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View Full Version : Question about wiring in an additional woofer to existing components



ninjatek
06-30-2006, 09:16 PM
I currently have a set of Focal 130v2 5 1/4" + 1" tweet components

http://www.focal-america.com/Products/Polyglass/PolyglassV2.html

http://www.focal-america.com/Products/Largeimages/Large_Images/130V2_large.jpg

The amp I have will push 70x4 at 4 ohms, and I have the focals on the front two channels and infinity kappa 6x9's on the rear channel.

I want more midbass. I have the focals in qlogic kick panels (of which I seriously
reinforced with dynamat. I had to use a spacer for the focals because they were too deep, and I made the spacer out of about 15 layers of dynamat..

THe amp is pushing 70rms to each component set, at a 4 ohm load. The components are only rated to 60rms. However, if I give the amp a 2 ohm load, it will do 100 watts, so if I doubled up the components, I could get 50 watts rms to each components and get more overall power. Since the components are only rated at 60rms, I would rather just give them 50rms and have another 50rms to give to another component set.. However, I really dont want to add more tweets, I was just thinking about ordering the bigger 6.5"s focal woofers from the same line and putting them in the doors. Or I was thinking about getting a similar focal 6.5's.. This way I would have 6.5's in the doors, 5 1/4's and 1 inch tweets in the kicks with 100rms pushing the whole set.

If I order the 6.5's from the same line, they wont be 4 ohm speakers because its the 6.5 combined with the tweeter that gives a 4 ohm load. So if I want to give it a straight 2 ohm load, I need to find another woofer that is 4 ohms independantly. My only issue is how I would wire this in. THe amp has a crossover on it, but it would be set to low pass around 80hz. The components have a crossover that takes out the highs from the woofer. If I wire the 6.5 independant of the focal crossover, they will habe the lows taken out, but the woofer would be playing all the highs too.. I was thinking about just running the 6.5" in with the focal crossover.. Im not sure if the crossover is built for the lower impedance, or if it matters...

Question. Would it be best to wire the additional woofer in with the existing component's crossover, or run it independant and use something like a bass blocker to sweep out the highs?

squeak9798
06-30-2006, 09:38 PM
If I order the 6.5's from the same line, they wont be 4 ohm speakers because its the 6.5 combined with the tweeter that gives a 4 ohm load.

Generally if the comp set is rated to be 4ohms nominal, then the woofer itself will have an impedance of 4ohms and the tweeter will likely be anywhere from 4ohms to 8ohms.


Would it be best to wire the additional woofer in with the existing component's crossover,

You can't. The crossover and it's crossover point and other mechanisms are designed to be used with a specific impedance, in this case likely 4ohms (atleast on the woofer output). If you wired another woofer to the woofer output on the xover, you would present a 2ohm load to the woofer output on the crossover, altering the crossover point and causing other mechanisms, such as a zobel network, to be ineffective and probably cause decreased performance.

The most effective method of doing what you're proposing would be to run an active setup.

ninjatek
06-30-2006, 10:08 PM
The most effective method of doing what you're proposing would be to run an active setup.

i need to work with my existing amp. im not sure how I could go active in this situation... could I not just use an inline passive filter to remove a certain level of highs from the additional woofer?

atoz350
07-01-2006, 02:06 AM
You can so a semi active/passive setup by keeping the setup that you have right now, and running a larger midbass driver with it using its own amp. Just high pass your existing components to about 250hz and lowpass the midbass around the same. If you get an amp with an adjustable subsonic filter, you can cut the midbass at around 60hz - 80hz.

ninjatek
07-01-2006, 04:59 AM
im trying to work with my existing amp, which can handle a 2 ohm load... as of now, it is only seeing a 4 ohm load. im trying to find a way to hook up an additional mid bass driver to get more from the amp... which is why i wanted to hook the additional driver into the existing component's crossover..

squeak9798
07-01-2006, 09:59 AM
which is why i wanted to hook the additional driver into the existing component's crossover..

Which will not work, so scratch that from your list of options.


