power, crossover fq, spl

pgriffiths

Ok ,I have an Alpine CDA-9830 HU, a Polk C400.4 amp, 2 mmc650 coax's and 1 mm2104 sub in a sealed subzone .66 cf enclosure with polyfill. I've only got 1 10" sub because it's in a 1990 240sx and I need at least a little trunk space and I'm more interested in sound quality than in outrageous SPL's. I know the Alpine unit is a 4V head so I set the input selectors to high on both channels. The pre-EQ is set to bypass for both channels. The front channels drive the coaxes and the rear channel is bridged for the sub (200w). I have both slope switches set to 12 db, the frequency multiplification switches on x1 and both crossover fq's set at approx 80hz with the front set on HP and the rear set to LP. The coaxes sound great and are plenty loud (although at 3/4 gain and HU all the way up) but if I turn the fader to listen to just the sub (which by the way is connected from the HU to the amp through the sub out rca connectors on the Alpine and not the rear rca outs (which may be the problem )) the volume is not very loud even though the cone excursion would seem to indicate that it should be! Polarity of the wiring is correct Any ideas? Also how do you accurately set the crossover points. Do you use a setup cd or is a scope the only way? Should the slope be set to 24db. Since I don't have rear speakers, should I hook the rca cord to the rear channel rca outs on the head instead of the sub out rca's? Should I change the input switches to low? By the way the gain on the rear bridged channel is almost maxed. I was told 200 watts should be ok for a single 10. Was I misinformed? Sorry to be so long-winded but wanted to make sure I gave enough info.
I listen mostly to progressive rock and rock fusion like Dream Theater, Greg Howe, Dave Martone, Satriani e.t.c.

Pete

MacLeod

First off, Dream Theater RULES!!!

Second, turn your gains WAY down. They shouldnt be any higher than the "noon" position.

Here is a link to a gains tutorial website. Follow that.

Second, 200 watts is the bare minimum you should be using on that sub. Its a 300 watt sub and should be getting that much for best output.

200 watts isnt a whole lot really and especially with yours in the trunk its not gonna be too

You should also take out the polyfill too. Your box is built to proper spec (.66) so polyfill isnt needed. That could be robbing you of some volume.

You may also want to try downfiring the box too. This will add volume but at the expense of a little clarity. Mount it in a corner and firing down but use spacers so its off the floor by 2-4 inches.

Check the enclosure for leakes and make sure its built properly.

Try these and get back to us.

neomagus00

YES! someone else pimped my site! :D

anywho, i'll partially agree with mac on the 'no higher than noon' bit, because at that voltage and switch position, you should be at around 12 o'clock, perhaps a tad higher. the link will provide more detailed instructions.

in fact, all of that is excellent advice. the part that confuses me is the lack of bass when the fronts are faded away. you're right in thinking that the sub output shouldn't be faded, and it seems not to be, but the synergy of fronts and sub provide a lot more bass than either alone, so, yeah...

pgriffiths

Thanks MacLeod and Neomagus. I am working 12 hour shifts for the next couple of days but I have put the gains around noon in the meanwhile. I can turn the HU all the way up and it's not as loud as I would like especially on older cd's that weren't recorded as loud as more recent recordings. Sunday I'll check the sub for leaks and take out the polyfill. The mmc650's actually put out some pretty good bass and quite a bit louder than the mm2104 although not as deep obviously. I'm confused about the 300w peak rating on the box for the mm2104 as I thought the only wattage rating that meant anything was rms which on the box says 125w. In other literature it says 600w peak which I know is meaningless because it's measured over a very narrow frequency range.

neomagus00

you may have one of the misprinted boxes, there was a short run of them at some point. the mm2104 is indeed 300W RMS.

if you're finding that the coaxes overpower the subs, that's easily taken care of... turn their gain down... but if the bass actually decreases when you fade to the rear, you may wish to move the xover points a bit. they don't necessarily need to coincide, but they'll need a bit of eq-ing if they don't.

