Need urgent help!

[gperkins_1973]

Hi there,

I am waiting delivery of 2 FI Q18 dual 1 ohm subs to wire them in series to give me 4 ohms as I want run them from a behringer Europower 4000 at 4 ohms bridged.

I keep reading that it is better to have dual 4 ohm subs and run them parallel to get 2 ohms.

Iam really worried Ive made the wrong decision and spent £700 on dual 1 ohm subs and won't be as good as dual 4 ohm subs in parallel.

The behringer Europower 4000 runs 2 x 1200 watts rms into 2 ohms and 2400 watts rms bridge.

Some advice would really be appreciated.

cheers graham

[Mike P.]

As long as the amp has enough power to take the subs to Xmax (which it does) you'll be fine.

[gperkins_1973]

mike,

For future upgrade can you wire a single Dual 1 ohm sub in series on itself into the behringer Europower 4000 to get 2 ohm's. Basically what I am trying to say is, is it possible to run each dual 1 ohm sub of its own amp so each sub is getting 2 x 2000 watts each. Then I ca buy another behringer Europower 4000.

cheers graham

[Mike P.]

You don't need another amp. You can wire both D1 subs together for a 4 ohm load and run the EP4000 in 4 ohm bridged mode, or you can wire each D1 sub in 2 ohms each and run one sub per channel on the EP4000. Either way will work.

[gperkins_1973]

Mike,

Cheers for that. I was thinking with regards of sending more power to the subs. If I wire 1 D1 sub to one amp in 2 ohms can I use the 2.x 1200 watts rms to feed that one sub and then do the same to the other sub.

I take it I feed the spare channel to the second amp to run the second sub as there is only one sub output from the onkyo.

I am just thinkin ahead just in case one amp wont be enough. I have read a couple of threads saying that one amp was not enough to run the two subs.

Are there any benefits to running subs in parrallel and series.

Would this it be possible.

cheers

[Mike P.]

I have read a couple of threads saying that one amp was not enough to run the two subs.

That is application specific. Room size, room gain, box size, sealed or ported, corner loaded, room interaction issues, all play a big part in how a sub performs. If the amp is anywhere close to it's rated output you'll have 120+ db at 20 hz, your nowhere near the subs Xmax, and you don't need a Hi-Pass filter.

Even if you gave each sub 1800 watts (NOT recommended) to reach Xmax, the difference is less then 2 db.

Are there any benefits to running subs in parrallel and series.

With two D1 subs that would result in a 1 ohm load, only car audio amplifiers are capable of handling that.

[gperkins_1973]

Mike

Is there no way I can run one D1 sub in series by itself to get 2 ohms and then connect that to one amp running in two ohms which is rated at 2 x 1200 watts so that all 2400 watts is going to the sub. Obviously not ideal but I could run more than half of the 1200 watts bridged.

Connect one sub to the first behringer using just one of the output channels in 2 ohms (2x1200 watts) and then take the spare output of the first amp to connect to the second amp and then the other output channel connect to the other sub (2 x 1200 watts)

I have attached a diagram to show what I mean. Not sure if this is possible as they will be in series to double up the ohm rating.

cheers

Graham

[Mike P.]

You can't run 2 x 1200 at 2 ohms on a single D1 sub, it won't work. Even if it did, you would blow the sub.

[gperkins_1973]

Mike,

Just looked at the specifications and it does run 2 x 2ohms at 1200 watts. Could I wire it this way but turn the gain down so that I am running less than full power. I suppose in theory would I notice the difference between 1200 watts and 2000 watts or would it be better down the road to get a more powerful amp that will run 4 ohm bridged say 3000 to 3500 watts rms.

cheers

Graham

[Mike P.]

Just looked at the specifications and it does run 2 x 2ohms at 1200 watts

Yes, that's what I've been telling you. These are your only wiring options.

[gperkins_1973]

Mike,

Sorry about this. I was hoping I could run all the amplification from one amp to one sub but it looks like I can't. Never mind.

What do you think would the better option. Wire them as two seperate channels in 2 ohm or as one channel bridged 4 ohms. Are there any advantages over the two options. 2ohm or 4ohms.

With wiring them in 2 channels 2 ohm would I have to balance the two subs as I would have to use both gain inputs on the behringer where as in bridged mode I would only be using one gain input to control the two subs.

cheers

Graham

[Mike P.]

My personal preference would be 2 separate gain controls. It gives you the ability to verify that each sub is working properly since both subs are in the same cabinet.

[gperkins_1973]

Mike,

Thanks for that. What if the gain controls were slightly out say one was slightly up more than the other, would that unbalance the two subs in any way.

cheers

Graham

[Mike P.]

The result would be slightly more power to one sub, an unnoticeable difference.

[gperkins_1973]

Mike,

Sorry if this sounds like a dumb question but if you have the gain knobs on the front of the behringer amp on full does this mean that all the available power will be available to the subs which then just leaves the onkyo's sub channel level to be adjusted to 75db.

Is that correct.

cheers

Graham