About the only thing you can do is either purchase a 6.5" woofer and custom design and build a 3-way crossover to run all 3 drivers (6.5" woofer, 5.25" woofer and tweeter), but this will take a lot of time and knowledge to properly design a custom crossover that will optimize the performance of the system. Or you could purchase a 6.5" component set and run the 6.5" woofer from the crossover that came with it's component setup and wire the inputs of that crossover directly to the amplifier outputs. Warning though; This may or may not work as you would have the tweeter output on the xover unused, and on some crossovers this will lead to a short circuit being presented to the amplifier...which your amplifier will not like at all and could possibly damage the amplifier.

After rereading the original post....the best option, out of the equipment you already have, is to ditch the rear speakers and use those rear outputs on the amplifier to power the auxillary woofers. Could the xovers on your amplifier actively cross the 6.5" woofer? If so, this option is a no-brainer IMHO.

Also, why not just purchase a whole new component set...one with a stronger mid driver that'll deliver the performance you are wanting?

ninjatek
07-01-2006, 01:04 PM
Which will not work, so scratch that from your list of options.


About the only thing you can do is either purchase a 6.5" woofer and custom design and build a 3-way crossover to run all 3 drivers (6.5" woofer, 5.25" woofer and tweeter), but this will take a lot of time and knowledge to properly design a custom crossover that will optimize the performance of the system. Or you could purchase a 6.5" component set and run the 6.5" woofer from the crossover that came with it's component setup and wire the inputs of that crossover directly to the amplifier outputs. Warning though; This may or may not work as you would have the tweeter output on the xover unused, and on some crossovers this will lead to a short circuit being presented to the amplifier...which your amplifier will not like at all and could possibly damage the amplifier.

After rereading the original post....the best option, out of the equipment you already have, is to ditch the rear speakers and use those rear outputs on the amplifier to power the auxillary woofers. Could the xovers on your amplifier actively cross the 6.5" woofer? If so, this option is a no-brainer IMHO.

Also, why not just purchase a whole new component set...one with a stronger mid driver that'll deliver the performance you are wanting?


The reason I dont want to step up to a new component set is because I really love the way my focals sound, and I would really just like to supplement them. I think I have decided that I am just going to buy an additional component set from teh same line, just with the bigger "6.5" woofer. This way I have identical tweeters and woofer structure. I will adjust the crossover on the new set to lessen the impact of the additional tweeters. This way I can take it down to a 2 ohm load and better distribute and utilize the power of the amp.

helotaxi
07-01-2006, 03:37 PM
You really aren't making better use of the power though. By going to 2 ohms you are running less power to the current set of comps and leaving less power for the new midbasses. Providing more than the rated power to a comp set isn't that big a deal since you really don't use much power at all thanks to the dynamic nature of music and the sensitivity of your ear to higher freqs. Having power on tap IS important for midbass and you will want to supply as much as possible. Running the amp at 2ohms decreases the ammount of power for the midbasses and decreases the ammount of reserve power for headroom.

As squeak recommended, I would run just an additional midbass rather than adding the tweeter, too. That midbass i would power off the rear channels of the amp and I would power the 6x9s off the HU. If the amp has a crossover, use it to split the signal between the comps and the midbass in the 200-300hz range (this will also raise the powerhandling of the comp set). This will give you the best sound with the amp and speakers that you already have. I would avoid adding the full second comp set because the extra tweet and the additional driver playin midrange will mess up the part of the sound that you currently like. Make sure you give the new midbass a good environment in which ot work. Properly deaden the door and properly separate the front and rear waves of the driver with either a sealed pod or a proper IB setup in the door.

ninjatek
07-01-2006, 03:58 PM
You really aren't making better use of the power though. By going to 2 ohms you are running less power to the current set of comps and leaving less power for the new midbasses. Providing more than the rated power to a comp set isn't that big a deal since you really don't use much power at all thanks to the dynamic nature of music and the sensitivity of your ear to higher freqs. Having power on tap IS important for midbass and you will want to supply as much as possible. Running the amp at 2ohms decreases the ammount of power for the midbasses and decreases the ammount of reserve power for headroom.

