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Title: Finding trhe perfect x-over point
Post by: AllenDeneau on August 01, 2015, 04:35:28 pm
I've got a rare weekend to myself and my mind is running wild with questions and one I've begun to really ponder is, what's the best way to find the right x-over point for your subs?

I don't have a SMAART system so I can't use measurement system to determine it. I have factory specs and my ear and I am pretty happy with the x-over points I end up with in various deployments but, is there a quicker, more scientific way?

I have Peavey SP2G's over Peavey SP118's powered by a side of a PLX 3402 per box. My usual setup, if possible, is to have the main sitting right on top of the sub if that'll get the horns over the audience's heads.

Here are the speaker specs.
SP2G -3dB is 65Hz and box tuning frequency is 55Hz
SP118 -3dB is -10dB is 38Hz and box tuning frequency is 36Hz minimum x-over point recommended is 90Hz at 18dB per octave

I've been pretty happy with crossing them over at 80-90Hz by using my ear but shouldn't I be able to sue the info above and maybe the frequency response charts and get it about right?

Thanks to all who chimed in on my other posts about tuning the subs, they have sounded great with good low end, for what they are.

Anyway, I'm always looking to learn more of the "science" of our industry and I think this is certainly something I can improve upon.

Thanks.
Title: Re: Finding trhe perfect x-over point
Post by: Keith Broughton on August 01, 2015, 05:41:46 pm
I've got a rare weekend to myself and my mind is running wild with questions and one I've begun to really ponder is, what's the best way to find the right x-over point for your subs?

I don't have a SMAART system so I can't use measurement system to determine it. I have factory specs and my ear and I am pretty happy with the x-over points I end up with in various deployments but, is there a quicker, more scientific way?

I have Peavey SP2G's over Peavey SP118's powered by a side of a PLX 3402 per box. My usual setup, if possible, is to have the main sitting right on top of the sub if that'll get the horns over the audience's heads.

Here are the speaker specs.
SP2G -3dB is 65Hz and box tuning frequency is 55Hz
SP118 -3dB is -10dB is 38Hz and box tuning frequency is 36Hz minimum x-over point recommended is 90Hz at 18dB per octave

I've been pretty happy with crossing them over at 80-90Hz by using my ear but shouldn't I be able to sue the info above and maybe the frequency response charts and get it about right?

Thanks to all who chimed in on my other posts about tuning the subs, they have sounded great with good low end, for what they are.

Anyway, I'm always looking to learn more of the "science" of our industry and I think this is certainly something I can improve upon.

Thanks.
I would suggest that unless you can get access to a SMAART (or similar) system, tuning by ear is OK.
Looking at specs and trying to determine a x over point can be problematic.
If it sounds good...well...then it sounds good  ;D
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 01, 2015, 07:47:12 pm
when ever i have built a new speaker system i look at the factory recomended frequency upper and lower range limits. i use an active crossover and have a seperate amp for the number of different drivers i'm using. i have test music i use. i adjust the crossover point between 2 drivers at a time and i have a couple of sound guy friends come over so they can tell me what there ears like. i have found that the old audiophile crossover point of 130hz to be the best sounding between the woofer and the mid. the mid and the horn always has a sweet spot and it varies with the drivers. i have Radian 2" 850PB drivers with DDS horns i use on everything including my home system. the sweet spot for the horn to a 10" mid is 1960hz , and 1500hz when using the horn with a 12" mid. the crossover points are well within the manufacturers frequency range. if i cross my horns lower the sound becomes harder and not as smooth. if i cross higher lots of music detail becomes vailed. In the 80's John Solicito of JSE Infinate slope loudspeaker fame told me that once you got the drivers in there frequency range the rest was listening and you have several people evaluate the sound. use good undistorted recordings. i tried playing with the crossovers once before we did sound check with the other guys on stage jamming and came up with the same crossover points i had. i have used a lot of different brands of drivers over the years. i have used 12db/oct , 18db/oct and for many years i only use the Ashly 24db/oct crossovers. if you want to use passive crossovers use the same type and slope that you would use for an active to get the same results. also try different polarity on all the drivers while you adjusting the crossovers to see whats best. and its best to do this outside with the speaker on a small platform up off the ground or pavement and in the middle of a yard with no wind. it can be a hassle but you only have to do it once unless you change drivers types and brands.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 02, 2015, 02:59:51 pm
http://www.prosoundweb.com/article/tuning_without_tools_working_through_a_system_to_get_it_up_to_speed1/
Title: Re: Finding trhe perfect x-over point
Post by: AllenDeneau on August 03, 2015, 11:47:53 am
http://www.prosoundweb.com/article/tuning_without_tools_working_through_a_system_to_get_it_up_to_speed1/

Thanks guys...

