Rsd65cs Crossover Planning Help

[Phoenixcolt]

Hey guys, I checked the manual but it doesn't say anything about the frequencies, what is the passive tweeter crossover frequency and slope on these comps?

I wanted to run the mids active using my hp deck crossover and my low pass amp crossover, but the amp I will be using has a max crossover frequency of 500hz. I was just planning on running the tweets off the passive crossover.

I wanted to do it this way so I could apply individual time correction to the mids and tweets.

[Phoenixcolt]

You guys think the RSD crossover will run properly if I only hook up the tweeters through it and then pick up a different crossover solution for the mids like the Audiocontrol 2XS?

This way, I would high pass the mids with the amp, and low pass the mids with the 2xs using an appropriate crossover module, and the tweets would be highpassed with the RSD passive.

[kg1961]

i can't see why it would not work

[Phoenixcolt]

Thanks man,
The main possibility I found online would be if it changes the ohm load that the amp will see. I know I was told years ago that I should not run half a set of components (2 tweets or 2 mids) off of the Ti Elite crossover, but that one and the Rsd are different so I don't know if that recommendation was something specific to the Ti Elite xover.

[ttocs]

cross overs are dependent on the ohm load of the speaker to determine what freq the speaker will be crossed over at. So taking a cross over that is made for a 4 ohm woofer, and putting two woofers in parallel so it sees a 2 ohm load would drastically change the freq, and make it not operate optimally. I don't think that not hooking half of the speakers up would change the freq of the other speaker, but it will change the load the amp sees. Depending how its set up will determine how its effected but as for the sound(freq) output you should be fine its the volume that will be the question.

Don't quote me on this, eric would probably be the man to ask as this makes me try to think back to my theory classes 10+ yrs ago...

[Phoenixcolt]

Thanks ttocs, I will pm Eric in a cpl days if he doesn't see the thread and see if he can offer some insight for us.

I think I may end up just going fully active with an Audiocontrol 6XS but I am worried about blowing tweeters. Is it common practice to install a small inline capacitor to prevent accidental tweeter murder?

I found a pretty good thread that was right up my allel on diyma, but I still don't know if 3500 Hz is a good frequency for RsD tweeters:
http://www.diymobileaudio.com/forum/tec ... ctive.html

[ttocs]

I have an ax204 I am not using if it helps you I could part with. Need $$$ to fund the rebuild of my mustang...

A capacitor is no gurantee that it will be saved. It just acts as a high-pass cross over and will also cut a good portion of the volume of the signal out as well. The best way I know of to do it is to take a small light bulb to take some of the power out of the DC that is created when a signal is clipped. Bose has used these for years and if you crank them up you can often see the light inside the port glowing when it is clipping. The secret to keeping your speakers working it to keep the signal going too them clean. You can have it cranked up LOUD as long as you have everything crossed over correctly and you have not reached the point of clipping for long periods. Listen to the signal an when it starts to disort/sound bad, turn the volume down a notch or adjust the eq for those freqs down if you can.

[Phoenixcolt]

I have an ax204 I am not using if it helps you I could part with. Need $$$ to fund the rebuild of my mustang...

A capacitor is no gurantee that it will be saved. It just acts as a high-pass cross over and will also cut a good portion of the volume of the signal out as well. The best way I know of to do it is to take a small light bulb to take some of the power out of the DC that is created when a signal is clipped. Bose has used these for years and if you crank them up you can often see the light inside the port glowing when it is clipping. The secret to keeping your speakers working it to keep the signal going too them clean. You can have it cranked up LOUD as long as you have everything crossed over correctly and you have not reached the point of clipping for long periods. Listen to the signal an when it starts to disort/sound bad, turn the volume down a notch or adjust the eq for those freqs down if you can.

I probably would consider the ax204 but I think I'm gonna need more than a 2 channel xover unless the passive xover will work for just the tweeters.

[LowandLoud]

A capacitor is no gurantee that it will be saved. It just acts as a high-pass cross over and will also cut a good portion of the volume of the signal out as well. The best way I know of to do it is to take a small light bulb to take some of the power out of the DC that is created when a signal is clipped.

If the light bulb is wired inline with the tweeter, would it not stay lit as long as there is power to the tweeter? How is this done?

LL

[ttocs]

It had to do with the type of bulb and how it was set up in the cross over. Can't remember what style it was exactly but from what I remember when you crank it up into clipping and the top/bottom of the signal is clipped, and at that point its basically a short burst of DC current which is horrible for speakers. The light would just simply light up and burn off some of that dc current to keep it from going to the speaker.

[LowandLoud]

Huh, thats a great idea. I wonder why it isnt common practice?