As squeak recommended, I would run just an additional midbass rather than adding the tweeter, too. That midbass i would power off the rear channels of the amp and I would power the 6x9s off the HU. If the amp has a crossover, use it to split the signal between the comps and the midbass in the 200-300hz range (this will also raise the powerhandling of the comp set). This will give you the best sound with the amp and speakers that you already have. I would avoid adding the full second comp set because the extra tweet and the additional driver playin midrange will mess up the part of the sound that you currently like. Make sure you give the new midbass a good environment in which ot work. Properly deaden the door and properly separate the front and rear waves of the driver with either a sealed pod or a proper IB setup in the door.

thanks for the post.

I would agree about making better use if I haven't already experienced how the current components are handling the power they are being given. As of now, the amp is pushing 70x2 rms to the pair. With the gain set dead center (nominal), I can take the HU to 24/33 with the eq flat before the woofers start popping. If I increase the gain, the max volume level I can push to goes down... The speakers are rated up to 60rms. If I drop to 2ohms, they would get a rated 50x2rms to the pair, and leave another 50x2rms for another set.

The reason for me considering the upgrade is to get additional midbass. The rear 6x9's, being ran from the amp ( channel 3/4 from the amp also pushing the components) provide a good amount of midbass, and if I take these off the amp, I know that whatever I gain from additional components will be lost by taking the 6x9's off the amp.

So, I am considering the logic in your post about leaving headroom for power, but to me, it seems like, considering the efficiency of the components, it would be better to give the components just under their rated power and have another set with the same power, than to drop out the 6x9's, loose that midbass, only to give the new components/midbass woofer more power than it can take...

I'm really starting to lean towards getting an additional set of components and just setting the tweeter level to -12db on the crossover so that the additional highs arent overbearing..
btw, if you go to general discussion, i have a post with pics of my car. The current components are in kick panels (that i seriously sound deadened). The previous owner of the car already dynamatted the doors.

I have some thinking to do... The whole purpose of this is to get MORE volume out of my existing amp.

Gary S
07-01-2006, 09:30 PM
Which will not work, so scratch that from your list of options.




Also, why not just purchase a whole new component set...one with a stronger mid driver that'll deliver the performance you are wanting?


- I think that's the best suggestion.... lots of sets out there with 4.8mm or more excursion... some 3-ohm versions also... Kicker, Orion, PPI... set the crossover lower around 60hz and you would be in business.

I would get the best kick panel install with the best components first and listen to that before you start throwing drivers all over the car and make it look like The Best Little ***** House in Texas. Your imaging and soundstage will be ruined.

But for what I said to work, the kicks would have to be sealed.


Edit: For the soccer moms out there, I did not say anything bad... it was just a movie quote!

Also: While i like the kevlar and "W" series focals, the "V" series are nothing special... they can easily be replaced.

ninjatek
07-01-2006, 10:07 PM
- I think that's the best suggestion.... lots of sets out there with 4.8mm or more excursion... some 3-ohm versions also... Kicker, Orion, PPI... set the crossover lower around 60hz and you would be in business.

I would get the best kick panel install with the best components first and listen to that before you start throwing drivers all over the car and make it look like The Best Little ***** House in Texas. Your imaging and soundstage will be ruined.

But for what I said to work, the kicks would have to be sealed.


Edit: For the soccer moms out there, I did not say anything bad... it was just a movie quote!

Also: While i like the kevlar and "W" series focals, the "V" series are nothing special... they can easily be replaced.

I'm happy with the focals I have, I got them cheap from a friend/dealer and I can still do the same. The current components are already in kick panels, and they are deadened with dynamat pretty heavily. They are not completely sealed, but I did use some foam to help in that regard.

The new components would be put in factory locations, which would be the woofers in the doors and the tweets in the dash.

Pics of existing setup

http://i15.photobucket.com/albums/a371/techboyjk/my%20car/accord_kicks_2.jpg

http://i15.photobucket.com/albums/a371/techboyjk/my%20car/accord_kicks_1.jpg

squeak9798
07-01-2006, 10:18 PM
Those look like Q-Logics.

Willing to build your own kicks, or have your dealer/friend build them for you?

ninjatek
07-01-2006, 10:30 PM
Those look like Q-Logics.

