dual subs noob question

[Foxrox]

I just got my second sub. Never had two subs before so I'm learning...

AVR is Denon X4300H. Subs are PSA 15V.

I didn't have time to go through audyssey right away, so I just set the second sub exactly the same as the first (all settings, distance, trim, etc.), put it symmetrically across the room, switched my Denon to two subs, and turned it on.

Imagine my dismay when it seemed quieter than one sub... I was thinking I had a major acoustic/placement issue. It's still possible I do have an issue, but placement options are limited. I'll play around as much as I can at a later date.

So a little later, still no audyssey run, I play around with it a bit. I try switching back and forth between one sub and two in the Denon speaker setup. I do the same test with one sub physically switched off. I started to notice some things...

It seems to me that the Denon automatically cuts output to each sub when two subs are selected, like it's trying to match the output of one sub, even though all the settings are identical for both subs. Is this the case?

As an example, I was playing a 35Hz test tone, switching back and forth from one sub to two, with the volume turned up a bit. The SPL was pretty close with one sub or two (no I don't have a meter), but it seemed to be really pushing the one sub, while with both playing it was much "easier" for the subs to achieve the same SPL. I think my initial perception that it was quieter may have been because of this. Someone please tell me this is working correctly.

 

[lovinthehd]

Since you haven't rerun Audyssey (and am assuming you've not reset your avr to factory spec), hard to know. One of the advantages of your avr is that it can handle two subs in terms of level/delay. How did you place the subs?

 

[Foxrox]

The room is almost rectangular but a couple feet wider on the back half and attached to one small hallway at a back corner. Roughly 15.5 ft wide by 30 ft long. HT is at the narrow end. MLP is centered with viewing distance of about 10 ft. The distance to my center is only 7.8 ft. The subs are 3-4 feet from the end wall and right next to side walls, placed symmetrical to the MLP. There is a full width built-in entertainment center. That’s why they are away from the end wall. Center-side-wall placement is not an option either as the back 2/3 of the room is used for something else. Hope all that makes sense. I might do a sketch to get advice if necessary, but as noted, I’ll probably play around with placement in the future. Not much time right now.

I just want to know if the AVR automatically reduces output to each sub when two subs are connected instead of one, with all else being equal... or if I’m crazy.

 

[lovinthehd]

I'd have to experiment, never tried what you did. I think if I wanted I could actually do the dual sub setup with SubEQ in my 4520 and not do the rest of the Audyssey run, but I've not tried that. Why not now that you did what you did, try resetting the avr and then setup manually (and you could copy level/delay settings for speakers)....and then a new Audyssey run. See if you have a preference for any particular setup....

ps Not sure what would change when you add the second sub, would think despite any level/delay differences the same filters would have been applied, which may or may not be beneficial. Rather than ears, use measurement gear otherwise....

 

[Foxrox]

Well I think I figured this out and feel a bit stupid now... when I was switching between one sub and two with “the same settings” it wasn’t the same settings at all. The Denon was kicking on and off the Audyssey settings at the same time, namely Dynamic EQ. On with one sub. Off with two. So it’s no wonder I was hearing the difference.

I’ve now run Audyssey with both subs and getting outstanding results. Much more head room than before.

 

[fuzz092888]

Well I think I figured this out and feel a bit stupid now... when I was switching between one sub and two with “the same settings” it wasn’t the same settings at all. The Denon was kicking on and off the Audyssey settings at the same time, namely Dynamic EQ. On with one sub. Off with two. So it’s no wonder I was hearing the difference.

I’ve now run Audyssey with both subs and getting outstanding results. Much more head room than before.

Dynamic EQ no bueno.

 

[lovinthehd]

Dynamic EQ no bueno.

Some like it. ADTG ?

 

[Foxrox]

I prefer it. Probably because I’m a bass head. Audyssey set my subs to -8.5 and -9.5. I turned them both up by 4 dB. And I run them at +7 in the sub level setting. And I run Dynamic EQ.

 

[lovinthehd]

I prefer it. Probably because I’m a bass head. Audyssey set my subs to -8.5 and -9.5. I turned them both up by 4 dB. And I run them at +7 in the sub level setting. And I run Dynamic EQ.

So you raise them to -4.5 and -5.5 and then go where to then change to +7 friom there?

 

[fuzz092888]

Well that’s excessive lol

 

[Foxrox]

In the audio settings there is a “Subwoofer Level Adjust” setting. I turn the subs up and down there more often than going into the individual speaker trim settings. It’s quicker and no scrolling through the test tones to get there.

 

[lovinthehd]

In the audio settings there is a “Subwoofer Level Adjust” setting. I turn the subs up and down there more often than going into the individual speaker trim settings. It’s quicker and no scrolling through the test tones to get there.

Kinda what I thought you meant. That's a lot of boost (roughly 16dB).

 

[Foxrox]

I’m a sucker for bass. Probably comes from having a ported 10 in the cab of my s10 pickup back in high school.