Ok, I'm starting to try to comprehend what all the numbers mean with drivers and how to come up with what numbers are good and bad. So far I just have a ton more questions.
I'm good with Amplifier numbers and what they mean. I know how to use parallel/series to modify ohm load, etc. The basics I've known for a while. I have my cars systems pretty much where I want them, but I would like to add a 12" sealed sub to one of my cars and a couple 10" sealed to another. I like tight punchy stuff and listen to alot of folk, classic rock, and jazz. In the search for the most bang for buck, here are the issues: Let's say that I buy a DVC sub at 2ohms per coil. Using a 2 channel amp (we'll assume 1-ohm stable) I can get anywhere from 1 to 8 ohms load depending on how its wired/bridged.
Since they're rated at different wattages for different loads, will how they're hooked up make a huge difference? How?
Is my goal to choose the lowest stable load to get the most wattage? Or does a high load use the lower wattage more efficiently making it more of an equal comparison?
Let's make one more hypothetical. (please forgive my imaginary numbers, I might be way off) Let's assume (theroetically) that two subs offer similar numbers and qualities, but one is a big magnet sub with a sensitivity of 85dB and RMS of 400w, and another has a smaller magnet, sens at 92db, and RMS of 200w. Assuming that they get equal SPLs running at their RMS, does one offer an advantage over the other besides cost to purchase?
Does the tighter suspension of the big magnet offer an advantage, or does the less expensive efficient sub get the nod for bang for buck?
Which offers the better sound?
What numbers can I look at in the specs that will tell me which sub offers the target sound I want? Are their numbers that will tell me that sub A will give me accurate bass at my desired SPL but sub B will be a little loose at that SPL?
I know that's a lot of questions, but I'm trying to get a grip on what I should be looking for. I've had several subs including a couple 12s in ported boxes, single 10 in a sealed box, dual 10s sealed, and they've all been the smaller magnet "economy" subs from good-ish names like Audiobahn, Eclipse, and JL. I usually run them right at RMS and I've been somewhat satisfied, but to get the SPL of bass I like I have to sometimes push the signal to the point where its no longer accurate and a little muddy. I want there to be more SPL available than I need so I'm never pushing it. Should I be looking at the $400, low-efficiency drivers and run them with 1000 watts, or ... something else...? Nothing is more frustrating than being in the middle of a Janis Joplin tune and having it distort when the bass solo comes in.
I'm good with Amplifier numbers and what they mean. I know how to use parallel/series to modify ohm load, etc. The basics I've known for a while. I have my cars systems pretty much where I want them, but I would like to add a 12" sealed sub to one of my cars and a couple 10" sealed to another. I like tight punchy stuff and listen to alot of folk, classic rock, and jazz. In the search for the most bang for buck, here are the issues: Let's say that I buy a DVC sub at 2ohms per coil. Using a 2 channel amp (we'll assume 1-ohm stable) I can get anywhere from 1 to 8 ohms load depending on how its wired/bridged.
Since they're rated at different wattages for different loads, will how they're hooked up make a huge difference? How?
Is my goal to choose the lowest stable load to get the most wattage? Or does a high load use the lower wattage more efficiently making it more of an equal comparison?
Let's make one more hypothetical. (please forgive my imaginary numbers, I might be way off) Let's assume (theroetically) that two subs offer similar numbers and qualities, but one is a big magnet sub with a sensitivity of 85dB and RMS of 400w, and another has a smaller magnet, sens at 92db, and RMS of 200w. Assuming that they get equal SPLs running at their RMS, does one offer an advantage over the other besides cost to purchase?
Does the tighter suspension of the big magnet offer an advantage, or does the less expensive efficient sub get the nod for bang for buck?
Which offers the better sound?
What numbers can I look at in the specs that will tell me which sub offers the target sound I want? Are their numbers that will tell me that sub A will give me accurate bass at my desired SPL but sub B will be a little loose at that SPL?
I know that's a lot of questions, but I'm trying to get a grip on what I should be looking for. I've had several subs including a couple 12s in ported boxes, single 10 in a sealed box, dual 10s sealed, and they've all been the smaller magnet "economy" subs from good-ish names like Audiobahn, Eclipse, and JL. I usually run them right at RMS and I've been somewhat satisfied, but to get the SPL of bass I like I have to sometimes push the signal to the point where its no longer accurate and a little muddy. I want there to be more SPL available than I need so I'm never pushing it. Should I be looking at the $400, low-efficiency drivers and run them with 1000 watts, or ... something else...? Nothing is more frustrating than being in the middle of a Janis Joplin tune and having it distort when the bass solo comes in.
to answer in the following:
the idea is to get more power to the woofer by means of a low impedance.
the magnet size and suspension will affect the theile small parameters, and thus any choice will be based upon what you concider desirable. i'd wager low to mid Q would be your best bet -- 0.3 to 0.4 Qts is my guess.
in anycase, there are a number of interesting sealed box woofers becoming popular for car audio. large available Xmax will allow for sealed boxes to work better then in the past.
my view on car audio is that the entire setup must be concidered. there's always more than one way to get a result. like concidering an expensive woofer vs two less expensive woofers, a 6.5" - tweeter component set vs a 8" - 5.25" - tweeter component set vs a dual 6.5 - tweeter component set. then you have the bizzar floor mounted mids that make no sense...
in the above, a sigle woofer would probably work with eh single 6.5, whereas a dual woofer setup may require a beefier front stage. the idea is to get most of the sound from the front stage, leaving the woofers only for the lower bass.
depending on country, i would suggest you concider the elemental designs e12a, though the 15a may not be a good idea as it has thus far had problems with the cone coming detached from the former... in anycase it's been getting good reviews in terms of sound and output.
the idea is to get more power to the woofer by means of a low impedance.
the magnet size and suspension will affect the theile small parameters, and thus any choice will be based upon what you concider desirable. i'd wager low to mid Q would be your best bet -- 0.3 to 0.4 Qts is my guess.
in anycase, there are a number of interesting sealed box woofers becoming popular for car audio. large available Xmax will allow for sealed boxes to work better then in the past.
my view on car audio is that the entire setup must be concidered. there's always more than one way to get a result. like concidering an expensive woofer vs two less expensive woofers, a 6.5" - tweeter component set vs a 8" - 5.25" - tweeter component set vs a dual 6.5 - tweeter component set. then you have the bizzar floor mounted mids that make no sense...
in the above, a sigle woofer would probably work with eh single 6.5, whereas a dual woofer setup may require a beefier front stage. the idea is to get most of the sound from the front stage, leaving the woofers only for the lower bass.
depending on country, i would suggest you concider the elemental designs e12a, though the 15a may not be a good idea as it has thus far had problems with the cone coming detached from the former... in anycase it's been getting good reviews in terms of sound and output.
Let me see is I can maybe help with this. Lets take some of the veriables out of this. I will use my trust old, but will hopefully die with 😀 , Mcintosh MC431M. Its rated at 4x100 RMS. The cars was my 95 Nissan Maxima. Channels 1 and 2 were running mids and highs. Fronts were MB Quart premiun 6.5 coax in the stock location with a set of 1" MB Quart tweeters mount in the stock location in the pillers. Rear fill was another pair of MB Quart coax in the stock location. Rear were att. using resisters but later there own PPI ProMos 12, yes thats 12.5 a channel. ALl pairs upgrades using Musicomp XOs, 5 total.
Anyways I have used the basic setup for testing different subs and enclosures. To help with your queation one of the setups was using 4 JL 10W0s in a 2 cubic foot sealed enclusure with a divider. These are JLs bottem of the line subs. They are rated at 125 watts apiece. They were 8 omh drives wired up to give channels 3 and 4 on the Mac 4 ohms apiece. With this setup I had way more bass then I did mids and highs. It was still quit clean and clear but was loud, somewhere in the range of a good 135db. I found the best OX point to be about 80HZ.
The next one I am going to mention is my current one. Same mids and highs, same Mac amp now running fronts on channels 1 and 2. For sub I have a single PPI Pro 12. This is PPI atempt at a super high sound quality sub. Yes these are the same one Arma Gates used to set the SPL record over and over but hers were running freeair and that a hole other topic. Its 4 ohms, channels 3 and 4 of the Mac bridged to it. The enclosure 1.5 cudes sealed. I found that the best OX piont was an amazingly low 64HZ. With this setup the sound was totally different. The low end have way more detail and definition but not as much overall SPL. The match to the mids and high is exellent for not seamless as you might get in a car. Somehow the low end actually sound like it has more authority, like there is way more "junk in the trunk" just waiting to be let out. Granted even my trusty Mcintosh in underpowered for this type of sub, the quality is amazing.
I guess my piont is that if you like things on the bass heavy side and done want to spend a ton of money do yourself a favor and get some good, cheap subs and bang away. Dont get me wrong, I loved those JLs and I still have then sitting here just waiting for another project. But if you like a good clean sound spend a little extra on nicer subs or sub. Also, in car audio there are SO SO SO many variables. Look around, demos some things, do whatever you need to do to sleep at night but in the end its going to all come down to your setup, your car itself, you enclusure that actually makes a difference.
