SVS SB4000 or SB16 Ultra

[Richx200]

I have tried for months to get a decent curve with my two subs. No matter what I do REW, MSO, Room Correction, MiniDSP, and moving the subs around. I can't get rid of two nulls that bring my max gain down by 25-38db below 60hz. My last resort is to buy two additional subs. Since I have two SB4000s, I have a choice of two more SB4000s or SB 16 Ultras.

I need is a little help on which sub would be the better choice; room size and space isn't a problem, only the ******* nulls.

A pair of SB40000s would cost $3600.00 the SB 16 Ultras $3230.00 (Sale)

Cost isn't an issue, only a bonus if the 16s would better deal with the nulls.

Thank you for your time.

 

[staticV3]

Have you tried using REW's Room sim for finding optimal subwoofer positions?

 

[MarkS]

More subs are unlikely to help. Have you tried moving the listening position, including making it not equidistant from any two walls?

 

[Old_School_Brad]

More subs are unlikely to help. Have you tried moving the listening position, including making it not equidistant from any two walls?

More subs are actually likely to help as they can be distributed so that the nulls in the room are remedied.

@Richx200
I'd get two more SB4000.
With four powerful subs you won't be driving them very hard so it'll not make sense to get the SB16 Ultras.
Also; get into REW and investigate its room simulator.

 

[MarkS]

More subs are actually likely to help as they can be distributed so that the nulls in the room are remedied.

This is true only if you can at least somewhat alleviate the nulls with two subs, which the OP says he has not been able to do. If the null is not getting filled no matter where the sub is, then the null is not getting filled no matter where the sub is, so more won't help. Moving the listening position is the remedy.

 

[Old_School_Brad]

This is true only if you can at least somewhat alleviate the nulls with two subs, which the OP says he has not been able to do. If the null is not getting filled no matter where the sub is, then the null is not getting filled no matter where the sub is, so more won't help. Moving the listening position is the remedy.

If the null disappears when you change the listening position, you can most likely achieve a similar effect by repositioning the subwoofer(s).

 

[Mort]

To answer your question, more subwoofer driver surface area will not help. Raw output is not your issue.

The 16s are a good deal if you need them or want them but they won't help over the sb4000 if the solution is more subs. (It might not be.)

 

[Ellebob]

Nulls happen at certain locations in the room. In the theoretically perfect sealed rectangular room this will be at the half and quarter points of each dimension but these locations can be in different locations in real rooms. The biggest fix for these IF POSSIBLE is to move the seating. It is very difficult to fix a null with limited placement flexibility.

Knowing if it is a length, width or height mode can help with figuring out good placements of seating and subs. For instance (and I have no idea what you have tried so far) you can not mitigate a room mode in length dimension it two subs stay in the front of the room. One sub needs to be in the back of the room and one in the front of the room to fix a length mode problem. Besides placement then you can adjust the timing (phase) between the subs to get a better response. You shouldn't look for a flat response you should look for a response that can be EQ'd meaning no major or uncorrectable dips.

 

[Richx200]

Have you tried using REW's Room sim for finding optimal subwoofer positions?

Yes, and the only place the nulls don't appear is in the center, windows and one door.

 

[Richx200]

Have you tried using REW's Room sim for finding optimal subwoofer positions?

Yes, and the only place the nulls don't appear is in the center, windows and one door.

 

[Richx200]

If the null disappears when you change the listening position, you can most likely achieve a similar effect by repositioning the subwoofer(s).

This is true only if you can at least somewhat alleviate the nulls with two subs, which the OP says he has not been able to do. If the null is not getting filled no matter where the sub is, then the null is not getting filled no matter where the sub is, so more won't help. Moving the listening position is the remedy.

Yes, and the only place the nulls don't appear is in the center, windows and one door.

 

[Richx200]

I tried REW, MSO, ARC Room Correction, MiniDSP, and moving the subs around as per Sim room and all I got was no nulls at the center, windows and one door. The room is decoupled and sealed 20' x 13' x 8' one would think that the dimensions look good but, NO. I tried to aline the sub with REW and the best I could get see attached, timing, phase and EQ does nothing. The nulls just eat up all the gain. To get any bass at all, I have to max out the AVR and the subs gain. EQ. has no effect on the nulls. Thought I would try the additional subs

 

[Oddball]

This is a difficult issue as you might have gathered from the wide variety of responses. In some instances and rooms, your MLP might be the reason why you can’t really correct your bass response. This can be explored in simulation programs so you better understand if additional subs could help. Provided that room is regularly shaped.

