$30 scosche sub box arrived today...

[robspeed325i]

i should amend that, if you get a 2-ohm dual voice coil sub, aka one with two, 2-ohm coils, you can wire it for 1 ohm, and thus using a 1-ohm stable amp, make the most power for the least $ per watt. trouble with that is 1-ohm stable amps are more $$. You can also compromise and get one with dual 4-ohm coils, and thus wire it for 2 ohms total, and just get a 2-ohm stable amp (or a 1-ohm stable one with a margin of safety--which never hurts in the "budget" class of amps)...

[Stephen]

just get a 4 ohm woofer and you dont have to worry about compatibility too much. also check the woofer specs to see if a 1.25cu.ft. box is big enough. Im guessin for 90% of 12ers it will be. I guess mostly you want to get a woof designed for sealed boxes. i think shipping is free at certain places if you spend enough $$. dont expect too much at a budget level like this, and be aware that bass is addictive! once you have a little, typically you end up wanting more! that being said, an el-cheapo setup can probably match a high-dollar one up to a certain level. if anything, get a bigger amp than you need, just dont turn it up all the way (or enough to blow the woof). more power is always better since you are just as if not more likely to kill a woofer with clipping distortion (too little power) than by smoking it or breaking it physically (too much power). a trick is to set the amp gain so that the woofer is making all the sound it can safely make without distorting or bottoming out at the level that is comfortable to listen to as far as the other speakers go. that way, you can never blow anything without blowing your hearing too (which you will naturally avoid i hope). one other thing that would be useful is an amp with speaker-level inputs so you can just tap into one of the rear speakers (which you will likely remove) for signal...

Hmm, If i could get a setup for cheap, it might climb the priority list a bit, haha

[robspeed325i]

Hmm, If i could get a setup for cheap, it might climb the priority list a bit, haha

hehe i feel that emotion... if i already didnt have everything else i needed, i wouldnt be spending a dime on this stuff. that and my bass addiction!! ;-p

[Stephen]

hehe i feel that emotion... if i already didnt have everything else i needed, i wouldnt be spending a dime on this stuff. that and my bass addiction!! ;-p

Yeah, exactly, any money i spend on subs cant be spent on wheels :(

[E30 Cabrio]

Just a thought - would using the spare tire well work for a subwoofer?

It seems to be an ideal place for one. Maybe not quite deep enough, but if you laid some carpeting to line it and put a sub in there it would not use up trunk space and you would have a built in sub box, although you would have to have some kind of grille to protect the subwoofer if you planned on putting anything in the trunk.

Opinions?

[robspeed325i]

Just a thought - would using the spare tire well work for a subwoofer?

It seems to be an ideal place for one. Maybe not quite deep enough, but if you laid some carpeting to line it and put a sub in there it would not use up trunk space and you would have a built in sub box, although you would have to have some kind of grille to protect the subwoofer if you planned on putting anything in the trunk.

Opinions?

where would you put the spare tire? :)

[E30 Cabrio]

where would you put the spare tire? :)

In the trunk?

Or run without one and keep a can of "Spare tire in a can" in the trunk.

Or run-flats?

Just wondering how it would sound if someone utlitized the existing well in the trunk.

[robspeed325i]

ive seen it done actually, not in person but online. one guy did a sick f*ckng install in an e46 323 using a few very small drivers. google "spare tire subwoofer" and im sure youll find some examples..

[robspeed325i]

that actually reminds me... some dude makes boxes that literally fit INSIDE your spare! so you can keep both (or all three): trunk, spare, and sub...

[Stephen]

I know people who dont run spares, a can of fix a flat in the truk as a subsititue... or maybe really big disk brakes

[StereoInstaller1]

First, let me tell you that I have nothing against you, nor do I have any desperate need to be "right", even though you suggested that I find a way to make my boxes "cheaper", like the big guys do.

No thanks. My intent is to provide an absolutely superior product at affordable pricing. The boxes I build are the culmination of 28 years of experience, but nowhere near the best I can do...but in my opinion, the best bang for the buck that I can do.

I will take a $50 amp and a $50 sub in one of my boxes over any $250 amp and $250 woofer in a sealed or ported prefab, seriously.

Cleaner, clearer and louder, plus it fits the damn car.

phase delay (not sure what you mean by cancellation) *is* transfer function, or vice versa. the idea being that the long bass wave needs more room before it hits its peak.

OK, so you are confused about a couple of audio terms. Perhaps you were misinformed by your local shop, I don't know.

Let me tell you what Transfer function means as a term in Audio.

Keep in mind I have been installing high end car audio for 28 years, and know the guys who invented that terminology, being Richard Clark.

