Onkyo 607 and "Double Bass" Feature

[Kali157]

Hello all. I just got my Emp Tek E5Ti tower speakers. Well, I got them over a week ago, but my wife and I were out of town. Anyway, ran Audyssey and it predictably set the fronts to full band. I set my center to 80Hz, my surrounds to 90 Hz, and my sub to 100Hz. Then I noticed a feature of Double Bass. This is the explanation according to Onkyo:

"With the Double Bass function, you can boost bass output by feeding bass sounds from the front left and right channels to the subwoofer... Double Bass function on. Bass from the front left and right channels is also fed to the subwoofer (default)."

So if I use this when my fronts are at full band, anything bellow 100Hz for the fronts will ALSO be sent to the sub as well, correct? I just want to make sure that I read that right. I would love to use the full band of my new fronts but keep the support of the sub. Any reason why I should keep this off and turn my fronts down to 80Hz?

Btw, I am listening to music with the E5Tis and I am REALLY enjoying them. Very nice sound.

[derzauberer]

Originally Posted by Kali157

Hello all. I just got my Emp Tek E5Ti tower speakers. Well, I got them over a week ago, but my wife and I were out of town. Anyway, ran Audyssey and it predictably set the fronts to full band. I set my center to 80Hz, my surrounds to 90 Hz, and my sub to 100Hz. Then I noticed a feature of Double Bass. This is the explanation according to Onkyo:

"With the Double Bass function, you can boost bass output by feeding bass sounds from the front left and right channels to the subwoofer... Double Bass function on. Bass from the front left and right channels is also fed to the subwoofer (default)."

So if I use this when my fronts are at full band, anything bellow 100Hz for the fronts will ALSO be sent to the sub as well, correct? I just want to make sure that I read that right. I would love to use the full band of my new fronts but keep the support of the sub. Any reason why I should keep this off and turn my fronts down to 80Hz?

Btw, I am listening to music with the E5Tis and I am REALLY enjoying them. Very nice sound.

Yes there is a good reason to turn off double bass and set the crossover to your towers at 80 Hz. You already have a subwoofer!. I wouldn't recommend using the Emp Tek E5Ti towers full range. Speakers with merely dual 6.5 inch woofers are no match for a subwoofer when it comes to reproducing the lowest bass found in movies. The subwoofer is designed to handle the lowest bass at far higher output sound levels (spl ca 105 db to 115 db) in the 20 Hz to 120 Hz range. Your towers are not full range, that is, capable of -/+ 3 db from 20 Hz to 20K Hz. Yours are +/- 3 db from 50 Hz to 20K Hz. Your towers are really meant to be set to small, as well as the rest of the speakers you have. I wouldn't set the crossover frequency any lower than 80 Hz for your towers. Let your subwoofer handle the bass below 80 Hz

As far as Onkyo's double bass feature goes, most HT experts don't recommend turning on that feature which is found on many AVRs going by different names. Just take their advice and avoid it. It can actually decrease bass performance. Place your towers at a location where they can give the best imaging, smoothest frequency response above 80 Hz, and best sound dispersion. Place your sub where it is more capable of producing the smoothest bass response. Then you're all set for the best HT experience you can get.

I suggest that you read this bass management guide. Also read small vs large speaker setting.

[Kali157]

Thanks for the response. I have read the posts you linked. I understand that on regular cross over, setting the fronts to full band prevents any low Hz in the fronts from going to the sub. But I this is NOT the same thing. According to the description of "double bass" low end info will be sent to BOTH tower and sub.

Here is my thinking: let us say that a range of sounds from 120Hz to 20Hz is sent to the front right speaker. If I set the speaker to full band (sub cross over set at 100Hz), 120Hz to 20hz will be sent to speaker and 100Hz to 20Hz will be sent to sub. Now I know my towers cannot handle all the way down to 20Hz. According to Emptek my towers go to 50Hz. I know this may not be 100% accurate, but let us use this for now. So as I understand it, of the 120Hz to 20Hz sent to the tower, only 120Hz to 50Hz will be played. I don't see how this is a bad thing? No holes unlike setting the speaker to full band without double bass, since the sub still plays the 20Hz to 100Hz info. Am I missing something?

derzauberer, you mentioned that HT experts recommend against the Double Bass. Any links? I am curious how it decreases bass performance. Ironically it is often argued that 2 subs are better than one. So if a 60Hz sound came through the tower channel, having BOTH tower and sub play the sound would be a good thing right? Again, am I missing something?

