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JBL M350 mid tops + M355 bass bins use of internal crossover?

#1 User is offline   nekro 

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Posted 14 March 2007 - 12:37 PM

I have a pair of JBL M350 full range/mid tops and a pair of JBL M355 bass bins, I've only ever used the M350s on their own. I know they have an internal crossover so can I just link the 2 pairs of speakers and run them all from one amp?

I'm not sure what power rating the M355s have, but I have a C-Audio RA3000 amplifier - would this be enough to run the lot?

#2 User is offline   Chris Hinds 

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Posted 14 March 2007 - 04:57 PM

From a quick internet browse I can find that your Bins are rated at 350W @ 8 ohms, your tops at 500W @ 8 ohms. Your amplifier is rated at 400W into 8 ohms. All found by some brief Google searches though admittedly speaker data is via eBay.

Your mid/tops will have a crossover in them between the main driver and the horn, but this will not run the bins. You need to know if the bins have a crossover in them and the easiest way might be to take the back plate off and take a look. If it's just bare wires then no crossover, if there's components chances are you have one.

Either way the amplifier is inadequate. With a crossover in the bins the amp will see an 8 ohm load, and since your demand at 8 ohms would be 350 + 500 = 850W and your amp can only make 400W you'd be severely underpowered. Really you need an amp capable of delivering 1600W if that's the intended running configuration. Better still would be an active crossover and another amp to handle the subs with a tad more power.

Regards

Chris

#3 User is offline   Furryface 

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Posted 14 March 2007 - 05:29 PM

In agreement with Chris.

Back in the day had quite alot of dealings with the old M-series. You'd probably look at another RA-3001 if they were still available and it were still the early 90's - oh and you wanted to run the system two way active.. That said you can still pick up such amps for pretty money these days. I remember the M350 had an internal passive crossover inside and also believe that the bass M-355 had one to link to the M-330/M350/M360 but can't find any of my old manuals for it at the moment. Chris's advice there is spot on too, open the connector panel up and see what components there are there. If there are none you need and external active x-over and another amp. If there are some then you need a much bigger amp to drive all of the compoenents together.

let me know what you find I may have found my manuals and schematics in the meantime

Cheers

#4 User is offline   nekro 

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Posted 15 March 2007 - 10:35 AM

I'm quite sure the M350 are 350w at 8ohms, which I guess still means the RA3000 would be significantly underpowering them.

I have a PSL KA1202 but no external crossover, is there any way I could run these 2 amps together without using an external crossover?

thanks

#5 User is online   MarkPAman 

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Posted 15 March 2007 - 12:30 PM

 nekro, on 15 Mar 2007, 10:35 AM, said:

............ is there any way I could run these 2 amps together without using an external crossover?


Not a good one.

Click
MarkPAman
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and sometimes I just sits"
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#6 User is offline   TonyMitchell 

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Posted 15 March 2007 - 01:00 PM

All M-Series boxes are rated at 8 ohms and all boxes are rated at 350w RMS
(M330 12", M350 & M360 15" and M355 15" bass)

Great boxes, we used to have 18 of them!

#7 User is offline   nekro 

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Posted 15 March 2007 - 02:19 PM

managed to download the technical spec to confirm the power rating and the M350 are 350w at 8ohms, I guess I'll have to buy a crossover then

#8 User is offline   nekro 

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Posted 19 March 2007 - 01:08 PM

I've managed to borrow a Behringer SUPER-X PRO CX3400, can some advise me on the correct set up?

THe tec spec for the M350 says:

frequency response: 32hz - 18khz
crossover frequency: 1100hz

not sure about the M355.

If I'm splitting the signal with the external crossover then do I still need to flip the switch for the internal crossover on the speakers?

#9 User is offline   Matt Riley 

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Posted 19 March 2007 - 04:26 PM

Starting settings for the Behringer would be crossover point set to anything between 80 and 120 hz. If it is the xover that I think, then every input and output does different things depending on the mode it is operating in. Set it to two way stereo, and patch in accordingly. Then set the input and output gains at 0, the delay at 0, ensure that the outs are unmuted, and have a play with the frequency knob on the left to see what sounds good and what doesn't.

M

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