Dual Subwoofer placement Help

[ryanosaur]

A mini dsp 2x4 would be enough? Or would I need the HD one.

I don't use one currently and don't recall the differences.

I was quite excited to get a second sub and now I am just disappointed

My rec still stands... set them up on the front wall, left and right, and enjoy.
You can definitely try setting one up in back, but the shenanigans will only increase until you can manage two subs independently

Cheers guys. I wish you a good weekend

To you too!

 

[lovinthehd]

Thanks for the tips
Now that I know that my sub isn't *really* capable of dual subs I am probably giving up the idea of adding the other sub for now. I will definitely do some experimenting
Dumb of me that I didn't get the better AVR when I first got the system. The x2700h would support it I think so maybe in the future I will update it.

I am not sure if I am able to figure out the mini dsp with REW honestly, but worth a try.

Thanks again for the ideas

No, the dual sub feature of Audyssey is only incorporated in the X3xxx and above series. So generally the 3700 these days unless you can still find a 3600.

FWIW the minidsp HD is the most capable of the units (unbalanced, balanced and HD are the basic three models of the 2x4), particularly for delay management and also has up to a 2V output level if needed for the sub amp (the basic unbalanced model is limited to .9V).

 

[Tctfox]

T

I don't use one currently and don't recall the differences.

My rec still stands... set them up on the front wall, left and right, and enjoy.
You can definitely try setting one up in back, but the shenanigans will only increase until you can manage two subs independently

To you too!

Thanks The front setup is probably quite problematic as it wont solve my bass hole at all in the middle seat. Unless I move a lot back which would mess with my stereo triangle. But I will definitely try out symmetrical front and symmetrical (trying to have them as symmetrical to the listening position as possible ) front/back.

I saw this video series and especially this video.

I think I could definitely manage to do that. And the 300 Dollars for the mic and minidsp would be a better investment than a sub I only need one feature of it. I also checked the minidsp docs but they seem a bit more confusing

 

[ryanosaur]

mess with my stereo triangle

If you are putting your LP in a null because of an unwillingness to set up your room properly, just because you think you need to sit in an equilateral triangle with you mains, you are doing it wrong.
It is, however, your system... Please enjoy!

 

[Tctfox]

If you are putting your LP in a null because of an unwillingness to set up your room properly, just because you think you need to sit in an equilateral triangle with you mains, you are doing it wrong.
It is, however, your system... Please enjoy!

I get you. I will experiment a couple of things and then decide if the minidsp is worth it

Listening position and subwoofer placement mainly

cheers

 

[Tctfox]

I mean generally this hobby is really complicated, a lot of different opinions. But thats what I like about it. Thats why experimenting is cool and even better with gear like REW. My room just has limitations. I cant move my mains further into the room or closer together as it would cut the screen. For me its 50/50 for sound and video when watching movies. I can defenitely play with listening position and subwoofer placement. Thats the most reasonable thing to do in my situation. With REW I could find good sub/ listening Position and fine tune timings. So I guess for my room this will help a lot

So this was quite a long thought of mine. No one needs to respond to that

 

[ryanosaur]

No one needs to respond to that

But we will!

I agree, this can be complicated. It can also not be.
IMO, the biggest complication isn't the various aspects of physics we have to deal with (though that is complicated for any not well versed in electrical engineering and acoustics who decide to delve into that) rather the BS and dogma spouted by those who reek of old vinyl and rotting album covers telling us all the things we have to do to get into the club. I've never taken green sharpie to one of my CDs and I'm perfectly content with that!
Proper setup is extraordinarily important, much more so than some "sacred geometry" or cable witchery. Figuring out how to work within the limitations of our rooms is a challenge we all face. Adaptability and creative problem solving is our friend... well, that, and a penchant for sorting through all the BS to find some truth about what will make a real difference to our setup.

Cheers!

 

[Tctfox]

It's the level and distance for two subwoofers you'll have to do yourself.

Hei there again

So I decided to learn how to use REW and MiniDSP. I read tons of stuff today and watched tons of videos. I think I am mostly ready to go. There is one big question I just couldn't answer yet. So before I can start level matching and time aligning my 2 subs I´ve read on many places that I need to "match" the overall db level of the avr to match 75DB.
for example in this video at that timestamp ( I read that i need to do this at many places but didnt find an asnwer on how)

What I don't get what speaker should I use to do that? I cant control my fronts with the minidsp as I connect the subs to it. Should I just do it with one of the subs? But then again I do this when I level match them both right? Maybe I am just stupid and missing some utterly obvious fact but I just cant understand how to set the avr volume in the right way to not mess up further testing

I hope my question was understandable
My main language isn't English and its still quite hard to understand complex things like this for me

 

[ctsv510]

Audyssey will set the speaker volumes so nothing you need to do there. Gain match your subs to ensure they’re putting out the same level of SPL close to the driver, probably in the 85 dB range. If your subs are too loud when you run took correction, you can use the miniDSP to turn them down a few dBs. Most would raise that back up after Audyssey and it’s very convenient to just use the miniDSP gain control rather than play with two subs’ gain knobs that you already spent time gain matching.

