2 Way Crossover with 2 Woofers

[trazex]

Hello,

I've been getting into diy home audio. The process is very exciting, but as I'm new to this, I have a lot of questions, specifically regarding crossovers and how to match the drivers' nominal impedance to that of the amp.

I've decided to make a 2 way speaker with 1 tweeter and 2 woofers. Here's my equipment:

1. Tweeter: Dayton Audio RST28A-4ohm
2. Woofers: 2x Dayton Audio RS180P-8ohm
3. Pre-assembled 2 way crossover: Dayton Audio XO2W-2K 2-Way Crossover 2,000 Hz. This crossover can be set to either 4ohm or 8 ohm load. I intend to use it with 4ohm load.
4. Integrated Amp: Denon PMA-600NE, capable of handling 4ohm load

I want to wire the drivers in a way that the amp wont be damaged and will be able to drive them without problem. It would be perfect if it's possible to wire the 3 drivers so that the nominal impedance is 4 ohms.

I've come up with the following wiring diagram (see the attached picture 2), but i'm not really sure if that's the way to do it. I need a second opinion on this.

What do you guys think? Will I be able to drive these speakers without damaging the amp (and will the nominal impedance be 4 ohms) if I wire them like shown in the picture? If not, it'd be great if you can explain to me how wiring multiple woofers to a 2 way crosssover works. Hell, I'll attach a picture where you can literally draw it out for me, haha.

Thank you very much in advance.

Cheers,

Yordan

 

[highfigh]

Hello,

I've been getting into diy home audio. The process is very exciting, but as I'm new to this, I have a lot of questions, specifically regarding crossovers and how to match the drivers' nominal impedance to that of the amp.

I've decided to make a 2 way speaker with 1 tweeter and 2 woofers. Here's my equipment:

1. Tweeter: Dayton Audio RST28A-4ohm
2. Woofers: 2x Dayton Audio RS180P-8ohm
3. Pre-assembled 2 way crossover: Dayton Audio XO2W-2K 2-Way Crossover 2,000 Hz. This crossover can be set to either 4ohm or 8 ohm load. I intend to use it with 4ohm load.
4. Integrated Amp: Denon PMA-600NE, capable of handling 4ohm load

I want to wire the drivers in a way that the amp wont be damaged and will be able to drive them without problem. It would be perfect if it's possible to wire the 3 drivers so that the nominal impedance is 4 ohms.

I've come up with the following wiring diagram (see the attached picture 2), but i'm not really sure if that's the way to do it. I need a second opinion on this.

What do you guys think? Will I be able to drive these speakers without damaging the amp (and will the nominal impedance be 4 ohms) if I wire them like shown in the picture? If not, it'd be great if you can explain to me how wiring multiple woofers to a 2 way crosssover works. Hell, I'll attach a picture where you can literally draw it out for me, haha.

Thank you very much in advance.

Cheers,

Yordan

IF (the big 'if') the tweeter can handle 2KHz and the spec sheet shows the Fs as 775Hz, you'll still need to make sure the crossover for the woofers is correct. I think you would be better off calling Parts Express tech support and having them calculate for a dedicated crossover, or someone here can do it. Rather than just wire the woofers parallel, you might be able to use what's often called a 2-1/2 way design, which means the high pass between one woofer and the tweeter is similar to this crossover but the other woofer has a low pass set at a lower frequency, to help augment the bass where the narrow cabinet has problems producing below a certain frequency. This is usually just a coil, but the type (air core vs iron or ferrite core) and value (inductance) need to work correctly.

The 2KHz crossover point is actually right about where it should be with this tweeter- the main think will be in getting the tweeter's level to work with the woofers- that can be done pretty easily- since the tweeter's sensitivity (they called it 'Output') is specified at 2.83V, you'll need to find the spec for 1Watt, since that voltage with a 4 Ohm driver is actually 2Watts and you may not need to adjust the tweeter's output much, if at all (depending on the room's acoustics and your preference).