Its also about matching your needs and equipment. If you are one that like "butt bass" music then a sinlge low eff. sub on 200 watts is only going to leave you wanting more. On the other hand if you like quality jazz, rock and classical then you will be finding reasons to drive your car just to enjoy your system. As for matching your equipment what I am saying here is if you have a 1000 watts, true wattage I am talking here, amp you would not put that on a pair or even 4 JL 10W0s. Yes, I am the first person to say you can not have to much power ( Hell I have one car with 8, yes 8, Butler Tube Drivers in it with a total wattage of 3600watts) but there this a piont of things just being a waste, specailly if you are tight on money. Now if you had a sub like a JL 12W7 you would not want to go out and buy a 100 watt amp and put on it. The W7 is a power pig and you would get better bass from a good set of coaxs
.
As for what numbers to look for, well, its the sad truth that in the car audio world numbers have become a selling piont and so are "fudged" more often then not. Take my Mcintosh MC431M. Car Stereo Review tested one and on the bench it put out 251 watts per channels out of a amp rated at 100 watts. Now I know this one was a good thing, 2.5 times better then rated specs. This is Mcintosh we are talking about and this is the very very rare exeption. I lot of specs more stated better then would be tested, specailly with subs. I know a some easy ways to test the wattage of an amp but not a lot of people have the stuff to test speakers.
Sorry this ended up being so long. I just want to see if I could help here. Look around and see what you think will serve your needs the best, experiment, experiment, experiment and most of all have fun.
Anyways I have used the basic setup for testing different subs and enclosures. To help with your queation one of the setups was using 4 JL 10W0s in a 2 cubic foot sealed enclusure with a divider. These are JLs bottem of the line subs. They are rated at 125 watts apiece. They were 8 omh drives wired up to give channels 3 and 4 on the Mac 4 ohms apiece. With this setup I had way more bass then I did mids and highs. It was still quit clean and clear but was loud, somewhere in the range of a good 135db. I found the best OX point to be about 80HZ.
The next one I am going to mention is my current one. Same mids and highs, same Mac amp now running fronts on channels 1 and 2. For sub I have a single PPI Pro 12. This is PPI atempt at a super high sound quality sub. Yes these are the same one Arma Gates used to set the SPL record over and over but hers were running freeair and that a hole other topic. Its 4 ohms, channels 3 and 4 of the Mac bridged to it. The enclosure 1.5 cudes sealed. I found that the best OX piont was an amazingly low 64HZ. With this setup the sound was totally different. The low end have way more detail and definition but not as much overall SPL. The match to the mids and high is exellent for not seamless as you might get in a car. Somehow the low end actually sound like it has more authority, like there is way more "junk in the trunk" just waiting to be let out. Granted even my trusty Mcintosh in underpowered for this type of sub, the quality is amazing.
I guess my piont is that if you like things on the bass heavy side and done want to spend a ton of money do yourself a favor and get some good, cheap subs and bang away. Dont get me wrong, I loved those JLs and I still have then sitting here just waiting for another project. But if you like a good clean sound spend a little extra on nicer subs or sub. Also, in car audio there are SO SO SO many variables. Look around, demos some things, do whatever you need to do to sleep at night but in the end its going to all come down to your setup, your car itself, you enclusure that actually makes a difference.
Its also about matching your needs and equipment. If you are one that like "butt bass" music then a sinlge low eff. sub on 200 watts is only going to leave you wanting more. On the other hand if you like quality jazz, rock and classical then you will be finding reasons to drive your car just to enjoy your system. As for matching your equipment what I am saying here is if you have a 1000 watts, true wattage I am talking here, amp you would not put that on a pair or even 4 JL 10W0s. Yes, I am the first person to say you can not have to much power ( Hell I have one car with 8, yes 8, Butler Tube Drivers in it with a total wattage of 3600watts) but there this a piont of things just being a waste, specailly if you are tight on money. Now if you had a sub like a JL 12W7 you would not want to go out and buy a 100 watt amp and put on it. The W7 is a power pig and you would get better bass from a good set of coaxs
.As for what numbers to look for, well, its the sad truth that in the car audio world numbers have become a selling piont and so are "fudged" more often then not. Take my Mcintosh MC431M. Car Stereo Review tested one and on the bench it put out 251 watts per channels out of a amp rated at 100 watts. Now I know this one was a good thing, 2.5 times better then rated specs. This is Mcintosh we are talking about and this is the very very rare exeption. I lot of specs more stated better then would be tested, specailly with subs. I know a some easy ways to test the wattage of an amp but not a lot of people have the stuff to test speakers.
Sorry this ended up being so long. I just want to see if I could help here. Look around and see what you think will serve your needs the best, experiment, experiment, experiment and most of all have fun.
Opps, forgot about the impedance part of the equation.
SOmeone correct me if I am wrong but I have learned that as you lower the impedance, THD goes up and slew rates decrease, both not good, along with some other not so good things. I guess for subs these things dont bother most people. I know you will never find a D class amp in one of my cars, AKA, they sound like mud to me with their almost no slew rates.
Also keep in mind that your amp will be working overtime into low impedances, I am not one for overworking things and them going up in smoke. If it is designed for it its not a big deal, if it is not I am sure it will let you know. I have a Zapco C2K 6.0 that is rated 150x2 running bridged on two 4 ohm Polk Momo 10s running 2 ohms putting out over 1300 watts. Want to talk about chest slamin tight bass, WOW. on the other hand in my "Butler Car" I have two Polk Momo 6.5 midbass drivers in each door. Each door have its own TD2150 (150 waats x2, 600 watts bridged) and instead of bridging the amp to get the most wattage out of it I am running it stereo, well one channel for each driver anyways. My reason for this is that the goal for this car was to have very high sound quality but to be able to play at high SPL if need be. I wanted the added control on the drivers that run non-bridged adds. Again this is for mids and highs where things get a little more tricky. 5% or even 10% THD below say 80HZ is hard for even the best of us to hear, but that much in the upper region makes me run for cover.
Hope this helps
SOmeone correct me if I am wrong but I have learned that as you lower the impedance, THD goes up and slew rates decrease, both not good, along with some other not so good things. I guess for subs these things dont bother most people. I know you will never find a D class amp in one of my cars, AKA, they sound like mud to me with their almost no slew rates.
Also keep in mind that your amp will be working overtime into low impedances, I am not one for overworking things and them going up in smoke. If it is designed for it its not a big deal, if it is not I am sure it will let you know. I have a Zapco C2K 6.0 that is rated 150x2 running bridged on two 4 ohm Polk Momo 10s running 2 ohms putting out over 1300 watts. Want to talk about chest slamin tight bass, WOW. on the other hand in my "Butler Car" I have two Polk Momo 6.5 midbass drivers in each door. Each door have its own TD2150 (150 waats x2, 600 watts bridged) and instead of bridging the amp to get the most wattage out of it I am running it stereo, well one channel for each driver anyways. My reason for this is that the goal for this car was to have very high sound quality but to be able to play at high SPL if need be. I wanted the added control on the drivers that run non-bridged adds. Again this is for mids and highs where things get a little more tricky. 5% or even 10% THD below say 80HZ is hard for even the best of us to hear, but that much in the upper region makes me run for cover.
Hope this helps
Let's see if I can answer the original questions 🙂
1. The only audible difference of hooking up your subs in different ways (parrallel or series) will be a different load (impedance), which relates to the amount of output power and how loud the subs will be. THD is also increase with a lower impedance, but you won't hear that at all.
2. Having the lowest impedance is generally a goal... with stipulations. If you have already picked out an amp and the output power is too much with a 2 ohm load, then either keep the gain down or make the sub 8 ohms.
3. Its hard to compare two different subs like that. If you're worried only about SPL, then go with the sub that handles more power and wire it to the lowest possible impedance. If you're going to run the mids and tweeters off the head unit, use the smaller sub since the larger powered sub will overpower everything else.
4. You have to weigh all of the T/S specs together.
5. You have to listen to the subs to judge which sounds best. T/S specs can tell you something, but it doesn't exactly tell you how it sounds.
6. Just go listen to the different subs and let your ears tell you what you like 🙂
Just as a closing thought: the install can make or break the system. You can spend thousands on equipment, but if not used properly, it can sound just as "good" as a $200 system.
1. The only audible difference of hooking up your subs in different ways (parrallel or series) will be a different load (impedance), which relates to the amount of output power and how loud the subs will be. THD is also increase with a lower impedance, but you won't hear that at all.
2. Having the lowest impedance is generally a goal... with stipulations. If you have already picked out an amp and the output power is too much with a 2 ohm load, then either keep the gain down or make the sub 8 ohms.
3. Its hard to compare two different subs like that. If you're worried only about SPL, then go with the sub that handles more power and wire it to the lowest possible impedance. If you're going to run the mids and tweeters off the head unit, use the smaller sub since the larger powered sub will overpower everything else.
4. You have to weigh all of the T/S specs together.
5. You have to listen to the subs to judge which sounds best. T/S specs can tell you something, but it doesn't exactly tell you how it sounds.
6. Just go listen to the different subs and let your ears tell you what you like 🙂
Just as a closing thought: the install can make or break the system. You can spend thousands on equipment, but if not used properly, it can sound just as "good" as a $200 system.
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