Sorry for the extremist title

I want to have an open discussion about whether or not a subwoofer is even necessary.

In my system, (standard audio upgrade) I put in 1X 4 channel amp to power all my speakers. The focal polyglass 6X9s in the back are wired in parallel and bridged to channels 3 and 4 with a LPF at the amp set to 50hz with a 12dB/div roll off. I did plenty of research, and the nifty thing with these focals is that the rolloff from 100hz -> 50hz is about 12db giving you a very flat response from 50 to 100 and furthermore the sensitivity from 50hz and down is just as good as the highest quality 10" & 12" subs you will find.

Infact! The power-handling on the dual 6X9s is better than a single 10".

Let's move one to the acoustic environment. By design, a subwoofer typicaly projects it's sound outward (duh all speakers do this). So what happens is you throw a box in the trunk of your car, you make sure it's bolted and sealed, and it shakes your car!! The downside to this setup is your bass profile goes all the way to the trunk. Which is why the bass always feels like it's "moving forward". As an audiophile, I despise this feature.

Alternatively, we setup our 6X9s as subwoofers like I described, and you now move the bass profile to the middle of your car, and the 6X9s pound towards center in unison turning your car into something like the inside of a very large sealed dual 10" box! So now, rather than projecting sound and vibrations from the back, we are compressing the entire environment

Now I'm not delusional as to think this is going to out-bass a 500 watt dual 10 or single 12, but I'd put my system up against any 10" subwoofer system any day. And because of of the careful calculation, I'm certain my response is the tightest you'll almost ever hear in a car.

I look forward to hearing a counter argument from someone pro-subwoofer. But don't get me wrong, it's not that I don't like subs (I love them), I just think there place is in larger vehicles like suvs, not mini coopers.

 

all personal preference when it comes to sound, I was an audiophile for a while and now im not... Still personal thing.

 

Sorry, but I respectfully disagree. Perfection is 100% sound deadening with a perfectly flat response, your aim should be perfect sound replication. EQs were made so you can have personal preference on the sound.

Tho the objectional side of me wants to validate your statement with the many other possible ways you can build the system, (like people who go for volume on a ported sub for example), but if your talking sound quality, I think this way is superior. The only downside is the backseat doesn't have a balanced sound in this config.

Sorry I can be very polarizing when I debate - makes for stronger points.

 

The IA system doesn't waste any space at all really... and the amount it improves the cruddy stock speakers is immeasurable.

 

Immeasurable? Unlikely, I got tools to measure. But the stock audio system is one of the crappiest I've ever heard - no doubt a sub kit would make a world of difference... Does it come with tweeters??? Cuz you need those too.

 

Makes for a lonely discussion as most will not even bother to participate.

 

I don't mind being told. My only reference is my acquired knowledge, and my memory isn't perfect. That being said, it can be challenging to find people who can talk on the same wavelength. Perhaps the question "sub box vs an equalaterally inward firing enclosed area" is better suited in another forum.

 

This whole audio system thing in cars... mind you in a car, which is one of THE worst places to listen to music is EXTREMELY subjective. What sounds great to me will sound like crap to you. There is no debating that point.

Fact - The audio system in pre 2010 MINIs is horrible. in 2010 and newer with the HK system it is still pretty bad.

Fact - adding a sub like the Integral Audio sub makes a huge difference for the better. At least now the stereo in the car is enjoyable.

How much money do you want to spend to make the system sound right for you?

I have the IA sub and will get the IA front Soundstage upgrade when its released at the end of the summer. That will be over $2000 spent fixing the crap audio system in this car. Some will say that is way too much to spend and some will say its still not enough.

This can be a never ending debate and at the end no one is right and no one is wrong.

 

I found some good deals at a car audio sale and spent about $900 (otherwise worth around $1500) for my complete focal system with amp. Did all the work myself, took a couple days. I'm sure my components are superior to this IA system you guys speak of (tho if you guys have a sub system, we're almost comparing apples and oranges, tho it brings us round circle to the OP), but you're probably saving yourselves a butt-load of work I guess. It's a trade off.

I wanted better tweeters, but I wasn't prepared to drop an extra $700 at the time. Might do it at a later time when I find someone who wants some cheap lightly used focals

 

If you're lightly using them, then what's the point of spending all the money?

 

That was my exact point when I said its a preference thing. If your into sound then go for it if not, then dont. My HK system is enough to satisfy me, twisties acceleration and braking are what im after so no need to worry about it.


I used to be an audiophile but grew out of it...


at least you can have a nice song on while i blow past you

 

+

 

Wow, Eirhead, with all due respect, I must admit to being just a bit impressed. You managed to originate and continue a thread in which I doubt you made one valid point or argument. The only thing certain is that there is an incredible amount of science and art behind the subject that totally escapes your grasp. In the future, if you’re going to try to “polarize” a debate with “strong points” it works best when those points are valid!

