Maelstrom 18 Hypex plate amps volume control keep failing

[warek]

My subwoofers volume controls keep failing.

I have professionally made, by audio specialist, 4 Maelstrom 18 inch subwoofers in 125 litre cabinets, with Hypex 8.0 (800 watt) subwoofer plate amps. I also have a MK MX200 with a DS Speaker antimode 8033 run through a Yamaha Adventage rxa3000 processor.

I use subwoofer mono on the Yamaha setup calibration and front out RCA subwoofer jack into the Antimode 8033. The room is 7 metres by 5 metres with cathedral ceilings up to 4 metres and open plan with an adjoining kitchen about 5 by 5 metres also with cathedral ceiling.

I use DS Speaker and chain the 4, 18 subs via RCA leads to one of the DS Speaker output and one sub, usually the MK to the other DS Speaker output. I do not notice any difference by turning the phase control 180 degrees on the sub connected to the second output on the antimode 8033.

I actually get better bass, as in more impact with explosions etc. if I run the antimode in bypass, which is my most often, used setting. I calibrate the subs individually using a test tone to have an output of about 95 -98 DB C weighed slow with a sound pressure meter held about 1 centimetre from the cone of each sub and am surprised that I need to put the sub volume control at ¾ level to get that output and on one sub I need to adjust its volume control to maximum to get that SPL. Is this normal? On the MK I can get that level with bass volume control between 0 and +2 DB and it has bass volume adjustment up to + 9 Db.

I have had this setup for 5 years and over that time I have had 4 control/filter boards volume control fail on the Hypex plate amps. Hypex tech support has no idea, and the control board volume controls have not been adjusted, usually set and forget and yet they still fail. Sometimes they fail in that the sub runs at maximum volume and cannot be turned down, but usually there is no volume. When I add a new control/filter board they are work fine but can fail at any time.

This is too much of a coincidence and I wonder if there is an error in my setup or if there is an electrical fault in either the antimode or the Yamaha? If so how would I go about isolating the fault?

I also have 2 Behringer feedback destroyer pro DSP1124P that I have never used and wonder if I may get any benefit of using these in my system in addition too, or as a replacement for the Antimode and if so would welcome any suggestions as to how to connect them?

Thanks for any suggestions

 

[TLS Guy]

My subwoofers volume controls keep failing.

I have professionally made, by audio specialist, 4 Maelstrom 18 inch subwoofers in 125 litre cabinets, with Hypex 8.0 (800 watt) subwoofer plate amps. I also have a MK MX200 with a DS Speaker antimode 8033 run through a Yamaha Adventage rxa3000 processor.

I use subwoofer mono on the Yamaha setup calibration and front out RCA subwoofer jack into the Antimode 8033. The room is 7 metres by 5 metres with cathedral ceilings up to 4 metres and open plan with an adjoining kitchen about 5 by 5 metres also with cathedral ceiling.

I use DS Speaker and chain the 4, 18 subs via RCA leads to one of the DS Speaker output and one sub, usually the MK to the other DS Speaker output. I do not notice any difference by turning the phase control 180 degrees on the sub connected to the second output on the antimode 8033.

I actually get better bass, as in more impact with explosions etc. if I run the antimode in bypass, which is my most often, used setting. I calibrate the subs individually using a test tone to have an output of about 95 -98 DB C weighed slow with a sound pressure meter held about 1 centimetre from the cone of each sub and am surprised that I need to put the sub volume control at ¾ level to get that output and on one sub I need to adjust its volume control to maximum to get that SPL. Is this normal? On the MK I can get that level with bass volume control between 0 and +2 DB and it has bass volume adjustment up to + 9 Db.

I have had this setup for 5 years and over that time I have had 4 control/filter boards volume control fail on the Hypex plate amps. Hypex tech support has no idea, and the control board volume controls have not been adjusted, usually set and forget and yet they still fail. Sometimes they fail in that the sub runs at maximum volume and cannot be turned down, but usually there is no volume. When I add a new control/filter board they are work fine but can fail at any time.

This is too much of a coincidence and I wonder if there is an error in my setup or if there is an electrical fault in either the antimode or the Yamaha? If so how would I go about isolating the fault?

I also have 2 Behringer feedback destroyer pro DSP1124P that I have never used and wonder if I may get any benefit of using these in my system in addition too, or as a replacement for the Antimode and if so would welcome any suggestions as to how to connect them?

Thanks for any suggestions

I think it is most likely vibration. I would get the amps out of the sub.

 

[warek]

I think it is unlikely, the cabinets are made of 45 mm marine ply, total weigh is about 50 kg and there is a recessed section on the back to isolate the plate amp from rest of the cabinet, the leads go through and then that hole is also sealed.

Very little cabinet vibration when in use, I can sit a vase of flowers on top.

Thanks for the suggestion

 

[TLS Guy]

I think it is unlikely, the cabinets are made of 45 mm marine ply, total weigh is about 50 kg and there is a recessed section on the back to isolate the plate amp from rest of the cabinet, the leads go through and then that hole is also sealed.

Very little cabinet vibration when in use, I can sit a vase of flowers on top.

Thanks for the suggestion

If it is the actual control that is failing, it is vibration. That would be the only thing that would kill it. If it is electronics associated with the control failing then there may be something wrong with the ancillary equipment. It is impossible to trouble shoot this at long range.

You will need scopes etc to look at what signals are being sent to the amp and looking for damaging DC offset.

This is the problem today, people buy exotic gear and have no service sense. If you are going to buy complex gear, then you need a heavy investment is test gear and gain the knowledge to use it.

I have always kept an extensive test bay, for sorting out problems and service.

 

[TheWarrior]

Just to be clear, each 18" sub has its OWN Hypex DS8.0?

As long as one plate amp isn't being bridged to power two subs, then yeah I'd take a look inside and see how much internal bracing was used. The thickness of the material is meaningless when dealing with any size woofer, it must be braced! Therefore TLS may be right!

 

[warek]

Just to be clear, each 18" sub has its OWN Hypex DS8.0?

As long as one plate amp isn't being bridged to power two subs, then yeah I'd take a look inside and see how much internal bracing was used. The thickness of the material is meaningless when dealing with any size woofer, it must be braced! Therefore TLS may be right!

One plate amp per sub. Thanks for the suggestions, I spoke with the designer/builder who said he had ongoing failures with Hypex plate amps and has now swapped to Dayton Audio plate amps and has had no volume control failures in the last 3 years using the same cabinet design. It is well braced.

I have got the part number for the volume control pots from Hypex and it is an Alps http://www.alps.com/prod/info/E/HTML/Potentiometer/RotaryPotentiometers/RK11K11/RK11K1120A5T.html

We will replace some and see if the new ones are more reliable

Have a good day

Warek