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Discussion Starter #1
After getting severely 'hooked' by this forum..........I am now building two subs. My DIY PE knockdown project is running smoothly in another thread.
This thread is for my MartyCube build attempt. I got all the wood cut........now for some glueing and nailgunnin'!
I will purchase a standalone amp for this project. Any ideas? I have a line on a used Dayton sa1000....but, I will consider other good options........Behringer? Others? 18" Ultimax will go in.:coocoo:

Should be good!:eek:
 

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That's a pretty small cabinet for a UM18
 

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I use a crown xls 2000 with my ported ultimax 18. Very nice amp. No fan noise. Accepts balanced and unbalanced. I love it.
 

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The MQ-600 is very nice but you'd need a way to set a highpass to save your woofer somewhere in the low teens. The MQ doesn't have that so you'd need a MiniDSP or the like. May still be a viable option but worth mentioning you'd need another piece of get behind it.

IIRC the crown does have one sort of software settings to allow that so it's a decent option depending on cost.
 

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Yes i use the crown with a balanced mini 2x4 for high pass. A bit tricky to get connected but otherwise is great product!
 

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Discussion Starter #8
I need more info on the mq600........photos of innards an'all.
Xls2000 seems like a fine Amp too.........please post a picture or two of your hookup method...........
 

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I need more info on the mq600........photos of innards an'all.
Xls2000 seems like a fine Amp too.........please post a picture or two of your hookup method...........
The Crown can be run with just regular RCA cables and also regular speaker wire. The MQ-600 would require using XLR or TRS cables.

Craig posted a couple pictures here, and I'm sure if you send him a PM he might post some nudes for you as well.

http://www.hometheatershack.com/forums/members-craigsub-2498/

The Crown is just as good IMHO, and I also like the XLS 1500 (if it has enough power for your application), but the MQ-600 is cheaper than the 2000 by a bit and well.... I can sometimes be cheap hehehe....

MQ-600 front:



MQ-600 back:

 

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Discussion Starter #10
Awesome.....thanks. If I were to go with mq600.....then I would NEED a MiniDSP? With the Crown xls...I wouldn't......it has filters built-in......? Just trying to get the best option..........
 

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Awesome.....thanks. If I were to go with mq600.....then I would NEED a MiniDSP? With the Crown xls...I wouldn't......it has filters built-in......? Just trying to get the best option..........
The MQ-600 would need the Mini-DSP. I believe the Crown would allow you to set a highpass for your ported sub (you dont need one with a sealed sub) to what you want but you would want to confirm that.

For my Martysub I have a high pass set at 17hz (using the plate amp) as once it gets lower than that my driver can start to have problems.
 

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Discussion Starter #12
Sorry.....I am a bit confused....why would you set the highpass filter at 17hz?...........on the crown amp for example...wouldnt you set the lowpass filter to say 100hz? Everything below 100hz goes to the sub.....?
 

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Sorry.....I am a bit confused....why would you set the highpass filter at 17hz?...........on the crown amp for example...wouldnt you set the lowpass filter to say 100hz? Everything below 100hz goes to the sub.....?
Yes and yes. However you need to roll the sub off at its tuning point in order to save your sub from getting frequencies it cannot reproduce without starting to cause problems with the voicecoil.

If your familiar with the concept of a "subsonic filter" is very similar.

Most plate amps on normal subs already have a subsonic filter built into them. Pro amps do NOT, so you need to set one.

Found these with a quick google search and hopefully they explain it better than I did...


With regards to subwoofers, a high-pass filter is often used on ported subwoofer designs to protect the driver from over-excursion at or below the tuning frequency of the box. They are also sometimes used on sealed subwoofer designs to prevent sending unnecessary power to the subwoofer for frequencies that cannot be reproduced. For example, a ported subwoofer tuned to 20 Hz may require a HPF near 16-17 Hz to prevent the driver from exceeding its maximum rated excursion. WinISD Pro can be used to see the effects of different HPF frequencies on a given design.

Read more: http://www.hometheatershack.com/forums/subwoofer-amps-high-pass-filters/43902-low-pass-high-pass.html#ixzz3bq2kIP00

In the case of a subwoofer there would be a low-pass so that only frequencies below what the mains are playing are sent to the subwoofer and there could be a high-pass to prevent very low frequencies that have the potential to damage a subwoofer. For instance, for vented subwoofers frequencies below the tuning frequency result in very large excursion demands which could cause the driver to attempt to move further than it can mechanically resulting in what is called bottoming which can result in mechanical damage to the driver.

Read more: http://www.hometheatershack.com/forums/subwoofer-amps-high-pass-filters/6567-high-pass-filter-low-pass-filter.html#ixzz3bq2xuWGB
 

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Discussion Starter #14
Ok...got it! You set the AVR crossover at say 80hz........then you set the sub amp hpf at 17hz.....everything below 17hz is filtered away so the sub doesn't overload/bottom-out.(relative to the subs tuning frequency of course).
As my martycube is ported......this is important........I just want to get it right so I dont blow something.

I am very tempted by the Dayton SA1000 or Crown xls2000...........I think either of these will go well with the martycube. Shucks.....can't wait to try it out!
 

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Ok...got it! You set the AVR crossover at say 80hz........then you set the sub amp hpf at 17hz.....everything below 17hz is filtered away so the sub doesn't overload/bottom-out.(relative to the subs tuning frequency of course).
As my martycube is ported......this is important........I just want to get it right so I dont blow something.
Yup. Almost "all" plate amps you'd get from say parts express or another online vendor have built in low pass filters. Its also why lots of folks PREFER pro amps, so THEY can set that number and tune their boxes low.

It would be bad if you've got a box that can dig to say 10hz, but your plate amp has a subsonic/high pass setup at say 20hz......

Now you'd want to double check me on the Crown to make sure it can set a high pass filter that low, but if it can then its a good bet. And even if it "cant" its still a nice option since you can use RCA connections and regular speaker wire....

However on a spec's level the MQ-600 has better wattage spec's at both 4 and 2 ohms.....
 

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The crown amp has high pass built in but only down to 50hz. You disable it in the main screen menu

You WILL need another high pass/ eq. Minidsp 2x4 balanced.

The balanced minidsp 2x4 will be needed. It has a higher output voltage that pro amps need to achieve full volume. The unbalanced May still work but it's not worth wasting money just get the balanced version.

The balanced version also uses xlr cables, they are better for shielding/noise and are cheap.

The actual connection is tricky but worth it and relatively easy. If you want download the minidsp balanced manual and check how it is done,

Believe me. It's worth it.
 

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Discussion Starter #18
Ok.....thanks for the info on the Crown amp. I read the manual, but I couldn't find what you found.
I am already seconds AWAY from pulling the trigger on a MiniDSP........
 

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Ok, make sure you get the correct plugin too. Otherwise won't work the same. I use 4way advanced plugin. It will do up to 4 subs
 
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