Seems general consensus is to use my ears unless I have something like SMAART...

Like I said, I'm pretty happy with my results but I was just wondering if there was a quicker, easier or better way to accomplish this task.

Tim, great article. I've read it a few times in the past and it's always good to revisit. Correct me if I missed it but your article dealt more with matching up pass bands and equalization and how it effects the x-over point, yes? Are you using a measurement tool to set your x-over point?

Keith, I agree that specs are many times problematic, I usually just look at them to give me a general idea of what I want and/or need to do with regard to a starting point. Agreed, if it sounds good, it is good

Jeff, thanks for the detailed description..
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 03, 2015, 02:37:49 pm

Thanks guys...

Seems general consensus is to use my ears unless I have something like SMAART...

Like I said, I'm pretty happy with my results but I was just wondering if there was a quicker, easier or better way to accomplish this task.

Tim, great article. I've read it a few times in the past and it's always good to revisit. Correct me if I missed it but your article dealt more with matching up pass bands and equalization and how it effects the x-over point, yes? Are you using a measurement tool to set your x-over point?

Keith, I agree that specs are many times problematic, I usually just look at them to give me a general idea of what I want and/or need to do with regard to a starting point. Agreed, if it sounds good, it is good

Jeff, thanks for the detailed description..

Crossover points are usually based on the manufacturers suggestions. Especially the high pass frequencies.

So, pick whatever frequency the manufacturer suggests, then match up the low pass of the sub so that it plays nice. In other words, high pass is fixed and you adjust the low pass to match it.
Title: Re: Finding trhe perfect x-over point
Post by: AllenDeneau on August 03, 2015, 05:05:32 pm
Crossover points are usually based on the manufacturers suggestions. Especially the high pass frequencies.

So, pick whatever frequency the manufacturer suggests, then match up the low pass of the sub so that it plays nice. In other words, high pass is fixed and you adjust the low pass to match it.

Understood and agreed. The SP2G has a -3dB down point at 65Hz which is much lower than I need it to go with the SP118 subs. The Sp118 manual states that a "minimum recommended active crossover frequency and slope" is 90Hz at 18dB which I tried and it sounds ok, but 80-85Hz, I think is where I landed, sounds better. I use the -6dB point for the upper corner for the sub and the lower corner for the main. This gives me minimal overlap, per my ears only, and also helps reduce some of the 100Hz mud in the system organically.

It sounds pretty good to me but that's not to say it can't sound better, that's why I was asking if there were other ways I hadn't considered.

I was just wondering if there were other ways to accomplish what I've been doing.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 03, 2015, 08:54:25 pm
Not really. Unless you have much bigger and better toys.

I think you are on the right track.
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 04, 2015, 12:31:22 am
Understood and agreed. The SP2G has a -3dB down point at 65Hz which is much lower than I need it to go with the SP118 subs. The Sp118 manual states that a "minimum recommended active crossover frequency and slope" is 90Hz at 18dB which I tried and it sounds ok, but 80-85Hz, I think is where I landed, sounds better. I use the -6dB point for the upper corner for the sub and the lower corner for the main. This gives me minimal overlap, per my ears only, and also helps reduce some of the 100Hz mud in the system organically.

It sounds pretty good to me but that's not to say it can't sound better, that's why I was asking if there were other ways I hadn't considered.

I was just wondering if there were other ways to accomplish what I've been doing.
try 130hz. i have tried many different woofer to mids crossover points and 120-140 always sounds best. i dont agree with crossing below 120 on the woofer to mids.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 04, 2015, 10:24:16 am

try 130hz. i have tried many different woofer to mids crossover points and 120-140 always sounds best. i dont agree with crossing below 120 on the woofer to mids.

This doesn't make any sense at all.

What if his subs won't play up that high? There really is no right answer for a crossover point. It depends on everything in the system. Not just the low mid driver.
Title: Re: Finding trhe perfect x-over point
Post by: Mac Kerr on August 04, 2015, 12:20:13 pm
try 130hz. i have tried many different woofer to mids crossover points and 120-140 always sounds best. i dont agree with crossing below 120 on the woofer to mids.
This doesn't make any sense at all.
What if his subs won't play up that high? There really is no right answer for a crossover point. It depends on everything in the system. Not just the low mid driver.

You two are talking about 2 different things. Jeff is talking about the crossover from his woofer to his midrange in a multiway system, Everyone else is talking about the crossover from the subwoofer to the full range.

I would rarely recommend extending a sub above 90-100Hz, particularly if there is a chance of any vocals getting into the subs.

