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Elite Shackster
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Does the WinISD graph using the Monolith Driver, Amp and Enclosure give 102dB @ 20hz too?
We cant model it based on the BK amp, we dont know what they have done to it. We can model a peerless xxls driver, and in a 90 litre ported enclosure, then use 300watts to see what it gives. It shouldnt be far off but there isnt really any way to know how accurate it would be, the exact particulars of the design isnt something BK would release.
 

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HTS Senior Moderator
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Zactly. The Beringer kept tripping at 20Hz into 4 ohms bridged for a reason..... Won't handle it. The BASH amps have been proven over time to be gutsy and reliable. If you NEED 2000 watts, buy a Crown. If not, as in this application, the plate is a great buy with more flexibility, more features, and enough power to do the job for less money

Bryan
 

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Discussion Starter #64
We cant model it based on the BK amp, we dont know what they have done to it. We can model a peerless xxls driver, and in a 90 litre ported enclosure, then use 300watts to see what it gives. It shouldnt be far off but there isnt really any way to know how accurate it would be, the exact particulars of the design isnt something BK would release.
It would be an interesting comparison to the two graphs for my sub.
 

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Discussion Starter #65
Zactly. The Beringer kept tripping at 20Hz into 4 ohms bridged for a reason..... Won't handle it. The BASH amps have been proven over time to be gutsy and reliable. If you NEED 2000 watts, buy a Crown. If not, as in this application, the plate is a great buy with more flexibility, more features, and enough power to do the job for less money

Bryan
Hey Bryan, welcome back.

Do you know what the O-Audio 500w amps peak power is?
 

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Elite Shackster
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Zactly. The Beringer kept tripping at 20Hz into 4 ohms bridged for a reason..... Won't handle it. The BASH amps have been proven over time to be gutsy and reliable. If you NEED 2000 watts, buy a Crown. If not, as in this application, the plate is a great buy with more flexibility, more features, and enough power to do the job for less money

Bryan
Can you explain to me why my EP4000 is doing a sterling job of powering my dual driver sub without even getting warm, even at ref level?

It would be an interesting comparison to the two graphs for my sub.
I just did a quick model using a 90 litre ported design, tuned to 20hz, with a pre loaded peerless driver (which might not be the one in the Monolith) and 300 watts. It actually show 108 db @20 hz max. Thats not the whole story though as port speed models as being too high, with port resonances that are to low down really and driver excursion goes nuts at 18hz with full power. The Monolith is obviously different from that model, probably with an on board filter to protect the driver low down and possibly using a tighter driver (lower Vas), but it shows what can be done to a degree. It certainly shows the Monolith is highly likely to be able to achieve what its specs show on paper.

You should notice the curve artificially levels out, then drops like a rock. Thats typical of a ported sub, and shows you how the sealed subs response is naturally smoother. This can work out to make a sealed sub more musical, and can make it easier to EQ into your room.
 

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Discussion Starter #67
I'm not sure, but the potential Monolith Curve looks better than either of the 2 curves for my possible sub.

Not sure now, what I stand to gain.:ponder:
 

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Elite Shackster
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Here is another graph. Ive adjusted it to give 102db at 20hz like the Monolith. Along side it is the AV15-X in its 85 litre enclosure using 500 watts. You be the judge :whistling:
 

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Discussion Starter #70
Actually, with external measurements of 650 x 450 x 450 in a cabinet made with 25mm MDF give internal measurements of 600 x 400 x 400?

Therefore 96 litres.
 

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Discussion Starter #73 (Edited)
Those are external dimensions. You need to account for the MDF material thickness (1"), driver displacement, bracing displacement, and if you want a plate amp, you'll also need to give a little for amp containment. Dont forget the driver baffle is 50mm thick to flush mount the driver.

use this:

http://www.hometheatershack.com/forums/enclosure-volume-calculator/
Thanks for the link. My design, which is a downward firing one, would mean the bottom is 50mm thick right?

Still looking at about 90 litres though?

Box width - 26 inches
Box Height - 18 inches
Box Depth - 18 inches

Mat thickness - 1 inch
Bracing volume - 500 cubic inches (this was a guess including double thickness bottom, and internal brace)
Port Vol - 0
Driver Volume - 0 (couldn't guess this, but thought it would be no more than 3 litres)
No of Drivers - 1

Total Net Volume - 3.266 ft
Total Net Volume - 92.489 Litres
 

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Elite Shackster
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I work in mm, as so does the place that cuts the MDF. Height is 23.6 inches (allowing for reduction due to extra driver baffle), width and depth are 17.7. That equates to 87.248 litres. minus 3 litres for driver and about the same for bracing and you end up with about 80 litres. This will be offset using acoustic wadding to give an effective volume of around 85 litres total but it will be reduced further if you use a plate amp unless I extend the cabinet so its outside of the calculated volume.
 

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Discussion Starter #75
Cheers.

Having a bit of a play with WinISD shows that seemingly fairly large changes in volume has very little effect on the plotted curve.
 

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Your Behringer is doing just fine because it's not running in bridged mode - his will be.

As I said before - either amp will do the job. I just think that for less money, you're still getting enough juice and a better feature set with the plate amp.

Bryan
 

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The Behringer amp is probably the cheapest new amp you can get for a sub that's not a plate amp.

Also it's a very stable amp and will provide plenty of output. You can't even use it's full power with a normal household outlet. Behringer has their issues, but they also have a few good products. The EP2500 is one of them. Still on a budget I'd suggest the O-Audio.

You will not get 115db out of a sealed sub at 20hz. you couldn't probably handle that in our house anyway.
 

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Elite Shackster
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Cheers.

Having a bit of a play with WinISD shows that seemingly fairly large changes in volume has very little effect on the plotted curve.
Depends on what your looking at. TFM hardly changes, but look at other stuff like cone excursion and spl output and they change.
 

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Elite Shackster
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Your Behringer is doing just fine because it's not running in bridged mode - his will be.

As I said before - either amp will do the job. I just think that for less money, you're still getting enough juice and a better feature set with the plate amp.

Bryan
But I'm also running a 2 ohm load, which should be more difficult for the amp. IMO, power isnt really an issue with these amps.
 

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Yes. 2 ohms is more difficult but the amp appears by the specs to be more stable in stereo mode than in bridged mode. As you said though, you're not likely even close to using the full rated power of the amp so it's not as much of an issue.

Bryan
 
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