mixing subs

[suzook1]

Hi all

I have a ULS-15 which I finally got set up... LOVE IT. MY plan is to add a second later on when I have funds.

The question is, for now can I mix subs or is it not recommended. I have another sub that still performs fairly well and was going to add it to the mix.

any comments?

[suzook1]

care to comment

[pr@j]

Well, there are probably a few things to consider before doing this - in theory there is nothing WRONG with mixing subs, more a matter of your personal preferences and tastes.

1. Make sure that your A/V receiver can handle the load placed on it with the additional sub - this includes, the impedance rating of the subs combined. Are both subs powered by their own built in amplifier? Does your current receiver have 2 subwoofer outputs, if not, how will the 2nd sub get a signal - this is important to avoid overloading your receiver.

2. Crossover frequencies for both subs will play a part in the final experience/result you get

3. Power handling, if 1 sub is substantially more powerful than the other, you may not necessarily gain a huge increase in SPL

4. You could use 1 sub for mid-bass and the other for lower end, allowing more headroom for each sub, and the overall quality of your bass could improve.

That said, you won't know until you try it.

[elwaylite]

I went thru this recently, and after the research I decided to go with a second VTF15h.

After running Audyssey XT32 with dual sub eq, this thing sounds great. Id just get a second ULS-15.

[SteveO]

Originally Posted by elwaylite

I went thru this recently, and after the research I decided to go with a second VTF15h.

After running Audyssey XT32 with dual sub eq, this thing sounds great. Id just get a second ULS-15.

I am thinking about updating my receiver to one that has Audyssey XT32 with dual sub eq and the x4000 is at the top of my list and I see thats what you have.
Would you recomend this receiver? Now that I have dual VTF15h's I am wondering if this would be a noticble improvment over a 5 year old unit.

[suzook1]

I have an Onkyo 5010 so it should be able to handle the 2 subs. The second sub is merely a stop gap for a few months until I can get the wife to not notice and new sub coming through the door

[elwaylite]

If the 5010 has dual sub EQ, Id not worry about the X4000. XT32 and dual sub eq did a great job with dual VTF15's IMO.

[swiharta]

I have a VTF-2 mk4, bought for a small to medium sized room in my old house, and I now live in a loft with a much larger living room. The kitchen and foyer area are in a continuous space with the living room, aside from the kitchen's normal height (non-loft) ceiling.

I haven't experimented at all with moving the subwoofer around, but there is a real lack of upper bass presence. I can hear the deep lows well enough for my liking, but I want to crank it up to hear the upper bass more, but that just increases the super deep bass as well, and probably annoys neighbors.

Part of this could well be attributable to a gap in this range of sound reproducible by my system, which also consists of a GoldenEar SuperCinema Array soundbar and the SuperSat 3 surrounds. I believe they roll off above 100hz, but I was hoping the sub could take care of that, no problem.

So I'm thinking maybe all I need is a second subwoofer, and I was looking at the ULS-15, a mis-match, the topic of this thread.

Question is, I assume the VTF-2 will shift it's role into something more like a "mid-bass module" (MBM-12 on steroids) relative to the ULS-15.

So perhaps a very relevant question to this thread is, what are the best locations, generally or specifically if you like, referred to in Hsu's MBM-12 description: "The best location for mid bass punch is usually not the best location for deep bass."

[SME]

Originally Posted by suzook1

Hi all

I have a ULS-15 which I finally got set up... LOVE IT. MY plan is to add a second later on when I have funds.

The question is, for now can I mix subs or is it not recommended. I have another sub that still performs fairly well and was going to add it to the mix.

any comments?

Unless the subs are both the same model, mixing subs is generally not recommended. There are two problems you may encounter with different subs. First, when properly gain matched, one sub will likely be much so much louder than the other that the other doesn't contribute much. A potentially bigger problem is that the two subs may have different phase responses and may interfere with each other at some frequencies.

As others have suggested, your best option is to purchase another ULS-15.

[SME]

Originally Posted by SteveO

I am thinking about updating my receiver to one that has Audyssey XT32 with dual sub eq and the x4000 is at the top of my list and I see thats what you have.
Would you recomend this receiver? Now that I have dual VTF15h's I am wondering if this would be a noticble improvment over a 5 year old unit.

I have mixed feelings about the dual sub capability in Audyssey XT32. On the plus side, the auto-setup will time align the two subs for you. This is very helpful if the subs are at different distances from the main listening position. On the minus side, the auto-setup level-matches instead of gain-matches the two subs. Depending on your configuration, this can substantially limit your headroom.

Another more serious concern is that the auto-setup may sometimes get the distances wrong. I have witnessed this problem with Audyssey MultEQ XT when calibrating multiple subs on a single sub output, but I can work around it by measuring and changing the distance after the auto-setup. This works because the EQ correction is not sensitive to the detected distance for a single sub. With two subs, however, the EQ correction *is* sensitive to the relative distances detected because it corrects the time-aligned subs as one.