pgriffiths

I took the polyfill out and noticed a little change in volume. Not much though. No leaks as far as I can tell. I know I'm going to have to get an amp more along the lines of the c500.1 to be able to set the gain at a realistic level and get the volume I want. If I do I might as well get another 2104 as I've read here that the c500 and (2) 2104's is a pretty good match. I don't want to have to turn my h/u up to max to get the volume I want for the coaxes either so I will probably bridge the c400.4 and drive each coax (mmc650) with a bridged channel. That way I can turn the gain on that amp down to 11 oclock or lower (it's at 1 oclock now) and have plenty of headroom and not have to turn the h/u all the way up. I'd rather have the amp idling than clipping. Sound reasonable or will I notice the higher distortion level that results in bridging the amp? I experimented with the slope setting on the sub channel and really notice the difference in the rolloff. 24db has hardly any above 80hz info bleeding through but the volume is quite a bit lower. I wish the crossover adjustment had a detent at 80hz so I would know I'm really set at that crossover point. Any tips on how to set the crossover and slope by ear. What should I be listening for? Lack of muddiness, thump, volume or a combination of these things? I feel even with underpowering the 2104 with 200w it should be louder. I shouldn't be able to talk easily over it when listening to the sub by itself should I? It sounds muffled to me and not the thump in the chest kinda bass I feel with say a home stereo! Maybe it's because the snap in the bass drum is in the frequency range above 80hz and the coaxes are handling that but I'm expecting to hear it from the sub but in a home stereo the woofer (not sub) uses a higher crossover point and thus playing both the thump and the snap. Make sense? As far as downfiring, I don't want to sacrifice sq or take up space in the corner of the trunk and I plan on mounting the sub enclosure to mdf on the back of the fold-down rear seat so it fires up against the hatchback window with the seat up and is pointed towards the dash in the seat down position. It sounds closer to the sound and volume I'm looking for with nothing between the sub and my ears (obviously).Will the 100w extra watts per speaker (assuming I get another 2104) really make that much difference in volume? Also do you see any advantage to having 2 separate sealed enclosures for the subs as opposed to using a single enclosure built for two? For instance better cone control and or sq. Lastly if I add the c500 to the setup do I need to upgrade the power wire from 8 gauge to 4 and use a dist block split into 2 8 gauge feeds to the amps?

neomagus00

lots of info!

otay... HUs are meant to be turned way up, that's what the volume control is for... you want the gain on the amp to be as low as possible, for noise reasons, and that means keeping the volume on the HU high (not all the time, but you get my drift).

you will notice the distortion from bridging, it can become significant. will it displease you? maybe, maybe not, it's your ears.

you don't need a detent at 80, it's really really hard to hear even 10 Hz either way (try playing with a 31-band eq if you don't believe me).

you're correct in your assesment of the thump, it's midbass, and is well beyond the range of the sub. in your tweaking, you're looking for whatever combination of crossover points and slopes, and eqing SOUNDS GOOD! it's all about the music, screw the 'proper' setup...

doubling the wattage to a given sub increases your volume by 3dB. adding another identical sub also increases your volume by 3 dB. both are audible, but the real advantage of the extra power is in the headroom - it allows more of the snap and verve to come through, with less distortion.

there's no reason to build 2 separate enclosures when 1 will suffice. i'm partial to both subs sharing one chamber, but most people put a solid divider in the middle.

finally, you will need at least 4 gauge to run a sub amp, yes. all the momo amps take 4 gauge power and ground inputs, so you should use that - bring 4 gauge from the battery and split it into 2 4-gauge runs.

MacLeod

One word for ya: PARAGRAPHS

Your post makes my eyes cross.

pgriffiths

Sorry about that Mac. I'm usually at work and trying to type in a hurry so paragraphs were the last thing I was thinking about.

I do want to thank both you and Neo for the advice though and yes Dream Theater rules! If you like rock fusion check out Prashant Aswani. He kicks some serious ****!

Neo: What I mean't by not wanting to turn the HU all the way up was that I have read that even in HQ units ,distortion is introduced by the HU at the upper limits of the volume knob. I'm assuming they were talking about pre-amp distortion and not that produced by the internal amps.

MacLeod

Well by high he doesnt mean maxed out.

For instance, my Alpine goes to 35 on the volume. I have my gains set to where my volume is around 15 for normal listening, 20 for sprited and 25 for loud, windows open listening.

pgriffiths

See that's my point though. I have an Alpine too and I have to turn it up to 35 for the volume I want with the gain set at 12-1 o'clock and if it's a cd that's older, like 80's era rock, when they didn't master them as hot, then its not loud enough at all.

