View Full Version : Sub crossover suggestion

12-10-2003, 01:30 AM
The main issue here is not the crossover on the sub, but the crossover on your receiver. Most receivers don't give you a lot of options, but usually 80Hz is one of the choices and I think it's a good option for your setup.

12-10-2003, 02:47 AM
I thought if you set the individual speakers to "small" on the receiver, then it sends the bass normally earmarked for each respective speaker to the sub at the crossover point setting of your sub. If you set a speaker to "large", then all frequencies intended for that speaker are sent to it, and the sub only ouputs the LFE channel. I will have my sub connected via a line-level input to the receiver.

12-10-2003, 03:31 AM
if you set the speakers to small...it sends frequencies lower than the crossover point(some receivers have one set point, or multiple points) on the receiver to the sub. The sub's crossover is independent of this, and usually not used if you are using the crossover on the receiver.

if you set the speakers to large, it sends full range to speaker. Some receivers also allow you to set a crossover point as well when speakers are set to large, and send frequencies below that point to the sub as well. In this case, some people use the crossover on the sub to fine tune.


12-10-2003, 04:37 AM
That's... disappointing. My base model Sony doesnt allow for fine tuning in "large" mode so i guess i'm stuck with the hardwired crossover in the receiver. My fear is that it is something high. In fact, i recall someone saying Sony chose 100hz as the crossover point. If that's the case, then i might be better of going with "large", or eventually getting a new receiver.

12-10-2003, 05:29 AM

The best way to determine the settings is to play with them when you have your speakers set up in your room. I ended up with a combination of reciever cross-over and subwoofer cross-over to work best in my room. When I change to a new room and pick up a couple of new speakers (hopefully soon), I fully expect to spend some quality alone time with my sound meter once again. As with everything else with audio, theory is fine, but nothing is more important than your own ear.

12-10-2003, 09:07 PM
I pulled out my sony receiver manual last night and it had some interesting comments with respect to this. It said unless you had "satellite" type speakers (i guess implying cubes) or unless your speakers arn't "full range", then they recommend "large" setting since some bass is directional and during movies it is actually a good thing to hear where a booming explosion is coming from.

It also said if you set "sub" to yes if you have one, and if so, then set the crossover point as high as possible. That statement tells me that "large" on my receiver bypasses the receiver's hardwired crossover, but makes your own sub's crossover "live". It also recommended setting the sub crossover as high as possible for the LFE effects intended for it. I guess i'm to take that to mean if there's an LFE effect, but its above your crossover setting, then those effects are either lost or outputted to your other speakers.

Based on that, i guess i will probably go with large, and 90mhz crossover (max setting for VTF-2).

(edit) Another thing i found interesting in the manual. For satellite placement, Sony recommends placing them behind you on the back wall and firing them foward, as opposed to dolby's opinion to place them on the side walls slightly behind you and fire them at each other. I will have to follow sony's advice here as i dont have two side walls. Sony's advice on surround placement shouldnt necessarily be discarded considering their involvement in this field (ie: SDDS sound and their proprietary DCS field).

12-10-2003, 10:03 PM
That configuration will lead to extra loud bass from 90Hz to the bottom end of the speaker extension due to overlap. What makes the subwoofer crossover 'live' is whether it is set for 'In' (on) or 'Out' (off).

While it's up to you what sounds best, the easiest way to not have overlap or gaps is to set the speakers to 'small', the sub to 'yes', and the sub crossover to 'out'. As described already, this will send everything over the receiver crossover setting to the speakers and everything below it and the LFE track to the subwoofer.

12-10-2003, 10:31 PM
That's not the way i'm interpreting it from the manual. Lets say a cannonball from "Patriot" hits behind you and to your right, but far in the distance, then the bass should rightfully come from the back, left speaker - not nondirectionally simply because it was below your receiver's crossover. Also, I dont think that bass will necessarily be duplicated in the LFE channel, unless they encoded it to do so. As i'm interpreting my manuel, even bass below the crossover point, when using "large" mode will not necessarily come from the sub, unless there's a specific LFE call for it.

Losing bass directionality by going with "small" on movies i think will steal a lot of the sound effect on movies - per Sony's own statement that this would be the result. That explanation sounds logical to me. Even if there's an LFE call and you have "double bass", i dont see the harm there - it would just be an emphasis, perhaps easily compensated for by just lowering the bass output level.

