# How to tell what crossover will work best?



## jayfng (Jul 23, 2009)

Hey im looking into buying anyother 2way speaker tower and a sub to go with my home sound system. but i have no idea how to pick out a crossover and set up the rest of my sound system. I've been told by the "experts" at the place im buying the stuff to get any crossover and the same amp i own and run the sub in mono. but i don't belive it will work. please help me

first off here is the list of stuff im buying or own atm.

2way speaker tower. i'll own two of these
JBL JRX125 Dual 15" 2-Way Speaker System 245-814

Sub i'll own one of these
JBL JRX118S 18" Compact Subwoofer System 245-816

Amp. I own one of these. but i was told to buy another and run it in mono for the sub.
QSC GX5 Power Amplifier 500 Watts/ch at 8 ohms 245-652


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## bigdozer (Sep 14, 2011)

I guess you're trying to wake me up in North Carolina! 

What are you doing for signal/video?


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## jayfng (Jul 23, 2009)

bigdozer said:


> I guess you're trying to wake me up in North Carolina!
> 
> What are you doing for signal/video?


im just running it from my computer with rca cables and a 3mm jack. gonna buy a sound card that runs rca outputs. probly somthing like this card

Buy the Creative Labs X-Fi HD PCI Express Sound Card at TigerDirect.ca


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## bigdozer (Sep 14, 2011)

The equipment your looking to buy is mainly used for Djs/Band setups. It would be outrageously loud in a home. If you dont have neighbors within a half mile you should be ok.

The amp you have would be a good match for the sub or towers your looking at. 

The sound card only has one set of rca outputs. Your gonna have to get the Y splitters to split the signal to both amps. I would look into getting a nice graphic equalizer to split the signal.


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## bigdozer (Sep 14, 2011)

Oops accidently posted before i was done.

Some of my older friends do stage/sound setups. Basically they do exactly what your doing. The only exception is they have a mixer board as the main "head" unit. 

As far as a crossover i would get something rack mountable to go with your amps. You may have to get two. One for the sub and one for the towers. Just google rack mountable crossover. If you had more outputs on the sound card you could find a program so you could change the frequencies for each channel. 

Check around and do your research before unloading on a bunch of equipment you dont need.


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## jaythorpe522 (Sep 7, 2010)

The description of the speaker includes this:



> JBL's JRX125 is actually a "quasi three-way" design. This means that the upper woofer covers lows and mids but the bottom woofer uses a lower crossover frequency and covers only lows, acting as a built-in subwoofer.


If you add in a sub and split the signal with the crossover, you're going to almost entirely lose any output from the 2nd woof in your 125s. You should get the same speaker with just one 15" woof if you're going to get a sub. Or, split the signal but no crossover; just a LPF for the sub if it doesn't have one built in (it'd surprise me if it doesn't).

I, also, question why the heck you're putting this into a home theater system; this is stage stuff and if you're not in a totally dead acoustically treated listening environment, the horn tweet is gonna bounce all over the place and make horrible phasey filtering in the highs, and you'll rattle the neighbor's windows running two of those GX5's.

jw

[EDIT:] whoops, shoulda followed the links first. Sub *doesn't* have the built-in filters, so now I see -- you wanted the crossover just for that. I still say that if you're getting the Sub, go with the speaker with just one 15 instead of 2. The GX5 does have a built-in X-over; trying to find if it's selectable, or, what the specs are.... says 180Hz. OK for your JBL sub. Doesn't say if it's got a superlow cut (a 25 or 30 Hz HPF that protects the woof from spikes outside of the hearing range).

At any rate, if you get the 125s, you should feed the full range, not a split signal, 'cause otherwise you're wasting a lot of that 2nd woof.

Hope this is helpful

jw


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## jayfng (Jul 23, 2009)

bigdozer said:


> The equipment your looking to buy is mainly used for Djs/Band setups. It would be outrageously loud in a home. If you dont have neighbors within a half mile you should be ok.
> 
> The amp you have would be a good match for the sub or towers your looking at.
> 
> The sound card only has one set of rca outputs. Your gonna have to get the Y splitters to split the signal to both amps. I would look into getting a nice graphic equalizer to split the signal.


