Amp for DIY sub

**letzleta** · **02-06-07, 08:13 AM**

I just checked PE's website and now the due date on the Bash 500 amp is 4/6/07. I am not willing to wait that long. I need some help locating an amp now. What would you reccomend? It will be pushing a Dayton Titanic 15" in 300 liters ported. The enclosure is not finished yet so tuning and volume are still up for change.

I can get the Dayton 540 Watt plate amp for $250, but are there better options for that price? The Behringer amps are talked about on here alot, but how do you implement crossovers with those rack amps?

In summary, I need to know where to get 500+ watts for $250 or less. Thanks.

**JorgenMan** · **02-06-07, 08:28 AM**

With a Behringer or any other pro amp, you have to build your own highpass filter. See the links for some examples.

http://www.subwoofer-builder.com/active-filter.htm
http://sound.westhost.com/project99.htm

**letzleta** · **02-06-07, 08:53 AM**

How hard is it to build one of those crossovers? Also, how much does it cost to build one?

Changing the rumble filter on the Dayton amp voids the warranty, that worries me slightly as I feel the factory setting of 18hz is too high. Is anyone familiar with changing the rumble filter on the Dayton 540watt plate amp?

**Otto** · **02-06-07, 09:26 AM**

Quote:

letzleta wrote:

How hard is it to build one of those crossovers? Also, how much does it cost to build one?

I guess it depends on how familiar you are with assembling electronics. It's not a terribly complicated circuit, but if you want to do it nicely, it can be a little work. In college, we made printed circuit boards using a process that's somewhat similar to photography. Other options are to put it on a "bread board" or "wire wrap" on a pre-drilled board. I would probably pass on those options due to reliability concerns. You could also solder on a pre-drilled board, which is more time consuming, but will improve reliability over everything but the PCB. Once you're done with assembly, put it all in a nice little box. I think you would be fine to use a little wall wart power supply.

The parts aren't that expensive. I'm thinking less than $40 even counting the power supply and box. I'm pretty sure you could get all the parts at Radio Shack or online at Mouser, Digi-Key and maybe PE... FWIW, it's amazing how much wall warts cost at Radio Shack (IIRC, they can easily go up to $20). They're super easy to find at any thrift store for about $1. I'm not a big thrift store shopper, but when I do hit one, I always poke around for power supplies. I don't care if the plug on the end fits anything I have or not; it's so easy to change the plug with a $2 part from RS.

I don't know anything about modifying the HP filter on the Dayton. If it's a simple mod, I wouldn't hesitate to do it if it were on my amp. I bet modding the fan on the Behringer will void the warranty, and I was ready to do that until I moved that amp to the basement.

BTW, I use a Behringer EP 2500 with no high-pass filter in an IB configuration. I haven't had any real problems running that way, but this thread makes me consider putting a HP filter at about 10 Hz...

**BoomieMCT** · **02-06-07, 10:06 AM**

Try this OAudio amp or this Rythmik Amp. The OAudio one is pretty tuneable and the Rythmik one can be ordered with whatever rumble filter you want. They both have more switches and knobs then the PE one.

All that being said, I ordered two of the 500W Dayton BASH amps last year and they haven't arrived yet. I don't want to cancel my order as last year's price was way low. I have a BFD so the extra knobs mean less to me.

**letzleta** · **02-06-07, 10:21 AM**

Boomie... thats funny because I had that rythmik amp in my watch list on ebay.

Which brings me to my next question... will I notice a difference between 540 watts RMS and 380 watts RMS? Will 380 be enough for the Titanic?

**JorgenMan** · **02-06-07, 10:23 AM**

Looks like the price on the Nady XA-900 has dropped down to $150. 400W/ch @ 2 ohms, 300W @ 4 ohms, 200W @ 8 ohms, 675W bridged mono @ 4 ohms.

**BoomieMCT** · **02-06-07, 10:25 AM**

Quote:

letzleta wrote:

Boomie... thats funny because I had that rythmik amp in my watch list on ebay.

Which brings me to my next question... will I notice a difference between 540 watts RMS and 380 watts RMS? Will 380 be enough for the Titanic?

Peak output will be 1-2 dB less. Whether or not you notice the difference depends on your listening tastes and room size.

