Replacing my 2 sealed 18s with 4 X dual 12s??

[weltersys]

However I did do my research on the BMS when I decided to get it.
Has the sensitivity and xmax to be able to EQ to desired taste or whatever without too much worry.
Might as well stick. Thanks for all the input.
Now just a 4 channel amp to run them. Bearing in mind I have an AVP with Dirac.
But a bit of pre EQ would be desirable to shape the response before Dirac gets it's Mits on it

With about 20-30dB of EQ range, (+/-15dB) you could flatten the response down to 10Hz.
PEQ can be configured to to run “before” Dirac in the Monoprice HTP-1 AVP you mentioned getting.
What is the frequency and boost /cut range of the PEQ in your AVP?

 

[weltersys]

Which impedance have your chassis?

That's a good question- the BMS 18N862 is available in both 8 and 4 ohm versions.
All my simulations were based on the 4 ohm (RE 2.7 ohm) version, though the OP never stated which.
If they are the 8 ohm (RE 5.56) all the voltage/power estimates I made are off by 3dB.

Also just noticed the NX-6000D also changed the indicator LED light values from the NU-6000D, even though the maximum power is the same 🙄.
The NX-6000D LEDs are -40, -6dB, -3dB and 0dB/limit.
With an 8 ohm load, -6dB would be about 400 watts/56volts, 4 ohm would be 750 watts/55volts.

 

[trojantrow]

Sorry I should have clarified. They are 8ohm versions.

And I currently have an XMC1 emotiva processor.

The issue with the emotiva is that you cannot run PEQ before Dirac. It's one or the other.

So at.tjr moment I need to run PEQ on the NX6000D before Dirac or Dirac thinks that the subs need a stupid amount of boost sub 30hz because they have so much sensitivity high up.

What I do is use the NX to set the levels and gains and also delays, flatten the peaks out of each woofer and try and get them the same as each other response wise. Then run Dirac

If I had a HTP1 I believe I wouldn't need DSP as I have the PEQ before Dirac built. In

 

[trojantrow]

With about 20-30dB of EQ range, (+/-15dB) you could flatten the response down to 10Hz.
PEQ can be configured to to run “before” Dirac in the Monoprice HTP-1 AVP you mentioned getting.
What is the frequency and boost /cut range of the PEQ in your AVP?

Dirac cuts as much as needed and boosts a maximum of 10db.

Without Dirac. The PEQ can boost or cut 12db.

To be honest. In room I can flatten the response all I want with the range I have in the NX6000d all the way to 20hz and then let dirac in the AVP do the rest and set a house curve.

Although I have a hard time getting my head around where the best place to apply EQ is? In the NX or the AVP.

Something about the pre out of the AVP works in a certain voltage range so EQing in the AVP reduces head room or something. I,m probably wrong. Something about clipping the outputs of the AVP or the input of the NX?

 

[trojantrow]

I don't want to turn this thread in to something it's not but I'm running another set set up today and going to take some measurements of what I have now. Without Eq at opposite corners of the room.

From there will be able to get better context if how they work in my room.

Just doing this for interest purposes if anyone cares.

But I thank you all for the feedback I've gotten so far

 

[IamJF]

I would suggest to make the woofers linear with Amp DSP (nearfiel measurement) and let the room correction do from the AV preamp. Check the woofer also at listening position - it makes no sense to linearize to 20Hz when you have a huge resonance at 25Hz for e.g.

Btw - with 2 subs the best location should be at the middle of the front and rear wall (or side walls). Did you test that?

 

[Cableaddict]

Looks like the BMS 12 inch has less than half the xmax of 18. Which is what's causing this issue.

Obviously I've got another 2 corners filled so room response and more room gain etc could balance it out. It's not like I've ever really pushed the 18s to their limit either.

But finding a more all-round woofer which extends lower with a bit more xmax and is still good for music would be ideal.

I like the sensitivity of the pro drivers too. Not too much power required

I can tell you from personal experience that a well-designed (reasonably large) dual 12" BR sub will be noticeably louder than a sealed 18". Not a huge difference, but definitely not LESS overall perceived volume over their full frequency range.. However, it's very unlikley that it will sound as good. They also will NEVER reproduce the ultra-lows that HT folks tend to enjoy. (below 39 Hz or so.)

You might compensate for that with some Aura shakers or the like, mounted to you chairs & couch, but it's not quite the same thing. Of course, if your walls aren't very rigid, going with the 12's and shakers will lower LF transmission into the rest of the house, so that might be a consideration.

For HT, you might consider building custom cabinets for those same 18" drivers. The cabinet shape can be almost anything, as long as the internal volume stays the same and the sides are rigid.