Willing to build your own kicks, or have your dealer/friend build them for you?

btw, I love tool... 10,000 days has been in my cd player for the past 3 days. I went to KC back in MAY (from St. Louis) to see them live... they sound soo good loud, in concert or in the car...

in regards to your post.......

nope. I have 2 layers of dynamat on these things. They seriously weight 3-4 times what they did w/o the dynamat. while they aren't completely sealed, I am willing to modify them to increase the seal. I have foam on the inside lip as well to help prevent free air flow from behind the kicks.. I like how they look "factory". I have gone through custom kicks and with what I have I dont see any reason not to work with what I have instead of starting over from scratch. Also, there isnt much room down there, and if I went custom, I highly doubt anything less than a seriously expensive kick could be formed to wrap around my hood release, etc.

its not that the components dont have good midbass, they sound great, but I want more, and its at a point that only additional components will bring it. (that or a much better, more expensive set) id rather just double it up with the same components so that there is a consistency in the material and design creating the sounds...

helotaxi
07-01-2006, 11:51 PM
Additional components aren't going to fix the midbass problem or help with you the mids that you have popping. They are popping because you are feeding them too low a signal, not necessarily too much power. By raising the crossover freq, you can run them at a higher volume without them popping. To that add a dedicated midbass with its own amp channel crossed over between the mid and sub and you are in business. We aren't talking out our *** here, we actually know what does and does not work well.

ninjatek
07-02-2006, 03:03 PM
Additional components aren't going to fix the midbass problem or help with you the mids that you have popping. They are popping because you are feeding them too low a signal, not necessarily too much power. By raising the crossover freq, you can run them at a higher volume without them popping. To that add a dedicated midbass with its own amp channel crossed over between the mid and sub and you are in business. We aren't talking out our *** here, we actually know what does and does not work well.

well let me just say that im not trying to "stop" the popping in the current components. they are loud, and I simply think the popping is from me taking them to the max. so rather than trying to milk more out of them (and i have plenty of power left), id rather sacrifice some of that unused headroom to drop it to 2 ohms and be able to add an identical set.

Ive come to the decision, after listening to what i have, that I want more from the entire front stage. mids and highs. my subs can more than keep up and they are responsive up to 400hz, so i will probably roll them off at 150 or so.

so yea, regarding what I was originally dispusting in the post, the ideal thing would be to get seperate midbasses and amp them, but now that I have had time to think about what I really want, i think i will be best to double up on the components.

I have the 5.25 woofer component set. My doors accept 6.5, and while the tweeter that comes with the set is the same as in mine, the woofer is bigger.. Should I stick to the same size woofer and just use a spacer in the door? aka stick with the exact same component set for the sake of consistency?

Gary S
07-02-2006, 06:55 PM
Those Q-Forms can be sealed, I've seen it before... talk to some installers/shops in your area. If done well, It will make a noticeable difference.

Q-Forms are a double-edged sword... they get the speakers in the right place "speaker placement", but they are not enclosures "installation quality". The makers should be shot for selling an inferior product. I'm not joking. If I still worked with a retail company, the first thing I would do is have them pulled from the shelves... along with slick 50 that clogs oil filters.

helotaxi
07-02-2006, 07:02 PM
The mids you currently have are popping at high volume because you are feeding them too low a frequency. For the same power level a speaker tries to move twice as far at half the freq. For example, your mids would probably be fine if you highpassed them in the 120hz range, but at 60hz they would reach their max excursion and then some with the same amount of power. By adding a dedicated midbass, you can move the crossover point higher and they won't pop at all.

The next problem with your idea is that you will have to feed the new midbass and the current midrange the same frequencies. The frequencies, not the power are causing the popping. You need to send these freqs to the new midbass to get any midbass response and the current midranges clearly can't handle them, so simply adding another driver to the mix wont fix this.

Problem three is cancellation. If you add another midrange and expect that to fix the lack of midbass response without addressing cancellation issues and have them playing the same frequencies, chances are you will do more harm to the response of the system than good and what litle midbass you do currently have will go away. Adding a second tweeter will also trash the high freq response of the system and leave you with a nasty, peaky response. Ading extra tweeters to a system when you care about he quality of the sound is one of the last things you really want to do.