Mac
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 04, 2015, 04:00:01 pm
Fair enough, but the OP is talking about a passive 2 way box over a sub. Not much room for a low-mid driver in there.
Title: Re: Finding trhe perfect x-over point
Post by: Mac Kerr on August 04, 2015, 04:38:17 pm
Fair enough, but the OP is talking about a passive 2 way box over a sub. Not much room for a low-mid driver in there.

Being a 2 way box it doesn't have a mid driver, it still has a low driver and a high driver unless it is specifically designed as a mid/hi box.

Any 2 way that gets down to under 100Hz can be used with a sub below 100hz.

Mac
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 04, 2015, 04:44:19 pm
Being a 2 way box it doesn't have a mid driver, it still has a low driver and a high driver unless it is specifically designed as a mid/hi box.

Any 2 way that gets down to under 100Hz can be used with a sub below 100hz.

Mac

I see your point and concede. I am of a mind that any 2-way cabinet has a mid and a hi. A low and a hi would leave a hole in the (mid)dle. At least that's the way my reptile brain interprets it...


 :o
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 04, 2015, 06:19:18 pm
This doesn't make any sense at all.

What if his subs won't play up that high? There really is no right answer for a crossover point. It depends on everything in the system. Not just the low mid driver.
i have never heard of a woofer that will not go to 130hz. all 18's will go to 130hz. what brand of woofers are those ? are they 21" ? why would it depend on all the other drivers in the system ?
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 04, 2015, 06:21:38 pm
Being a 2 way box it doesn't have a mid driver, it still has a low driver and a high driver unless it is specifically designed as a mid/hi box.

Any 2 way that gets down to under 100Hz can be used with a sub below 100hz.

Mac
so why not cross the 2way box at the same frequency as the additional woofer.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 04, 2015, 11:12:15 pm
i have never heard of a woofer that will not go to 130hz. all 18's will go to 130hz. what brand of woofers are those ? are they 21" ? why would it depend on all the other drivers in the system ?

Many bandpass boxes won't. Plenty of folded horns won't do it well. Also many, many subs just don't sound good playing freqs that high. Just because they can, doesn't mean they should. For most rigs, your male vocals will be coming out of the PA right into most peoples' shins....
Title: Re: Finding trhe perfect x-over point
Post by: duane massey on August 05, 2015, 08:32:56 pm
For most rigs, your male vocals will be coming out of the PA right into most peoples' shins....

This might be a good thing for some of the "singers" I've heard lately.
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 05, 2015, 09:39:36 pm
i can sing very low way lower than any rock singer ever sang and i cant get below about 150hz. i have listened over a long period to music while playing with my crossovers. i have 7 Ashly crossovers 2-XR4001 and 5-XR1001 and 2 are in my home system. they are 24db l-r. the guy singing bass in these 2 Elvira videos is way lower than we sing or any rock singer that i know of. i just did another listening test he does come in the woofer below 130hz but its very faint. i was using my Radio Shack digital spl meter and the spl was between 97 and 102. one thing that is thumping hard below 130hz is the bass drum. i can sing almost like the Molly Hatchet guy in the 3rd video and i dont hear him in the woofer at all. i can just barely hear a tad of Bob Segar on some of the words in the 4th video. i did this long ago and thought you guys might like to try it with your systems. i spent a lot of time long ago trying different crossover points.
http://www.youtube.com/watch?v=-qK-9eIF2yI
http://www.youtube.com/watch?v=OdFghZmdwXk
http://www.youtube.com/watch?v=kAQHPdbGtt8
http://www.youtube.com/watch?v=XG-wuWNIyzI
Title: Re: Finding trhe perfect x-over point
Post by: Mac Kerr on August 05, 2015, 09:43:42 pm
i can sing very low way lower than any rock singer ever sang and i cant get below about 150hz.

I don't know how low you, or anyone else can sing, but I hear vocals in the subs even with a 100Hz crossover if I don't use aux fed subs. For anyone near the subs it sounds very bad.

Mac
Title: Re: Finding trhe perfect x-over point
Post by: g'bye, Dick Rees on August 05, 2015, 09:55:39 pm
I don't know how low you, or anyone else can sing, but I hear vocals in the subs even with a 100Hz crossover if I don't use aux fed subs. For anyone near the subs it sounds very bad.

Mac

I just did around 90 or a bit below with no problem.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 05, 2015, 10:44:34 pm
I just did around 90 or a bit below with no problem.

