Subwoofers, Speakers & Amps

If you cross the cut off frequencies of the mids and subs, you will see a bump in frequency response at that point. Ideally, you want to filter the mids a little higher and the subs a little lower, so there's a small gap. An example might be mids playing 150 Hz-up, and subs working 100 Hz-down. Fine tuning is required to get it just right.

Shintsu wrote:

Eww, subs do a nasty job when they're turned up to produce mids. Trust me, I've toyed with my Energy home sub and when set to 150 hz crossover with my bookshelf speakers...YUCK. Completely localizable and the bass it produces is nasty. Just what I experienced with a 12" home sub. Use a mid to produce mids, not a sub. They just don't do a good job at it.

Obviously a 12" isn't going to produce very good mids, the bigger the speaker, the worse it is at producing highs, and the better at producing lows. An 8" is right in the alley of producing those frequencies though.

AA wrote:

If you cross the cut off frequencies of the mids and subs, you will see a bump in frequency response at that point. Ideally, you want to filter the mids a little higher and the subs a little lower, so there's a small gap. An example might be mids playing 150 Hz-up, and subs working 100 Hz-down. Fine tuning is required to get it just right.

Okay, thanks for the info. I'm just tired of the decent sized gap I have right now between my 10 and 5.25's. The 10 is producing a little higher than normal, because it's in a smaller enclosure, but I'll be remaking that box to proper specs when I get the 8's

Tossing around phrases/words like midbass and rear fill dont count when what these words mean are over looked.

Midbass has a range that subwoofers dont work in. Thus subwoofers are subwoofers, not woofers or midbass speakers.

Rear fill is just that, fill. Its not meant to image- to add to or distract from. Its just filler. So at any point if you can notice you have rear fill you dont have rear fill, you have speakers in the back that are to loud...

http://caraudiocentral.net/ryan/docs/Learn_rearfill.pdf

http://www.termpro.com/articles/rearfill.html

Well, right now I have a gap between my 10, and my 5.25" speakers. I can bridge that gap with the 10 by changing the filter, but at that point I'm sacrificing the low end frequency, and to get that back I need to turn the boost up. Then I'm getting too much of the higher frequency, so it sounds bad. I figure with the 8's running on a different channel I could adjust their frequency to the higher portion that I either lacked or had too much of (depending on the frequency I had set). Then I could adjust them to the proper volume for that frequency and the 10 to its proper volume.

Also, When I have the LPF cut off at 80Hz, the 10 sounds good. At 125Hz it starts sounding bad and I figure the 8's would still sound good there.

First, set all of your EQ and boost controls to flat. A 10" sub and a pair of 5.25" components can and will work well together if you tune the filter slopes correctly.

Invest in front components that can play down to 100 Hz or so without distortion, or try the ones you have. Use a steep (18-24 dB/oct) active filter (before amp) to cut off the components at or below 150 Hz. Try to set it as low as possible - if they'll go down to 90 Hz cleanly at volume, go for it. If it distorts, move back up. Tune by listening loud with sub off (and no 8"s).

Now filter the 10" sub using a softer slope (12 dB/oct) starting a bit lower than your high-pass to the components. If your high pass was 120Hz, set the low pass in the 80Hz range to start. Adjust amp gain to match the level of the fronts. Listen to some music, bass tones, and a sign sweep. You'll hear any peaks or valleys in the crossover range. If you hear a peak where the fronts cross the sub, set the sub low pass lower. If you hear a hole, move the low pass frequency higher.

Trust me, you don't want those 8"s in there. It'll never sound right. The fewer the speakers, the better.

Aaron, I currently have 2 12" Infinity Perfects in a pretty big vented box. I was toying with the notion of getting a sealed enclosure because they are more than loud enough now and I really just want more accurate response. It's adequite now but I wouldn't mind a smaller enclosure. I would possibly even switch to a single sub instead of two.

What do you think would be the best size to have the one 12" Perfect sub? Are there any good resources you would recommend for a low price enclosure. I would rather have a rectangular enclosure like with a dual sub enclosure because i need surface area to mount the amps and stuff.

I don't know the exact best size off hand, but Infinity should recommend different alignments for different listening preferences. If you don't have the spec sheet, I'm sure it can be found on line for download.

Whatever options Infinity recommends, I would choose the largest sealed box. This will give the flattest, lowest, and most accurate bass. It will not be as loud as a vented or smaller sealed box, so you may consider using both subs if you can fit them. If you're feeling creative, you can use both drivers in an isobaric configuration (piggy back or clamshell). This will effectively form a "super sub" with twice the mass, half the compliance, and double power capacity, giving you the sound quality of the large sealed box but using only half the space. It will only be as loud as a single driver in a big box, but it will play just as low in a box half the size.

I'm happy with a single 8" in the car, so a single 12" sealed would be more than adequate for me; the iso would be fantastic. But if you are used to the extra output of your current 2 sub vented set-up, just be aware that you will loose a fair amount of SPL moving to a sealed single driver or iso. Imo, the SQ gained more than makes up for it.