LL

[ttocs]

because I think when most companies are given the choice of adding a $1 part that can save a speaker, or have the ability to sell you a new speaker a few years from now when it blows that they do not pick the solution that we would hope.

[LowandLoud]

You are probably right about that.

Makes me wonder if, 20 years from now, people will be reminiscing about present day speakers and saying things like "remember how bullet proof they were" or "I used that set for 17 years in 6 cars without an issue". I highly doubt it.

LL

[ttocs]

I know a lot of people that like older home audio equipment for reasons from better/more solid wood/constructed cabinets to gear that was made to play for decades. Shit find an old Marantz home stereo and the only thing you probably need to do to get it to play is to clean the pots.

[Phoenixcolt]

cross overs are dependent on the ohm load of the speaker to determine what freq the speaker will be crossed over at. So taking a cross over that is made for a 4 ohm woofer, and putting two woofers in parallel so it sees a 2 ohm load would drastically change the freq, and make it not operate optimally. I don't think that not hooking half of the speakers up would change the freq of the other speaker, but it will change the load the amp sees. Depending how its set up will determine how its effected but as for the sound(freq) output you should be fine its the volume that will be the question.

Don't quote me on this, eric would probably be the man to ask as this makes me try to think back to my theory classes 10+ yrs ago...

I just realized this morning that I should be able to figure this out with a DMM (I think). I can measure the Ohm loads of the tweeters and mids by themselves, then hook them up to the crossover and see what ohm load I get from the crossover input, and then unhook the mids and see if the crossover input ohm load chages.

If it doesn't I think I would be ok. If it does, I will probably go passive initially and active when I can pick up an Audiocontrol 6XS.

[Eric D]

Most 2-way passive crossovers consist of two separate circuits internally, one for the tweeter, and one for the mid. These two circuits are then connected in parallel at the input terminals to the crossover. If you buy a set which is "bi-amp" compatible, that just means instead of connecting the two circuits in parallel, they ran the leads to two sets of input terminals, so you can be more flexible with the setup.

Yes, you can run just tweeters off a 2-way passive crossover, but I highly suggest you take the crossover apart, and cut traces to isolate the mid section of the crossover so it is not used at all. You can then solder jumpers in there later on if you want to put it back to the way it was.

If you have a set of 4 ohm mids for example, you cannot run them off one passive crossover, by wiring them in parallel or series to the mid output of the crossover. This would give you either 2 or 8 ohm, which will change the crossover point of the passive crossover.

Using a DMM to measure impedance will probably not work, as DMMs measure resistance, not impedance, which although similar, are not the same thing.

I highly suggest you use a light bulb to protect the tweeter. At low power the light blub is just a short, and does not affect the circuit. At higher power (and therefor higher current), the light blub becomes more resistive, this is when it begins to light up. The more power, the more it lights, and the more it keeps from getting to the tweeter.

If you use to big of a light bulb though, it will offer no protection for the tweeter.

[Phoenixcolt]

Most 2-way passive crossovers consist of two separate circuits internally, one for the tweeter, and one for the mid. These two circuits are then connected in parallel at the input terminals to the crossover. If you buy a set which is "bi-amp" compatible, that just means instead of connecting the two circuits in parallel, they ran the leads to two sets of input terminals, so you can be more flexible with the setup.

Yes, you can run just tweeters off a 2-way passive crossover, but I highly suggest you take the crossover apart, and cut traces to isolate the mid section of the crossover so it is not used at all. You can then solder jumpers in there later on if you want to put it back to the way it was.

If you have a set of 4 ohm mids for example, you cannot run them off one passive crossover, by wiring them in parallel or series to the mid output of the crossover. This would give you either 2 or 8 ohm, which will change the crossover point of the passive crossover.

Using a DMM to measure impedance will probably not work, as DMMs measure resistance, not impedance, which although similar, are not the same thing.

I highly suggest you use a light bulb to protect the tweeter. At low power the light blub is just a short, and does not affect the circuit. At higher power (and therefor higher current), the light blub becomes more resistive, this is when it begins to light up. The more power, the more it lights, and the more it keeps from getting to the tweeter.

If you use to big of a light bulb though, it will offer no protection for the tweeter.

Thanks for chiming in Eric!

So if I am just running the tweeters off of the passive, wouldn't that throw off the ohm load as well?

[Eric D]

Here is an example...

4 ohm tweeters connected to a passive crossover will still be a 4 ohm load to the amplifier. The difference is that say you had a crossover point of 5kHz, below 5 kHz the impedance (ohms) would climb.

