Rd-700 Hi, I have the roland rd700. I'm playing through a small behringer mixing board with effects, into a JBL powered speaker and horn, but the sound is not as quality as i like. Its a bit hollow and a bit tinny, though many others may not notice it. Do I need a power amp to improve the quality. I'll be playing outside often also. How can I get that rich, crisp pro sound? Thank You, Friend! Tom

It's probably not cost effective to repair it' Check the horn driver and the raw woofer to see if they are still good, and if so retain then as spares.

Generally, there are two possible problems- The horn diaphragm is blown or the power amp to the horn is broken. The diaphragm being blown is more likely. Remove the driver and run a voltmeter across the terminals. If it doesn't show continuity, replace the diaphragm. If it does show continuity, take the cabinet to the repair shop.

Hi,I was jamming yesterday and while playing not very loud the mixer went off and never worked again,also cut out the stereo amps I was using to power big speakers,been using it for about 5 hours one a week for last few months with no probs,Q:is there a fuse inside that may have blown? There was a 3amp in the normal plug which stated 5amp but worked fine for ages,I replaced it with another 3amp seeing I didn't have a 5 amp but no power,have you any ideas what to do because I need this working quick and can't afford another one,it's a behringer xenyx 1222fx mixer. Any help would be amazing Thanks Mike

Register and download the manual for free at retrevo.com

http://www.retrevo.com/support/Behringer-EP4000-Amps-manual/id/23591dj795/t/2/

http://www.raltron.com/cust/tools/parallel_resistance.asp

It's ohm's law, dude. 1/a + 1/b = 1/total. One each 8- and 4-ohm speaker in parallel per channel would be 2.7 ohms (nominal). So it will work in theory.

How you manage the potential difference in volume between dissimilar speakers on the same amp channel is a mystery.

Distortion will kill any speaker, not power. Stay within the amp's usable range.

Hi,

The following power cords will work with your speakers

You can purchase the power cord from the following site if you are in the UK:

http://www.power-adapters.co.uk/jbl-7000042001-acdc-18v-power-supply-adapter-p-7165.html

You can purchase the power cord from eBay if you are in the US:

http://cgi.ebay.com/AC-Power-Supply-Adapter-Charger-JBL-700-0042-001-/350422898000

Regards,
sjstore2

Hi duane
To answer your question;
Usually you would use an ohm/impedance meter or multimeter to test the voice coil right at the horn`s terminals then with the crossover network connected you would go down the line all to the speaker box terminals to check for an open line.
But if you don`t have a multimeter you can rig a small AAA battery with two wires connected and listen for a "click" sound as you touch and release the horns terminals.
Of course this would only tell you if you have an open voice coil but it is often enough.
Hope this help Good luck

This is a wild educated guess.

I repaired a Behringer guitar amp that had a DSP effects in it (BX1200 I believe).

The effects were on a seperate board and the board had its own 5 volt power supply. The filter capacitor for the 5 volt power on the board was UNDERSIZED and it had degraded causing the 5 volts to drop out of regulation, dipping to 4 volts. This caused the DSP effects to fail.

YOUR device MAY use the same DSP OR design.

Check the 5 volt power with an OSCILLOSCOPE to look for dips below the 5 volt operating point that occur at 120 HZ.

Trash. Don't run your bass through speakers not designed for it. Likewise (from personal experience) don't allow microphone feedback to get into consumer speakers. Bye-bye tweeters in either case.

This should be your manual, if not, they have a catalogue of a fair few more!

http://audio.manualsonline.com/manuals/mfg/roland/td10.html