This stuffs for dj's and band setups? damn to bad  oh well its great for partys playing movies games and other ****  the "two" amps will work for this? also that card was to show u want i "might" get for my computer. i had a nice $130 card with 8 rca outputs but cant find it on tigerdirect. and an EQ to split the signal? i thought only a crossover would work



bigdozer said:


> Oops accidently posted before i was done.
> 
> Some of my older friends do stage/sound setups. Basically they do exactly what your doing. The only exception is they have a mixer board as the main "head" unit.
> 
> ...


 i have no idea what crossover will work or how to find one that will work. i know the frequencies of the 118 & 125. i just dunno how to find a crossover that does the "right frequency" 

understand what im trying to say? if not ill add more detail



jaythorpe522 said:


> The description of the speaker includes this:
> 
> If you add in a sub and split the signal with the crossover, you're going to almost entirely lose any output from the 2nd woof in your 125s. You should get the same speaker with just one 15" woof if you're going to get a sub. Or, split the signal but no crossover; just a LPF for the sub if it doesn't have one built in (it'd surprise me if it doesn't).
> 
> ...


this was very helpful. i did look over the specs and overview of the tower when i first bought it. i've owned one 125 for about a year or more. fricken love it. have the volume low, and its great for games and movies, and for when its party night its good and loud. i started looking in "finishing/adding more" to my home theater system. by adding around 125 so the sound comes at u in from the left and right sides, not just left or right. and im looking into the sub for deeper bass.

Yes my room shakes a little the bass hits u good, u hear all the sounds beautifully. im moving to a house and im hosting a party for the nov 4th weekend. "i want to rattle the town" as ill be having it outside and inside. yes im crazy for buying this **** but i just love the sound.

about the split signal, i found a crossover that could work? let me know what u think or tell me what u know as i have no idea.

*Recommended crossover settings: 30 Hz high pass filter, 24 dB/octave and an 80 to 100 Hz low pass filter, 24 dB/octave.* i dont think the crossover has that tho

ART 311 Stereo 2-Way Crossover with Sub Out 245-862


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## jayfng (Jul 23, 2009)

jayfng said:


> Hey im looking into buying anyother 2way speaker tower and a sub to go with my home sound system. but i have no idea how to pick out a crossover and set up the rest of my sound system. I've been told by the "experts" at the place im buying the stuff to get any crossover and the same amp i own and run the sub in mono. but i don't belive it will work. please help me
> 
> first off here is the list of stuff im buying or own atm.
> 
> ...



*YES, i will post a picture of my "home theater system"*


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## jayfng (Jul 23, 2009)

ok i found a site in canada which may be cheaper. but i dont know how to tell which on will work with my stuff

Analog Cross-overs | ROLLS DBX BEHRINGER Vancouver Montreal Toronto Canada


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## bigdozer (Sep 14, 2011)

The crossover youre looking at in canada will work fine. It has seperate crossovers for sub and your mains.

I suggested an eq so you could have more control over the sound of the main towers. Most have multiple outputs so you could run two amps off one eq. 

Check around for programs for your pc that have eqs and crossover frequencies that you could change. My cousin had one on his pc a few years ago that worked good but i cant remember the name of it. 

Be sure to get the proper cable to hook all this together.

Keep us updated.


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## jayfng (Jul 23, 2009)

ART 311 Stereo 2-Way Crossover with Sub Out 245-862
^^ that crossover is from the site in which i first bought my stuff but the shipping for the rest of the stuff is $500 aint i dont wanna pay that much plus duty fees

Analog Cross-overs | ROLLS DBX BEHRINGER Vancouver Montreal Toronto Canada

I need help finding a crossover from this site ^^ in which its from canada and shipping should be cheaper



bigdozer said:


> The crossover youre looking at in canada will work fine. It has seperate crossovers for sub and your mains.
> 
> I suggested an eq so you could have more control over the sound of the main towers. Most have multiple outputs so you could run two amps off one eq.
> 
> ...


I thought about getting an EQ with the crossover but how would i hook it up? 

I could find a program for crossover and EQ on the pc but it willn't help much when i switch my system over to my tv.

As it stands i will need to buy an adapter or a new internal soundcard/ external soundcard .

I'll keep this updated till i get the order placed  then when i move i'll post a few pictures of the home theater system


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## jaythorpe522 (Sep 7, 2010)

The crossovers on that site aren't exactly what you're looking for. They could work, but your speakers have (unless I'm mistaken?) one input for the 2/"3"-way system, and built-in crossovers for lows and highs, so with something like the CX2310 you're going to have to essentially bypass either the mid or high outs and waste an output.

If you had separate boxes -- eg a box on a stick with a horn tweet and a 12", stuck in a box on the floor with 2x15" -- on each channel, plus a sub, then you'd need that sort of crossover. But you're only driving one physical speaker (which happens to have 3 drivers, but that's irrelevant for this exercise) on each channel of the mains amp, so the crossovers on that page are mostly useless for you.