On the loudest cd's ,35 is pretty close to my loudest desired listening level and no I don't have a problem with my hearing. Lol.

neomagus00

i tune with my HU at 90% of max, using a pure test tone... yeah, it's gonna lose a few dBs on those old recordings, but that's what the last 10% is for; because yes, you're right, even 'non-clipping' HUs often clip at the top end of the volume...

and you guys are expounding dream theater (yes, mac, i can spell it your way )... any suggestions for a good first CD for me to sample?

pgriffiths

I'm not too up on the last couple of releases but I pretty much like everything they put out before that, mainly because I love progressive rock and I am a guitarist and John Petrucci ,DT's guitarist, is one of my favorites.

Three you can't really go wrong with though are:

1) Images and Words.
2) Awake.
3) Scenes from a Memory.

MacLeod

If youre turning your h/u to 35 and its still not loud enough then you need a better amp or your hearing checked. Even on Operation Mindcrime I dont have to turn it up passed 30 and thats with the windows down.

When Dream and Day Unite was their first and although its great, their first singer kind of sucked.

Images and Words was a little "processed" for me. Great album but far from their best.

Awake is awesome. More funky than heavy but very progressive and well produced.

Falling Into Infinity is one of my favorites. They got Derek Sherinian on keyboards and he has a very ballsy way of playing. This album is a little heavier and darker but has awesome songs from start to finish. My 2nd favorite of theirs.

Scenes From a Memory. This is their concept album. Very progressive and complex with a new keyboardist, Jordan Rudess who was admitted to Julliard at the tender age of 9! This one is also good from start to finish. More of a mainstream feel. Not very heavy.

6 Degrees of Inner Turbulance is kind of along the same lines as SFAM. Its a litte heavier and more technical. Its a 2 disc set with the 2nd disc being a single 45 minute song!!

Train of Though. My alltime favorite. Heavy. Very heavy. As heavy as any of the 80's metal bands yet well produced and very technical with excellent performances from all.

Train of Thought, Awake and Falling into Infinity would be my top 3 picks.

pgriffiths

You know Mac, I'm wondering if when I was setting up the Alpine, and trying to figure out where everything in the menus were, if I inadvertantly set something, like one of the bands in the EQ for instance, that would be causing my problems.

Not the most intuitive interface that I've seen and it's easy at first to forget where you access different options from. 5 seconds goes by quickly when you're stumped. Lol.

You know in hindsight, I probably should have gone with the c300.2 for the fronts and the c500.1 for the sub especially since I'm not using rear speakers. I was thinking I could do it all with 1 amp and was told by Polk that 200w (2 channels bridged on the c400.4) would be enough for 1 10" sub. The c400.4 is only 75w/ch and 150w(c300.2) would have been a better match for the mmc650's which I can't say enough good things about! I'm still amazed at the bass these small speakers can put out.

As an Alpine owner, maybe you could tell me something I'm a little confused about.

When you go into the user EQ menu where you can define and save your own EQ curve, does it default to that setting every time you turn the unit on or do you have to recall it each time with the preset button?

I would agree that Images and Words is not one of their best cd's but it was the first one that I heard and for that reason has special meaning to me. It was during that tour that I first saw them in concert and to this day remains as one of the best sounding concerts I have ever been to. Not to mention the fact that every one of them is a master musician!

I've always been a prog head though. Used to be a huge King Crimson, Genesis, Yes, Gentle Giant and Rush fan.

MacLeod

That is a possibility. There are tons of features on there. You can not only choose your treble level but you can center the frequency and choose the bandwidth and a bunch of other things.

You could try unhooking the negative cable from the battery for about 30 seconds. This will wipe out all your settings and start over at default which is basicaly "flat". Then take out your manual and read over each tuning feature and then right down your settings for future reference and then tune from there.

Once you set and save your EQ, its stays that way until you unplug the battery. As far as I know it doesnt have a battery backup so when it loses power it loses its saved info as well.

