L-pad on Woofer question.

[acmv]

Hi,

My current set up is a 2 way system, comprising of one 15" woofer, 8 ohm driver cutting at about 600hz and a 1", 16ohm compression driver for the top, cutting at about 1200hz.

I have place a 8ohm L-pad across the woofer after the crossover net work. This was because I was having too much bass initially, therefore put the L-pad to control the bass.

About a week back, I received a pair 16ohm L-pad from Parts express. I removed the 8ohm from my existing woofer, and changed in the new 16ohm L-pad instead.

The result was fantastic, the clarity of the bass improved, separation in the bass region is much better. There was no change in the loudness, but the bass just get more musical.

My current bass crossover is a 3mh coil, with a 20uf cap shorted across. I would like to know why am I getting this experience? By using a 16 ohm L-pad what load does the woofer see? Is they a change in cross over frequency?

Many thanks for your replies, I am looking forward to your precious opinion. Thank You.

Regards

[jcrobso]

In general the woofer is used without an L-pad. This is because most of the time the efficiency of the other speakers is higher than the woofer.
By using a 16 Ohm L-pad the crossover will see a 16 Ohm instead of an 8 Ohm load. This could possibly affect the crossover frequency.

[Loren42]

Hi,

My current set up is a 2 way system, comprising of one 15" woofer, 8 ohm driver cutting at about 600hz and a 1", 16ohm compression driver for the top, cutting at about 1200hz.

I have place a 8ohm L-pad across the woofer after the crossover net work. This was because I was having too much bass initially, therefore put the L-pad to control the bass.

About a week back, I received a pair 16ohm L-pad from Parts express. I removed the 8ohm from my existing woofer, and changed in the new 16ohm L-pad instead.

The result was fantastic, the clarity of the bass improved, separation in the bass region is much better. There was no change in the loudness, but the bass just get more musical.

My current bass crossover is a 3mh coil, with a 20uf cap shorted across. I would like to know why am I getting this experience? By using a 16 ohm L-pad what load does the woofer see? Is they a change in cross over frequency?

Many thanks for your replies, I am looking forward to your precious opinion. Thank You.

Regards

I'm sorry, but you are hopelessly lost. You never put an L-Pad on a woofer. You are dissipating huge amounts of power into heat, which will soon smoke your L-Pad. At best case 33% of your power is being dissipated through the L-Pad. Once you turn the L-Pad down, more and more power gets dissipated through the L-Pad until the L-Pad is dissipating 100% of the power from your amp.

Also, your crossover points are way out of line for a 2-way system. Putting the 16-Ohm L-Pad will indeed change your crossover point, but I can't calculate that without the specific drivers you are using, the detailed enclosure tuning and volume, and a rough schematic.

I will try to help you, but let's first start with the two drivers you have. Please list the brand and model and I will try to look them up.

Next, I need details on your cabinet enclosure to determine how the woofer will behave.

Finally, you are kind of screwed with the impedance differences between the horn and woofer. You might use two horns in parallel to match impedance, but that raises other problems.

I think in the end you have only two choices; one, get a different horn that is the same impedance as the woofer and compliments the woofer's frequency response, or two, bi-amp the system.

Bi-amping may work, but we still need to work on the crossover point for the two drivers. You can adjust that with an active crossover once we determine where that point should really be.

Please give us the data and I will try to help you get pointed in the right direction.

[acmv]

Hi Loren42,

Thank You for your reply, here is the information on my setup. The speaker, Ramsa WS-A300-K. The crossover, a copy of the NL200t3 battery version. Hope that the infor provided will be of assistance to you, looking forward to your posting.

Regards
acmv

[Loren42]

Hi Loren42,

Thank You for your reply, here is the information on my setup. The speaker, Ramsa WS-A300-K. The crossover, a copy of the NL200t3 battery version. Hope that the infor provided will be of assistance to you, looking forward to your posting.

Regards
acmv

I would need the make and model of both of the drivers (horns and woofer) and the internal volume of the woofer cabinet (less speakers, braces, and ports) and I need the number of ports (looks like two ports), port diameter and port length. You may have to take a best guestimate based on measurements with a tape measure.

The only thing I can find on Ramsa is some pictures, so I am totally in the dark with what drivers they use. Are they JBL? If so I need to know what they are to get the Thiele/Small parameters. Then we can begin to help you.