Transfer function is basically a concept of determining a given spaces' frequency response is, measured by placing a decent quality loudspeaker (transducer, if you will) of known performance and then measuring (using a calibrated microphone) different responses in the vehicle (or other environment) to determine the frequency response and resonance points of that environment.

The point of doing so is by determining the overall frequency response allows you to plot a specific response curve for the general output of your system, basically the inverse of what the environment has as a natural response.

As far as a "long bass wave", consider that a 20Hz wave is over 50 feet long. That length is not gonna happen in ANY car, much less an E30...yet my car has excellent response below 20Hz. Why? Because there are such things as quarter waves (Hmmmm...12 feet? Still ain't happening) and 1/8th waves...which at 6 feet, still need some help.

Anyone throwing the "long wave" crap is wrong. Physics says so.

the other day I was in a stereo store and standing right in front of a 12" sub in a vented box with 1000w on it, and other than the room shaking, i felt almost nothing. when i walked around the room, the bass grew and shrank in intensity by dramatic amounts depending on where I was standing.

The word "System" basically infers that as soon as you change ANY parameter, you have changed all parameters.

In other words, what you heard in that sound room has NOTHING to do with what you hear in a car.

Just the same as what the system in your buddy's Integra sounds like has nothing to do with the same pieces in an E30.

What you experienced in that room is called "Standing Waves", a basic concept of audio. You will find that vented boxes, being primarily a resonance magnification concept, have a MUCH greater effect on standing waves.

Considering that the people in a car are generally stationary, that poses no problem.

It is for that reason that I am putting my sub on a "leash" and am going to experiment on the best location and orientation within the trunk.

Excellent idea, especially as you are still experimenting.

In my case, having built roughly 2,000 boxes in my life for many different cars, generally already know what to expect, not to mention how many thousands of cars I have installed basic prefab boxes, amps, etc. in.

I guess what it really comes down to is experience.

Ive never listened to your box, and im sure its fine. you may overcome cabin-size issues with sheer brute force.

No, quite the opposite in fact.

I will say this emphatically: The box I build will make BETTER, lower, cleaner, tighter bass with 10% of the power required to achieve the same SPL as the prefab you are using.

My design works with the design of the car, and focuses the energy INSIDE the vehicle where you can hear the sound...not rattling the trunk as cannot be changed with your basic prefab box.

no need to call other people names just because they disagree with you or are trying something else. (hmm, defensive much?)

Just exactly WHERE did I call you or anyone else names? Seems to me you are the one attacking here.

I call it as I see it.

I will say that the easy, lazy way to make some kind of bass is just exactly what you have done, vs. the extreme skill and precision fabrication of what I do.

90% of the installers in the world cannot build a box as precise as mine, much less cheaply. I have also been doing this for longer than they have been breathing, remember?

It is highly unlikely that any of them have done as many of this specific car, either. I have been specializing in this era of BMW since they were new.

and its not about how much sound you get inside, its the quality of that sound, aka how much low bass you achieve vs 60hz boom. Again, not saying anything about your setup, for all I know it is 100% fantastic.

Yeah, clarity and frequency response are my #1 goal. SPL is basically meaningless to me. If my car can do 120db, I am content.

I do require completely controlled bass below 30Hz in all cases, and expect 20Hz or below.

I have not yet metered my car, as no one I know has anything beyond a SPL meter, but my experience tells me the car does about 132ishdb...plenty of loud.

To me, the clarity of what my car does is astonishing. I listen to lots of" live to 2 track" recordings, stuff on the DMP label, or Sheffield Labs, or Rounder records...all of which have stunning clarity.

I like the fact that I can hear the bass guitarist fingering his fretboard so clearly. Not one single person who has heard my car is anything less than amazed.

This is just a way, way, way less expensive and simpler setup, which MAY suck a lot of ass! we shall see...

Having pulled that exact same box out of a car and installing one of mine, with no other changes, we got about 10db more SPL, at least 1 full octave lower, and far far cleaner, more detailed bass.

What you have works just fine. I am sure you will enjoy it...but ask any of the dozens of people who have one of my boxes and heard it, you will hear that it is the least expensive way to quality bass.

As far as your "experimenting" goes, hell, man it is all about the learning, isn't it?

Luke

[Stephen]

So Luke, whats your two cents on adding a little bass on a budget. Im looking for ridiculous audio quality, but the little pioneer speakers lack a little bottom end

[E30 Cabrio]

Luke, what would you suggest for Cabrio's?