So, I don't feel like going out and buying filters right now, I think I have some 150hz filters that I used for the speakers in the seat of my fiero, I just need to find them, but would it work fine just using the filter on my amp? The only problem with my amp is that it's just marked lowest and highest that it can be cut off (lpf and hpf), but it's just a guess and check deal by spinning the knob. hpf goes from 50hz -1khz cutoff and lpf goes from 30hz-250hz cutoff. I guess I'll just test it out until the 5.25's start to distort. What volume should the stereo be at when doing this. Right now 15 is decent listening volume and at about 45 of 55 it starts to distort but is uncomfortable on the ears anyway.

Also, the setup I have right now, I either need "Loud" turned on high on my head unit, or on low with the bass turned up quite a bit, or I don't get much bass out of the sub. I'm thinking that if my EQ's are all off and I get clean sound, when I turn the EQ's back up so that the sub hits, it will distort the 5.25's again. Am I wrong in thinking this?

The components I'm using are nothing special, but I'm on budget right now as I can't find a great paying job, and I'm in college.

Pioneer DEH-P5800MP head unit, Quantum Q52 5.25" components in stock location (frequency response=35hz-35khz, sensitivity=91db).
Those are powered by Formula MACH-5231 4-channel amp (2ohm stable, hpf, lpf, and full range...4,3,2 channel bridgeable, only using 2 of the channels right now).
Lightning Audio 10" sub in about .6ft^3 box (supposed to have .75ft^3, 250rms/750max)
Powered by scosche 2-channel amp (bridged 250rms/550max)

Okay, just tested it. With sub off I can turn the filter on the amp all the way down and still have distortion free sound, but I don't get very loud mids...I can barely hear bass. I tested it with a few different types of music, along with a bass excursion test. Then I turned the sub on and tuned that so that I couldn't hear any gaps. I used a few different types of music and the bass excursion test again. I don't have a sign sweep, so I couldn't use that. The music sounds clear now, but the mids are almost non existent. I know the stock location isn't the best, because of location and the fact that it isn't a great enclosure, but the mids should still be a little louder than they are. I adjusted my equalizer to help improve the mids, and I get vibration in the speakers when I get it to a good volume. I had this same problem when I put the speakers in in the first place. I took them back out and felt around for loose parts while hooked up and I couldn't find any. maybe I just need different components. Kinda sucks if I do since I haven't really used these. I bought them a year ago for my Conquest, never used them and just installed them in like December. I think the warranty is void.

Any suggestions?

I do think a set of good components would help. They are among the most important pieces of equipment in the system, imo.

Try turning off the sub, then set EQ and bass boost to flat, and turn the high-pass filter up to ~500Hz. See if you can get some good some good sound out of the front components by themselves. If it sounds good loud, try lowering the high pass down to 250 Hz, 150 Hz, etc. See how low you can go without hearing distortion at comfortably loud volume level.

Okay, I'll do that in the morning when I get up. I don't think the neighbors would like the noise at 4 in the morning.

I know one thing, before I put them in the car I put them in some small enclosures that I had (basically just shelf speakers), because I wanted to hear they sounded. They sounded great in the small enclosures hooked up to my Pioneer shelf system. i almost bought MB Quart components for $60, but when I went to buy them they weren't on sale any more, so they were like $150. I went the cheap route and spent $35 shipped on these.

Maybe I should take my KLH shelf speakers and hook them up and see if I can get those to sound good, if not then it's probably not the speakers?!?

It's just mind boggling as to why these don't create hardly any bass, yet the KLH shelves in my room are 4", with 1" tweeter and produce decent bass. (obviously the enclosures doing)

Thanks for the help. I'll post my success (or failure) in the morning

Don't you people sleep at night?

I nap between posts!

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It's just mind boggling as to why these don't create hardly any bass, yet the KLH shelves in my room are 4", with 1" tweeter and produce decent bass. (obviously the enclosures doing)

It's all about the enclosure. You put your 5.25" in a box volume it likes, there will be bass, maybe too much. Trick is to know what volume it likes, because it's different with every speaker.

could I finish enclosing the spot in the door and then spray the back with undercoating to deaden it? Right now It's kinda half an enclosure because they left huge holes in it for the wires. It wouldn't be a very big enclosure, but I think it would help a little. 5.25's don't need much of an enclosure. I'll go look for my hpf's right now. Then I'll try your technique.

And to the question about sleep...I'm on my spring break, so I try to make every day last as long as possible, lol...screw sleep

Okay, it sounds nice now, no distortion, but when I turn the sub off, the bass from my 5.25's isn't the best sounding. It's kind of a muffled bass sound. The 5.25's are at what I would guess 110hz cut off, anything lower and it had a really poppy sounding bass.

With the sub on it doesn't sound bad though, so I'm not completely disappointed.

Now, with those 8's I said I might get. They were $80 shipped and were MA Audio MA80QS, would I be better off getting those or spending $70 shipped on one MB Quart RWE-204. I plan on eventually getting rid of the 10 and putting a 12 in for deeper, louder bass. So, I would either have one 12 and 2 lower end 8's or one 12 and 1 high quality (lower end of that brand) 8. The MA Audio 8's are 200 watt rms each. The MB Quart is 150 RMS.

