Need Crossover Help

K

Kyle Braunlich

Junior Audioholic
Ratings
3 1
#1
I have been fooling with my SM55 definitive speakers and have found that a crossover of 60hz seems suitable. I however have the problem that this takes away from my subwoofer (Definitive Pro Sub 1000). Is there a way to have both play the the 60hz to 80hz frequency. Also if that's not a good idea please tell me. I also have a Pro Center 1000, I just wanted to know if a 120hz cross over is good, or if I could get away with a 100hz crossover. My receiver is a Denon avr-x1400h.
Thanks for any help.
-Kyle Braunlich
 
William Lemmerhirt

William Lemmerhirt

Audioholic Ninja
Ratings
2,100 6 1
#2
I have been fooling with my SM55 definitive speakers and have found that a crossover of 60hz seems suitable. I however have the problem that this takes away from my subwoofer (Definitive Pro Sub 1000). Is there a way to have both play the the 60hz to 80hz frequency. Also if that's not a good idea please tell me. I also have a Pro Center 1000, I just wanted to know if a 120hz cross over is good, or if I could get away with a 100hz crossover. My receiver is a Denon avr-x1400h.
Thanks for any help.
-Kyle Braunlich
The problem is you’ll likely have too many competing sources and will end up with muddy bass. Not too familiar with their subs. But if I wanted to try this kind of setup, I would use the regular line in on the subwoofer and therefore using the crossover section on the subwoofer vs the AVR. Set the AVR’s XO to 60hz, and set the sub to 80hz. Too many cooks(too many cascading filters)... you know.
Are you experiencing poor bass? Spending time with placement and integration will go a long ways, and is totally worth it.
 
lovinthehd

lovinthehd

Audioholic Overlord
Ratings
5,522 19 47
#3
Well with a 60hz or 80hz crossover both your speaker and sub are still playing frequencies in between, a crossover isn't a brick wall, it's the low and high pass filter slopes crossing over each other. It's partly speaker and sub range capability, part preference or avoiding localization of the sub. I'd say experiment with 80-100 range for the crossover, I'd think 120 is a bit too high for that sub's upper range capabilities and 60 might even be too high for the speakers' low range but you seem to get good results with it so maybe it's okay. Not sure why William is saying to set the low pass filter on the sub to 80, I'd just set it as high as possible if the LFE in on that sub doesn't already cut it out of the circuit.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
302
#4
I have been fooling with my SM55 definitive speakers and have found that a crossover of 60hz seems suitable. I however have the problem that this takes away from my subwoofer (Definitive Pro Sub 1000). Is there a way to have both play the the 60hz to 80hz frequency. Also if that's not a good idea please tell me. I also have a Pro Center 1000, I just wanted to know if a 120hz cross over is good, or if I could get away with a 100hz crossover. My receiver is a Denon avr-x1400h.
Thanks for any help.
-Kyle Braunlich
It actually a common myth that multiple overlapping LF sources create response problems or bad sound. Not true, there is nothing wrong with this, as long as they are integrated properly. The problem is that many receivers and processor do not allow this. They use true crossovers and force you to set the mains as small with a symmetric hand-off between speakers. Something that might make sense with mid and high frequency drivers located close but makes far less sense with subwoofers far from the mains and with the period of the frequencies being very long.

The speaker you are using doesn't have a lot of dynamic range in the LF's, so while running it full range is probably the best option (and then using the subwoofer with an 80hz crossover). To make this work with most receivers, you would either need it to be a type that has some kind of "double bass" that allows subs and mains to operate simultaneously or use the main line-out of on the processor or receiver for the subwoofer and using the subwoofers own crossover. Once you have done that, you will need to make sure it's setup right, so you can certainly tune by ear if there is no other option. Measurements are nice, however, to allow you to optimize the integration. Muddy bass is very often caused by integration problems. With multiple LF sources there is greater problems with interference, so you need to be sure the phase and level is just right. Even crossover can be tricky. These aren't brickwall filters, so sometimes I will set a lower crossover than I want because the response is combining in an elevated fashion at the integration point.

My Geddes Subwoofer Youtube video discusses the theory and concepts that underly these ideas.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Ninja
Ratings
2,100 6 1
#5
Well with a 60hz or 80hz crossover both your speaker and sub are still playing frequencies in between, a crossover isn't a brick wall, it's the low and high pass filter slopes crossing over each other. It's partly speaker and sub range capability, part preference or avoiding localization of the sub. I'd say experiment with 80-100 range for the crossover, I'd think 120 is a bit too high for that sub's upper range capabilities and 60 might even be too high for the speakers' low range but you seem to get good results with it so maybe it's okay. Not sure why William is saying to set the low pass filter on the sub to 80, I'd just set it as high as possible if the LFE in on that sub doesn't already cut it out of the circuit.
Not sure I fully hatched that one before sending it out to the world. Lol. I think I was thinking of limiting the overlapping frequency range. Maybe?
 