I'm planning on adding a sub and would like to upgrade the rear speakers as well,
I've swapped out the rear stock speakers with some low-cost Blaupunkt speakers which have improved the sound over stock, but looking for more improvement but it's hard to find something that fits back there. I believe I have about 2.25" of mounting depth to work with.

Thinking of layering some Dynamat or carpet between the sheet metal and the speaker magnet if it will even fit, and a low-profile, powered sub-woofer under my seat or a Bazooka tube in the trunk.

Front speakers will eventually be replaced and maybe even relocated but they'll do for now.

Sorry if I'm hijacking the thread but finding Cabrio specific info is difficult and the listening environment changes as well with the top down/up...

[robspeed325i]

Im going to just bold my replies rather than do quote unqote...

First, let me tell you that I have nothing against you, nor do I have any desperate need to be "right", even though you suggested that I find a way to make my boxes "cheaper", like the big guys do.

I'm just on a severely limited budget, and it cant hurt to ask, no?

No thanks. My intent is to provide an absolutely superior product at affordable pricing. The boxes I build are the culmination of 28 years of experience, but nowhere near the best I can do...but in my opinion, the best bang for the buck that I can do.

Respect.

I will take a $50 amp and a $50 sub in one of my boxes over any $250 amp and $250 woofer in a sealed or ported prefab, seriously.

Cleaner, clearer and louder, plus it fits the damn car.

Hehe. The scosche also fits, with probably less work than your port solution requires, just a bit of hammering and sound deadening removal needed. No measuring, drilling or laying in the trunk on your back required...

OK, so you are confused about a couple of audio terms. Perhaps you were misinformed by your local shop, I don't know.

Let me tell you what Transfer function means as a term in Audio.

Keep in mind I have been installing high end car audio for 28 years, and know the guys who invented that terminology, being Richard Clark.

Transfer function is basically a concept of determining a given spaces' frequency response is, measured by placing a decent quality loudspeaker (transducer, if you will) of known performance and then measuring (using a calibrated microphone) different responses in the vehicle (or other environment) to determine the frequency response and resonance points of that environment.

AKA Standing Waves.


The point of doing so is by determining the overall frequency response allows you to plot a specific response curve for the general output of your system, basically the inverse of what the environment has as a natural response.

As far as a "long bass wave", consider that a 20Hz wave is over 50 feet long. That length is not gonna happen in ANY car, much less an E30...yet my car has excellent response below 20Hz. Why? Because there are such things as quarter waves (Hmmmm...12 feet? Still ain't happening) and 1/8th waves...which at 6 feet, still need some help.

Anyone throwing the "long wave" crap is wrong. Physics says so.

Well, are we talking 1/16th waves, since the seatback is no more than 3' from your head? My rear-facing idea also comes from a guy with a lot of experience building Iasca-winning e30s. His advice = seal it and face it to the rear. You say physics says the long wave is crap, but we know physics dictates all of this stuff. IMO, understanding why your box works is understanding the real physics, not tossing it out because it doesn't fit what we (or others) think it should (or should not).



The word "System" basically infers that as soon as you change ANY parameter, you have changed all parameters.

The word you are looking for is "implies."

In other words, what you heard in that sound room has NOTHING to do with what you hear in a car.

Absolutely agree! Im not new at this either, although its been a while since ive been INTO it, if you know what I mean. I also wouldnt begin to compete with you on total raw experience, but Im no neophyte.



Just the same as what the system in your buddy's Integra sounds like has nothing to do with the same pieces in an E30.

What you experienced in that room is called "Standing Waves", a basic concept of audio. You will find that vented boxes, being primarily a resonance magnification concept, have a MUCH greater effect on standing waves.

Considering that the people in a car are generally stationary, that poses no problem.

Except and unless they happen to be "stuck" in the wrong part of the "room." You may also be benefitting from a wide distribution of output point sources, at least in the V1 boxes. You have the woofer at the center/back of the "room" and then the two ports in the extreme corners, pointed at the "ceiling". There are a lot of interesting sub designs that remove the so-called room effect by distributing subs either in mono-or dipole configuration throughout a room, or at least on one wall of a room. I was just reading yesterday about this on DIYMA, pretty interesting stuff. Again, just ignoring the physics of the matter kind of, I dont know, takes some of the fun out of it. There has to be a reason (or reasons) WHY your box works so well, and defies the "rules" if you will.

Excellent idea, especially as you are still experimenting.

In my case, having built roughly 2,000 boxes in my life for many different cars, generally already know what to expect, not to mention how many thousands of cars I have installed basic prefab boxes, amps, etc. in.

I guess what it really comes down to is experience.

No, quite the opposite in fact.

Hmm i am just noticing this is removing the stuff you are quoting from me...

