Hey there, first time poster here.
I've had a decent amount of experiance installing aftermarket audio systems, and am attemping my first truely custom install. I would like your opinions on my few questions and my overall setup, it will be SQ oriented, I have no need for useless ears.
Head Unit(in custom dash panel): Pioneer Premier DEH-P880PRS
Front speakers in fiberglass door pods(since I drive a stick and my feet are big): Infinity Perfect 6.1 components
Rear speakers in a location to be decided: Infinity Perfect 6.1 components
Hifonics ZXi 6406 4 channel amp for components
Subs: I've decided to go with two 12" Infinity Kappa Perfects, but have not yet decided what Ohm or which amp to power them. Reccomendations?
I would like to go with Hifonics to match my other amp but I'm not going to be in car shows or anything, so it really doesnt matter.
For my sub box, I have decided to remove my rear seat(like anybody can fit back there anyway) and make a custom wall with the subs in it and a box(with a divider between the two of course) 'glassed onto the back of it.
Here is what I have to work with, sorry for the lighting, I will take better pictures if needed. The first picture is my old setup (test fit) with the speaker boxes turned around to smile for the camera.
http://www.cardomain.com/ride/2109074/1
I have not yet decided to mount the subs in the wall facing the cabin or to mount them in the 'glassed box facing the rear of the hatch. I havent really had much experience with the different configurations in a hatchback, but I would assume I would get better sound quality with the subs facing the cabin. Keep in mind it is a hatchback.
Sorry for the long post, but any advice or comments over any part of the setup will be greatly appreciated.
Thanks in advance.
Gary
Replies (13)
swez on 07/6/2006 08:11:03
Gary,
You have some nice ideas brewing here. However, am wondering if you are willing to run a single sub here. Frankly 350 - 500 watts RMS to a single sub is plenty of bass in a hatchback design.
We can expect a nice peak in bass due to "cabin gain" ( or, transfer function) affects in a hatchback of roughly +12-15dB. If you like it low and feel the bass, go for a ported design enclosure, port tuned to about 30 Hz.
The tricky part is the rear mid/high component mounting locations. These will be tricky to dial in and balance them out with your front comps as they will be notably louder and "beaming" at head level. If not careful, the upper mids and highs will sear your ears off. (on axis mounted to your wall, will surely give that effect) Not desirable at all for high SQ applications. Another tactic can be used for better dispersion and less "beaming" affect.
I like the enclosures shown in your pics. It's just a matter of placement for them and proper phase alignment to your front comps and sub.
Care to collaberate on some ideas?
Swez
Ash on 07/6/2006 18:12:59
Believe it or not, I had a 92' 240 up to a year ago with only two 8"s mounted in a sealed box with .33 cft each, driven with a JBL BP300.1 The box was more rectangle in order to set the drivers closer to the back. With a F3 of around 70-80hz, they matched the car perfectly as the hatchback model has a high lift of around 40hz which extended the bass very smoothly. Very SQ'ish. The sealed trick in this car is to have a low Q (.7) with a high rolloff to avoid the large hump around 40.
If you go ported to the low 30's in this car you will need to have a EQ (HU equipped will work also) to cut down the lows around 40-45hz a bit to keep the response even.
As for rear fill, I didn't use. I fitted 5.25" comps in the doors with the tweets on the far corners on the dash.
One of the cleanest systems I've had and very simple at that.
Grdevs24zero on 07/6/2006 19:05:46
I'm always up for some Ideas, and thank you both for the quick responses. I have edited the link on the first post with more pictures of the old install and the space I have to work with for the new one. If there is anybody out there that would like pics from other angles or what not feel free to ask, film is free for a digi cam.
I have heard this Infinity sub before in my friends car, we built a sealed box for his coupe. He is using a not-so-dandy amp to power it so I guess I didn't take into account the difference between hatchbacks and coupes and bad amps and good amps. However, the crispness and tone of the sound is something I've never heard in any sub I've had the chance to experience. It makes no difference to me how many subs I use as long as it sounds good.
I am aware of the staging and phase of the four component sets(I want four because I dont want to know the sound is coming from the front) and I just used the fader on the head unit and amp gains on the last install for a simple way to balance it out.
