Thanks I got that.
Thanks
swez on 08/16/2006 21:53:20
Hope it works out well fer ya!
Good luck and let us know OK?
Swez
All,
How the power is shared, between the speakers?
In my case, I have a 350wrms x 4ch @ 2ohms
If I use 3 x 8ohm 100rms speaker and one 4ohm tweeter with a high pass caps on a channel in parallel, how is my power shared and is this ideal for the system?
Thank You
Regards
b_bass59
Replies (9)
swez on 08/14/2006 14:08:23
Are these 8 ohm speakers subs, midbass or midrange?
A make and model # will help and a hyperlink is also good.
What are you trying to accomplish here? From what I see at the moment, if these three, 8 ohm speakers are subs or MB drivers that can go down to 40 Hz., they could make for a nice tri-subwoofer application.
Give us the big picture of what you hope to do in this install. With that and specs on the 8 ohm speakers and your tweet, might have a few ideas for you.
Swez
b_bass59 on 08/15/2006 22:07:36
Hi,
Swez,
The 8ohms speakers are for midrange and they are Alpha 6a.
The problem I have is that, these speaker are 100wrms each and the tweeter is a 100w max it don't have the rms value, on them.
My question is how the power is shared between the speakers,
If the tweeter is 4ohms and its on a high pass cap, with 3x8ohm alpha6a speakers in parallel on 350rms @ 2ohm amp channel.
Thank you
Regards
swez on 08/15/2006 23:52:29
OK, the Alpha 6's in parallel = 2.67 ohms. The tweeter is almost 2 x that number. 2.67 + 4.0 = 6.67 ohms. (Usable, but not efficient)
That means the Mids will get 67% of the power and the tweet will see the rest... 34%, above the passive crossover value. This in a series circuit application.
If the tweeter has a max input value of 100 Watts, (Peak) it's RMS value is somewhere between 25-50 watts RMS.
Mids: 2.67 ohms = That's about 300/3 or 100 watts RMS/speaker off just 1 channel
Tweet: 4.0 ohms = If the tweeter has it's own channel, it will see about 175 watts RMS @ 4 ohms. This power will fry that tweet in a heart beat, w/o an attenuator.
However, if you have three mids and one tweeter off one channel, we have to calculate the coupled resistance in this network. We have 2.67 ohms in the mids, coupled with a 4 ohm tweeter.
We can do this in "Series" to get a net ohmic value in the circuit of 6.67 ohms. Here, that amp channel that delivers 350 watts @ 2 ohms, will now deliver a net wattage of about 105 watts to the network. Remember, the mids will get 66.7 % of that (~70 watts) and the tweeter gets about 33.3%, or ~35 watts. Workable, but not efficient huh?
Now, suppose we wire all this up in parallel. We have a problem Houston... this nets a 1.6 ohm load and the amp will balk at that load for sure.
Questions for you... Who makes Alpha 6's? Is that an Eminence brand model? Is this for Home Theater, Live sound car audio or some other application? Can you bi-amp this suystem if needed?
I ask as this is a rare combination of speakers for car audio. However, it makes sense in HT and live sound applications.
Swez
b_bass59 on 08/16/2006 06:08:02
Hi,
Ok the alpha6a are eminence, but look at this when i check the ohms across the tweeter with the capacitor on it, its reads infinity.
when I check it across the whole network its 2.67 ohms.
this puzzled me, if the tweerer reads infinity how much power does the tweeter get, because i think if the meter reads 2.67 ohms the amp sees 2.67ohms.
Thanks
swez on 08/16/2006 09:36:20
Correct, when a Capacitor is in the circuit and it gets a DC voltage, it will block all DC. Hense, an Infinite reading. (An ohmeter uses DC voltage to measure ohmic values)
AC voltages below the passing frequency of the Cap/tweet load will also be attenuated. Audio signals are AC voltage. Power supply and meter testing voltages are DC.
From what I see here, your best bet is to use a Bi-amp arrangement here. That means, the mids get their own amp channel and the tweeter gets it's own amp channel too.
However, the tweeter only takes 25-50 watts RMS.power here. If you feed it too much w/o a tweeter protection circuit or attenuation, it will fry a delicate tweeter voice coil.
FYI: The other "SAFE" option here, is to wire the mids in parallel, (2.67 ohms) then connect the tweeter/cap in series. You get a net ohmic load of 6.67 ohm. That's safe for your amp and 105 watts RMS to this circuit is enough to drive the mids to good SPL levels. The tweeter will either need a fuse, power bleeding circuit or a vairable attenuator to protect it from excess voltage/wattage that can harm the tweeter.
Do you have links to the mids, tweet and amplifier used here? Seeing that, I may have a few more suggestions for you.
Swez
PS With this tweet, it may be better if you used a 2nd order filter network to block lows. A cap, is a 1st order filter and only filters at a
-6dB/octave slope. (Fair, but may not be adequate) A 2nd order filter has a -12dB/octave slope and will protect the tweeter much better too.
b_bass59 on 08/16/2006 12:26:49
Thanks alot.
What I'll do is to run the tweeter with the HU (pioneer 480mp) and the eminence on the amp, is that a good idea.
Thanks again
Regards
swez on 08/16/2006 19:03:02
Yes, that should work as you'll get about 22 watts RMS of clean power off the HU. Be sure to use at least the filtering cap in series with the tweeter to HU speaker wire.
BTW, this is a Bi-amp configuration we had discussed earlier.
Swez
b_bass59 on 08/16/2006 20:08:12
Thanks I got that.
Thanks
swez on 08/16/2006 21:53:20
Hope it works out well fer ya!
Good luck and let us know OK?
Swez
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