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My room is changing so I've not dialed it in yet. I believe the least amout of gain from the AVR is the goal but from there I'm not entirely certain. A lot of factors (AVR out, MiniDSP gain, Cleanbox gain, Amplifier attenuator).

Yes, a ground wire from the Crown to the Denon. Mine was the same.
 

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Not at the moment. All I did was loosen a case screw off the back of each and run speaker wire between the two. Nothing special.
 

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Discussion Starter #2,565
25Hz if possible or 31Hz if people would prefer and music centric tiny dev.

Dude, you are awesome. I just love the look of the devs
67% of 45Hz is 30ish Hertz, that would probably be as low as of should go. The thing about Devastators, it's going to be 36" to 40"s tall more than likely. Just really narrow...
 

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I'd think that the BAMF would be one killer musical Dev.
 

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67% of 45Hz is 30ish Hertz, that would probably be as low as of should go. The thing about Devastators, it's going to be 36" to 40"s tall more than likely. Just really narrow...

It is impractical and silly and overly complicated for the output. The thought of it makes me giggle, but please don't waste your time. I guess if anyone is in need of an impossibly narrow and absurdly tall sub it could be a thing.

Thanks for killing it in this thread.

I've had a devestatingly good time.
 

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Discussion Starter #2,568
Right now effort has been focused on getting around the weakest part of the designs, a slot port with a 90 degree bend. Not good for noise, not good for compression. Great for: simple assembly, cost and form flexibility. We will see if I can come up with something workable.
 

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Right now effort has been focused on getting around the weakest part of the designs, a slot port with a 90 degree bend. Not good for noise, not good for compression. Great for: simple assembly, cost and form flexibility. We will see if I can come up with something workable.
Would you consider the down firing designs to be an improvement in the state of the art? Obviously they trade off floor space unless you stack multiple. Do they avoid the 90 degree bend you are referring to?
 

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Discussion Starter #2,570
Would you consider the down firing designs to be an improvement in the state of the art? Obviously they trade off floor space unless you stack multiple. Do they avoid the 90 degree bend you are referring to?
The lack of a 90 degree bend in the slot port is an advantage. Moving into a more ideal solution, 8 diameter smooth pipe with large flares. Velocity handling before compression and noise is much higher than a slot vent, even with no bend. Passive radiators would be the next solution, but that gets expensive. After that we start to get into things that are pushing Hornresp's ability to accurately simulate. Using quarter wave pipes for the low frequency resonator vs Helmholtz resonator (BR)for LF. The problem with the QWP is the 3rd order resonance of the pipe. 20Hz tuning results in nasty cancellation around 60Hz. Tuning the HF QWP at the same frequency of the LF QWP null creates weirdness in the model. However, it could potentially get the usable bandwidth out past 80Hz, vs 50Hz since the massive null is no longer present in the SPL graph. There are many question marks surrounding that though. Form factor flexibility is close to zero, good news is it can be taller.
 

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The lack of a 90 degree bend in the slot port is an advantage. Moving into a more ideal solution, 8 diameter smooth pipe with large flares. Velocity handling before compression and noise is much higher than a slot vent, even with no bend. Passive radiators would be the next solution, but that gets expensive. After that we start to get into things that are pushing Hornresp's ability to accurately simulate. Using quarter wave pipes for the low frequency resonator vs Helmholtz resonator (BR)for LF. The problem with the QWP is the 3rd order resonance of the pipe. 20Hz tuning results in nasty cancellation around 60Hz. Tuning the HF QWP at the same frequency of the LF QWP null creates weirdness in the model. However, it could potentially get the usable bandwidth out past 80Hz, vs 50Hz since the massive null is no longer present in the SPL graph. There are many question marks surrounding that though. Form factor flexibility is close to zero, good news is it can be taller.
Oh so its the bend in the port, not the bottom of the quarter wave that is impacting performance.

Would the QW benefit from a different design or is "big box" good for it?
 

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Discussion Starter #2,572
Oh so its the bend in the port, not the bottom of the quarter wave that is impacting performance.

Would the QW benefit from a different design or is "big box" good for it?
The vents suffer the most due to the volume of air sitting inside the port and also the lower resonate point of the BR system. Both push higher velocity. The QW bend can be an issue for things like an Alpha going full war mode. Most of the shorter QWs have a higher resonant frequency and end up being EQd down so that usually does not become an issue. The HF QW usually has less velocity to begin with, since there is not a large air mass, just the volume of the air in the tube, which also helps to keep velocity down. The stepped fronts lower velocity at the mouth, due to a much larger cross sectional area.
 

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Questions

Devastators set up in minidsp
12db @20hz .7q

So I started clean everything off in the devastators and 4 micro Marty's

Now with the devastators leaving the 12db out
I have lost about 20db,

Avr set to 0
Crown dci 2 1250 at max.
No clean box at this time. Cables are on there way.

I guess my question
How do do room correction in minidsp with dev set up with gain in the output.

The devastators are not even close to micro output.

