Get an exclusive sneak peek into our new project. >>> Click Here
Our native mobile app has a new name: Fora Communities. Learn more.

80hz hi-pass + 45 hz low pass at Same time = trouble?

1719 Views 19 Replies 10 Participants Last post by jostenmeat, May 23, 2007

jostenmeat

Discussion Starter · May 22, 2007

Hello all, any input would be greatly appreciated here. My center channel is rated to go down to 75hz(-3db) and everything else is set to full-range. What I desire is: 1) optimal performance for music and HT 2) some semblance of convenience.

I believe, for the moment as my stuff is all new, that I prefer the x-over around 40-45 hz for music listening, while using 80hz as the point for HT (also to protect my center). To use the receiver's x-over, I must go to the OSD (pain to turn on tv each time, as well as probably hurting the unit with so many 'strikes') to do so. My sub is a JL F113 and pre/pro is NAD T163 So- I've been trying to find a convenient compromise:

I'd like to know what kind of negative effects I should be expecting by using both the receiver's and sub's x-overs? Is this an absolute no-no? I can set the low-pass on the sub at 24hz/8ve. The difference between 40hz and 80hz is one octave exactly, of course.

--------------------------------------------------------------------------------------------------------

Side notes: I've been recommended to check out the sms-1. Although I'm sure there will be benefits with the unit, even with the very low x-over, it still does not have multiple inputs (well for me at least, I have zero xlr outputs). See, my Jolida cdp has two sets of rca outputs, and it could be nice to 'switch' between cd and Lfe outputs. Which brings me to another possibilty:

?: for HT should I defeat sub's x-over (with receiver permanantly set at 80hz), and for music simply unplug/plug cdp outputs and use sub's internal? (Can you guys see why I'm looking for some semblance of convenience?)

I have the option of upgrading the pre/pro to a Masters unit for a sum that I bet is worth it to do, but I just spent a ton. If serious strides in convenience are also part of the package, it may tip the scales I suppose.

Again, advice is most appreciated

-jostenmeat

See less See more

1 - 20 of 20 Posts

mailiang

· #2 · May 22, 2007

Using the 40hz crossover setting on the sub will limit your bass output above that point to your sub. I would defeat the subs crossover and use the receiver's and change the crossover setting depending on the source. If you can't defeat the 80hz setting, at this point, I would just leave it at that. The extra octave really shouldn't be a big issue especially with the sub you have.

Ian

jostenmeat

Discussion Starter · #3 · May 22, 2007

I truly appreciate the effort. However, by reading your post Im not sure that you understand my needs, or perhaps I am missing something...

1. The point is that I WANT to cut off frequencies above 40hz. For music. The extra octave is incredibly localizable.

2. Yes, I can change the x-over via the receiver, but it's highly undesirable by me to have to turn the tv on each time to do this.

*I MUCH rather listen to 2.0 music than 2.1 music if I have to x-over as high as 80hz.

Perhaps someone else can answer my first question stated:

"I'd like to know what kind of negative effects, if any, I should be expecting by using both the receiver's and sub's x-overs?"

Also, again, any insights into the options of a) manually plugging/unplugging lfe vs stereo while defeating/undefeating sub. b) any possible convenience I am looking for from an sms-1?

Or perhaps you are right mailang. Just turn on the tv every damn time....

See less See more

Kal Rubinson

· #4 · May 22, 2007

Quote:
Originally Posted by jostenmeat /forum/post/0

1. The point is that I WANT to cut off frequencies above 40hz. For music. The extra octave is incredibly localizable.

But if your center is -3dB at 75HZ, you will lose much of the information between 40 and 75Hz when you do this. You should get a center that goes lower if you insist on a 40Hz crossover point.

Quote:
2. Yes, I can change the x-over via the receiver, but it's highly undesirable by me to have to turn the tv on each time to do this.

Unfortunate but the only solution to that is to find an Outlaw ICBM crossover/bass manager and use it for the purpose. The front-panel control is a snap to adjust.

Quote:
"I'd like to know what kind of negative effects, if any, I should be expecting by using both the receiver's and sub's x-overs?"

Unpredictable amplitude and phase interactions.

Quote:
Also, again, any insights into the options of a) manually plugging/unplugging lfe vs stereo while defeating/undefeating sub. b) any possible convenience I am looking for from an sms-1?

The SMS-1 has a fixed HP filter at 80Hz, iirc.