That said, I understand that MultEQ XT32 has much better filter resolution than MultEQ XT, so upgrading is probably still well worth it. But keep in mind that, depending on your setup, it may be better to gain match the subs and then run auto-setup with the subs hooked up to one sub-out via a Y-adapter rather than relying on the dual sub EQ.

[SME]

Originally Posted by swiharta

I have a VTF-2 mk4, bought for a small to medium sized room in my old house, and I now live in a loft with a much larger living room. The kitchen and foyer area are in a continuous space with the living room, aside from the kitchen's normal height (non-loft) ceiling.

I haven't experimented at all with moving the subwoofer around, but there is a real lack of upper bass presence. I can hear the deep lows well enough for my liking, but I want to crank it up to hear the upper bass more, but that just increases the super deep bass as well, and probably annoys neighbors.

Part of this could well be attributable to a gap in this range of sound reproducible by my system, which also consists of a GoldenEar SuperCinema Array soundbar and the SuperSat 3 surrounds. I believe they roll off above 100hz, but I was hoping the sub could take care of that, no problem.

So I'm thinking maybe all I need is a second subwoofer, and I was looking at the ULS-15, a mis-match, the topic of this thread.

Question is, I assume the VTF-2 will shift it's role into something more like a "mid-bass module" (MBM-12 on steroids) relative to the ULS-15.

So perhaps a very relevant question to this thread is, what are the best locations, generally or specifically if you like, referred to in Hsu's MBM-12 description: "The best location for mid bass punch is usually not the best location for deep bass."

For mid-bass quality and quantity, the MBM-12 will likely perform much better than your VTF-2. If you are satisfied with the deep bass, then I suggest you get an MBM to go with the VTF-2. Or if you want the ULS-15 that bad, buy a ULS-15 *and* an MBM and retire the VTF-2.

Good placement of the MBM is important for best results. I can't tell from your picture where your VTF-2 is currently located. You may run into some issues getting a smooth crossover between a true sub and MBM (around 50 Hz) if they are located at different distances from the listening area. A digital delay device can be used to time align them, but this requires a fair bit of effort (and ideally, a measurement system) to get right. That said, you can probably get decent results by trying out both phase switch settings on the true sub. In this case, it's usually best to set the sub distance in your AVR to the distance for the MBM.

[swiharta]

Originally Posted by SME

For mid-bass quality and quantity, the MBM-12 will likely perform much better than your VTF-2. If you are satisfied with the deep bass, then I suggest you get an MBM to go with the VTF-2. Or if you want the ULS-15 that bad, buy a ULS-15 *and* an MBM and retire the VTF-2.

Good placement of the MBM is important for best results. I can't tell from your picture where your VTF-2 is currently located. You may run into some issues getting a smooth crossover between a true sub and MBM (around 50 Hz) if they are located at different distances from the listening area. A digital delay device can be used to time align them, but this requires a fair bit of effort (and ideally, a measurement system) to get right. That said, you can probably get decent results by trying out both phase switch settings on the true sub. In this case, it's usually best to set the sub distance in your AVR to the distance for the MBM.

Thanks for the advice. It sounds like the MBM may be worth trying. Would it be simpler to get a second VTF-2? For the room size I feel that it could be limiting to continue throwing money at the VTF-2 line, although my primary interest is in music rather than movies and in improving my upper bass response more than deep visceral bass.

I'm also thinking about the setup difficulties you touched on. I don't know if my receiver (Marantz 6006) has the ability to do different low pass filters for the different subs or how I would go about tuning the system in general using an MBM. Maybe a job for a pro who knows what they are doing.

[swiharta]

Also, what about three VTF-2's? Poor use of money?

[SME]

Originally Posted by swiharta

Thanks for the advice. It sounds like the MBM may be worth trying. Would it be simpler to get a second VTF-2? For the room size I feel that it could be limiting to continue throwing money at the VTF-2 line, although my primary interest is in music rather than movies and in improving my upper bass response more than deep visceral bass.

I'm also thinking about the setup difficulties you touched on. I don't know if my receiver (Marantz 6006) has the ability to do different low pass filters for the different subs or how I would go about tuning the system in general using an MBM. Maybe a job for a pro who knows what they are doing.

Adding a VTF-2 may be simpler than adding an MBM, but it may not give you what you are after. You don't need to configure separate low pass filters on your receiver to use an MBM. The MBM has a built-in high pass filter at 50 Hz. Your VTF-2 has its own crossover setting that you can adjust to 50 Hz. Connect each to your receiver using a Y-adapter and then set the crossover on your receiver as you would with just the sub. Depending on how much the localization bothers you, you may want to increase the speaker crossovers quite a bit to let the MBM handle more upper bass. Even if the soundbar is rated to 100 Hz, it may not be able to play very loud or cleanly down there. A lot of drums punch at 100 Hz or above.

Don't bother with 3 VTF-2s. You could consider a second VTF-2 and an MBM, but I don't know why you would since you seem satisfied with the deep bass. Even if you are looking for more deep bass, you may want to consider one of the more capable subs instead.

[suzook1]

well I finally found a second ULS for $700 and bought it. Arrived Friday and I am pleased as punch that I have matching subs