mm120 in a bandpass???

bayvanman

Hello, I have just bought a pair of the MM120's
(and a set of the MM465's:D)
Thanks to BBG Distribution here in the Uk.
I have checked out the box designs for the subs and the bandpass has caught my eye...
In all honesty has anybody actually built this enclosure and what results did you get.
Good, or, bad?

cheers

PoweredByDodge

I haven't done a bandpass with a polk momo or any other polk sub for that matter, so i can't specifically speak on them.. however, i have done band-pass designs before, and the overwhelming common outcome is this...

loud, boomy bass... but HORRIBLE sound quality. the low end stuff (like a good Sarah McLaughlan song) gets cut out, and the high end bass is not stuffy and not reinfoced well due to the loss of the low end.

this gives what some call the "one note" response. where you're bass on lets say a Rap song sounds the same as the notes you get during a country or heavy metal song... the only difference being the actual volume at which you hear it.

I instead suggest a sealed box for quality... a ported box can be built to achieve higher DB levels, but you'll lose a little sound quality as the momo's are specifically designed for sealed boxes. (0.66 cubic for the 10 / 0.88 cubic for the 12 PER sub).

if you want something flashy.. invert your subs.

build a box that's a tiny bit smaller than spec... (0.57 for the 10 / 0.79 for the 12) and INVERT your subwoofers, this means you have them mounted so that the basket is outside the box and they are firing inwards... this will show off the momo's big magnet and cage structure. REMEMBER -- when you invert a sub you must "switch" the + and - speaker wire leads... so insteadof running the + from the amp to the + on the speaker, run the + on the amp to the - on the speaker and the - on the amp to the + on the speaker.. this will cancel out the inverted phase of dropping the sub in backwards and make it sound exactly / almost exactly as if you had put it in normally.... but you get to have this cool looking install now

bayvanman

Thanks for the response.
Since I posted this topic, I have built a sealed enclosure for them and I'm running them inverted.
To say that I'm VERY impressed with the subs and components would be an understatement!!!

I've built a couple of bandpass boxes in the past (mainly for spl use), not trying for sq.
As for ported...I'm used to folded horns in my VW van.
Great sq and a flat response down to 30hz...

bayvanman

He he...cheers...
But I'm also used to high 150db's and 148db's at 34hz...

I'm was bored with bass orientated set ups, so I'm in the process of an sq daily driver.
Do you think that I've bought the right speakers...

(Plus, my customers love the sq...)

PoweredByDodge

ya i know the feeling... i recently rebuilt my truck into a "sorta sq" style... but after enjoying the quality / hating the lack of ear piercing power (for both highs and lows), i went and dumped about 200 - 250 watts rms / channel to my highs so life is a little less "clear" but a lot louder )

as far as "did i buy the right speakers".... well momo highs are superb, as are most of the polk highs... momo subs get a B+ in my book for SQ clarity.

There are a few subs out there that will give u a little flatter, little tighter response (an alpine type R or an Image Dynamics Q series) but the drawback is those other subs dont usually handle the power that a momo can continuously handle.

For a sub that you can beat on with 500+ watts all day long and not have to worry about, they're very very very good. As far as impressing customers --- Momo's are sharp... it's an italian thing [making note that I myself am italian -- yes.. bad joke i know]. --- anyway ... they're eye catchers... and if you really wanna stick out, mount them inverted (swap the power leads so that you maintain phase in the car) and cut like 0.09 cubic feet outa the box size and boom you've got the same sound with a helluva 'sexy' install.

I think that the next plateau over them would only be a radical upgrade to run 1,500 rms to one sub (Image Dynamics IDMax / Adire Brahma) and integrate some 8 inch mid-woofers (old Polk DX or Digital Designs 8"). Until you're part of the "I hope they come out with a 2 ohm stable miracle ear" club... be happy to be part of the "I set off every car alarm in the parking lot when I drive by" club.

bayvanman

Er, I am running them inverted (check above)
As for a sub that handles 1000+rms...
I have a Resonant Engineering 12" HC, 1200rms lots of xmax and a suprisingly good sounding sub.
At the moment, I'm the quietest member of my Team (Team Troublestarter UK). The two longest running members (there are only four of us ) are using ALOT of power. One is running 4 Zapco 9.0's, on a pair of DD Beasts. The other is using 6 Viper 2500.1ds...on 3 DD9515's.
I intend to compete next season (SPL)
I also intend to compete with the same vehicle in SQ...

PoweredByDodge

holy ****....


,....

lol.... that's some nice equipment, although I'll challenge you to put a Res. Eng. sub up against an IDmax -- where as most high spl subwoofers that are "good for sq" were designed as SPL and just "turned out good for sq" -- the IDmax instead was designed specifically for SQ and then it turned ot they were able to dump 50% more rms on it than they had thought...

good luck at hte comps !!!

bayvanman

IDMAX is going to be available in England soon...hopefully.
I can't wait to give them a try.

As for RE...is suprising how much certain "new" high power handling subs have in common.
I can think of three...

I have hardly competed this year, due to person reasons. Plus the van has been in the shop for over a year...