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Discussion Starter #1 (Edited)
EDIT:

Things changed - I can't DIY with any level of difficulty so I am having ED help me and am selling my PB13 Ultra and building 2 18" woofer sonotubes because they will do all the woodwork and put in t-nuts for me.

I still need help with putting the subs in phase and possibly with setting a time delay for them. The EP2500 have none of these features nor does the reckhorn I planned on using.

Would an external delay box effectively act as a phase control if they are not co-located?

I ask because I want to add an HSU MBM-12 when the new model comes out at which time I woulc co-locate the sonos and could move the delay box to the MBM IF that option will work like I asked above.
 

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You can estimate the line of sight delay using the fact that sound travels at about 340 m/s. So 11 feet is about 10 milliseconds delay. The phase difference will change with frequency but the room has a large effect. In the ideal case (i.e. outdoors), the 10 milliseconds corresponds to 180 degrees out of phase (cancellation) at 50Hz.

Other may have experience about how the above situation might sound.
 

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Discussion Starter #4
You can estimate the line of sight delay using the fact that sound travels at about 340 m/s. So 11 feet is about 10 milliseconds delay. The phase difference will change with frequency but the room has a large effect. In the ideal case (i.e. outdoors), the 10 milliseconds corresponds to 180 degrees out of phase (cancellation) at 50Hz.

Other may have experience about how the above situation might sound.
Does Audyssey on a .1 setup account for phase on two subs?
 

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I am interested in this too. I had always thought it was a bad idea to integrate two different sized subs without crossing them over (one for midbass and one for low) but I have seen a few setups were people tried it and claimed great results. The only experience I have is when I tried 2 different subs in my car and it sounded awful.
 

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Discussion Starter #7
I want to run 2 ED's co-located as a single subwoofer AND put an MBM behind be BUT I want to let the ED's and the MBM both cover the mid bass.

I plan on Eq'ing the ED's with Audyssey but only hooking up the mbm after that and using a radio shack meter only that wat the mid bass will be a bit more pronounced to my liking.

I am just wondering if I need a delay of some kind.
 

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If I use the Maelstrom 12 feet away and the svs right behind the seating area at 1-2 feet away do I need to buy some kind of external subwoofer delay? My reliever has Audyssey MultiEq XT if that helps.
Should I just sell the SVS and get a maelstrom or will the SVS be ok with the maelstrom if I put it nearfield?
I asked because I wondered if the different distances factored in you questions.

My answer to that is 'forget about it'. (could depend on the x-over point of course, but for subs then I stand by it)

That may answer your nearfield problem.

I thought for quite a while that I could distinctly hear the 'different arrival times' when I was mucking about with distributed subs, two extra ones at varying distances from the mains.

I was assured by Earle Geddes that there was 'not much scientific data to back up my claim', but nonetheless I was certain.

Until one fateful night that is! I used extra long rca leads to enable me to sit the dcx in my lap at the listening position, and dialled in long distance delays into the unit, which you can bypass with a flick of the switch.

You could hear a discontinuity in the sound at the moment of switching, but after that you simply could not tell that the 'signal was delayed'.

I am talking tens and tens of metres here.

Dunno what it was I heard, or thought I heard, but 'different arrival times due to different distances' was NOT it.

Here are a few 'references' and threads to read. The discussion is based on the premise that using multiple distributed subs is an excellent way to get smooth even bass response in the room over a wide area.

Different subs with different capabilities do not seem an impediment to that goal, which could suit you to the ground given that you have different subs with different capabilities!

http://www.mehlau.net/audio/multisub_geddes/

http://www.diyaudio.com/forums/showthread.php?s=&threadid=134568

http://www.diyaudio.com/forums/showthread.php?s=&threadid=130494

You have the perfect tool in REW (with it's rta function) to be able to give this a go
 

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Discussion Starter #9
I have decided to sell the SVS to fund my sonos but the Question does not change because I am looking to build 2 ED sonos and may not co-locate.

I will review all the info you have there but the simple answer I got from an Audyssey thread I read was to get an external delay box and delay the closer sub by 1 millisecond or eat foot it is closer to you then let audyssey EQ them. It never mentioned phase cancellation though. i might just keep everything co-located till I have funds for SVS's new Audyssey box which seems to handle phase internally and EQ each sub independently for up to 2 subs.
 

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I will review all the info you have there but the simple answer I got from an Audyssey thread I read was to get an external delay box and delay the closer sub by 1 millisecond or eat foot it is closer to you then let audyssey EQ them.
it does make 'sense' to delay the subs to reach the LP at the same time.

I have found it to be of no consequence. No real explanation why. Current 'theory' goes something like..'at these frequencies in the room, it is all about pressurisation'. And even that could be completely wrong.

Don't worry about it, just get the Fr right.
 

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There is no way to predict - too many variables - you'll simply have to experiment. For me, it took a day of moving the subs and my seat and fiddling with the subwoofer distance setting and channel levels to dial everything in. Don't be quick to dive into EQ options, save those for the very end - play with placement and distance settings in your processor first.

As for the SVS PB13 Ultra and a Maelstrom 18 ported sonosub, based on Ilkka's measurements on the SVS, I would say it could intigrate quite well, as SVS can dig quite deep while maintaining a flat FR with the different tuning modes. However, you wouldn't want them to be playing at equal levels, as the SVS will give up sooner.

I would calibrate them so that combined, with both playing a test tone, you are achieving the proper calibrated level at your seat, but indidvidually, the SVS should be set about 6db lower in level than the Maelstrom. Also, meausre them independently with RoomEQ Wizard to see what tuning option on the SVS will most closely match the Maelstrom in room response. My guess would be the 15hz option.
 

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Discussion Starter #14
Sorry Steve.

Because I am DIY inept I decided to go with Dual ED drivers (19ov.2) in sonos and have to sell the PB13.

I will update the first post cause I still have the same issues with different subs
 
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