I'm at a loss as to why you think that adding a second of a midrange that isn't producing adequate midbass and can't handle the frequencies in question without bottoming out is going to help the problem anyway.

You need a different driver to get good midbass. The 5 1/4s that you have now will not suffice and adding a second on each side won't help either. You need to provide power to that new driver to get good results from it. By running the new midbass on a seperate amp channel, you can set different frequencies for the midbasses and the midranges in the component set. You can also control the relative level of the midbasses and the components. You said the components were loud enough for you. The ammount of power that gets them loud enough for you will not be enough for good midbass. By wiring them on to the same channel, you will have the same power going to the comps as to the midbasses. By using the 4 channel amp to run the whole of the front stage, you can dial down the comps and still let the midbasses get the powr they need to perform.

camry_tuner
07-02-2006, 08:53 PM
y not just go /w a 3-way set up from focal if you can get them for cheap. they do offer a 165v3, which is the 3-way set up, throw the 6.5 midbass in the door, and modify the kick panel to fit the midrange. then just bridge ur amp to power them, they need ~100 iirc. then run ur kappas off the headunit. Sell your 130v2's and you're set

ninjatek
07-02-2006, 09:00 PM
y not just go /w a 3-way set up from focal if you can get them for cheap. they do offer a 165v3, which is the 3-way set up, throw the 6.5 midbass in the door, and modify the kick panel to fit the midrange. then just bridge ur amp to power them, they need ~100 iirc. then run ur kappas off the headunit. Sell your 130v2's and you're set

dual components would allow me to run at 2 ohms and get the extra power that I need to get the volume that i want.

helotaxi
07-03-2006, 01:01 AM
dual components would allow me to run at 2 ohms and get the extra power that I need to get the volume that i want.
You're not listening. You will not get the "extra volume" that you think you will. You're not increasing power by that much and the differing drivers are going to cause cancellation to the point hat you will be luck to stay at the level that you are at now.

Do what you want. You seem so set in what you are going to do that I don't know why you even made a thread asking opinions because you have ignored every bit of advice you have been given.

ninjatek
07-03-2006, 03:19 PM
You're not listening. You will not get the "extra volume" that you think you will. You're not increasing power by that much and the differing drivers are going to cause cancellation to the point hat you will be luck to stay at the level that you are at now.

Do what you want. You seem so set in what you are going to do that I don't know why you even made a thread asking opinions because you have ignored every bit of advice you have been given.

hmmmm... what if I use the exact same components? same size drivers? etc?

my logic is that the components are rated at 60rms. I could give one pair 70rms, or give 2 pair 50rms each.

camry_tuner
07-03-2006, 04:31 PM
just get a 3-way, bridge your amp, and run the rear fill off ur headunit, with that kind of front stage, you probably dont even need rear fill

o yea, btw, the 3-way set up will probably be louder than what you are planning on doing...

helotaxi
07-03-2006, 04:32 PM
You want more midbass and 5 1/4s aren't going to do that.

Go back and read my previous posts. I have explained in detail why adding another set of components is not a good idea and why simply adding a dedicated midbass is a much better option.

Forget about power to the mids. You will only get on the order of 1 db more volume out of adding a second set of comps and most of that will be lost to cancellation. Another of the same set still won't be able to give you midbass and the rest of the freq range will be hurt as well.

GordonW
07-03-2006, 05:44 PM
Use a coil and a Zobel (impedence compensation network) to block everything but midbass and bass from the second woofer, and parallel it BEFORE the existing crossover.

Basically, you're making a "2.5 way" speaker system... the second woofer is "helping" on the bottom, where the main woofer usually needs help most.

A good starting point would probably be around 300 Hz... for a 4 ohm midbass driver, that'd be about a 2 mH coil. A good starting point for a Zobel would be about a 5 ohm resistor and a 15uf cap, for a driver like that.

I've done this before, for some of the early comp cars I worked on... and it DEFINITELY worked. As long as you can get the new woofer NEAR the original one from the component set, they WILL combine output, and be significantly louder on the bottom end than a single driver...

Regards,
Gordon.