power amp for subwoofer

[BC Dave]

Hello,

I have a 1991 VMPS Original Subwoofer (passive) and have ordered a new 12-inch Megawoofer driver and 15-inch passive radiator for it, which should be arriving today. I have been using an Adcom GFA535-II to power the original driver and it has been amply (pardon the pun) powerful because the current woofer has dual voice coils and is being fed by both channels of the Adcom. However, the new driver has a single voice coil, so my power (60 rms per channel (100 into 4 ohms) with three dB dynamic headroom) will be whacked in half with one side of the dual-power-supply Adcom sitting dead. I have a very large room, so I believe I will need more power. I need to keep the price down for a used amp ($125 max US). I believe I'll need about 125-150 watts in . Would I be better trying to find a used Parasound or NAD stereo amp or monoblock Marantz, or should I be looking for a used subwoofer amp from Samson or Behringer? I really don't want a plate amp because of the hassle of cutting holes into the sub an the fact unwanted equalization may be applied to the VMPS. Thanks for any suggestions.

 

[jcPanny]

Sub amp

Can you bridge the Adcom? If so, it might work fine.
In your budget, a bridged audioSource or Behringer amp would work well. Ubid even has refurbished amps occasionally.

 

[jeffsg4mac]

You might want to try the Adcom first, you might be surprised. I have one and it is powerful little amp. If I can remember that far back I believe that amp really is more like 90 into 8-ohms and 120 into 4, when it was tested and reviewed. If you think after trying it you need more power then the Behringer A500 would be a great choice and is bridgeable, unlike the Adcom 535II.

 

[beppe61]

Hello,
... Would I be better trying to find a used Parasound or NAD stereo amp or monoblock Marantz, or should I be looking for a used subwoofer amp from Samson or Behringer? ...
Thanks for any suggestions.

Dear Sir,

I own an old Adcom GFA 545 and a quite new Samson Servo 260 that I bought for driving a pair of demanding (current hungry) Dynaudio speakers.
They both fail to give an adequate bass response, IMHO of course.
So that I am thinking about buying the Behringer A500 that, having a more substantial power supply, should give a better (more “solid”) bass.
To end my advice would be to try if you can the A500 or even, if you can live with the noisy fan, the very powerful Behringer EP1500.
Actually I am undecided between the A500 (220W/4 ohm) and the EP1500 (400W/4 ohm) presently.
In any case I would be very pleased to read your listening notes after you have purchased any amp.

Thank you very much and kind regards,

bg

 

[BC Dave]

thanks for comments, leaning towards A500

Thanks very much all for your comments. I went around the corner to a music store that sells Behringer stuff. They have the 1500 with the fan, which would drive me nuts. The A500 is not in stock, but they can get it for me for about $260 Canadian. The guy said the A500 is designed for studio applications and will be dead quiet. Bridged, with 500 watts, I would have power to burn. This seems a better bet than buying a 10-year-old stereo power amp for $150 and having it crap out in a couple of years.

 

[j_garcia]

You don't have to mount a plate amp IN the sub, it can be mounted in a generic box just to cover up the components... That's how I run mine I use a Rythmik 350w plate amp with my sub and it is a beast for the price. The 250w version is also a solid contender. http://www.rythmikaudio.com/nonservo_product.htm

 

[beppe61]

Thanks very much all for your comments.
I went around the corner to a music store that sells Behringer stuff.
1) They have the 1500 with the fan, which would drive me nuts.
The A500 is not in stock, but they can get it for me for about $260 Canadian.
2) The guy said the A500 is designed for studio applications and will be dead quiet. Bridged, with 500 watts, I would have power to burn.
This seems a better bet than buying a 10-year-old stereo power amp for $150 and having it crap out in a couple of years.

Dear Sir,

thank you very much for your very kind and extremely valuable reply.
1) in a home environment the fan "is" a problem indeed.
I know of people replacing/slowing down it.
Much better to do without it completely.
2) your approach is very sensible, and I think I would do the same.
Let's say that the first who tries the A500 will report his listening notes.
Do you agree ?


I wish you to solve your amplification issue in the optimum way.
Thank you very much again.
Kind regards,
beppe
italy

 

[jeffsg4mac]

Get your A500 here http://americanmusical.com/ They have great service, great prices and a payment plan option too. I bought my DEQ 24/96 and they spread the payments out over 3 months on my card. I had the unit in 2 days.

 

[annunaki]

The A500 is only bridgeable to 8 ohm loads. Keep that in mind when ordering your subwoofer.

 

[j_garcia]

The A500 is only bridgeable to 8 ohm loads. Keep that in mind when ordering your subwoofer.

Yep, exactly why I couldn't use one for my sub. I was all ready to buy it until I found that out. My sub is a dual vc driver wired in a 4 Ohm config.

 

[jeffsg4mac]

Yep, exactly why I couldn't use one for my sub. I was all ready to buy it until I found that out. My sub is a dual vc driver wired in a 4 Ohm config.

Is your sub 8-ohms per coil or 2?

 

[j_garcia]

8 Ohms ea, but there is only one set of binding posts for input. If I wanted to wire for dual 8 Ohm operation, I would have to open it up and rewire and add a second set of binding posts. The Behringer would then output 160x2 @ 8 Ohms, not the 500 when bridged (though I'm sure it would be enough). The plate amp also has a selectable subsonic filter and a continuously variable phase adjustment.

 

[annunaki]

Yep, exactly why I couldn't use one for my sub. I was all ready to buy it until I found that out. My sub is a dual vc driver wired in a 4 Ohm config.

If your sub has dual 4 ohm voice coils, the amp would work perfectly. A 4 ohm coil on each channel would be the same as an 8 ohm mono load. If your sub is dual 2 ohm coils wired in series to 4 ohms, yes, you would be out of luck. Unless of course you went with the EP1500.

 

[mtrycrafts]

8 Ohms ea, but there is only one set of binding posts for input. If I wanted to wire for dual 8 Ohm operation, I would have to open it up and rewire and add a second set of binding posts. The Behringer would then output 160x2 @ 8 Ohms, not the 500 when bridged (though I'm sure it would be enough). The plate amp also has a selectable subsonic filter and a continuously variable phase adjustment.

Well? That operation should be painless
You could get two @ $180 ea., still a bargain, and bridge

 

[BC Dave]

help please, ASAP

I have read some very mixed reviews on the Behringer A500 and have gotten cold feet on it. One studio guy I talked to said he wouldn't touch Behringer with a bargepole. I have seen a Samson Servo 550 at a very good price. Is this a better quality amp than the Behringer? I need a very quick answer cause I have to move on this immediately if it's a bargain (100 US range).
Cheers.
Dave

 

[j_garcia]

Well? That operation should be painless
You could get two @ $180 ea., still a bargain, and bridge

I know, but my current amp only cost $150 and is more than up to the task. I'm only using about 25% gain. Plus, two A500s would take up a lot of space too

 

[BC Dave]

okay, now what do I do?

I picked up a Behringer EP1500 to try out over the weekend. I had to go to Radio Shack to pick up two quarter-inch jack to female RCA adaptors and I hooked it up using the sub out on my Denon Dolby Digital receiver. The only bass I am getting is a 60-cycle hum, which increases in volume as I turn up the gain controls on the Behringer. Tried bridged mode, stereo mode and inputs 1 and 2 (left and right) Everything hums. I didn't get a manual with this amp so I don't know what could be causing it. Someone warned me that there can be an incompatibility problem between PA equipment and home theater equipment that can cause a hum, but others seem to be able to use the Behringers to power passive subs and speakers in such applications. Can anyone help? thx. Dave

 

[mtrycrafts]

I picked up a Behringer EP1500 to try out over the weekend. I had to go to Radio Shack to pick up two quarter-inch jack to female RCA adaptors and I hooked it up using the sub out on my Denon Dolby Digital receiver. The only bass I am getting is a 60-cycle hum, which increases in volume as I turn up the gain controls on the Behringer. Tried bridged mode, stereo mode and inputs 1 and 2 (left and right) Everything hums. I didn't get a manual with this amp so I don't know what could be causing it. Someone warned me that there can be an incompatibility problem between PA equipment and home theater equipment that can cause a hum, but others seem to be able to use the Behringers to power passive subs and speakers in such applications. Can anyone help? thx. Dave

You have a ground loop issue. Not sure how to solve it if it is not caused by a cable TV connection to the system. You can verify this by using a cheater plug on a temporary basis only; safety is at stake.
May need to ground all the components together? A common ground?