**BoomieMCT** · **02-06-07, 10:26 AM**

Quote:

JorgenMan wrote:

Looks like the price on the Nady XA-900 has dropped down to $150. 400W/ch @ 2 ohms, 300W @ 4 ohms, 200W @ 8 ohms, 675W bridged mono @ 4 ohms.

Where? I'd like to check that out.

**JorgenMan** · **02-06-07, 10:27 AM**

Quote:

BoomieMCT wrote:

Where? I'd like to check that out.

Musician's Friend, musician.com, just google "nady xa-900".

**letzleta** · **02-06-07, 10:33 AM**

I would jump on the nady in a second if I was sure I could build a x-over.

**BoomieMCT** · **02-06-07, 10:35 AM**

Quote:

letzleta wrote:

I would jump on the nady in a second if I was sure I could build a x-over.

How loud (or quiet) are the fans?

**letzleta** · **02-06-07, 10:38 AM**

Also, what kind of inputs do you use for the Nady or any other pro amp?

**JorgenMan** · **02-06-07, 12:09 PM**

Quote:

BoomieMCT wrote:

How loud (or quiet) are the fans?

A friend of mine has one sitting right above his TV and says it isn't a problem. I've only been over to his house once, but I didn't notice the fans at all.

EDIT: The Nady fans are louder, not quieter, than the Behringer fans. You can, however, replace the Nady fans with quiet PC fans (Panaflo, for example). I think the common fix for the Behringer is to put a resistor in series with the fan to slow it down, because the fans aren't a standard size.

**JorgenMan** · **02-06-07, 12:18 PM**

Quote:

letzleta wrote:

Also, what kind of inputs do you use for the Nady or any other pro amp?

You just stick mono RCA-to-1/4" adapters on the end of your RCA cable, no big deal.

**Bob in St. Louis** · **02-06-07, 01:12 PM**

This is a little over your price, but it'll have A LOT of headroom:
http://www.musicsupplycenter.com/Pro...Code=200%2D007

Bob

**Bob in St. Louis** · **02-06-07, 01:13 PM**

....Or this: (has one channel out, but you only NEED one)
You can't go wrong for $100

http://www.musicsupplycenter.com/Pro...Code=100%2D237

Bob

**rcarlton** · **02-07-07, 10:09 PM**

There is an amp from a SVS 20-39PC+ cylinder sub, it is the 525 watt BASH on the Klipsch forum. He's looking for $200.

**FlashJim** · **02-22-07, 01:12 PM**

Quote:

letzleta wrote:

In summary, I need to know where to get 500+ watts for $250 or less. Thanks.

I just sold my Nady XA-1100 in the Classified section for $175 +shipping. There are deals out there. Just look around.

I used the low pass filter on my receiver and no high pass.

**Brian Bunge** · **02-22-07, 07:29 PM**

If you are using the sub with a fairly recent DD or DTS surround sound receiver then you don't need a crossover. It's built into the receiver.

**Bob in St. Louis** · **02-23-07, 07:11 AM**

Quote:

Brian Bunge wrote:

If you are using the sub with a fairly recent DD or DTS surround sound receiver then you don't need a crossover. It's built into the receiver.

....Unless you're using a receiver that "flys in the face of conventional thinking" because it has TWO XO points that nobody you've talked too has a clue how to set it up...

Bob

**Chrisbee** · **02-24-07, 05:47 AM**

Quote:

JorgenMan wrote:

A friend of mine has one sitting right above his TV and says it isn't a problem. I've only been over to his house once, but I didn't notice the fans at all.

EDIT: The Nady fans are louder, not quieter, than the Behringer fans. You can, however, replace the Nady fans with quiet PC fans (Panaflo, for example). I think the common fix for the Behringer is to put a resistor in series with the fan to slow it down, because the fans aren't a standard size.

The Behringer fan is 24 Volts and is standard PC (home computer) size.

My replacement 24 V fan (Papst 8414 NGL) is totally silent as regards air movement but can be heard ticking from close up.

The original Behringer fan was so noisy I could hear it 12 feet away as a waterfall sound through the cones of my IB from where it was sitting in the rear enclosure.

On my IB the lower speed fan does not cause any overheating whatsoever. I monitored the heatsink for a while with a digital thermometer. The temperature only rose above ambient by a couple of degrees F even after an hour of Metallica @ 100dB.

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