Ive never seen DT live but I did get to go to a Mike Portnoy drum clinic. Best experience of my life!! Even got to meet him!

neomagus00

he looks like a corpse...

there's also the guy with the sunglasses, he looks pretty cool...

MacLeod

Umm....huh?

exalted512

Originally posted by MacLeod
Umm....huh?

word--i think neo is losing it
-Cody

pgriffiths

Ha ha ha. That's funny Neo! So Mac, are you a drummer then? Portnoy is a great drummer and if I remember right he's totally ambidextrous.

I think I'll reset the unit and try going from scratch and see if that's what's going on.

I have worked in a computer room for the last 28 years ,which as you might or might not know, is an environment with a lot of high level ambient noise. I am exposed to that noise for long periods of time (12 hour shifts) and it's a possibility that my hearing is affected.
I don't have trouble hearing anything or anyone though with the exception of my teen son. That's because he trys to talk without moving his lips! I understand better now what my mom meant when she said "Stop mumbling". Must be an age specific kinda thing. Lol.

MacLeod

Mike is THE drummer, but hes not ambidextrous. He plays right handed (traditional) just like I do.

Ive been playing since I was 16 however I no longer have a place to play so I havent touched them in 2 years.

Thats the thing that sucks about drums. No volume control. Thats really bad when you live in an apartment.

pgriffiths

Oh my bad! I'm thinking of Mike Mangini from Extreme. When I saw him he had his highest pitched tom in the center and lower pitched toms alternating left and right going outwards if that makes sense. When he did a fill, instead of turning in an arc he moved both arms from the center out ,in for lack of a better term, a breaststroke motion. Strange to see but sounded really cool. Check it out.
http://www.mikemangini.com/MMmm/mm2004.html
Click on media and then videos. Watch 6-9. I've never seen anyone do single handed rolls like him. Another great drummer!

Sounds like you need a Roland TD-20 like I'm getting my son. He's been playing since he was 3. Double bass freak and really good but he needs to learn about dynamics and contrast. He's always been a hard hitter.

MacLeod

Dude! Mangini is probably the fastest drummer on the planet. Freaking amazing.

I had the same problem when I started out. I learned how to play to Slayer's Reign in Blood and Metallica's And Justice for All so I was very much into heavy playing and double bass. I got to be very fast too. One of the fastes drummers in our local scene. But there were plenty of drummers that were 10 times better than me.

It wasnt until I got into Dream Theater back in 92 that I started to actually play rather than just being fast and heavy.

Make sure your boy gets to listen to plenty or Rush, Dream Theater and Queensrychs (nothing after Promised Land) in addition to whatever he's into now. Those will be plenty of good influences on him.

pgriffiths

Ok, I reset it and it looks like that WAS part of my problem. Must be that male "I don't need to read the manual" thing. Lol. The sub is performing much better after doing that and tweaking the crossover. Still going to get a c500 and another 10 though.

My mom did a promotional deal for Queensryche 10 or 15 years ago playing the part of the queen of England. I think it was for a video. She has been active in the past in the acting scene. She also hung out with Lonnie Mack and Stevie Ray Vaughan and called me and said come on up for your birthday, I have a surprise for you. I didn't make the effort to get off work because I didn't know and when I found out ,I about died!

My son is into cookie monster music. (Slipknot, Lamb of God e.t.c.)You know the atonal demon singing so prevelant in todays metal but he also likes Rush ,Pink Floyd and some older bands. You know I like the bands he listens to EXCEPT for the singing. They have some cool rythym stuff going on. I showed him the Mangini videos and he was amazed.

Thanks guys for your help. Now I've just got to figure out how to get a 26 1/4" enclosure in a 25" space. Lol.

AustinKP

Well, I don't know what happened, but I somehow missed this whole thread until now. I have an Alpine 9815. Yours should have i-Personalize. Just go to Alpine's website and you can set up the EQ, crossover points, and time correction online. Then it makes a file you download, and burn to a CD. Put the disc in, hold down a button, pick the file, and it sets it all for you.

You can have more than one profile on the disc and save them to different presets, i.e. one profile for when you're by yourself, a different profile when you have a passenger so the time alignment isn't messed up.

pgriffiths

Thanks Austin. Unfortunately the 9830 doesn't have i-personalize. The 9831 does. Wish I had it now damn you. Lol