See less See more

jostenmeat

Discussion Starter · #5 · May 22, 2007

Thank you so much for your reply Kal.

Fixed 80hz hi-pass means ix-nay on the Velodyne for me. I will definitely look into the Outlaw unit, many thanks.

I do not think I will lose any information between 40 annd 75 hz:

1) for Music, I only listen in stereo. So mains are full-range + some sub support. I see that I am probably being confusing, or perhaps not. I should have said two low pass x-overs. (Not a high and a low). I'm sure this doesn't change a thing, though, as far as the "unpredictable amplitude and phase interactions".

2) for HT, I WAS planning on simply defeating the sub's internal x-over (40-45hz) and let the receiver split the signal evenly between my 7.1 system.

Thanks again. (now where's my Outlaw bookmark....)

See less See more

ribbit

· #6 · May 23, 2007

i think the ICBM has been discontinued IIRC, you might need to look for it used.

jostenmeat

Discussion Starter · #7 · May 23, 2007

You are right. Nothing to be found so far on ebay, Audiogon, or avs. ribbit just sent you a pm, btw. Hmmm.... now about that M15 pre/pro......

deneb

· #8 · May 23, 2007

You might consider the SMS-1, it could tame the localizable 40-80hz octave. It's quite possible you have a peak somewhere in that range that is causing the sub to be localizable. I had a giant peak at 40hz in my room which made my sub localizable. After taming the node with my SMS-1 it made the sub much less localizable.

Kal Rubinson

· #9 · May 23, 2007

Quote:
Originally Posted by jostenmeat /forum/post/0

Thank you so much for your reply Kal.

Fixed 80hz hi-pass means ix-nay on the Velodyne for me. I will definitely look into the Outlaw unit, many thanks.

I do not think I will lose any information between 40 annd 75 hz:

1) for Music, I only listen in stereo. So mains are full-range + some sub support. I see that I am probably being confusing, or perhaps not. I should have said two low pass x-overs. (Not a high and a low). I'm sure this doesn't change a thing, though, as far as the "unpredictable amplitude and phase interactions".

OK. OTOH, duplicating the bass in the sub and mains results in similar "unpredictable amplitude and phase interactions".

Bone215

· #10 · May 23, 2007

jostenmeat

for what it is worth, both of the set up manuals for my two different subs say turn up the sub's crossover and just use the receiver's bass management, however, after much playing around I get better results with receiver set at 80 hz and I adjust my sub's crossovers to where I get better tighter response. As has been said before by others, the crossovers are not brick walls

go ahead and experiment and listen to what works in your room.

jostenmeat

Discussion Starter · #11 · May 23, 2007

Very interesting Bone. Sounds like a lot tinkering could come my way. Otoh, I might just listen to Kal's forewarning and drop the sub in stereo altogether

Thank you deneb, yet another proponent of the Velo unit.

See less See more

mailiang

· #12 · May 23, 2007

Quote:
jostenmeat: I only listen in stereo. So mains are full-range + some sub support. I see that I am probably being confusing, or perhaps not. I should have said two low pass x-overs. (Not a high and a low). I'm sure this doesn't change a thing, though, as far as the "unpredictable amplitude and phase interactions".

Quote:
Originally Posted by jostenmeat /forum/post/0

Very interesting Bone. Sounds like a lot tinkering could come my way. Otoh, I might just listen to Kal's forewarning and drop the sub in stereo altogether

Thank you deneb, yet another proponent of the Velo unit.

I agree. If you have hefty mains and are concerned with the subs response in the 2 channel mode why not just cut off the sub. I don't use my sub in the stereo mode since my mains can extend into the 30hz range. I find that the imaging is better and I don't have to worry about any localization issues. I do however use an outboard EQ to fine tune it that way.

Ian

J_Palmer_Cass

· #13 · May 23, 2007

Quote:
Originally Posted by Kal Rubinson /forum/post/0

OK. OTOH, duplicating the bass in the sub and mains results in similar "unpredictable amplitude and phase interactions".

Not any different "amplitude and phase interactions" that you can get when you use two or three subwoofers in your system (AKA "duplicate bass"). That is if one assumes that the end user knows how to do either setup properly!

J_Palmer_Cass

· #14 · May 23, 2007

NAD T-163

"NOTE: You can set Subwoofer to "On" even with "Large" front speakers, in which case bass content from any channels set to "Small" will be routed to both the subwoofer and to the front speakers; LFE-channel signal will pass only to the sub. In most subwoofer-equipped systems, setting front speakers to "Small" is usually the better option."