Are there any suggestions on where I should aim the door panel pods(I have never worked with components before, just co- and tri-axles). I am assuming that slightly up and back would be the Ideal position for a set of comps in the front, as it is the most popular.
Rear comps locations have given me the run-around since I have started thinking about this install, about 4 months ago, and have changed locations in my mind almost every week. The stock locations are slightly angled toward the cabin, but are designed for 6x9" and do not have much room to angle any round speakers for better imaging. Then I saw the rear arm rests(little cut outs in the pics, look like funny shaped depressed eggs) and thought about placing them in a 'glassed box angled forward(toward the cabin more) slightly. Then I started thinking as to how I would be able to keep the fiberglass attached to the plastic. I'm guessing I can use some plastic adhesion promoter(like I use to paint plastic bumpers) so the fiberglass and resin will adhere better.
The simplest solution would probably be to make more enclosures on top of the sub box like I did in the last install, but thats brings into play the harshness in the high freq. range that make me, and others I would think, cringe.
As for ported or sealed, I love the sound a ported box gives you, but I don't know if I have enough c^3ft of space next to the wall for the design. The whole purpose of this install was better sound while still being able to get the spare tire out and having access to the fuel sending unit(forward and right of the spare) without having to lift 60 lbs. sub, box, and amps out to get it done. Because of this I am leaning toward a sealed box(s) for more space.
However, anything is possible and I'm sure with your help I can pull off a ported box without taking up an insanely large amount of space typical of ported enclosures.
I thinks thats it, thanks again for the help.
Gary
swez on 07/6/2006 20:41:20
Am thinking a compact sealed enclosure may serve you very well here, based on Ash's comments. (I defer to his idea as he has a good deal of experience with how certain enclosures mate with the acoustical response in various vehicles) Here, he cabin gain factor on hatchbacks is likely to be substantial. Porting a box may compound that to a point where deep bass becomes less manageable. Ash makes a good point in his illustration as well. (I'll take his comments on this one as gosple)
Rear Comps:
Feel free to try a variety of locations and firing angles here. The enclosures look nice and may work very well for the added Midbass many desire from the rear stage. Consider aiming them at the rear hatch and bouncing mids/highs off the rear window and "get a feel" for the indirect radiation pattern this might yield.
We already know that direct radiating these speakers toward the front, provide harsh and overbearing upper mids and highs. (Rip your head off type stuff here) Aiming to the sides at 20-30 degree angles, off axis, will help tone down the highs and that may be all that is needed.
Also, try reversed polarity on these speakers and see what effects that may have on space/time aligments or cancellations within the vehicle. If MB/MR sound hollow and thin as a whole, that's not what you want.
Front Comps:
The pods for MB/MR down low on the doors, are always a good option. Using a slight upward angle may help bring out the mids, but not hurt the MB. As for tweeters, consider several different placements on a trial basis. Just stick them with 2-way tape to various locations and determine the best possible sound staging for them.
Some guys like their tweets high up on the doors and angled toward the windshield or dome light. Others mount tweets in the "A" pillars, angled toward the rear view mirror. Avoid aiming tweets directly at the driver and passengers' heads. This creates "beaming" highs that can be very difficult to tame later. An "off axis" tweeter usually sounds most pleasing and natural when they are obviously there, but not cutting your ears to shreds.
Comments?
Swez
Grdevs24zero on 07/7/2006 03:31:55
I should have mentioned before, I do not have anything left of the old setup. My sub, amp, and box went into my moms car, as well as my front speakers. My 4 channel amp and rear speakers/boxes went to a friend, and the head unit is in my garage awaiting repairs.
I could however, build those boxes again, with minor adjustments. They were made to fit in the back deck in my old coupe.
I have updated the cardomain page again with more pics of different speaker locations I tried out earlier today. I will experiment more tomorrow with different cutouts and locations and most likely make up my desicion for the rear stage.
Rear:
I am interested in what it would sound like with the speakers firing backwards, like Swez suggested. In my previous experiences, when speakers(especially highs) fire into glass, it gives the music a fake feel to it. This was with cheap speakers though, so I don't know how it would effect the sound in a properly tuned setup.
Fronts:
I could place the tweets in the very top of the A pillar next to the top line of the windshield, and I think it would be a very livable setup, at about 30^ off axis. This would leave room for my auto seatbelts to keep working and leave me room for my boost/fuel pressure guages.
I could also place them down in the doors with the mids, which was the origional plan with the cutout I placed on the door. How does everybody think this would sound? I cant imagine it being too bad, the car came with components from the factory in almost the exact same position.
For the amps and sub, can you think of a better sounding setup for $500-$800? I don't know if I should get a 2 Ohm or 4 Ohm sub, and if I should get a 2 channel amp and bridge it (like I did with my old Kicker) or go with a mono?
I've been looking hard to find an Adire Brahma or Koda with no luck, as I have not heard either of the two yet. It is very hard to find an audio shop here in Oklahoma with any of the really high end stuff.
On a side note: By switching the polarity, you mean hokking them up backwards? I've always thought that was bad for the speakers.
Gary
swez on 07/7/2006 11:38:12
I saw your new pics and the rear stock locations for the back speakers are just so-so. The new location you show, has merit and that can be a useful plan if you wish.
Yes, switching polaity on the rear speakers will not hurt the speakers. However, depending on where they are located & aimed, you may note some degradation of MB and cancellations in the cabin.
Much of this has to do with blending the front and rear speakers for best overall SQ performance. The time it takes rear audio signals to reach the targeted listening area are the key. The closer the front and rear signals are in phase alignment to each other at the listeners ears, the better they will sound. (minimal phase cancellations are the goal)
Got all that?
Swez
Grdevs24zero on 07/7/2006 16:32:29
Yeah I got all that, sound travels at about 1100 feet per second, which means 12" is about a 1 millisecond sound delay.
cplkittle on 07/10/2006 00:55:42
Swez, just curious why you recommended a 30 Hz tuned port in such a small vehicle. I have had good luck with 28-30 Hz on the ported side of a 4th order in some midsized SUVs including my own personal ride, but never thought anything that low did very well in smaller vehicles unless you are talking about a 15" driver.
Not ragging you, just curious..
Grdevs24zero..
Since you are looking for SQ and not showing the vehicle, hook up the rear components with plenty of slack in the wires, and move them around a bit with them playing to get the best sound location versus the best cosmetic location.
Grdevs24zero on 07/10/2006 04:26:11
I planned on doing just that.
This is the sub I plan on getting, it comes in dual or single coil, what are the advantages to a DVC over a SVC?
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14488
These are the amps I have to choose from.(post a link if you know of any better)
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16367
http://www.onlinecarstereo.com/CarAudio/ProductReview.aspx?ProductID=16412
Any comments?
Gary
swez on 07/10/2006 08:31:20
The SVC 4 ohm is good for 2 channel amps that can be bridged MONO. When using Class D amps, the DVC gives more wiring options, (Multi-sub installs) and a 2 ohm load for a single sub to get the most power from a given amp design. Also, most DVC subs can take more power than a conventional SVC in most brand lines.
Here, the most efficient combination would be:
1. Infinity Kappa Perfect 12d VQ (4+4 DVC) 2 ohms
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14490
2. Alpine MRP-M450
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16411
Here, we get a net 2 ohm load from the sub and 400 RMS @ 2 ohms from this amp. The amp consumes less power, but meets sub requirements and is a few bucks cheaper as well.
Yes, you can still use the M650 if you wish. It will give the sub reserve RMS power when you really want some serious bass and not clip the amp. This sub can handle the extra power for short durations too. However, a sealed enclosure design would help the sub with extra back pressure to prevent/limit over excursion at high bass SPL levels.
Swez
PS Kit,
The PTF can be set anywhere one likes, depending on the preference of the listener and the vehicle used. As you well know, cabin gain effects (transfer function) come into play with all vehicles. (a +10 to 15 dB gain at certain frequencies, near cabin resonance)
We also know that the PTF target will boost bass in that region by at least +3dB right? Well, if one is looking for a reasonably flat response curve, going to a low PTF will re-enforce deep bass that cannot be heard as well, due to the roll-off characteristics of a given sub/enclosure design. At 30 - 35 Hz., we can pick up +3dB of deep lows and not have an overly exaggerated bump in SPL, above 40-55 Hz. (A lower F3 point) Here, we feel more low bass than hearing it.
However, if a guy wants that added bump at say 40-50 Hz., then we can set PTF close to 40 Hz., and he'll get a substantial spike in bass SPL above 40 Hz. Fine for showing off... (SPL Slam) but as you well know, not the most balanced approach for SQ systems.
Really, it's a personal preference type thing. Do we want a low F3 point and smoother bass above say 35 Hz. Or, we can do the "Big Bump" thing and take full advantage of transfer function, use a higher PTF point and have a higher F3 point.
As you well know, it really depends on the "listener's preferences" and cabin gain characteristics of a given vehicle. That's why I often go either sealed or a low PTF port target. It's less exaggerated and sounds more natural to an SQ guy. But, we all have different preferences. Knowing what those preferences are, we adjust the parameters accordingly. (No offense taken either... good question)
cplkittle on 07/10/2006 14:30:54
thanks for bringing it all back to me. That makes so much sense. I got lost in the SPL game over the last year, and going back to the basics and thinking 'on paper' rather than on the fly is something I need to get back to.
Grdevs24zero on 07/10/2006 15:24:05
Ok, now since that sub is a DVC 4 Ohm, wiring the two coils in parralel will net you a 2 ohm load? This is assuming I'm correct that you have to wire both coils.
DominicanKiddo on 07/10/2006 22:29:52
Look at this site from our friends @ crutchfield http://www.crutchfieldadvisor.com/learningcenter/car/subwoofers_wiring.html. It has all the setups you need. And to answer your question, Yes you get 2Ohm in parallel 8Ohm in series.
To wire your speakers in parallel, connect the positive (+) leads of both speakers to the amplifier's positive (+) terminal, and the negative (-) leads of both speakers to the amp's negative (-) terminal. You can increase your system's impact dramatically by hooking up two subwoofers (in parallel) to each of your amp's channels.
I've had a decent amount of experiance installing aftermarket audio systems, and am attemping my first truely custom install. I would like your opinions on my few questions and my overall setup, it will be SQ oriented, I have no need for useless ears.
Head Unit(in custom dash panel): Pioneer Premier DEH-P880PRS
Front speakers in fiberglass door pods(since I drive a stick and my feet are big): Infinity Perfect 6.1 components
Rear speakers in a location to be decided: Infinity Perfect 6.1 components
Hifonics ZXi 6406 4 channel amp for components
Subs: I've decided to go with two 12" Infinity Kappa Perfects, but have not yet decided what Ohm or which amp to power them. Reccomendations?
I would like to go with Hifonics to match my other amp but I'm not going to be in car shows or anything, so it really doesnt matter.
For my sub box, I have decided to remove my rear seat(like anybody can fit back there anyway) and make a custom wall with the subs in it and a box(with a divider between the two of course) 'glassed onto the back of it.
Here is what I have to work with, sorry for the lighting, I will take better pictures if needed. The first picture is my old setup (test fit) with the speaker boxes turned around to smile for the camera.
http://www.cardomain.com/ride/2109074/1
I have not yet decided to mount the subs in the wall facing the cabin or to mount them in the 'glassed box facing the rear of the hatch. I havent really had much experience with the different configurations in a hatchback, but I would assume I would get better sound quality with the subs facing the cabin. Keep in mind it is a hatchback.
Sorry for the long post, but any advice or comments over any part of the setup will be greatly appreciated.
Thanks in advance.
Gary
Replies (13)
swez on 07/6/2006 08:11:03
Gary,
You have some nice ideas brewing here. However, am wondering if you are willing to run a single sub here. Frankly 350 - 500 watts RMS to a single sub is plenty of bass in a hatchback design.
We can expect a nice peak in bass due to "cabin gain" ( or, transfer function) affects in a hatchback of roughly +12-15dB. If you like it low and feel the bass, go for a ported design enclosure, port tuned to about 30 Hz.
The tricky part is the rear mid/high component mounting locations. These will be tricky to dial in and balance them out with your front comps as they will be notably louder and "beaming" at head level. If not careful, the upper mids and highs will sear your ears off. (on axis mounted to your wall, will surely give that effect) Not desirable at all for high SQ applications. Another tactic can be used for better dispersion and less "beaming" affect.
I like the enclosures shown in your pics. It's just a matter of placement for them and proper phase alignment to your front comps and sub.
Care to collaberate on some ideas?
Swez
Ash on 07/6/2006 18:12:59
Believe it or not, I had a 92' 240 up to a year ago with only two 8"s mounted in a sealed box with .33 cft each, driven with a JBL BP300.1 The box was more rectangle in order to set the drivers closer to the back. With a F3 of around 70-80hz, they matched the car perfectly as the hatchback model has a high lift of around 40hz which extended the bass very smoothly. Very SQ'ish. The sealed trick in this car is to have a low Q (.7) with a high rolloff to avoid the large hump around 40.
If you go ported to the low 30's in this car you will need to have a EQ (HU equipped will work also) to cut down the lows around 40-45hz a bit to keep the response even.
As for rear fill, I didn't use. I fitted 5.25" comps in the doors with the tweets on the far corners on the dash.
One of the cleanest systems I've had and very simple at that.
Grdevs24zero on 07/6/2006 19:05:46
I'm always up for some Ideas, and thank you both for the quick responses. I have edited the link on the first post with more pictures of the old install and the space I have to work with for the new one. If there is anybody out there that would like pics from other angles or what not feel free to ask, film is free for a digi cam.
I have heard this Infinity sub before in my friends car, we built a sealed box for his coupe. He is using a not-so-dandy amp to power it so I guess I didn't take into account the difference between hatchbacks and coupes and bad amps and good amps. However, the crispness and tone of the sound is something I've never heard in any sub I've had the chance to experience. It makes no difference to me how many subs I use as long as it sounds good.
I am aware of the staging and phase of the four component sets(I want four because I dont want to know the sound is coming from the front) and I just used the fader on the head unit and amp gains on the last install for a simple way to balance it out.
Are there any suggestions on where I should aim the door panel pods(I have never worked with components before, just co- and tri-axles). I am assuming that slightly up and back would be the Ideal position for a set of comps in the front, as it is the most popular.
Rear comps locations have given me the run-around since I have started thinking about this install, about 4 months ago, and have changed locations in my mind almost every week. The stock locations are slightly angled toward the cabin, but are designed for 6x9" and do not have much room to angle any round speakers for better imaging. Then I saw the rear arm rests(little cut outs in the pics, look like funny shaped depressed eggs) and thought about placing them in a 'glassed box angled forward(toward the cabin more) slightly. Then I started thinking as to how I would be able to keep the fiberglass attached to the plastic. I'm guessing I can use some plastic adhesion promoter(like I use to paint plastic bumpers) so the fiberglass and resin will adhere better.
The simplest solution would probably be to make more enclosures on top of the sub box like I did in the last install, but thats brings into play the harshness in the high freq. range that make me, and others I would think, cringe.
As for ported or sealed, I love the sound a ported box gives you, but I don't know if I have enough c^3ft of space next to the wall for the design. The whole purpose of this install was better sound while still being able to get the spare tire out and having access to the fuel sending unit(forward and right of the spare) without having to lift 60 lbs. sub, box, and amps out to get it done. Because of this I am leaning toward a sealed box(s) for more space.
However, anything is possible and I'm sure with your help I can pull off a ported box without taking up an insanely large amount of space typical of ported enclosures.
I thinks thats it, thanks again for the help.
Gary
swez on 07/6/2006 20:41:20
Am thinking a compact sealed enclosure may serve you very well here, based on Ash's comments. (I defer to his idea as he has a good deal of experience with how certain enclosures mate with the acoustical response in various vehicles) Here, he cabin gain factor on hatchbacks is likely to be substantial. Porting a box may compound that to a point where deep bass becomes less manageable. Ash makes a good point in his illustration as well. (I'll take his comments on this one as gosple)
Rear Comps:
Feel free to try a variety of locations and firing angles here. The enclosures look nice and may work very well for the added Midbass many desire from the rear stage. Consider aiming them at the rear hatch and bouncing mids/highs off the rear window and "get a feel" for the indirect radiation pattern this might yield.
We already know that direct radiating these speakers toward the front, provide harsh and overbearing upper mids and highs. (Rip your head off type stuff here) Aiming to the sides at 20-30 degree angles, off axis, will help tone down the highs and that may be all that is needed.
Also, try reversed polarity on these speakers and see what effects that may have on space/time aligments or cancellations within the vehicle. If MB/MR sound hollow and thin as a whole, that's not what you want.
Front Comps:
The pods for MB/MR down low on the doors, are always a good option. Using a slight upward angle may help bring out the mids, but not hurt the MB. As for tweeters, consider several different placements on a trial basis. Just stick them with 2-way tape to various locations and determine the best possible sound staging for them.
Some guys like their tweets high up on the doors and angled toward the windshield or dome light. Others mount tweets in the "A" pillars, angled toward the rear view mirror. Avoid aiming tweets directly at the driver and passengers' heads. This creates "beaming" highs that can be very difficult to tame later. An "off axis" tweeter usually sounds most pleasing and natural when they are obviously there, but not cutting your ears to shreds.
Comments?
Swez
Grdevs24zero on 07/7/2006 03:31:55
I should have mentioned before, I do not have anything left of the old setup. My sub, amp, and box went into my moms car, as well as my front speakers. My 4 channel amp and rear speakers/boxes went to a friend, and the head unit is in my garage awaiting repairs.
I could however, build those boxes again, with minor adjustments. They were made to fit in the back deck in my old coupe.
I have updated the cardomain page again with more pics of different speaker locations I tried out earlier today. I will experiment more tomorrow with different cutouts and locations and most likely make up my desicion for the rear stage.
Rear:
I am interested in what it would sound like with the speakers firing backwards, like Swez suggested. In my previous experiences, when speakers(especially highs) fire into glass, it gives the music a fake feel to it. This was with cheap speakers though, so I don't know how it would effect the sound in a properly tuned setup.
Fronts:
I could place the tweets in the very top of the A pillar next to the top line of the windshield, and I think it would be a very livable setup, at about 30^ off axis. This would leave room for my auto seatbelts to keep working and leave me room for my boost/fuel pressure guages.
I could also place them down in the doors with the mids, which was the origional plan with the cutout I placed on the door. How does everybody think this would sound? I cant imagine it being too bad, the car came with components from the factory in almost the exact same position.
For the amps and sub, can you think of a better sounding setup for $500-$800? I don't know if I should get a 2 Ohm or 4 Ohm sub, and if I should get a 2 channel amp and bridge it (like I did with my old Kicker) or go with a mono?
I've been looking hard to find an Adire Brahma or Koda with no luck, as I have not heard either of the two yet. It is very hard to find an audio shop here in Oklahoma with any of the really high end stuff.
On a side note: By switching the polarity, you mean hokking them up backwards? I've always thought that was bad for the speakers.
Gary
swez on 07/7/2006 11:38:12
I saw your new pics and the rear stock locations for the back speakers are just so-so. The new location you show, has merit and that can be a useful plan if you wish.
Yes, switching polaity on the rear speakers will not hurt the speakers. However, depending on where they are located & aimed, you may note some degradation of MB and cancellations in the cabin.
Much of this has to do with blending the front and rear speakers for best overall SQ performance. The time it takes rear audio signals to reach the targeted listening area are the key. The closer the front and rear signals are in phase alignment to each other at the listeners ears, the better they will sound. (minimal phase cancellations are the goal)
Got all that?
Swez
Grdevs24zero on 07/7/2006 16:32:29
Yeah I got all that, sound travels at about 1100 feet per second, which means 12" is about a 1 millisecond sound delay.
cplkittle on 07/10/2006 00:55:42
Swez, just curious why you recommended a 30 Hz tuned port in such a small vehicle. I have had good luck with 28-30 Hz on the ported side of a 4th order in some midsized SUVs including my own personal ride, but never thought anything that low did very well in smaller vehicles unless you are talking about a 15" driver.