I will say this emphatically: The box I build will make BETTER, lower, cleaner, tighter bass with 10% of the power required to achieve the same SPL as the prefab you are using.

My design works with the design of the car, and focuses the energy INSIDE the vehicle where you can hear the sound...not rattling the trunk as cannot be changed with your basic prefab box.

This is not true. It would be very easy to seal the open side and cut a hole on the slanted side and mount it against the ski hole of the car. What youd have is essentially a sealed version of your setup, for $30 instead of $200+ with shipping. I realize this is apples and oranges since you arent selling sealed versions, but tuned vented boxes, and your output will still be far better for that reason alone.

Just exactly WHERE did I call you or anyone else names? Seems to me you are the one attacking here.

Re-read your earlier post, watching for the word "retards." I am not doing any attacking whatsoever! Just where did *I* do any attacks?? See what I mean by defensive?? ;)

I call it as I see it.


As do the rest of us.


I will say that the easy, lazy way to make some kind of bass is just exactly what you have done, vs. the extreme skill and precision fabrication of what I do.


You forgot 85% cheaper! :D If I had the money id no doubt be on your wating list. This isnt about laziness, its about not having a workplace to do my own, or the money to buy one of yours.


90% of the installers in the world cannot build a box as precise as mine, much less cheaply. I have also been doing this for longer than they have been breathing, remember?


I don't doubt that, but I've heard similar things from a lot of installers and even mechanics who have been around a long time. Not all of them can be in the 90th percentile. Its just like 90 percent of drivers think they are better than everyone else on the road. Im NOT dissing you when I say this, its just something I've observed.


It is highly unlikely that any of them have done as many of this specific car, either. I have been specializing in this era of BMW since they were new.

That is cool, and again, respect. Ive also heard from a bud who has built some IASCA e30s, and he says a sealed bouncebox (rear-facer) will get me good sound. Not to say better than yours, but good enough for a budget setup. Also good enough to win IASCA events, for what its worth...

Yeah, clarity and frequency response are my #1 goal. SPL is basically meaningless to me. If my car can do 120db, I am content.

I do require completely controlled bass below 30Hz in all cases, and expect 20Hz or below.

So what frequency do you tune your boxes to? How do you manage the typical tuned-freq vented-box rolloff, or does cabin gain make up for that? I am admittedly a COMPLETE novice as it comes to vented boxes, so i defer entirely to you here. (I tend to the side of newbie even on things I know a great deal about, so that way I am *always* learning--try to have no ego, just to be an open book).


I have not yet metered my car, as no one I know has anything beyond a SPL meter, but my experience tells me the car does about 132ishdb...plenty of loud.

To me, the clarity of what my car does is astonishing. I listen to lots of" live to 2 track" recordings, stuff on the DMP label, or Sheffield Labs, or Rounder records...all of which have stunning clarity.

I like the fact that I can hear the bass guitarist fingering his fretboard so clearly. Not one single person who has heard my car is anything less than amazed.

Having pulled that exact same box out of a car and installing one of mine, with no other changes, we got about 10db more SPL, at least 1 full octave lower, and far far cleaner, more detailed bass.

What you have works just fine. I am sure you will enjoy it...but ask any of the dozens of people who have one of my boxes and heard it, you will hear that it is the least expensive way to quality bass.

As far as your "experimenting" goes, hell, man it is all about the learning, isn't it?

Luke

[robspeed325i]

and I have to continue my reply in another post, since apparently there is a limit for any one post size......

Like I said, if i had the cash id be on your waiting list. This approach is a budget shot, no doubt. The 10db you mention is probably attributable to the fact alone that yours is a ported setup, not to mention the losses in energy shaking the trunk. The lack of trunk rattle is a laudible goal by itself! And yes, it *IS* all about the learning. I do tend to get in trouble with long-experienced people in various fields because I tend to question them when they want me to just take their word for it. All that time at the tiller tends to give them two things: a big ego, and little patience. Theyve seen it all, done it all, and you aren't supposed to question it. My attitude is, I want to know the details, and try things and find out for myself whether I can do it better, faster, or in this case, cheaper. I apologize for that, its just a personality defect of mine.

Like I've mentioned before, my most-recent previous setup was a massively oversized IB-like sealed box, and it produced excellent low-end detailed response. It was also sealed to the cabin, through the ski passthrough, just like your Vx boxes are. Because it was so large, it lacked mid-sub (60hz) punch, but man did it ever rumble.

This time due to my lack of workspace and funds, im just doing it the easy/"lazy"/cheap way. as a bang-for-the-buck matter, I think I'll be doing OK. once i get myself financially together better, if you'll have me, I'll most likely be on your list!