The lead guitar player in my band can hit a solid 60hz on a good night. And I mean SOLID.
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 05, 2015, 11:00:06 pm
maybe its the type of crossovers you guys are using and that will make a difference. My Ashlys are 24db/oct. 18db and 12db will allow more to cross into the other drivers due to the shallower slope. i was under the impression that 24db/oct l-r crossovers had become the standard long ago. i wish someone made a 48db/oct active crossover. i knew a speaker builder that made 48db/oct passive crossovers but he retired and dissapeared several years ago.
Title: Re: Finding trhe perfect x-over point
Post by: Tim Weaver on August 06, 2015, 02:11:55 am
maybe its the type of crossovers you guys are using and that will make a difference. My Ashlys are 24db/oct. 18db and 12db will allow more to cross into the other drivers due to the shallower slope. i was under the impression that 24db/oct l-r crossovers had become the standard long ago. i wish someone made a 48db/oct active crossover. i knew a speaker builder that made 48db/oct passive crossovers but he retired and dissapeared several years ago.

There are 48db/oct crossovers out there. In fact most of the mid to high-end DSP's will do that.
Title: Re: Finding trhe perfect x-over point
Post by: Robert Lofgren on August 06, 2015, 03:21:32 am
I assume that there is some low-cut applied since this is vinyl but he has a great deep voice and show off in the end of the song.

http://youtu.be/adoeYmbEC2Q
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 06, 2015, 03:37:00 am
I assume that there is some low-cut applied since this is vinyl but he has a great deep voice and show off in the end of the song.

http://youtu.be/adoeYmbEC2Q
he got pretty low at the end. his voice has some weight to it.
Title: Re: Finding trhe perfect x-over point
Post by: John L Nobile on August 06, 2015, 07:25:18 am
A true bass vocal will get down to 80 hz while a baritone will go down to 100 hz. I've never worked with a true bass.
Tenors only go down to 130 hz.
This is from a vocal range chart and may only apply to a trained vocalist. Do they still exist?
Title: Re: Finding trhe perfect x-over point
Post by: Jeff Bankston on August 06, 2015, 05:04:35 pm
A true bass vocal will get down to 80 hz while a baritone will go down to 100 hz. I've never worked with a true bass.
Tenors only go down to 130 hz.
This is from a vocal range chart and may only apply to a trained vocalist. Do they still exist?
i dont know but the Oak Ridge Boy singer is the lowest i ever heard. i only listen to the Elvira song they do. I am a rock n roll guy.
Title: Re: Finding trhe perfect x-over point
Post by: AllenDeneau on August 06, 2015, 05:05:09 pm
WOW, it seems I hadn't been notified of the multitude of additional responses, sorry...

Yes, My system is actually comprised of a Main box with a High and a Low and an additional subwoofer.

130Hz, well, my subs sound like total crap crossed over that high, very floppy and muddy.

As per the manufacturer's specs, they recommend a 90Hz crossover point at a minimum and it sounds pretty good there but I've found that the system gels a bit better when I move the crossover point a bit lower.

Like I said, I'm pretty happy with my setting, I was just wondering if anybody had any tricks they'd like to share to help me get to the best possible crossover point a bit quicker, that's all.
Title: Re: Finding trhe perfect x-over point
Post by: John L Nobile on August 07, 2015, 10:59:13 am
i dont know but the Oak Ridge Boy singer is the lowest i ever heard. i only listen to the Elvira song they do. I am a rock n roll guy.

Singer with the Crash Test Dummies is the lowest pop vocalist I can remember hearing. Very nice character in his voice. I'd say that he's a true bass.

https://www.youtube.com/watch?v=w1c1j2szXTk

https://www.youtube.com/watch?v=vIbcqgXh5-4

I'd be setting my HPF at 80 for this guy.
Title: Re: Finding trhe perfect x-over point
Post by: Tim McCulloch on August 13, 2015, 10:21:05 pm
i dont know but the Oak Ridge Boy singer is the lowest i ever heard. i only listen to the Elvira song they do. I am a rock n roll guy.

He's a baritone when compared to Dan Britton or J.D. Sumner, who see-sawed back and forth in various record books as lowest pitch bass vocalists.

I've done gigs with Britton - could make a wedge 'dance' on the stage... right up until the woofer dies.
Title: Re: Finding trhe perfect x-over point
Post by: Robert Lofgren on August 14, 2015, 02:52:10 am
Here is one of my favorite singers - Ivan Rebroff

His vocal range was awesome!

http://youtu.be/yW2WoCKWlc0

Nina Hagen isn't too shabby either

http://youtu.be/eCv2OWsVS2U
Title: Re: Finding trhe perfect x-over point
Post by: Steve M Smith on August 14, 2015, 02:57:34 am
130Hz, well, my subs sound like total crap crossed over that high, very floppy and muddy.
When you see 130Hz written it seems quite low but the reality is that it's only an octave below mid C (261Hz) so there is a lot of musical content below that.


Steve.