Also, the MB Quart has an inverted rubber surround. What will that do for my sound as opposed to a regular rubber surround?

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could I finish enclosing the spot in the door and then spray the back with undercoating to deaden it? Right now It's kinda half an enclosure because they left huge holes in it for the wires. It wouldn't be a very big enclosure, but I think it would help a little. 5.25's don't need much of an enclosure. I'll go look for my hpf's right now. Then I'll try your technique.

Only do this if you are serious and want to invest in serious components. Car speakers are made to play fine using the space inside the door. Try plugging those extra holes with a plate of some sort. I used the stock tweeters (disconnected but still mounted) to cover the tweeter holes.

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With the sub on it doesn't sound bad though, so I'm not completely disappointed.

You are probably near the limits of your system's capability. You may need to invest in some better equipment to improve the sound.

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They were $80 shipped and were MA Audio MA80QS, would I be better off getting those or spending $70 shipped on one MB Quart RWE-204. I plan on eventually getting rid of the 10 and putting a 12 in for deeper, louder bass.

I still think you have the wrong idea adding 8" drivers. It's entirely possible to blend from two 5.25" mids to a single 12" sub. If it doesn't sound punchy enough, invest in some better 5.25" mids, or upgrade to 6.5" mid components. With enough power, you'll be happier than by adding 8"s. Like I said, I use a single 8" and it plays damn low, pretty loud, too. Invest in good equipment and you don't need as much.

Okay, well I plan on eventually replacing everything in my setup when I get the money. As you can see, everything in my system is low end. The head unit is a name brand, but one of the low models, the sub is made by Fosgate, but it's their lowest brand and lowest model (was $30).

I didn't really wanna buy new components yet, because I wanna match them to the proper amp when I do. Right now I don't have the money for a better amp. I guess maybe I should either sell one of my 6 cars or just wait until I have money.

I'm thinking the 4-channel amp is what's limiting my sound quality right now. I hooked some shelf speakers that I have up and they didn't sound the greatest (proper RMS too).

How hard is it to modify the door for 6.5" speakers? Also, where is the best place to put the tweeters in our cars? I have a rotozip (and many other tools) at my disposal, some 1/8" board, fleece, and fiberglass resin. I tried fiberglassing once, but the fleece was kinda rubbery when it hardened so I'm thinking I did something wrong. I want to try a little more before I mess up my door.

I'm assuming I would need to use 1/2" MDF for the speaker rings, from there I wouldn't really know where to go. Mount them away from the door somehow?!? Then wrap fleece and fiberglass?!? I saw a write up where someone did it and it looked almost stock when they were done.

Thanks again for your help.

Have you ever run an RE product?

If your on a budget and have about 150-200 WRMS on tap @ 2 Ohms then snag a Resonant Engineering RE sub.

Toss that bad boy in a 1.25 cubic feet box with a 4" port tuned to 35 Hz and enjoy the 9+ dB of gain before factoring in cabin gain. Insane sub for about $50...

These are the components I have
http://cgi.ebay.com/2-QUANTUM-AUDIO-5-1-4-360-WATT-COMPONENT-CAR-SPEAKERS_W0QQitemZ350173883388QQcmdZViewItemQQptZCar_Speakers?hash=item350173883388&_trksid=p3286.c0.m14&_trkparms=66:2|65:15|39:1|240:1318

Linking doesn't seem to be working, so I'll leave it like that. They looked good on paper.

I use this manufacturers drivers in the entry level home speakers I produce. They are very impressive for the price. I haven't used these particular drivers, but everything I have used from this company has been great.

http://www.madisound.com/catalog/product_info.php?manufacturers_id=136&products_id=8472

Ryan from Ohio wrote:

Have you ever run an RE product?

If your on a budget and have about 150-200 WRMS on tap @ 2 Ohms then snag a Resonant Engineering RE sub.

Toss that bad boy in a 1.25 cubic feet box with a 4" port tuned to 35 Hz and enjoy the 9+ dB of gain before factoring in cabin gain. Insane sub for about $50...

RE audio is a very good brand. if you guys are looking for information about any of the wiring, electrical, speakers, subs, u name it... head over to

http://www.caraudio.com/forum/

it's a very good forum and has a lot of info on it.

I jut joined yesterday I've been asking a lot of questions. was suggested to get Phoenix Gold 6.5's. I was told I couldn't really do better for the money.

What are you's guys's thoughts on MB Quarts amplifiers?
Namely this one: http://cgi.ebay.com/MB-QUART-DSC480-4-CHANNEL-1200-WATT-CAR-AUDIO-AMPLIFIER_W0QQitemZ350223867249QQcmdZViewItemQQptZCar_Amplifiers?hash=item518af81d71&_trksid=p3286.c0.m14&_trkparms=65%3A12

looks good on paper...

Looking to power one 12" sub and front components.