If you setup this way, you can use the subwoofer amplifier's low pass filter to fine tune the FR of your room and speakers. However as Mark Seaton said many times, if you don't use some type of audio measurement system that has a visual display (like True RTA), then it is difficult to integrate mains and sub properly.

Kal Rubinson

· #15 · May 23, 2007

Quote:
Originally Posted by J_Palmer_Cass /forum/post/0

Not any different "amplitude and phase interactions" that you can get when you use two or three subwoofers in your system (AKA "duplicate bass"). That is if one assumes that the end user knows how to do either setup properly!

Sure. There are many ways to screw up the sound.

mvaarani

· #16 · May 23, 2007

I had exactly the same problem: with music 40hz would be preferable instead of the 80hz used in movies. To solve this I bought a dvd-player with adjustable x-overs.

So, when listening music I'm using 40hz in my Denon DVD-3910 and analog 5.1-inputs. When watching movies I transfer the sound in digital format and use the 80hz crossover in my AV-receiver. Problem solved

I also tried using the subwoofers own crossover and adjust it so that countinues where main speakers roll-off naturally. It worked quite OK. But now I'm using the x-overs in the player since this also relieves some low bass my main speakers are trying to produce.

See less See more

TJEli

· #17 · May 23, 2007

You do not have to use the high pass in the SMS-1 if you dont want to. (it also requires that you run it through your processor loop).

You could do what I do. (I also listen to a lot of music) Run your mains (L+R) as LARGE in your processor. Run your center and surrounds as SMALL. Use an SMS-1 to dial in 2 different presets. One for music and one for movies. There are 6 presets available and you can set independent eq curves and LP freq. for each.

Since you are running your mains as LARGE and you listen to music in 2.0 or 2.1, you can leave your processors x-over at 80hz. It will only effect the speakers that are set to SMALL.

(This is assuming you have mains that are capable of being run LARGE)

-Eli

See less See more

jostenmeat

Discussion Starter · #18 · May 23, 2007

Everybody,

I appreciate all of the experienced input. I think I will drop the sub in 2-ch altogether. My mains go down to 25hz (-3db). It happens that the speakers that I was going to get did need a sub, and when I did a sudden upgrade, I could not cancel the sub order. So, I was just trying to use it anyways for music, since I have it already.

It looks like it will just simply be one helluva-an-overkill HT sub.

I believe I do hear these phase and amplitude issues with sub. The imaging is slightly compromised, and its hard to get the levels just right without introducing serious bloat.

In this way, I can also delay needing to buy a bass mgmt unit, or even perhaps the upgrade of the pre/pro. This is my first time owning any kind of audiophile gear, and I'll just leave it be for now. Even if I have decent ears, I am extremely likely to decrease the performance rather than increase it. Well, my thoughts for now in any case. Thank you all again.

See less See more

Macfan424

· #19 · May 23, 2007

2

A couple of comments about the SMS-1, more for the benefit of lurkers than for jostenmeat who seems to have settled on a solution.

While The SVS-1 only has an 80Hz, 6dB/octave high pass filter (which seems almost like a throw in they don't expect to be used often), it has several other options that some might find useful in similar situations. (A workaround for the HP issue might be to bypass it and use a separate high pass filter that meets your requirements)

The SMS-1 has five output settings that can be selected by the push of a button on its remote. It's low pass filter is adjustable in 1Hz intervals from 15Hz to 199Hz (and Off). The slope is adjustable in 6dB/octave intervals from 6 to 48dB/octave. It also has phase adjustments in 15 degree steps. All can be different in each mode, so it's easy to employ completely separate music and HT sub settings.

For many, these adjustments would sufficient to permit the sub to be used below the main speaker's natural crossover for stereo/music applications. Pretty much what many of us already do in 2.1 rigs which lack bass management. We just have to live with some of the "unpredictable amplitude and phase interactions" Kal referenced.

(They can be minimized.)

On the other hand, there doesn't seem to be much point to incorporating a sub if the main's go to 25Hz. Not much music below there, unless you love pipe organs. My primary music system mains do too, and I've never had any sense of needing a sub. Even for my pipe organ recordings.

See less See more

jostenmeat

Discussion Starter · #20 · May 23, 2007

Thank you as well Macfan. I did skim the online manual, but your distillation of it makes it very easy to digest its abilities. Cheers.

1 - 20 of 20 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.