Daryls crossover for the dayton 15 inch sub

[Terry m]

Hi,I was wondering about Daryl's rc filter mod and what was it's purpose.I built the dayton rs 390-15 sub,the box is slightly under 3cu ft and sounds great 200 watt amp to power it.I'm not up on electronics so I'm not sure what this filter does for you.

[Jeff B.]

Hi,I was wondering about Daryl's rc filter mod and what was it's purpose.I built the dayton rs 390-15 sub,the box is slightly under 3cu ft and sounds great 200 watt amp to power it.I'm not up on electronics so I'm not sure what this filter does for you.

The RC circuit interacts with the impedance peak of the driver in the sealed box creating a slight peak in the frequency response and a first order roll-off below the peak. If properly designed this circuit can be "tuned" to provide a peak that flattens and extends the response a little deeper, and then lowers excursions at very low frequencies due to the additional filtering. Tuning, or getting the correct values for a specific driver in a specific box is the key.

[philiparcario]

your sub in a 85 liter box has an f3 of 31 a q of .87 and a bit of a boom.. look at the graph . the rc filter will lower the bump from 50 to 100hz

[philiparcario]

if you read this thread you can see another rss390 hf builder has a kick or bump in a 4.1 cu ft box.


http://techtalk.parts-express.com/sh...d.php?t=221271


daryl's filter raises resistance and uses the energy spent to deepen bass a bit along with making the bump a bit lower and shifted out of the subs range. for instance if the bump in the graph i posted is moved to 150hz - 200hz due to the filter you don't hear it because the subs' hipass point is set at 80 or 100hz not 150 or 200hz. A lot of bright designers love to fight over this filter there claim is you are wasting power and energy you sub won't be as loud. I say you are spending the energy to go a bit deeper and smoother in a smaller box. The definition of waste is really what is in question. Not whether it works or not.

[Terry m]

Hi Philip,thanks for the reply I think I'll give it a try.I'm not to up on electronics.Any idea of what I need.I can figure out that 4 resistors and 5 caps basicly connected between positive and negative,4 resistors @ 20 watts 4 ohms not sure what type to use.And 5 caps 500uf, not sure what type to use and I guess the better the quality the better the sound? Any help would be great.Terry

[Terry m]

The RC circuit interacts with the impedance peak of the driver in the sealed box creating a slight peak in the frequency response and a first order roll-off below the peak. If properly designed this circuit can be "tuned" to provide a peak that flattens and extends the response a little deeper, and then lowers excursions at very low frequencies due to the additional filtering. Tuning, or getting the correct values for a specific driver in a specific box is the key.

Hi Jeff,so I would have to change the values of the caps and resistors to fit my box.Terry

[philiparcario]

Hi Jeff,so I would have to change the values of the caps and resistors to fit my box.Terry

sorry I have been busy for holidays. give me a day or 2 too advise on caps and resistors. you have a 200 watt amp and the


http://www.parts-express.com/pe/show...ss390hf-4%2015


sub above in a 2.95 cu ft box. please let me know the amp model. thanks phil

[philiparcario]

real fast look. reads 3 of these in parallel


http://www.parts-express.com/pe/show...number=027-378


and no resistors should hi pass the sub at about 25hz

moving the bump from 50 to 100hz

a bit around 85 to 135hz this would remove some of the boom boom boom if you use your amps xover at 80 hz.




in effect you would be bandpassing the sub from 25hz to 80hz with the subs sound in the 25hz to 80hz range a little flatter and cleaner then now. let me know your amp I need to know if it has boost or eq.

[Terry m]

Let me check the volume on the box it's been a while since I built it and I had to modify it to install the amp.Thanks Terry

[Terry m]

Yeah I checked the box volume it's 3.5 cu ft.It's a 200 watt hafler sub amp.Thanks Terry

[Terry m]

There is no boost on the amp.Terry m