At 2kHz the load may be 20 ohm, and at 100Hz, it may be 10,000 ohm (I am just throwing out numbers here).

Another way to state this is if you had some tweeters on a passive crossover, and you played a 100Hz sine wave into them, the amplifier would output almost zero watts into that load at that frequency. Now, if you played a 10kHz tone, you would get usable power into the load.

[Phoenixcolt]

Here is an example...

4 ohm tweeters connected to a passive crossover will still be a 4 ohm load to the amplifier. The difference is that say you had a crossover point of 5kHz, below 5 kHz the impedance (ohms) would climb.

At 2kHz the load may be 20 ohm, and at 100Hz, it may be 10,000 ohm (I am just throwing out numbers here).

Another way to state this is if you had some tweeters on a passive crossover, and you played a 100Hz sine wave into them, the amplifier would output almost zero watts into that load at that frequency. Now, if you played a 10kHz tone, you would get usable power into the load.

Ok, I think I am getting it.

Sounds like fully active or fully passive might be easier than a combination of passive tweeters and active mids. Maybe I should just run everything passive until I can find a great deal on a 6 channel electronic crossover.

Then when I am ready to go active, I will need to make sure I understand the light bulb modification fully.

[Eric D]

I think a fully active setup makes more sense than a half passive, half active one does. With fully active, you can more easily move the crossover point around to get the best performance.

But, depending on the components, I prefer a passive setup over an active one. My stance on this has historically caused many an argument, but I just don't think the average person's DIY active setup will outperform a manufacturer's passive solution.

If you do choose to go fully active, all you need to do to protect the tweeter is install a light bulb in series with one of the tweeters leads. The best source for a properly sized lightly bulb would probably be to steal some from a budget passive crossover.

[zeropoint0.5]

I think a fully active setup makes more sense than a half passive, half active one does. With fully active, you can more easily move the crossover point around to get the best performance.

But, depending on the components, I prefer a passive setup over an active one. My stance on this has historically caused many an argument, but I just don't think the average person's DIY active setup will outperform a manufacturer's passive solution.

If you do choose to go fully active, all you need to do to protect the tweeter is install a light bulb in series with one of the tweeters leads. The best source for a properly sized lightly bulb would probably be to steal some from a budget passive crossover.

I agree totally with Eric. I also prefer to listen to a passive setup over going active..... but working active will let you play louder......

the passive crossovers follow the speakers, so you will have the same sound from background to very loud volume......

As closer as you can install you're 2/3 way system 2gether, the better result..... don't be afraid to put power on it.......

[Phoenixcolt]

Thanks guys, i appreciate the insight.

Passive will be cool, i was just hoping to time align the tweets and mids separately but everything else involved in going active might be more than I want to get into.

Is it a bad idea to run passive crossovers back by the amps versus in the doors closer to the speakers?

Can't wait to have aftermarket components installed again, it's been about 6 years .

[dwnrodeo]

Thanks guys, i appreciate the insight.

Passive will be cool, i was just hoping to time align the tweets and mids separately but everything else involved in going active might be more than I want to get into.

Is it a bad idea to run passive crossovers back by the amps versus in the doors closer to the speakers?

Can't wait to have aftermarket components installed again, it's been about 6 years .

I currently have my Rsd65cs crossovers in the trunk next to the amp. It shouldn't really affect the signal. I switched from active to passive and I had separate wires going to the tweeter and mid from the amp anyways so I just installed the crossover near the amp.

[ttocs]

keep the cross overs away from power wires and it doesn't matter where they go. Doors are a common place for them because you do not need to run a 2nd set of speaker wires into it but with as wet/moist as a door stays the inside of it is NOT where it belongs...

[Phoenixcolt]

Got through most of my install Saturday and Sunday, but when I went to power up the amp Sunday night, I got noise in the right tweeter, kind of like a clicking.

I didn't have the interconnects hooked up to the headunit yet, but I had all of the other wires hooked up. The crossovers aren't buried yet so they aren't very close to the power wire.

Could the speaker wire from the amp to the crossovers pick up noise if it's too close to the power wire?
Could the right side speaker wire from the tweeter and mid be picking up noise from the power wire?
Could hooking up the remote wire from the sub amp to the amp for the highs cause any noise?
Lastly, and possibly most likely, could the amp for the highs interconnects be too close to the power wire? I had to hook up a coupler from my Stinger 6 channel Front interconnects to a shorter interconnect run to get it to the amp for the highs.

I didn't have noise from the subwoofer and sub amp prior to this. I have an Overdrive plus line driver on the sub amp just FYI.

Thanks in advance guys, hope I can figure this out in the next day or two so I can crank some tunes!