A Guide to Bass Management (Part I)

[HAMP]

Originally Posted by soundwave628

But beyond the receiver setting is really low gain fairly normal. After getting them both to -3.5 I reran with both running and it went to -4.5. I boosted it to -1.5

A meter will tell you what the SPL is actually at for each of those numbers. Also remember there is a difference between 'reference' and 'preference', and it sounds like you might have a preference for more bass then what is recommended for reference levels that the receiver is setting.

[soundwave628]

I use it mainly for home theater so yes I run the bass a little hot. Especially since both my subs are sealed. Eventually I do want to get an SPL meter just trying to do what I can with what I've got now.

[ezyl]

Hi guys, I bumped into a situation concerning my cross overs for bass management and did not get any response on another post previously so I'm hoping someone can help me on this,...

l bumped into a problem while playing low frequency test tones on my system. I was trying to hear/understand how the bass management in my receiver worked with respect to the main speakers and subwoofer. Let me explain,...

I went into my receiver menu and set main speakers to Small and crossover to 80Hz(Audessey chose 70). Just for the test, I set centre and surrounds speaker to none. Sub to ON.
Then I played frequency tones from BD player from 100Hz to let say 60.
When tones played from 80 to 100Hz all is good and the mains woofer are working it. But when I play below 80Hz, (my sub kicks in, all good) but i can still "faintly" hear sound from my main speakers and IT's bass drivers are physically moving. So sound is still played by main speakers (AND subwoofer) even for tones below cutoff I've selected. Checked back on menu and Double Bass is OFF.

Is my understanding for crossover on bass management wrong or is my receiver faulty. Kindly help to advise on my setup as per my signature. Thank you in advance.

[Shpongle DMT]

Ezyl, I don't think you have anything to worry about with what your experiencing. The purpose of setting a speaker to small with a crossover is to enhance the overall sound of your system when said speakers can't produce the proper SPL at lower decibels. What you want is for everything to blend together seamlessly. So the fact that you can still hear a faint sound coming through speakers set to "small" won't really be an issue IMO. Especially since you can still hear the sound at proper levels on the sub. Now if the "small" speakers were still trying to push the sounds at full volume that would be cause for concern. It could also be that the test tones your playing are not pure and the sounds actually have frequencies above to crossover setting.

If it's something that you can't hear during movies and music then I definitely wouldn't worry about it.

[ezyl]

Originally Posted by Shpongle DMT

Ezyl, I don't think you have anything to worry about with what your experiencing.

Hi Shpongle, thank you for the reply and reassurance. The frequency sweep files that I was playing was downloaded from RealTraps test tone.
I have to play music and movies more and see if I can detect if bass management is seamless. What I'm puzzled is, my understanding was by engaging bass management frequencies below crossover would be handled by subwoofer ALONE. Thus the "small" fronts would not have to strain to play lower frequencies below crossover and handle upper frequency more cleanly.
Am I flawed in my thinking, I've read the stickies to a considerable length and everything says otherwise.

[soundwave628]

From what I understand from reading the forums, crossovers are not a brick wall. They happen gradually probably so things blend better. So even with an 80hz it will play a little below that, how far I don't know and I don't know if its applying its full power. Also could a sub pressurizing a room cause a speakers cones to move?

[dlblumberg]

Hi Big Daddy, I've been reading your posts about bass management, subwoofers and receiver speaker calibration and thank you for them. The consensus from other sites seems to be in sync with much of your posted info, and this has led to my dilemma.

I have a Rel subwoofer which has both the LFE input as well as a hi-level input which connects directly to the receiver's main speaker outputs via a special neutrik speakon cable. On top of that, Rel then recommends setting the mains to 'large' in the receiver settings thus ensuring both the mains and the sub will be outputting the entire bass information.

Well, I'm sure I don't need to tell you that this contradicts much of the philosophy of your bass management post (also most of what I've read elsewhere) with regards to phase cancellation and so forth when there is overlap between the bass coming from the mains and the sub.

So this is my quandary. I've read and understood the arguments against using the exact strategy for which the sub I happen to own has been seemingly built from the ground up. Understand also that I got this sub long before I ever became aware of this counter information. I do find it kind of bizarre, though, that this one company seems to be building their equipment and recommending its usage in ways so diametrically opposed to the information offered by so many experts. Or am I missing something? Maybe there is something about the way Rel's are made that leads not to a contradiction but to an exception.

Do you have any thoughts on this subject? I would be incredibly grateful for anything helping to clear my confusion! Thanks again.

[Blu-Dog]

Originally Posted by dlblumberg

Hi Big Daddy, I've been reading your posts about bass management, subwoofers and receiver speaker calibration and thank you for them. The consensus from other sites seems to be in sync with much of your posted info, and this has led to my dilemma.

We all have a big dilemma. Big Daddy is not currently posting, so I don't have him to argue with, even though he's right 99% of the time. I wish he was around. He's smarter than I am, which I refuse to admit, but since it's obvious to everybody, I just ignore it.