 

[trazex]

IF (the big 'if') the tweeter can handle 2KHz and the spec sheet shows the Fs as 775Hz, you'll still need to make sure the crossover for the woofers is correct. I think you would be better off calling Parts Express tech support and having them calculate for a dedicated crossover, or someone here can do it. Rather than just wire the woofers parallel, you might be able to use what's often called a 2-1/2 way design, which means the high pass between one woofer and the tweeter is similar to this crossover but the other woofer has a low pass set at a lower frequency, to help augment the bass where the narrow cabinet has problems producing below a certain frequency. This is usually just a coil, but the type (air core vs iron or ferrite core) and value (inductance) need to work correctly.

The 2KHz crossover point is actually right about where it should be with this tweeter- the main think will be in getting the tweeter's level to work with the woofers- that can be done pretty easily- since the tweeter's sensitivity (they called it 'Output') is specified at 2.83V, you'll need to find the spec for 1Watt, since that voltage with a 4 Ohm driver is actually 2Watts and you may not need to adjust the tweeter's output much, if at all (depending on the room's acoustics and your preference).

Hey there,

Thanks for the reply.

This whole 2.5 way stuff still sounds very confusing to me, but it's definitely something that I'll check and deal with in the future.

My main concern right now is if the drivers I've chosen will work fine with my amp the way they're wired in the picture. Will I be able to listen to music with moderate volume without damaging the amp? Is it safe to proceed that way?

 

[TLS Guy]

Hey there,

Thanks for the reply.

This whole 2.5 way stuff still sounds very confusing to me, but it's definitely something that I'll check and deal with in the future.

My main concern right now is if the drivers I've chosen will work fine with my amp the way they're wired in the picture. Will I be able to listen to music with moderate volume without damaging the amp? Is it safe to proceed that way?

Since the driver are in parallel, that is a four ohm load. Off the shelf crossovers are never satisfactory. All crossover need to be custom. That design really needs to be 2.5 way. Driving two woofers in parallel up to 2K is not a good idea.

It should be possible to design a good 2.5 way speaker for those drivers. I can do that for you, but I would need to know the front baffle width.

 

[highfigh]

Hey there,

Thanks for the reply.

This whole 2.5 way stuff still sounds very confusing to me, but it's definitely something that I'll check and deal with in the future.

My main concern right now is if the drivers I've chosen will work fine with my amp the way they're wired in the picture. Will I be able to listen to music with moderate volume without damaging the amp? Is it safe to proceed that way?

A 2.5 way is a woofer with a low crossover point, placed where it will help the response most- if you look at the spec sheet for those woofers, you'll see that they start to lose steam around 200 HZ, so the woofer handling the lower frequencies should cut off in that area. The other will have a -3dB point wherever it will work best, without being so high that the cone/assembly doesn't break up terribly or resonate in a way that's unpleasant. An easy way to make sure the coil for the lower cutoff can be tailored to suit is by picking one that's larger than needed and check the response. If it works without screwing up the response, great and if it causes a dip, some of the wire can be unwound, to decrease its effect.

 

[highfigh]

Since the driver are in parallel, that is a four ohm load. Off the shelf crossovers are never satisfactory. All crossover need to be custom. That design really needs to be 2.5 way. Driving two woofers in parallel up to 2K is not a good idea.

It should be possible to design a good 2.5 way speaker for those drivers. I can do that for you, but I would need to know the front baffle width.

But if you look at the sensitivity and Fs of the tweeter, this crossover might actually work without doing much more. The sensitivity at 1W is about 89.5dB, which is in the neighborhood to meet the woofer. I would probably add a way to drop the level in a couple of increments in order to test it, but in an absorptive room, it might not be bad.

 

[TLS Guy]

But if you look at the sensitivity and Fs of the tweeter, this crossover might actually work without doing much more. The sensitivity at 1W is about 89.5dB, which is in the neighborhood to meet the woofer. I would probably add a way to drop the level in a couple of increments in order to test it, but in an absorptive room, it might not be bad.

You can't take a crossover off the shelf and expect the crossover wo work with different drivers. All crossover have to be custom. Those driver s have to potential to actually make a very good speaker, but not with an off the shelf crossover.