# Dual subs



## asere (Dec 7, 2011)

I have two subs the DXD 12012 and VTF3 MK4. 

Since the 12012 is sealed and the VTF can be ported Dr Hsu recommended that I consider setting the crossover on the VTF to IN and crossover to 50 Hz or so so it's capacity is more reserved for lower bass because the DXD 12012 has plenty of output for the mid to upper bass.
He recommended this because I mentioned that the Hsu quieter in certain areas of the room. Would this suggestion be correct?


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## 8086 (Aug 4, 2009)

> Would this suggestion be correct?


Your hypothesis sounds good. 

What harm can you do by using the scientific method to discover the truth on your own? You can do no harm here, so give it a shot and let us know the results.


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## asere (Dec 7, 2011)

8086 said:


> Your hypothesis sounds good.
> 
> What harm can you do by using the scientific method to discover the truth on your own? You can do no harm here, so give it a shot and let us know the results.


I tried it and lost db at MLP. It's not bad just not as loud. Higher output does not mean louder right? Does it mean it takes longer to run out of steam? Also how will I know if the Hsu is taking charge of the low output?


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## asere (Dec 7, 2011)

Dropping the Hsu to IN and 50hz it's like now having a second sub.


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## B- one (Jan 13, 2013)

Wish I had your dual sub problems to deal with.


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## asere (Dec 7, 2011)

B- one said:


> Wish I had your dual sub problems to deal with.


I'm not complaining it's just want to make sure I don't damage the hsu with the mid and upper bass while using the kreisel that is more powerful in that region. I could sell the hsu and just keep the other one but they both sound good together. I'm just trying to make sure no damage occurs.


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## hjones4841 (Jan 21, 2009)

Dr. Hsu likes using one sub for the lowest LFE and another set just a bit higher. That is why Hsu sells these:

http://www.hsuresearch.com/products/mbm-12mk2.html

But, always let your ears be the guide. You can always run the Hsu's level up a bit. You should hear audible "distress" from either sub if you begin reaching their output limits (distortion, cones bottoming out, etc.)


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## asere (Dec 7, 2011)

hjones4841 said:


> Dr. Hsu likes using one sub for the lowest LFE and another set just a bit higher. That is why Hsu sells these:
> 
> http://www.hsuresearch.com/products/mbm-12mk2.html
> 
> But, always let your ears be the guide. You can always run the Hsu's level up a bit. You should hear audible "distress" from either sub if you begin reaching their output limits (distortion, cones bottoming out, etc.)


Thanks for the link. The subs do sound nice together for mid and upper bass it's just that the hsu is a little quieter then the kk but blend in well. Like you said I will continue to listen and use both for mid and upper bass or use the hsu for just the lower bass.


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## asere (Dec 7, 2011)

Can someone tell me in numbers what is the range for low,mid, and upper bass? Learning here! Thanks


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## tonyvdb (Sep 5, 2007)

There is nothing written in stone but generally subsonic frequencies (what you feel not hear) is anything below 20Hz. From 20Hz to around 80Hz would be mid bass and 80 up to around 140Hz would be upper.


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## asere (Dec 7, 2011)

tonyvdb said:


> There is nothing written in stone but generally subsonic frequencies (what you feel not hear) is anything below 20Hz. From 20Hz to around 80Hz would be mid bass and 80 up to around 140Hz would be upper.


Hsu said to set it to 50 and IN one one sub just to get the lower bass but should it be set lower then 50 for that?


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## tonyvdb (Sep 5, 2007)

Thtat really going to be a trial and error thing, Your room response is going to play into this so I dont think anyone can answer that. Your going to have to see what works best.


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## asere (Dec 7, 2011)

tonyvdb said:


> Thtat really going to be a trial and error thing, Your room response is going to play into this so I dont think anyone can answer that. Your going to have to see what works best.


I think I'll do 30 so it will kick in only with lows.


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## hyghwayman (Jan 15, 2008)

I'm very interested in hearing / seeing what you think of the 30Hz setting. Also are you using your avr's crossover and if so where are you setting the crossover?


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## asere (Dec 7, 2011)

hyghwayman said:


> I'm very interested in hearing / seeing what you think of the 30Hz setting. Also are you using your avr's crossover and if so where are you setting the crossover?


Yes I will let you know. I am using the avr's crossover for the speakers crossed at 80hz with the sub set to OUT and the other sub at 30hz set to IN.

Can anyone tell me how I can measure where each sub bottoms out using an spl meter for an idea? 
I would disconnect the speakers from the avr to test only the subs individually but at what volume level do I leave the master volume on and do I use the test cd to get the master volume where it should be?
Also what Hz do I use?


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## asere (Dec 7, 2011)

Is a Radio Shack spl meter good enough to manually calibrate speakers/sub or is there a much better meter out there? I want to for once try the spl without Audyssey and see what I think.


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## recruit (May 9, 2009)

asere said:


> Is a Radio Shack spl meter good enough to manually calibrate speakers/sub or is there a much better meter out there? I want to for once try the spl without Audyssey and see what I think.


The SPL meter is one of the most common ways of calibrating your system so that all speakers and sub read the relevant 75db all round, saying that some people including myself like to run there subs slightly hot ie 78db or there abouts


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