Not ragging you, just curious..
Grdevs24zero..
Since you are looking for SQ and not showing the vehicle, hook up the rear components with plenty of slack in the wires, and move them around a bit with them playing to get the best sound location versus the best cosmetic location.
Grdevs24zero on 07/10/2006 04:26:11
I planned on doing just that.
This is the sub I plan on getting, it comes in dual or single coil, what are the advantages to a DVC over a SVC?
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14488
These are the amps I have to choose from.(post a link if you know of any better)
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16367
http://www.onlinecarstereo.com/CarAudio/ProductReview.aspx?ProductID=16412
Any comments?
Gary
swez on 07/10/2006 08:31:20
The SVC 4 ohm is good for 2 channel amps that can be bridged MONO. When using Class D amps, the DVC gives more wiring options, (Multi-sub installs) and a 2 ohm load for a single sub to get the most power from a given amp design. Also, most DVC subs can take more power than a conventional SVC in most brand lines.
Here, the most efficient combination would be:
1. Infinity Kappa Perfect 12d VQ (4+4 DVC) 2 ohms
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14490
2. Alpine MRP-M450
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=16411
Here, we get a net 2 ohm load from the sub and 400 RMS @ 2 ohms from this amp. The amp consumes less power, but meets sub requirements and is a few bucks cheaper as well.
Yes, you can still use the M650 if you wish. It will give the sub reserve RMS power when you really want some serious bass and not clip the amp. This sub can handle the extra power for short durations too. However, a sealed enclosure design would help the sub with extra back pressure to prevent/limit over excursion at high bass SPL levels.
Swez
PS Kit,
The PTF can be set anywhere one likes, depending on the preference of the listener and the vehicle used. As you well know, cabin gain effects (transfer function) come into play with all vehicles. (a +10 to 15 dB gain at certain frequencies, near cabin resonance)
We also know that the PTF target will boost bass in that region by at least +3dB right? Well, if one is looking for a reasonably flat response curve, going to a low PTF will re-enforce deep bass that cannot be heard as well, due to the roll-off characteristics of a given sub/enclosure design. At 30 - 35 Hz., we can pick up +3dB of deep lows and not have an overly exaggerated bump in SPL, above 40-55 Hz. (A lower F3 point) Here, we feel more low bass than hearing it.
However, if a guy wants that added bump at say 40-50 Hz., then we can set PTF close to 40 Hz., and he'll get a substantial spike in bass SPL above 40 Hz. Fine for showing off... (SPL Slam) but as you well know, not the most balanced approach for SQ systems.
Really, it's a personal preference type thing. Do we want a low F3 point and smoother bass above say 35 Hz. Or, we can do the "Big Bump" thing and take full advantage of transfer function, use a higher PTF point and have a higher F3 point.
As you well know, it really depends on the "listener's preferences" and cabin gain characteristics of a given vehicle. That's why I often go either sealed or a low PTF port target. It's less exaggerated and sounds more natural to an SQ guy. But, we all have different preferences. Knowing what those preferences are, we adjust the parameters accordingly. (No offense taken either... good question)
cplkittle on 07/10/2006 14:30:54
thanks for bringing it all back to me. That makes so much sense. I got lost in the SPL game over the last year, and going back to the basics and thinking 'on paper' rather than on the fly is something I need to get back to.
Grdevs24zero on 07/10/2006 15:24:05
Ok, now since that sub is a DVC 4 Ohm, wiring the two coils in parralel will net you a 2 ohm load? This is assuming I'm correct that you have to wire both coils.
DominicanKiddo on 07/10/2006 22:29:52
Look at this site from our friends @ crutchfield http://www.crutchfieldadvisor.com/learningcenter/car/subwoofers_wiring.html. It has all the setups you need. And to answer your question, Yes you get 2Ohm in parallel 8Ohm in series.
To wire your speakers in parallel, connect the positive (+) leads of both speakers to the amplifier's positive (+) terminal, and the negative (-) leads of both speakers to the amp's negative (-) terminal. You can increase your system's impact dramatically by hooking up two subwoofers (in parallel) to each of your amp's channels.
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