[randog]

I just got my cabinets back from Christof and assembled them yesterday. Thought I'd like to show them off a bit even tho the pictures aren't the best:

[mcgsxr]

That is a REALLY nice looking combo - enjoy!

mark in Canada

[Al Garay]

Looks very nice.

What size are the woofer cabinets? Did you go with 3.0cubic foot?

What did you decide to use for the crossover? Did you plug the port in the 1801s?

Al

[randog]

Thanks guys.

Al, they are exactly 3.0 cubic feet inside volume (we used an excel spreadsheet Chris made for all the dimensions and just to make sure I modeled it in CAD). The square panels were sized to fit the 1801 depth. The MDF is 1.5" everywhere. The geometry makes it inherently rigid as hell so there's no internal bracing. It worked out pretty cool (at least I think it will!).  

I'll be using a Marchand XM9 once the right x-o module arrives (80 Hz). I still need to get an amp to run them.

I didn't plug the port. Is that recommended?

[EProvenzano]

SMOKIN'  

[Red Dragon Audio]

how about a Behringer EP2500 to run the bass section?

$300 on eBay plus about $25 s/h.

450watts x 2 channels at 8ohms.  Not bad for bass control.  If your subs are 4ohms, then there is even more power on hand.

It weighs 35lbs so about the same as the Stratos but it's a class H amp which is just a more efficient version of class AB which is what the Stratos is.

If you buy it, don't like it, you can always sell it to me.

By the way, your "bass moduels"/"subs" look Phenomenal.

[David Ellis]

But... how do they sound??

If your subs are 4ohms, then there is even more power on hand.

Unfortunately, the amps dampening factor is halved , and the voice coils head dissipation/compression doubles when using a 4 ohm load.  Lower impedance loads are not a "win-win".

[David Ellis]

But... how do they sound??  Do you have an initial impression yet?

I recommend you plug the port.

Also,

If your subs are 4ohms, then there is even more power on hand.

Unfortunately, the amps dampening factor is halved , and the voice coils heat dissipation/compression doubles when using a 4 ohm load.  Lower impedance loads are not a "win-win".

[randog]

But... how do they sound??  Do you have an initial impression yet?

I recommend you plug the port.

Who cares!   KIDDING!

Seriously, I haven't gotten there yet. I'm still awaiting the crossover modules and have yet to purchase an amp.

I will play around with plugging the port. Also, am looking for feedback on damping of the sub cabinets. I realized after I assembled them that I overlooked that. Any recommendations by anyone here?

Thanks,
Randy

[Red Dragon Audio]

What impedence are your subs?  

Damping factor is greater than 300 @ 8ohms so according to what you say it's still 150@4ohms which is good.  Just use thick cables and you should be fine (say 8awg to run to the subs).

-What is the cutoff you are going to use for your subs/woofers?  100Hz? 200Hz? 50Hz?

-What slope? 6dB 12dB 18dB 24dB???

If you have a high cutoff point (around 150Hz or higher) I think you should use the same amp on the bottom as you use on the top.  So if you use Stratos up top, then use a stratos down low too (maybe stratos dual mono).

If you are crossing it over low (100Hz and lower) with a fairly steep slope (12dB or greater), you should be fine with the Behringer amp.

Of course, if you don't like it, sell it on eBay.

Behringer makes good stuff, and I think it's worth a shot.  When I get around to building my GR subs, I am thinking of use this amp in conjunction with the RDES xover/EQ.


Enclosure Damping
There really are many choices but I think you should just experiment and choose what sounds best to you in that enclosure.  One thing is for sure, you have a killer enclosure and resonance shouldn't be a serious issue.

I've used premixed concrete with good results as well as carpet padding, spray-on damping mix and dynamat (there are many cheaper alternatives to Dynamat and I think they are just as good for a lot less dinero).

[randog]

Thanks starch,

The SCC300's are rated at 8 ohms.

Based on past posts in this forum I'm planning to x-o at 80 Hz to start. Many folks here have experimented with the same monitors (1801's) and subs (SCC300's) and settled on that frequency... I'm going to borrow from their collective wisdom as a good place to start.

Slope is 24dB - Marchand XM9.

Money is tight and it's not the most cost effective approach, but I'm hoping to use the same amp make so that I can move the amps out of the cabinet and over near the speakers. One speaker and sub powered by one 2-channel amp and the other with the other. This will free up some space in my stuffed cabinet as well.

Thanks for the feedback,
Randy

[Red Dragon Audio]

Well I think that Behringer EP would be good to use just for the bass modules for a few reasons:

1) Lots of power and good damping factor into 8ohms (450watts x 2,  damping >300)
2) Gain control so you can match it with any type of amp up top.
3) Inexpensive; $329 free shipping (b-stock) just google it.

So if you want to experiment with tube amps or other SS amps with the 1801's, but keep the high power control on the bottom, you're good to go.  Your Marchand xover might have gain control for both top and bottom amps too but I wasn't sure.

[randog]

Finally updated those shabby pics.