William Lemmerhirt

William Lemmerhirt

Audioholic Ninja
Ratings
2,100 6 1
#6
It actually a common myth that multiple overlapping LF sources create response problems or bad sound. Not true, there is nothing wrong with this, as long as they are integrated properly.
hi Matt. I feel like this one might be slanted in my direction a little bit from the post I made. As I mentioned to HD, that one may not have been fully cooked and I should probably limit my multitasking to singletasking lol. I was also considering that if the OP had to ask, he probably wasn’t ready for a deep dive on the subject. I know it very quickly gets complicated. Apologies to him if I underestimated.
 
lovinthehd

lovinthehd

Audioholic Overlord
Ratings
5,522 19 47
#8
My Geddes Subwoofer Youtube video discusses the theory and concepts that underly these ideas.
No written article? I really don't like watching videos...gets in the way of listening to music while I use the computer :) Plus harder to revisit in a timely way, videos take too long as well.
 
K

Kyle Braunlich

Junior Audioholic
Ratings
3 1
#9
Thank you all for your replies. I came across bi-wiring. After doing so the sub and fronts meld together very well. It really brought out the bass in the sm55s.
 
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
302
#10
No written article? I really don't like watching videos...gets in the way of listening to music while I use the computer :) Plus harder to revisit in a timely way, videos take too long as well.

Hey Man, I have to go where my people are! Video is the future. Nobody reads anymore! I do videos on obscure topics like Geddes Sub approach and get 10 times the views that I get on articles of the same nature. I wish it wasn't so, I prefer to read as well, but the world is a changen. Everyone is consuming media in different ways today. Everything needs to be broken down into shorter bits to hold peoples attention, placed on the sites where they spend their time like Facebook and Instagram.

In my day job, we sometimes joke that the number of Instagram followers you have can be as indicative of your expertise as is the number of peer-reviewed articles you have.

This is all stuff I should probably write up one of these days. I give talks as part of my day job so those are easier for me to do, plus I'm a total egomaniac and love standing in front of a group of people with all eyes on me!
 
Last edited:
Matthew J Poes

Matthew J Poes

Full Audioholic
Ratings
302
#11
hi Matt. I feel like this one might be slanted in my direction a little bit from the post I made. As I mentioned to HD, that one may not have been fully cooked and I should probably limit my multitasking to singletasking lol. I was also considering that if the OP had to ask, he probably wasn’t ready for a deep dive on the subject. I know it very quickly gets complicated. Apologies to him if I underestimated.
It wasn't meant as an attack or slight. It is the most commonly stated way of describing sub/main integration. But it's a myth so I like to correct it. I know it can lead to confusion and delves too deep, but then I feel like maybe we should be telling people that a simple crossover is the easiest to achieve good results.

You have had nothing to do with this, so again, don't take it personally, but I think because the old THX hard crossover approach became standard, it led to an industry approach to bass management that is inconsistent with the science on bass integration and flawed. I feel like we need to educate everyone on this topic sufficiently so the industry changes it's ways and fixes bass management.

I also have a terrible habit of taking these threads off topic, so I will stop with this. Maybe post a thread dedicated to this.
 
lovinthehd

lovinthehd

Audioholic Overlord
Ratings
5,522 19 47
#12
Hey Man, I have to go where my people are! Video is the future. No body reads anymore! I do videos on obscure topics like Geddes Sub approach and get 10 times the views that I get on articles of the same nature. I wish it wasn't so, I prefer to read as well, but the world is a changen. Everyone is consuming media in different ways today. Everything needs to be broken down into shorter bits to hold peoples attention, placed on the sites where they spend their time like Facebook and Instagram.

In my day job, we sometimes joke that the number of Instagram followers you have can be as indicative of your expertise as is the number of peer-reviewed articles you have.

This is all stuff I should probably write up one of these days. I give talks as part of my day job so those are easier for me to do, plus I'm a total egomaniac and love standing in front of a group of people with all eyes on me!
I'll just take your videos as part of that meaningless "progress" then. I like Geddes to an extent, tho. Weird guys with headphones or muscles just don't do it for me :)
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis