Sign in to follow this  
glennrush

Impedance matching with 3 subs

Recommended Posts

glennrush    0

OK no laughing at my question please. I have an xti6000 and I would like to run 2 EAW LA 128z subs on each side of the stage and one JBL SRX728s as a center sub. No way I can match that to 2, 4, or 8 ohms. But I can make it 6 ohms by connecting two of the subs in series and then paralleling the remaining sub for a total of 6 ohms. Run the amp in bridge mode. Is this totally crazy or is it acceptably to mix series and parallel connections in this way to get the ohmage to an acceptable level? Any other suggestions?.

Share this post


Link to post
Share on other sites
mixwiz    0
OK no laughing at my question please. I have an xti6000 and I would like to run 2 EAW LA 128z subs on each side of the stage and one JBL SRX728s as a center sub. No way I can match that to 2, 4, or 8 ohms. But I can make it 6 ohms by connecting two of the subs in series and then paralleling the remaining sub for a total of 6 ohms. Run the amp in bridge mode. Is this totally crazy or is it acceptably to mix series and parallel connections in this way to get the ohmage to an acceptable level? Any other suggestions?.

You want to run 5 subs off one amp? Yes, that is crazy. I'd skip the SRX, center cluster EAW's, run in stereo and cross your fingers. You'd still be underpowered but it should give you better sound.

Share this post


Link to post
Share on other sites
glennrush    0
OK no laughing at my question please. I have an xti6000 and I would like to run 2 EAW LA 128z subs on each side of the stage and one JBL SRX728s as a center sub. No way I can match that to 2, 4, or 8 ohms. But I can make it 6 ohms by connecting two of the subs in series and then paralleling the remaining sub for a total of 6 ohms. Run the amp in bridge mode. Is this totally crazy or is it acceptably to mix series and parallel connections in this way to get the ohmage to an acceptable level? Any other suggestions?.

You want to run 5 subs off one amp? Yes, that is crazy. I'd skip the SRX, center cluster EAW's, run in stereo and cross your fingers. You'd still be underpowered but it should give you better sound.

no no no, i said that wrong, my mistake, Total of 3 subs two on each side one center. Recently saw a guy running 4 JBL SRX728s on one Xti6000 at 2 ohms outside no less. sounded great. I am currently using one xti6000 for my tops (EAW LA460's) and 3 QSC 3602 bridged, one for each sub and they still thermal out. Hate the QSC amps thinking about going to one Xti6000 for the subs.. waddya think??

Share this post


Link to post
Share on other sites
glennrush    0
OK no laughing at my question please. I have an xti6000 and I would like to run 2 EAW LA 128z subs on each side of the stage and one JBL SRX728s as a center sub. No way I can match that to 2, 4, or 8 ohms. But I can make it 6 ohms by connecting two of the subs in series and then paralleling the remaining sub for a total of 6 ohms. Run the amp in bridge mode. Is this totally crazy or is it acceptably to mix series and parallel connections in this way to get the ohmage to an acceptable level? Any other suggestions?.

You want to run 5 subs off one amp? Yes, that is crazy. I'd skip the SRX, center cluster EAW's, run in stereo and cross your fingers. You'd still be underpowered but it should give you better sound.

no no no, i said that wrong, my mistake, Total of 3 subs two on each side one center. Recently saw a guy running 4 JBL SRX728s on one Xti6000 at 2 ohms outside no less. sounded great. I am currently using one xti6000 for my tops (EAW LA460's) and 3 QSC 3602 bridged, one for each sub and they still thermal out. Hate the QSC amps thinking about going to one Xti6000 for the subs.. waddya think??

I mean 1 LA 128z on each side (jeeeesh I did it again)

Share this post


Link to post
Share on other sites
glennrush    0
That will theoretically work; you'll just be getting 4 times more power into the 728s than each EAW, so that sub may sound out of balance.

Kevin, why is that?? All 3 subs are a 4 ohm load. If I bridge the amp and series the EAW's I get back to 8 ohms if I then parallel the 728 To this load i get 6 ohms. The amp sees one load, why more power in the 728? If this is the case I need another solution.

Share this post


Link to post
Share on other sites
Kevin Heber    0

I guess it's just basic circuit theory. The amp will drop 100% of its voltage across both of your parallel loads: 1) the two EAW's; and 2) the 728.

So the 728 will receive 100% of the voltage, but the EAW's will receive 50% each. Since power is proportional to voltage squared, you get a ratio of 4:1.

Share this post


Link to post
Share on other sites
glennrush    0
I guess it's just basic circuit theory. The amp will drop 100% of its voltage across both of your parallel loads: 1) the two EAW's; and 2) the 728.

So the 728 will receive 100% of the voltage, but the EAW's will receive 50% each. Since power is proportional to voltage squared, you get a ratio of 4:1.

I get it, I think. Thanks for the education. I'll need a different solution.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this