Bass Mangaement

[tomvr975]

:) Hello, I am a newbie to this forum and wanted to get a few opinions on the subject of bass management for home theater. I use a pair of Boston Acoustics VR975 tower speakers that have built-in powered subwoofers as the front channels which are fed by Yamaha RX-Z9 AV Receiver. The set-up menu has the option of outputing low frequencies to the subwoofer only or to "both" which outputs the lows to both the low frequency driver and the subwoofer. If any of you have front speakers that have built-in powered subs, would like to have a few comments on how you set-up bass management and what crossover frequency are you using.

Thanks, Tom

[GMichael]

Hi,
Welcome to AR.

I output to both. My towers have built in amps for the woofers so I want to make use of that for 2 channel music. Their resistance goes up as you get below 80htz so it doesn't put much strain on my receiver. Have you looked at your towers' resistance curves? As long as yours do the same, I would go both.

[tomvr975]

Thanks for the reply. I don't know what the resistance curve is for the Boston 975's and there is no mention of it in the manual. They are rated at 8 ohms.

[kexodusc]

This is yet another one of those "it depends" scenarios.

I built a set of powered-towers for an individual last year (geez, maybe it was 2 years ago now?). We definitely set the speaker portion to small for a few good reasons.

First, the subs just did a better job at handling the bass than the woofers in the speaker portion did. Not that they were bad at bass. Quite the opposite. It's just that there's only so much a 6" woofer could do well compared to 2 capable 10" units. What this did is remove the burden of bass reproduction on the speaker, which in turn lowers distortion and allows the speaker to play louder, cleaner across the rest of the spectrum. More importantly, it can improve the woofer's transient response, sometimes significantly so.

Also, this particular person did pay attention to bass management, eq'ing and even room treatment. We found setting the system to "both" had undesirable results in the way of a few unavoidable peaks near the crossover region - this is somewhat dependent on the filter on your subwoofer- if it's 2nd or 3rd order you could be in trouble, if you're lucky and it's 4th order, you might be okay. It definitely made room eq'ing a lot easier.

I'm an advocate for this approach in principle in most sub/satellite systems, except where the subs don't handle the 60-100 Hz bass region well, or aren't intended to. My speakers are capable of bass down to the low 40's but I use my sub to handle everything up to 80 Hz, just becaue it does a better job. YMMV. I will concede that personal preference for how bass should sound, and the impact of room acoustics on bass response could be factors supporting running bass to both units.

Sometimes what measures best and what sounds best to your ears are two different things so tinker around and go with what brings the bigger smile to your face. Then come back on audio web forums and insult anyone who holds an opinion contrary to yours :D

[GMichael]

This is yet another one of those "it depends" scenarios.

I built a set of powered-towers for an individual last year (geez, maybe it was 2 years ago now?). We definitely set the speaker portion to small for a few good reasons.

First, the subs just did a better job at handling the bass than the woofers in the speaker portion did. Not that they were bad at bass. Quite the opposite. It's just that there's only so much a 6" woofer could do well compared to 2 capable 10" units. What this did is remove the burden of bass reproduction on the speaker, which in turn lowers distortion and allows the speaker to play louder, cleaner across the rest of the spectrum. More importantly, it can improve the woofer's transient response, sometimes significantly so.

Also, this particular person did pay attention to bass management, eq'ing and even room treatment. We found setting the system to "both" had undesirable results in the way of a few unavoidable peaks near the crossover region - this is somewhat dependent on the filter on your subwoofer- if it's 2nd or 3rd order you could be in trouble, if you're lucky and it's 4th order, you might be okay. It definitely made room eq'ing a lot easier.

I'm an advocate for this approach in principle in most sub/satellite systems, except where the subs don't handle the 60-100 Hz bass region well, or aren't intended to. My speakers are capable of bass down to the low 40's but I use my sub to handle everything up to 80 Hz, just becaue it does a better job. YMMV. I will concede that personal preference for how bass should sound, and the impact of room acoustics on bass response could be factors supporting running bass to both units.

Sometimes what measures best and what sounds best to your ears are two different things so tinker around and go with what brings the bigger smile to your face. Then come back on audio web forums and insult anyone who holds an opinion contrary to yours :D

Good points.

Tom,

I in fact have more than one set-up saved to my receiver's memory. For 2 channel, I have the mains crossed over at 40 htz, but for HT they are crossed at 60. This way the sub doesn't "take over" during music, but steps up to handle most of the base that's found in many movie sound tracks. It's what sounds best to my ears.
I've also found that my preferences change as the volume goes up or down.
In either case the mains are not being asked to do much below 40. Their 8 inch woofers just don't handle it as well as my 15" sub, IMO.