MMG Sub stands

[Andrew Pratt]

Okay that little voice has been whispering in my ear again...it sounds remarkably like thomasW for some reason Anywho we've been talking about building two sealed subs for my MMG's and using them as stands for the MMGs. The MMG's in their stock formation come with stands that tilt the speakers backwards and the botton of the panel sits on the ground. This isn't the optimum placement of the MMG's though since ideally you want your ears in the middle of the panel and they are better when placed vertical not tilted backwards. The plan is then to build some stands that raise the MMG's up and have a shiva driver in a sealed box to provide the bass. Also as others have noted the MMG's have incredible treble but their bass is a bit muddy so we plan on crossing over the shiva's at 250 hz or so. So that said Thomas what would you suggest we shoot for internal volume of the sealed subs? How do we go about building the crossovers?

[ThomasW]

Andrew

I was corresponding with JonMarsh last noc (he's lost somewhere in the midwest at a conference)

He thinks 250Hz is too high to XO, and that some of the good "dipole info" would be lost, So he is recommending XO at 125Hz,

Good passive XO's for LFE are $$$$ The reason is that the big inductors and very high value caps aren't cheap

So I'd recommend using John Pomann's DIY kit, the 4th order L-R @133Hz

http://members.aol.com/johnpomann/speakers/crossover.htm

This XO would be cheaper than a good passive XO. It will be cleaner sounding too. Email John for specifics. He's a very nice fellow. Also I'd suggest geting a little chassis from Radio Shack

For the higher budget there is the Marchand XM9-KK $259.




theAudioWorx
Klone-Audio

[Andrew Pratt]

Thomas how about using something like one of the palte amps like the PE Plate amp and using it to power the sealed shiva and do the cross over. It claims to have a high pass crossover at 125 hz which is right around where you now recomend. The plate amps don't have as much juice as the mono blocks do but they are cheaper

[ThomasW]

Andrew

These and most plate amps have mono outs for the sub. Not too good if the XO frequency is up in the 125Hz range. Also check the specs, high pass 6db/octave @125Hz 8 ohm! This sounds like a passive filter. The MMG's are 4 ohm. It might work, but would be less than optimal IMO. PE has a 30day money back quarantee, I don't know how that operates in Canada.

There's also the DOD 835II @$135 p/n DOD-835, the Ashly XR-1001 @ $289 p/n XR-1001 or the Rane MX @$219 p/n RNE-MX22. These are from http://www.markertek.com

http://www.i-mcm.com has the McLelland GE-152@$162 p/n 555-175

PE has the ART-310 @$199 p/n 245-880

All these are pro/semi-pro I don't have personal experience with any.




theAudioWorx
Klone-Audio

[Andrew Pratt]

The DOD looks like a decent unit for the money...My thinking is that for each MMG and Sub I'd set the denon to large mains sub off and then route the speaker wire to the crossover and from there run highlevel wires to the MMGs and a low level signal off to the Monoblocks then to the sub below the MMG's. I'd need two X20's one per side plus another monoblock so we're looking at a good chunk of change for all of them...hence the plate amp option...ie combine them together. What about a receiver that had an adjustable crossover or one locked in high at 100 for example?

[ThomasW]

Andrew

You've lost me! :?

set the denon to large mains sub off and then route the speaker wire to the crossover

Doesn't your receiver have line level outs? If not, then you need to rethink this whole idea or use passive XO's




theAudioWorx
Klone-Audio

[Andrew Pratt]

thomas my denon does have pre outs for all channels but it doesn't have pre ins therefor if I use the pre outs I'd need amps for the mains and for the subs. thats why I was looking at crossovers that had speaker level inputs and speaker level outputs with a line level out for the sub amp.

[ThomasW]

Oh, ok now I understand.

Plate amps aren't a good "investment". Think about it, a active XO and mono power amp for $90? The component quality has to be quite low. So the sound quality will be effected. I understand the attraction but......

My suggestion is to wait until you have the funds to go with an active XO and another the SoundStream mono. Get the second amp first if that "deal" is going to go away. We can always find an active XO. BTW, the is a "bass-list" deal for the Marchand stuff




theAudioWorx
Klone-Audio

[Andrew Pratt]

Thomas even if I got the second mono I would still need something to power the MMGs with if we went active (all line level) A quick solution would be to build the subs as planned and just run them off the denon's LFE out crossoved over at 80 for now. Then later pick up the crossovers to cross them over higher then the 80 its set to now...or look at some of the receivers like the outlaw that would allow me to cross the sub over at 120 or 140. There's the Sony 444 that would do the same but I wasn't very fond of the Sony DAC that I last heard and a good DAC is important for me given the digial connection from the CD changer.

[ThomasW]

That sounds like the way to start.

Also if you want we can make-up a low buck passive XO. You can then compare the two.

I'd suggest going with separates instead of another receiver. They just aren't cost effective in the long run. Start by buying ALL the Sound Stream amps you can afford. Use your current receiver as a pre/pro until we can find you a "deal" on a real one.




theAudioWorx
Klone-Audio

[Andrew Pratt]

thomas unfortunatly we're trying this at the wrong time since we are trying to save for our house downpayment so funds are very tight for toys. If I sell my current big tube I should have enought to build the two smaller sealed subs and get one of the monoblocks...I'll then start thinking about getting crossovers sorted out but until then I'll use the denon's 80 hz one (I won't be gaining much I know but I'll be set for the future)