(edit) Also, i dont quite understand the "live", on/off setting of the sub. I'll have my sub connected via line level inputs. If i go with "large", the sub will not be getting any bass but for LFE calls, regardless of whether its live or not. If its on "small", it will get everything below the receiver's crossover setting + all LFE's. So wouldnt you always want it "on". Off means off right?

(edit) As a reminder, i believe Sony's hardwired receiver crossover is 100hz. I didnt just pay 1300+ for a set of high quality surround speakers only to never let them go below 100hz.

12-11-2003, 02:16 AM
The directional nature of bass below 100Hz isn't noticable in most environments. It shouldn't be a problem, but like everyone has said - it's what sounds best to you that counts.

You can't compensate for a narrow band overlap (100Hz-70Hz) by changing the bass level, this would require something like a parametric EQ. If you don't mind, or like, the emphasis then more power to you.

It's unfortunate that your receiver doesn't have an 80Hz setting - I think that's ideal for most Ascend/Hsu setups.

There is absolutely nothing lost in the value of the speakers by cutting off the lower frequencies going to them. I guess if it bothers you to think that every time you use them, that might be an important psychological component to your configuration to consider.

12-11-2003, 02:33 AM
If you have your reciever set to 80Hz and the sub crossover in the in position set at 80Hz would it be the same as just setting the crossover on the sub to out?

12-11-2003, 02:55 AM
>The figure ive heard for identifying directionality in base is 80hz. I'm sure that's an approximation, but something to consider if 80-100hz is going to the sub when it might be more appropriately heard in the appropriate direction it came from.

>If the max setting on the VTF-2 sub is 90hz, then if i go with the "small" setting, am i to assume i will lose all sound in the 90-100hz range with the receiver's hardwired 100hz crossover?

>If i lose nothing in the value of the speaker by crossing over at 100hz, then why do speaker makers spend so much time advertising how low their speakers go. For example, I thought one of the main selling points of the CBM-340 was its 55hz@-3db ability, in addition to the wider soundstage. Any ole junk speaker with a 4" woofer or greater can do 100hz+.

>You still didnt address how there is "band overlap" if the receiver sends a bass hit to, say, the rear left speaker and there is no LFE info. On the "large" setting, the sub only gets LFE calls.

>I'm learning from our discussion, not arguing just so you know. My mind can be changed, and this is a learning process for me. I'm just getting conflicting advise from reliable sources (knowledgeable people here vs Sony).

12-11-2003, 03:33 AM
Found a site that helped me a lot, and notice the first option was what you recommended Bradjudy:


12-13-2003, 03:05 AM
After thinking about this, I guess I assumed some capabilities in your receiver that might not exist. It sounds like you can only set all of the speakers large or all small and that you cannot set your sub to handle info from the satelites below the crossover point. Is that correct?

In that case, it does make sense to use large for the speakers. Some receivers let you choose individual speakers to large/small and/or to have info below the crossover point go to the sub in addition to the LFE. Now that I think about it, I need to see how mine is currently configured.

This is where something like an ICBM is neat to have, but not worth $250 for me at the moment. Although, I think I saw one on the used rack at a local store....

12-13-2003, 04:56 AM
No, i can set each one individually to either small or large though there are some restrictions. For instance, if i choose small for the front L/R, i cant set my center to large. Also, If any of the fronts are set to small, i cant set my rear to large. When small is chosen, the bass redirection circuitry sends the bass to the sub below the receiver's crossover point - which is 100hz. I cannot adjust my receiver's crossover point like some nicer models, but 100hz is actually pretty good considering that's where the VTF-2's frequency range starts.

I think you were right from the beginning - i need to go "small" for all, subwoofer to "on", and disable the sub's crossover as to avoid conflicts with the receivers and to ensure the least amount of LFE material is lost.

12-13-2003, 06:57 AM
My Harman/Kardon has some different options and behavior than your Sony. I can set front/center/surround sets each to small/large without the restrictions you have. When using large I can select crossovers of 40 or 60 and when using small I can choose 80 or 100. With my receiver, you can have overlap between the fronts and the subwoofer in certain configurations (in particular, if the fronts are set to large and the sub is set to LFE+Fronts) - an item that appears to differ between our hardware and made my statements confusing.

When I set mine to small all around and a crossover of 80Hz, everything going to all of the speakers below 80Hz is redirected to the sub. I think most receivers behave this way when using 'small'.

It would be interesting to see the graphs of some movies and know how much information below 80/100 is being sent to the 5 main channels.