You noted that you already tried repositioning your 2 subs and that did not seem to help. That is bad news but would be helpful if you shared the room floor plan and what you have tires in terms of positioning.

In some very difficult rooms, having double bass array will help (2 front subs and 2 back subs with distances between subs to be explored/confirmed), but if your MLP is in a position that creates nulls from all sides this is not going to help.

 

[ivanj]

Yes, and the only place the nulls don't appear is in the center, windows and one door.

Have you tried the subwoofer(s) in these positions?

 

[Richx200]

Have you tried the subwoofer(s) in these positions?

Yes, and they cure the nulls, but I cannot position the sub there.

 

[scotchrocks]

So, if you're already using MSO, I'd recommend testing things out as if you have your new subs already.

Basically:

1. Take your REW measurements for your existing sub positions (2 existing sub positions x N listening positions).
2. Move your sub to 2 new locations where you plan to put your new subs and take REW measurements again (2 new sub positions x N listening positions).
3. Load all the sub measurements into MSO and run the optimization (4 sub positions x N listening positions).

This will allow you to simulate what improvements you might expect without having to even buy the subs yet. I would recommend repeating step 2 with various positions, and you can mix and match them in MSO under different configurations and see what combination of positions works best. Personally, I had a significant improvement in nulls with MSO when I added a third sub behind the listening position for my room. I think there's a very good chance for significant improvements by adding a 3rd and 4th sub in your case.

 

[Oddball]

I have not used the simulator as did not have a room where it would work but as noted above, placing you additional subs in the back, and generally, out of phase with your front subs might bring some improvement.

What exactly needs to be adjusted on phase is to bee seen and heard in your room though. If your MLP is not in the middle of the room, this should help, at least a bit.

 

[Richx200]

Thank you for all your time, thoughtful comments and suggestions. I do realize that knowing if the additional subs would cure the nulls is a roll of the dice. But since I've tried everything from Toole to web forums, additional subs seem to be my last shot. SVS does have a 45-day return policy, so if they don't work, I'll send them back.

I was hoping I would get some information on which subs would be the better choice, like if there would be any issues mixing the two sizes or if the four subs would sound better being the same or mixed, maybe I should get two PB4000s, would sealed and ported subs work?

However, again thank you all for your time

 

[scotchrocks]

If you use something like MSO or Dirac Live Bass Control, it should be able to blend and time-align the subs regardless of ported or not, but you might get cleaner results if everything is sealed. You could also plug the ports if you want to run the ported SVS subs in sealed mode, but you lose the ported SPL benefits.

Again, if you're comfortable with using MSO, I would definitely recommend moving an existing sub around, getting listening position measurements, and running MSO to simulate what the new subs could do for your nulls and room response. This should give you a good idea of what kind of improvements you can expect if you were to buy the additional subs. MSO has a lot of tools at its disposal beyond the subwoofer positioning (shared/independent PEQs, delays, etc.) to optimize response across multiple listening positions while maximizing SPL, so maybe it can address those nulls like it did for me.

 

[Golfx]

Thank you for all your time, thoughtful comments and suggestions. I do realize that knowing if the additional subs would cure the nulls is a roll of the dice. But since I've tried everything from Toole to web forums, additional subs seem to be my last shot. SVS does have a 45-day return policy, so if they don't work, I'll send them back.

I was hoping I would get some information on which subs would be the better choice, like if there would be any issues mixing the two sizes or if the four subs would sound better being the same or mixed, maybe I should get two PB4000s, would sealed and ported subs work?

However, again thank you all for your time

Hi I would also hire a remote calibrator to give you advice. Jeff Mery does multiple sub calibrations (Bison HTA) has user name @fattire over on AVS. He was able to dial into my laptop and be of great assistance. He has also putout some instruction Youtube videos. It helps just to have someone so experienced it can save you time and money.