Lemme try 'draw'ing a picture of what you need:
*

SOUND CARD
Left Out---[ HPF ]--|--[ Room EQ ]--[ AMP 1 (ch 1/L) ]--[ L JRX125 ]
....................|
Right Out--[ HPF ]--|--[ Room EQ ]--[ AMP 1 (ch 2/R) ]--[ R JRX125 ]
....................|
..........*(Mono Sum)*\----[ LPF ]----[ AMP 2 (BRIDGE) ]--[...SUB....]

[ HPF ] is a 25 or 30 Hz high pass/low cut filter that will protect your speakers from damage.
[ LPF ] is whatever frequency the sub specifies (I think you said it's 100 Hz?)*

So, a crossover is really not so necessary. You can accomplish this with a couple of decent EQs, with the bonus that you can then tune your listening room. In fact, the more I sit here, the better that idea sounds, because you're gonna want to tweak those horn tweet highs and 15" for mids is prone to muddiness, so feeding your source into an EQ with multiple outputs that includes a summed mono, which you can run into a separate filter for your sub, would be much better than getting a crossover you really don't need.

jw


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## bigdozer (Sep 14, 2011)

The axemusic.com website you posted a link to has eqs that would work.


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## jayfng (Jul 23, 2009)

jaythorpe522 said:


> The crossovers on that site aren't exactly what you're looking for. They could work, but your speakers have (unless I'm mistaken?) one input for the 2/"3"-way system, and built-in crossovers for lows and highs, so with something like the CX2310 you're going to have to essentially bypass either the mid or high outs and waste an output.
> 
> If you had separate boxes -- eg a box on a stick with a horn tweet and a 12", stuck in a box on the floor with 2x15" -- on each channel, plus a sub, then you'd need that sort of crossover. But you're only driving one physical speaker (which happens to have 3 drivers, but that's irrelevant for this exercise) on each channel of the mains amp, so the crossovers on that page are mostly useless for you.
> 
> ...


 let me understand this. get an EQ and have the one output go to the 125s amp and another output go to a crossover then to the 118 amp?
SUB:
Recommended crossover settings: 30 Hz high pass filter, 24 dB/octave and an 80 to 100 Hz low pass filter, 24 dB/octave. 



bigdozer said:


> The axemusic.com website you posted a link to has eqs that would work.


doesn't an EQ only tune the frequencies? and a crossover cuts them out?


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## jayfng (Jul 23, 2009)

i called up axemusic and they said any crossover will work. so whatta do?

also this is how he told me it would go

Music --- crossover--- output highs/mids ----- EQ ---- amp ---- speaker tower
output lows ------ amp ---- sub

said that the 125s will work good. it kinda looks right. but will any bass go to my 125s?


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## bigdozer (Sep 14, 2011)

If you hook it up that way you wont get the bass from the towers like you want. I would hook it up the way they told you. If you want more bass from the towers you can bypass the crossover and run EQ---amp---tower. The tower basically has a subwoofer built in. If you run a crossover cutting the lows your just wasting that speaker. You will want the crossover for the sub cabinet though.


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## jaythorpe522 (Sep 7, 2010)

jayfng said:


> i called up axemusic and they said any crossover will work. so whatta do?
> 
> also this is how he told me it would go
> 
> ...


This is crap advice from someone who either doesn't know the gear or doesn't care to give a thought to the advice he's giving. You will get very little bass to your 125s and you'll be wasting the lower driver and the real benefit of having that box. What you want is what I 'drew' -- full-band audio to the mains, mono summed lows to the subs.

Them saying "any crossover will do" is like you calling an auto mechanic, telling them the make & model of your car, size of wheels, and how long you want a new set of tires to last, and them saying "any of our tires will drive on roads".

If you know what your source is going to be (audio card, mixer, many different ones, whatever), I can try and recommend a piece of gear or two to be the correct setup. Budget is helpful too.

jw


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## jayfng (Jul 23, 2009)

bigdozer said:


> If you hook it up that way you wont get the bass from the towers like you want. I would hook it up the way they told you. If you want more bass from the towers you can bypass the crossover and run EQ---amp---tower. The tower basically has a subwoofer built in. If you run a crossover cutting the lows your just wasting that speaker. You will want the crossover for the sub cabinet though.


i dunno what u are talking about? and i get that a crossover for a sub


jaythorpe522 said:


> This is crap advice from someone who either doesn't know the gear or doesn't care to give a thought to the advice he's giving. You will get very little bass to your 125s and you'll be wasting the lower driver and the real benefit of having that box. What you want is what I 'drew' -- full-band audio to the mains, mono summed lows to the subs.
> 
> Them saying "any crossover will do" is like you calling an auto mechanic, telling them the make & model of your car, size of wheels, and how long you want a new set of tires to last, and them saying "any of our tires will drive on roads".
> 
> ...




i got ahold of someone from parts express. they recommended that i get this, as it will work great. lets me select how low the main 125 will go and how high the sub will go.
Behringer CX2310 Super-X Pro 2way Stereo Crossover | Vancouver Montreal Toronto Canada

I'm probly gonna run with a audio card. haven't looked into it as haven't finalized what im getting as for EQ and crossover. might get one or both, but i might just get a crossover and use a computer program for the EQ. Also if i can i'll just ad and adaptor to my RCA cables so they can still work


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## jayfng (Jul 23, 2009)

For and EQ whats better for a pa system 31 or 15 bands?


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## jayfng (Jul 23, 2009)

i really need to hear back from u guys to know if this will work. the crossover and what EQ 15 or 31 bands. i think 31 will be best but i dunno. i really like to fine tune the music.


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## jaythorpe522 (Sep 7, 2010)

Sorry for the delay -- Jewish holiday of Sukkot (sometimes aka Feast of Tabernacles, 'cause ya eat outside in makeshift huts... anyway...).

When I looked at the 2310 it looked like it was a true crossover -- that is, the sub goes up to a certain point, and the mains come down to that exact same point, no overlap. If I am mistaken, and the top of the low frequency range can be higher than the bottom of the high frequency range, then the 2310 will do exactly what you want.

The more bands the merrier for a room EQ. Your money your choice, but make sure you have a good reference mic and a plan for tuning the room, or you're just fiddling with knobs.

I know you were frustrated with the lack of response in-thread, but I think there's a forum rule (either written or unwritten) about advice via PM. ask the same question here and I'll do my best to give an educated response!

jw

PS -- do it today or tomorrow -- wednesday @ sundown starts another 3 days incommunicado...


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## joeten (Dec 4, 2008)

Hi for clarification 
ASSISTANCE VIA PM
This practice is prohibited in TSF. The very reason that there are Support Forums is to assist ALL members with a variety of problems. Displayed posts are very useful and can save a staff members having to repeat solutions that have been dealt with previously. i.e. members are able to help themselves. Looking for help via PM not only prevents this but it is also annoying and harasses staff


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## jaythorpe522 (Sep 7, 2010)

whoops -- didn't mean to be a tattle. I'd like to point out that I'm neither annoyed, nor staff


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## joeten (Dec 4, 2008)

No No your fine, that is just the rules there is a link at the top of every page and it is always advisable for members to read them it saves making mistakes,as I said you have not done anything I saw your comment and posted the relevant rule for clarity


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## jayfng (Jul 23, 2009)

jaythorpe522 said:


> Sorry for the delay -- Jewish holiday of Sukkot (sometimes aka Feast of Tabernacles, 'cause ya eat outside in makeshift huts... anyway...).
> 
> When I looked at the 2310 it looked like it was a true crossover -- that is, the sub goes up to a certain point, and the mains come down to that exact same point, no overlap. If I am mistaken, and the top of the low frequency range can be higher than the bottom of the high frequency range, then the 2310 will do exactly what you want.
> 
> ...


sorry about that, it was the "72" hour time frame or maybe 24hours? in which i sent the message but now i can't see my message. look below

rule = You may not ask for assistance via PM unless you have not received a reply to your query within 72 hours.

i freaked a little, going off into stuff i have no idea about... but sorry miss read this rule. look below

rule = You may not offer assistance via PM under any circumstances.
sorry for the rule breaking

I did get my answer for the pm or part of it. i was told my amp with its crossover would work great. and then u answered from my question here that the more the nobs the better for room EQ. i dont have a mic or any test gear besides hearing. its worked alright for now. 

Questions: so i couldn't really find a soundcard that would work... via xlr outputs. so now im gonna try to get a mixer or effect? with rca or usb input and xlr output. but i dont have a clue what to look for in a mixer where i dont get screwed over in cost, but i dont want somthing where illl feel like i wasted money on... 

So really i need help finding a mixer... and some knowledge of what a mixer does. i have a few basic ideas, with the help of google and wiki. i was hoping i would avoid buying a mixer, know ill be known as a "dj"

DJ Mixers | VESTAX TONIUM Stanton RANE PIONEER Numark NOVATION NATIVE Instruments M Audio Hercules Ecler DENON BEHRINGER AMERICAN DJ ALLEN & HEATH Vancouver Montreal Toronto Canada


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