Do I need the clean box for this
Or put the 12db gain back in and fix on the micros

Picture before and after

3108675
 

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Discussion Starter #2,574
Questions

Devastators set up in minidsp
12db @20hz .7q

So I started clean everything off in the devastators and 4 micro Marty's

Now with the devastators leaving the 12db out
I have lost about 20db,

Avr set to 0
Crown dci 2 1250 at max.
No clean box at this time. Cables are on there way.

I guess my question
How do do room correction in minidsp with dev set up with gain in the output.

The devastators are not even close to micro output.

Do I need the clean box for this
Or put the 12db gain back in and fix on the micros

Picture before and after

View attachment 3108675
This looks like a scenario for experimentation and tinkering. You probably want most of the mid bass coming from the front location. It will be a lot of back and forth. First get the time alignment right and then mess with EQ and gains from there.
 

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How does a narrow mini devastator with a PA460-8 stack up against a dual driver VBSS PA460-8 tuned to 15hz? I'm guessing the the dual driver VBSS will have an advantage in the low end but not sure.

I like the fact that I could always upgrade to the LaVoce SAF184.03 in the narrow mini devastator. I'm thinking of doing 4 of either. One in each corner but I might get a better response across all seats using 4 dual VBSS's vs 4 mini devastator's. Or maybe I should just jump right to the LaVoce drivers as I read they have a 10db advantage at 20hz over the PA460-8 in the mini devastator.

I believe I've read on here that the mini devastor sounds "better" than the VBSS no matter what the graphs read. I figure no matter which way I go I'll be happy with the amount of bass I'll get in a 22' x 17.5' x 10' room. Any help would be appreciated! Thanks.
 

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Discussion Starter #2,576
How does a narrow mini devastator with a PA460-8 stack up against a dual driver VBSS PA460-8 tuned to 15hz? I'm guessing the the dual driver VBSS will have an advantage in the low end but not sure.

I like the fact that I could always upgrade to the LaVoce SAF184.03 in the narrow mini devastator. I'm thinking of doing 4 of either. One in each corner but I might get a better response across all seats using 4 dual VBSS's vs 4 mini devastator's. Or maybe I should just jump right to the LaVoce drivers as I read they have a 10db advantage at 20hz over the PA460-8 in the mini devastator.

I believe I've read on here that the mini devastor sounds "better" than the VBSS no matter what the graphs read. I figure no matter which way I go I'll be happy with the amount of bass I'll get in a 22' x 17.5' x 10' room. Any help would be appreciated! Thanks.
I would definitely recommend going straight to the SAF, heck if you can wait longer the 18DS100-4 would be even more capability. A band pass enclosure keeps a sub buried deep within the enclosure. That should help some with mechanical noise that might make it through the direct radiator/cone. Then you have loads of mid bass headroom, so the woofer will be moving less for a given amount of output higher in the range. A lot of little things can add up. Even in a smaller room pushing the equipment less has advantages, such as less wear and tear mechanically on the subs and less heat being produced in the coils, that also means less heat being produced inside the amps. Not all of us can realistically get extra headroom, but if you can you really should. Power and heat produce problems you want to avoid if possible.
 

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This looks like a scenario for experimentation and tinkering. You probably want most of the mid bass coming from the front location. It will be a lot of back and forth. First get the time alignment right and then mess with EQ and gains from there.
I have added delay on the devastators (1)
I have added delay to the micros.

Then I run room eq.

Family movie curve
my movie curve

This is what I am confused about.
Crown dci 2 1250 at max volume
Avr at 0 to get 80db to gain match

My micros are at 12 on the nx6000
3109114
 

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Discussion Starter #2,578
I have added delay on the devastators (1)
I have added delay to the micros.

Then I run room eq.

Family movie curve
my movie curve

This is what I am confused about.
Crown dci 2 1250 at max volume
Avr at 0 to get 80db to gain match

My micros are at 12 on the nx6000
View attachment 3109114
I have not seen too many success stories using RCA outputs directly into Crowns. I gave up on my setup and used line amplifiers to push the signal voltage higher for the XLS and CTS amps. It made a big difference. The Berries do not care as much about input signal voltage.
 

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I have not seen too many success stories using RCA outputs directly into Crowns. I gave up on my setup and used line amplifiers to push the signal voltage higher for the XLS and CTS amps. It made a big difference. The Berries do not care as much about input signal voltage.

So hook the clean box up and see.
I that what you are saying
 

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I believe I've read on here that the mini devastor sounds "better" than the VBSS no matter what the graphs read. I figure no matter which way I go I'll be happy with the amount of bass I'll get in a 22' x 17.5' x 10' room. Any help would be appreciated! Thanks.
As I have BOTH in my system at the moment [VBSS are a part of my 3way MAINS]..... the DEVs do indeed sound better than a VBSS all day, every day. Second... IF you can, put the 18DS100-4 in your DEVs. Third, we have the same sized rooms and I can tell you that 4 DEVS in that space WILL be awesome. See my sig....

Juju
 
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