Originally Posted by dlblumberg

I have a Rel subwoofer which has both the LFE input as well as a hi-level input which connects directly to the receiver's main speaker outputs via a special neutrik speakon cable. On top of that, Rel then recommends setting the mains to 'large' in the receiver settings thus ensuring both the mains and the sub will be outputting the entire bass information.

That's overkill, even for the REL which doesn't play skull-busting bass anyway. The REL excels and clean, smooth sound, and won't bust the windows out, but if set up right, your dialogue won't get overwhelmed and you'll get all your source material in a nice, balance way.


You only need for your receiver to send bass (including subwoofer tones) to the sub. You can vary all of that at both the sub, and the receiver, but you only need one connection. If it's Neutrik "speakon" connections on the receiver, you can use those; if it's an RCA connector, use a good quality cable and you're OK. The converters you can get sometimes introduce noise coming out of an RCA on the receiver side, going to speakon. I tried it, and gave it up


Next, you can leave the high level inputs alone. If you have an older receiver without a sub-out connection, it's OK, otherwise, stay away from it. Your REL should have a switch to accept one type of input or the other, not both.


Next, if your speakers are huge (like stadium size), you can go large on the crossover setting, otherwise, set them to small. This does not mean they are small speakers - this means they're not doing subwoofer chores. You have a sub for that. If you're lucky, you can set the signal going to the speakers at the receiver, and place it around 80 hz to start. This means the really low tones are diverted to the sub, and only higher tones (still pretty deep) go to the speakers. That takes less power for the speakers, and you'll note that clarity increases. It also means less work for the speaker's crossover, and less amperage slamming the little guy. That cleans up sound, a lot.


Set the subwoofer's internal crossover at around 80 hz, if you can. Do the same on the receiver, if it can be controlled. This is the THX recommended crossover point; it's not some law, but it's a good place to start, and I've been running mine that way for a long time. Then fiddle with it. Equipment varies, so you may make changes, but start there.

Originally Posted by dlblumberg

Well, I'm sure I don't need to tell you that this contradicts much of the philosophy of your bass management post (also most of what I've read elsewhere) with regards to phase cancellation and so forth when there is overlap between the bass coming from the mains and the sub.

Don't sweat the cancellation stuff for now. It gets worse if you have two subs, or weird stuff with dead spots in the room (nulls, they call them), or the environment you're in with furniture or speakers in odd positions in there. Your first real problem is dual signal sources, and I'd drop the high level connections as soon as you can.

Originally Posted by dlblumberg

So this is my quandary. I've read and understood the arguments against using the exact strategy for which the sub I happen to own has been seemingly built from the ground up. Understand also that I got this sub long before I ever became aware of this counter information. I do find it kind of bizarre, though, that this one company seems to be building their equipment and recommending its usage in ways so diametrically opposed to the information offered by so many experts. Or am I missing something? Maybe there is something about the way Rel's are made that leads not to a contradiction but to an exception.

REL is an odd duck. They're advertising earth shaking bass, but they don't build that way - they build for speaker blending, and they're excellent at that. Stay away from their explanations. Go with Big Daddy's advice when in doubt. Other folks in here are pretty sharp, too, and will say many things along the lines I mentioned.


I don't know your other gear - speakers or receiver, for example, and I don't know what source material you're listening to. REL makes good gear, for quality listening, so you should have little problem dialing it in. Tweak the settings at normal listening levels, and keep track of what you're doing so you don't do it twice or forget where you set things.

Originally Posted by dlblumberg

Do you have any thoughts on this subject? I would be incredibly grateful for anything helping to clear my confusion! Thanks again.

Take your time...remember, sources are different...and take breaks whenever foul language seems unavoidable.


Good luck!

[dlblumberg]

Hey Blu-Dog, thanks so much for the quick response and all your advice. With all that in mind, I'll give her a whirl and post back the results, soon....

Thanks again!

[Pastor G]

How do you add more subwoofers that have only two inputs on the back. I have two subwoofers that can be connected to my receiver. I want to go to four subwoofers but my two Klipsch subs only have two input jacks.

[superpacman]

Originally Posted by Pastor G

How do you add more subwoofers that have only two inputs on the back. I have two subwoofers that can be connected to my receiver. I want to go to four subwoofers but my two Klipsch subs only have two input jacks.

You will need to use 2 splitters. 1 out each of your AVR sub output. Each splitter will have 2 outputs, just connect each sub to them.

[Pastor G]

Thanks a lot. One male to two female should do it.

I appreciate it Superpacman

[superpacman]

Originally Posted by Pastor G

Thanks a lot. One male to two female should do it.

I appreciate it Superpacman

If you are connecting 4 subs, then you will need 2 of those.

You are welcome.

[Fors*]

Thank god Big Daddy created all these stickys.....I am finding out just how much I needed to brush up on since he created them 14+ years ago. Wherever you are Big Daddy, here is a big shout out to you bud!

[xquad]

So, how will it work? I have Denon avr-4800h. In the settings I chose LFE=120 setting. My sub is Klipsch R-112SW. On there I set LPF to 120 according to sticky guide. But after I ran Audyssey, it tells me that my Atmos Klipsch RP-140SA should be set to 150 crossover. If I do that, frequencies between 120 and 150 will be lost, right?

Please explain / suggest.
Thanks!