Dual Subs & Soundstage

[walter duque]

It's really just a stab in the dark at what the problem(s) might be. You now have a pair of top notch subs with a good set of speakers... I suggest you now make a relatively small investment in room measurement and analysis gear. This will pinpoint any problems quickly and allow you to optimise what you have for your room. These are both excellent options with abundant on online support:

• Dayton Audio OmniMic V2 Precision Measurement System ($298 shipped)
• miniDSP UMIK-1 ($75 ex. shipping) plus REW (Free!)

What makes you state that he has top notch subs and good speakers??

 

[ImcLoud]

walter---- post #5

 

[walter duque]

walter---- post #5

SVS great subs. Def Techs I had over 20 years ago, to me not even in the same league as SVS. You got high end subs and low end speakers. Def Tech, nice piano black, plastic top caps and cheap drivers. Subs are great though. That's just how I see it. To each is own.

 

[jinjuku]

It could be phase, it could be placement that is causing a null cancellation above the fundamental (My bet). Run the room correction.

It could be having both running is creating a reinforced standing wave that it doing something with energy suck out at a harmonic and killing the imaging. That would also track with having either one unplugged and it going away.

Stack your additional sub in the location with the original and set the phase to the same.

Then REVERSE the phase on ONE of them and repeat some familiar content.

Would really like to hear what happens. I am going to say either way your soundstage is unaffected.

 

[walter duque]

It could be phase, it could be placement that is causing a null cancellation above the fundamental (My bet).

Could be the processor. Subs are great, speakers are good.

 

[jinjuku]

Could be and he certainly needs to run it's correction routine.

 

[walter duque]

Could be and he certainly needs to run it's correction routine.

I used $100.00 Jensen speakers and 10K subs with my Perreaux amps and it sounded pretty good. It's not the speakers or the subs. Do you have 2 sub outs?? Or are you splitting one signal??

 

[jinjuku]

Walter I agree he needs to run the room correction. It's just food for thought if the correction doesn't, well, correct.

 

[GIEGAR]

What makes you state that he has top notch subs and good speakers??

SVS great subs. Def Techs I had over 20 years ago, to me not even in the same league as SVS. You got high end subs and low end speakers. Def Tech, nice piano black, plastic top caps and cheap drivers. Subs are great though. That's just how I see it. To each is own.

You've completely missed the point Walter. My comment was not about a critique of the OP's subs/speakers. Rather it was a friendly preface/aside in the hope that he would be reassured that his gear is fine and therefore be more receptive to the recommendation to invest in measurement gear to optimise it's performance.

What useful purpose does critising the OP's speakers serve?

Could be the processor. Subs are great, speakers are good.

Isn't that what I said in the first place?

 

[walter duque]

[

QUOTE=GIEGAR;1044683]You've completely missed the point Walter. My comment was not about a critique of the OP's subs/speakers. Rather it was a friendly preface/aside in the hope that he would be reassured that his gear is fine and therefore be more receptive to the recommendation to invest in measurement gear to optimise it's performance

.


Got a little off track last night (sometimes the Guinness starts talking a little more than me). Now back to the OP's problem. I can't tell if that pre amp has 2 sub outs. If he is using a splitter or not if there is only one sub out. My next move would be daisy chaining the subs and see what's happening.

 

[Muzykant]

Once again, thank you all for your help. UMC-200 has one balanced and one unbalanced subwoofer output. I am not sure both can be used simultaneously, so I am using unbalanced with a splitter.

I am not sure how to connect the sub bypassing the crossover. When the sub is connected to the sub output, the choice is 40-250 Hz crossover with 12/24 db slopes. I suppose, I can connect the 2 subs full range through the unused surround back outputs while retaining the easy plus/minus 10 db remote level adjustment. Never mind! However, I will still need the subwoofer output selected to "on" because there is no option of running the fronts crossed over without using the sub. What will trying SVS crossover give me?

I am still searching for the microphone my UMC-200 included, but have a feeling I (or my family) threw it away with the box. Never expected to use it. I do have another UMC-200 at my other place, so I can look there.

As for my speakers... I started building my system with a pair of SM-65s, partly because I was not planning on buying a subwoofer at a time and needed extended bass in a small package, and partly because of rave reviews these got (even here at Audioholics). At a time I was not aware of some of the audiophile brands that I learned about later. Perhaps I could have made a wiser purchase decision. But I really like these speakers' sound definition and soundstage. All my musician friends who heard the system always comment on the clarity these provide.

 

[ImcLoud]

here is what I use as a balance splitter https://emotiva.com/products/accessories/xbal-1x2


Are you using a splitter at your subs? I would come out of the umc 200 with a single rca cable and go to a splitter I would run that splitter to both inputs on sub #1, then run the rca outputs from sub #1 to rca inputs of sub #2 with a double rca cable... I would put the subs internal cross over either off or all the way up.. I would set the mains to cross at 80 and set the subs for the same thing.
How are you balancing the system? with an spl meter?

 

[walter duque]

Did you try daisy chaining the 2 subs?

 

[Muzykant]

Great! I can purchase that balanced splitter and use two XLR cords which I have. Would that be better than using the unbalanced? Also, what is the reason for splitting the signal to connect the first sub with two cables rather than one?

I have not balanced my system. I assure you, there is a reason I am posting in this section of the forum.

 

[Muzykant]

Did you try daisy chaining the 2 subs?

Not yet. I will try to get to it today.

 

[ImcLoud]

Great! I can purchase that balanced splitter and use two XLR cords which I have. Would that be better than using the unbalanced? Also, what is the reason for splitting the signal to connect the first sub with two cables rather than one?

I have not balanced my system. I assure you, there is a reason I am posting in this section of the forum.

In my experience connecting to both of the inputs is better than just one. I would try it the way I listed above, with the rca cables and splitters.. I would also invest in an spl meter... you can get them from $9-$100 Mini Digital Sound Level Meter - Decibel Meter - Amazon.com

First the subs must be in phase and leveled, using test tones and spl meter, plug them in how I listed above and try each phase, pick the one which is loudest for each sub.... Then set each subs level, turn sub 1 on and 2 off, set level on sub to 50% and on umc to 0, check the level with the test tone and meter, say its 90db, then shut that sub off and set the second sub to match it at 90db using that subs volume control , not the umc's leveler... Now they will be in phase and balanced

How I set my umc200 is measure all the distances from the speaker baffle to the center listeners position and set all the levels to the same db with the spl meter and test tones... So say you start the test tones and the first speaker is 90.2db set them all to the same thing, then set the sub...

I think your subs are crossed wrong, out of phase, wired wrong,and out of balance, lol making everything crazy when they are both on fighting each other and your mains... I spend a lot of time setting up dual subs, balance is important, you would think the volume setting for each should be in the same spot, but it is never the case, they are always different...

 

[Muzykant]

I would need only 1 splitter to be used on UMC-200, as I have 2 rca outputs on each sub, correct?

 

[ImcLoud]

yes, come out of your umc with a splitter, run that to sub 1 {both inputs} then run a double set of rcas from sub 1 outputs to sub 2 inputs...

 

[Muzykant]

Quick question... Do the outputs in the subwoofer's amp bypass its volume setting?

 

[ImcLoud]

I believe so..