 

[Tctfox]

Yeah I've read a lot more and I understand quite a lot more now about everything. I will do the Subwoofer tuning before Audyssey so I need to set a matching volume before too.

I only miss one detail now. What to set the distance for the subwoofers. I have one now and it already measured distances with Audyssey. I guess I will leave it that way as I aim for as symmetrically as possible anyway

 

[lovinthehd]

Yeah I've read a lot more and I understand quite a lot more now about everything. I will do the Subwoofer tuning before Audyssey so I need to set a matching volume before too.

I only miss one detail now. What to set the distance for the subwoofers. I have one now and it already measured distances with Audyssey. I guess I will leave it that way as I aim for as symmetrically as possible anyway

The distance (delay) setting for the sub set by Audyssey likely accounts for any inherent delay in the sub itself, and I'd probably just use it as set.

 

[ryanosaur]

The distance (delay) setting for the sub set by Audyssey likely accounts for any inherent delay in the sub itself, and I'd probably just use it as set.

This!

Any Sub Amp with DSP built into it will add delay to the signal chain. This is why you will often see Subwoofer Distances being set roughly twice the actual distance after room correction does its thing.

 

[Tctfox]

Perfect

My miniDSP will arrive next week or so. I will do multiple things with it


1) Find good placement of the subs by moving listening position and subwoofer position around and doing measurements (here I am not sure if I should do measurements always together or both single and together)
2) Level Match both Subs (before that I will find the right avr volume)
3) If a good place is found I can time allign them
4) Redoing audyssey

 

[ctsv510]

There is more than one way to do things, but I measure individual sub responses at each location possible, at every 90° orientation. Don’t be afraid to point a driver at a wall, you may be surprised at how good the response looks. And make sure you’re measuring with a timing reference.

Then pick I two of the best measurements in the Alignment Tool in REW to see their summed response and play with delaying one sub until you get the smoothest summed response.

I’ve done this multiple times for two subs and recently for three and it works quite well.

 

[Tctfox]

There is more than one way to do things, but I measure individual sub responses at each location possible, at every 90° orientation. Don’t be afraid to point a driver at a wall, you may be surprised at how good the response looks. And make sure you’re measuring with a timing reference.

Then pick I two of the best measurements in the Alignment Tool in REW to see their summed response and play with delaying one sub until you get the smoothest summed response.

I’ve done this multiple times for two subs and recently for three and it works quite well.

Thanks for this detailed response I appreciate it!

Could you elaborate on the timing? I wouldnt know where to do that and why to do it

 

[ctsv510]

Thanks for this detailed response I appreciate it!

Could you elaborate on the timing? I wouldnt know where to do that and why to do it

There isn’t much to it. In the preferences screen in REW (as well as the measurement screen) there is a “Timing Reference Output” selection box. You would just choose a speaker channel here (I use channel 5 for surround left speaker). This adds a quick chirp to the beginning of your sweep to set a timing reference point to all the measurements so REW can calculate timing/phase changes. Without it you wouldn’t be able to use the Alignment Tool.

Soundcard Preferences

 

[Tctfox]

So I did some testing today and so far it doesnt look that great. I got many dips even aftee trying various sitting/subwoofer positions. So I am double checking.

Can I use the LFE channel to do the tests, or do I have to use for example the right channel and unplug the speakers?
I did set cross over to the max and disabled audyssey.

 

[Tctfox]

Imgur.com/a/WVyKeNi
Best result so far
Front sub is a bit in front of the front right speaker but not much. This yielded best results so far. The other sub is in the rear at same distance from the side wall. I tried this and both in the front with several seating positions too.

 

[ctsv510]

So I did some testing today and so far it doesnt look that great. I got many dips even aftee trying various sitting/subwoofer positions. So I am double checking.

Can I use the LFE channel to do the tests, or do I have to use for example the right channel and unplug the speakers?
I did set cross over to the max and disabled audyssey.

Use LFE.

Imgur.com/a/WVyKeNi
Best result so far
Front sub is a bit in front of the front right speaker but not much. This yielded best results so far. The other sub is in the rear at same distance from the side wall. I tried this and both in the front with several seating positions too.

What is this showing? Can you share your mdat file with all the individual sub measurements you took?