I don’t know the exact components you are using but it can be very damaging to those components if you wire drivers in parallel (your 6x9's) and then power them through a bridged amplifier (channels 3&4).

I’ll explain…

Most car audio drivers present a load of about 4ohms nominal to the amplifier. When you wire them in parallel you divide the impedance by the number of drivers. Hence, 4ohms/2drivers = 2ohms nominal total load. Now most car audio amplifiers are rated to drive down to 2 ohms per channel but only 4 ohms when bridged. You are most likely driving a 2 ohm load on an amplifier rated to drive 4 ohms or greater in your configuration. Generally very bad voodoo… don't say I never did anything for you!

Maybe you should do a little more "research" and re-wire your system before you burn out your amp. Then you can go back to “polarizing”

Sorry to be so harsh but I dressed for the party you put on.

Good luck with your Re-wire

 

My amp is rated up to 1ohm per channel. It's a Focal Solid 4 if you wanna double check, I referenced the manual BEFORE I installed like a good little tech.

By profession I work with studio audio and amplifiers that are hundreds of times larger than a car audio amplifiers. My amp's thermal protection will turn itself off before I'll damage anything - I could have bought a bigger amp. But it goes loud enough for me.

I was toying with the idea of building my own amp from scratch originally... (just in case you think I'm not familiar with ohms law 'n all that)

And when I say lightly used, I mean, used for like 2-3 months then sold off, with an amp that isn't capable of blowing them.

 

Ya that's cool, if I had got the HK system initially, I wouldn't have bothered to do any upgrading. That's cool and all - to each to their own.

But you guys are skipping over the point of the thread. What I'm trying to say is, 2 high enough quality 6X9s are capable of putting out so much bass in such a small environment, that you can have a completely stealth audio upgrade without a gaudy subwoofer taking up precious trunk space.

Albeit, it's probably more work to get at the 6X9s than it is to fish cable to a subwoofer, but I'm the kind of person who likes to take as much time as possible to do a job the best I can.

 

Some good points made in this thread. I too dabble in the hobby of sound, but not really in my car.

Cars are different than houses or rooms. SPL doesn't really matter b/c you are sitting less than 3 feet from the speakers. Power isn't really an issue either. To increase sound levels by 3 db (arguably the smallest change discernible by the human ear), you have to double wattage to the speakers. if the stock system is not too quiet, you probably don't need more power.

I'm not a huge fan of subs in cars... added weight. A nice set of tweeters and some mids that can handle a solid low frequency is good enough for me. The HK system is just fine. I don't experiment with critical listening in my mini. I'd rather hear the engine and exhaust (and maybe some tire squeal), but that's just me.

As far as subs go, it shouldn't matter how or where it's mounted (especially in a MINI). LFE is, by definition, the most unilateral frequency sound wave... directionality shouldn't be a concern. I'm not a fan because I find it too hard to adjust the highs and mids to match the overbearing sub.

Focals are a great brand, though. I had them in my S2000.

 

You could if you could tune them to only produce 60-70hz or less(assuming you have them amp'd seperately from the system and can assign their frequencies). Dedicatting the rear speakers could work. Giving them more input responsibilities than the lows your trying to reproduce would distort sound. A small 8inch would do the trick but its not something you will be able to crank up the volume extremely loud, as 6x9's are not designed with bass in mind IMO*.

 

The Integral Audio subwoofer system takes up no additional space in the car.

http://www.integralaudio.com/index.p...er-system.html





This was purpose built and designed for this car. Its an amazing upgrade. I am happy with the sound and the product.

 

There is a fine line between "polarizing" and offensive. Don't forget that this board has a lot of members who have spent hard-earned money to purchase subwoofers - many of them from my company. But assuming that you didn't mean to be offensive, and for the sake of others reading this who might want more accurate information, I'll bite....

I'm not sure if you came up with that setup on your own, but that is a completely inappropriate speaker for the way you have configured it. The Focal Polyglass 690's are a coaxial speaker with an Fs of 63Hz. You can run them full range, but the low frequency output is going to be limited below 63Hz. By LP-ing them at 50Hz you asking them to reproduce the only area of the frequency spectrum they WEREN'T designed for. It's like asking the shortest kid in school to play center on the basketball team - they can certainly try, but they aren't going to be very good at it. It's a good speaker, just not for use as a subwoofer.

Additionally, the roll off is dependent on the enclosure - which in this case is lossy and of a very imprecise/indetermined volume - you aren't going to have a second order (12dB/octave) type roll off, and if you think you are I'd like to see the modeling & measurement you did to get there. Cabin gain does give you something close to a 12dB/octave boost, but that starts higher than 50Hz in the MINI because it is so small. The bottom line is that the assessment of the response is way off - and in no way is going to approximate a flat power response.