[Big Daddy]

Originally Posted by Kali157

Thanks for the response. I have read the posts you linked. I understand that on regular cross over, setting the fronts to full band prevents any low Hz in the fronts from going to the sub. But I this is NOT the same thing. According to the description of "double bass" low end info will be sent to BOTH tower and sub.

Here is my thinking: let us say that a range of sounds from 120Hz to 20Hz is sent to the front right speaker. If I set the speaker to full band (sub cross over set at 100Hz), 120Hz to 20hz will be sent to speaker and 100Hz to 20Hz will be sent to sub. Now I know my towers cannot handle all the way down to 20Hz. According to Emptek my towers go to 50Hz. I know this may not be 100% accurate, but let us use this for now. So as I understand it, of the 120Hz to 20Hz sent to the tower, only 120Hz to 50Hz will be played. I don't see how this is a bad thing? No holes unlike setting the speaker to full band without double bass, since the sub still plays the 20Hz to 100Hz info. Am I missing something?

derzauberer, you mentioned that HT experts recommend against the Double Bass. Any links? I am curious how it decreases bass performance. Ironically it is often argued that 2 subs are better than one. So if a 60Hz sound came through the tower channel, having BOTH tower and sub play the sound would be a good thing right? Again, am I missing something?

1. Most front speakers cannot go very low and you are putting way too much strain on them by sending ultra low frequencies to them that they may not be able to handle without distortion.
   
2. Subwoofers are made to handle ultra low frequencies and have their own separate amplifier. Ultra low frequencies belong there.
   
3. Redirecting the bass to the subwoofer relieves the receiver amplifiers from having to work on reproducing the low frequencies and this greatly improves the headroom.
   
4. If you happen to be using Audyssey MultEQ calibration for room correction, you will achieve much better low frequency performance because the MultEQ subwoofer filters have 8x higher resolution than the filters in the other channels.
   
5. One of the most important factors in receiving good bass sound in a small HT room is placement of the low frequency sources. Although the subwoofer can be moved around the room in order to find the optimum position, the front speakers cannot be moved to other spots in the room. In addition, when the bass frequencies are directed to both the front speakers and the subwoofer, there may be some phase cancellation problem for some of these frequencies.
   
6. Low frequency waves are not directional. When you use two subwoofers, you can move them around and place them properly for optimum results and minimum phase cancellation problem. You can’t do that with front speakers.

This is the response Chris Kyriakakis, Chief Technology Officer at Audyssey, gave to one of the questions in his “Large vs Small” blog.

http://www.audyssey.com/blog/2009/05/small-vs-large/

LFE+Main or Double Bass is an option that was specifically created by AVR makers to appease customers who were personally "offended" when their speakers were designated Small. With this option, the bass from the supposed Large speakers is not lost and is redirected to the subwoofer. The problem is that in the overlap frequency region between the sub and the speaker the bass is doubled and therefore not correct. Having a sub is only beneficial if the content between it and the satellite speakers is properly spliced so the blend doesn't cause issues. Just playing the same content from both doesn't do that.

Yes, there is a benefit in distributing the bass from multiple sources. But the only way to do that correctly is with more than one subwoofer.

[Kali157]

got home a few hrs ago and got to play around with the settings. Double bass got boomy... okay okay, I will let that go. Just sounded like a good thing. I was trying to get a bigger low frequency coverage b/c the lows are great at the seated movie area. But when we play Rock Band in the middle of the room, the bass noticable drops. Thanks for the responses anyway.

Maybe looking at another Bic Pl200 sub... uh oh... jeez... I need a vacation from this site... Actually that didnt work. I pulled the trigger on my Emp tek towers while we were out of country... what a nerd.

[SlaughterX]

The feature is good for listening to stereo music, as it adds subwoofer support where you would have just been using the two front speakers before.

[LordoftheRings]

"Double Bass" is only there to screw things up, just don't ever use it.