There are two types of power handling - thermally-limited and displacement-limited. Thermal is the ability of the voice-coil to dissipate heat. Displacement is physical - how far can the cone move. At low frequencies displacement is generally the only relevant one, and that is the case here. This is because distance the speaker diaphragm travels is inversely proportional to frequency. The Polyglass 690 has an XMAX of only 2.5mm. It also has 40% less cone area than the 10" in our Model 1101S, which has an XMAX of 12mm. Ignoring for a moment that multiple separate drivers DO NOT equate to a single larger driver, those two 690's would need 5 times the XMAX to have the same displacement ability.

The human ear's ability to localize sound is inversely proportional to wavelength. Most people can begin to tell where sound is coming from pretty well by 100Hz. Below 80Hz though, you can't discern the source location. Ignoring that fact for a moment though, the wavelength of sound at 80Hz is ~14ft. The distance between the center of the woofer in our subwoofer system and the center of the rear speakers is about 18". That's a phase angle of only 38 degrees. You're never going to notice that.

 

Typically 6X9s are regarded as the poor-man's subwoofer. I just went and bought the best 6X9s money could buy... Which really isn't THAT much money when you start putting them up against subs.

I'm satisfied with the level it reaches, and my limiting factor isn't even the 6X9s, it's the amp! My 6X9s are moving maybe 50% - 60% of their range of motion at max volume. I could push more power if I wanted.

The magnets on these 6X9s are large. They're tight, and they reproduce lows quite accurately. Like I said, the low pass filter is set at 50Hz. The system bangs. Also because the 6X9s are banging inward they phase each other out after the first pass. It makes it very unimpressive at stop lights, but inside the car you can make yourself deaf.

 

Thanks for jumping in Kevin. You know the science of sound. All I know is that your subwoofer kit sounds great. Plus its a stealthy install and VERY easy to remove if need be.

 

Not sure which manual you referenced, but the Solid 4 is only rated to 4 ohms when bridged. http://www.focal-america.com/wp-cont...olid4_Spec.pdf

It won't. But the short-circuit protection will. And if your amp doesn't go into protect mode right away, you probably don't have them wired parallel.

I'd suggest you double-check your wiring configuration to be sure. If you DO have them wired parallel and the amp isn't going into protect mode, there could be a problem with the protection circuitry. If that is the case, you won't realize you have a problem until you need a new amp.

 

I see this in my future


just gotta wait

 

Excuse me! But unless I'm mistaken the Focal Solid4 has a power rating of 200w into 4 ohms when bridged. Below are the Technical specifications from their web site located here: http://www.focal.com/en/car-audio-so...lis/solid4.php

Focal Solid 4
Technical specifications
High-pass filter 50 - 150Hz (12dB/oct)
Low-pass filter 50 - 150Hz (12dB/oct)
Remote control yes
Maximum cross section of speaker wires 10mm2 7 AWG
Fuse(s) 2 x 25A
Nominal power measured at 14.4V continuously into 4 Ohms THD + N<=1% 4 x 75W
Input impedance 20 kOhms
Damping factor @ 4 Ohms 50 to 1kHz
Signal/Noise ratio (RMS) >100dB (A)
Frequency response 10Hz - 60kHz
Input sensitivity 0.2 - 5V
Maximum cross section of power cables 35mm2 - 2 AWG
Protections - Short circuit - Thermal overload - Overvoltage - Polarity reversal
Dimensions (HxWxD) 13/4 x 1113/16 x 77/8
Signal/Noise ratio (1 Watt output) >80dB (A)
Nominal power measured at 14.4V continuously into 2 Ohms THD + N <= 1% 4 x 100W
THD + N @ 4Ohms 0.02% @ 1kHz
Power in bridged mode measured at 14.4V continuously into 4 Ohms THD + N<1% 2 x 200W

I think you can see that the last spec refers to the "bridged" rating. I'm very familar with focal/JM Labs products. I have used them for over 20 years. The amp you are using is not rated to drive a 2 ohm load in bridged mode and only a fool would do an installation that way regardless of the thermal protection circuit.

Kevin is being way too kind to you by explaining all the fundimental mistakes you have made. I wouldn't bother.

My original statement still stands... I doubt you made one valid point or argument in this whole thread.

You kind of remind me of Brer Rabbit and the Tar Baby... everytime you say something you make your situation worse.

 

I'm going by the manual that came with the amp, not the online spec sheet. I can make a scan when I get home, but I'm on the road til friday. And it is wired in parallel, I hard wired the entire car myself.