I was into car audio and home theatre sound systems between the early 1990's up until the early 2000's, in my teens and 20's. My main focus was really into car audio, with subwoofers specifically. I am from the Pittsburgh area. I can remember that there were about 4-5 private car audio businesses and Circuit City and Best Buy in an area just northwest of Pittsburgh. Each of the multiple businesses offered a different variety of subwoofers for each car. I also remember the Crutchfield catalogs from that time too. I can remember the companies that offered such equipment like MTX, Orion, US Amps, Autotek, Cerwin Vega, Kicker, Phoenix Gold, Polk, Kenwood, Sony, Pioneer, Soundstream, Rockford Fosgate, Alpine, Infinity, Bazooka, Profile, etc... It seemed like in my home town, that MTX was the king and everyone had either MTX Thunderpros or Thundercast subwoofers.
Back in the early to mid 1990's, it seemed that very large ported and moderately large bandpass boxes were the king and queen in the car audio community. Many of the cars that these subwoofers were going into were older cars from the 1960's up until the early 1990's. These older cars often had very large trunks. Also 25-30 years ago, I can remember amplifier power costed between $2-$5 per watt. Due to the high cost of amplifier power, it seemed that speaker companies were putting out subwoofers that had a very high sensitivity ratings that often required large ported or bandpass boxes in order to get more spL.
In the early to mid 1990's, I can recall two companies that often reported very high sensitivity ratings for the subwoofers, and they were JBL and Cerwin Vega in the range of 92db-98db for their 8, 10, 12, and 15 inch subs. Most of my knowledge from speakers came from those early Crutchfield catalogs, and what was in online forums. It seemed that Kicker and Cerwin Vega put out the best subwoofers in those catalogs at that time. I remember if you wanted great transient response or so called "tight" bass you went with the Kicker Competition line. If you wanted very high output with a given wattage output, then you went with the Cerwin Vega XL subs. I can remember that the Kicker Comp subs requiring a moderately sized sealed boxes and the Cerwin Vegas needing large ported boxes.
Then something happened in 1996. I was reading a car audio magazine, and Kicker introduced the Solobaric line which mimicked the loaded Isobaric type subs. These subs doubled their cone mass and increased motor strength allowing them to go into boxes half the size of their Kicker COMP line. At the same time, POLK audio introduced their DB line of subs that also went into very small sealed boxes. These newer heavy massed cone subs were put on the market because trunk space was getting smaller with newer cars, and also amplifier power cost dropped in price as well. It seemed that these new very small sealed box subwoofers had a very very LOW sensitivity rating compared to regular subs. It seemed that the market was ripe for customers wanting to put subs into their tiny trunks... or just will not put a larger box in the trunk.
I have had various subwoofer systems in my 1986 Buick Somerset in the late 90's. I had four CV XL's 12 inch subs in 2 cu foot a piece tuned to 36hz hooked up to an Autotek 90 Mean Machine at 400 watts. The CV XL's power handling was about 250-300w RMS. I absolutely loved the sound of my Vegas. My buddy had a 1986 Dodge Lancer Hatchback with two Kicker Comp 15's in a 6.8cu ft. box powered by an Autotek 90 bridged at 2ohms(the amp wasn't 1ohm stable and he had problems with it). The sound from those 15's were amazing, so I sold my CV 12's and got two Kicker Comp 15's. However, I didn't take into account that his hatchback was a lot different from my coupe in terms of sound transfer function. IMO, it seemed that the Kicker 15's lacked a "Full" forceful sound, and that they sounded "Hollow" to me. I can remember wishing to myself that CV would come out with a version of their XL's that would handle a lot more power. In 1996, CV came out with their Vega V-Flex sub, which is my favorite speaker of all time. It seemed like they added a little more mass to the cone dropping the sensitivity rating by 2db, but also dropped the Fs rating too. It seemed like those 12 inch CV Vega V-Flex subs could keep up with or flat out outperform any other 15 inch speaker out there. I tested this by using my Autotek 90 bridged at 4ohms for the Kicker 15 and the CV V-Flex 12. The Kicker in 3.5cubic feet sealed and the Vega V-Flex in 2.2 cubic feet ported. The CV Vega V-Flex was a lot louder, sounded deeper, and fuller. It also seemed to "almost" have the same transient response of the Kicker 15. Then I had two CV Vega/V-Flex 12's in 2.75 cubic feet a piece(28hz tuned), which increased their deep bass between 25-45hz, but very little above 55hz. Then I thought, if the 12 inch Vega could be louder than any other 15, then their 15 inch CV Vega/V-Flex would be just as loud as an 18inch from another company. So I then put two Vega/V-Flex 15's in a 9 cubic foot ported box with a 96 cubic inch port area tuned to 28hz. I then hooked up a US 400 X Exterminator Amp rated at 1600w at 4ohms bridged, but probably put out 2100w from what other sources said. I was going after the loudest and deepest trunk system in the area, and I achieved that hitting around 149-151db at certain times/frequencies. I can remember plugging up the port if I wanted to play any "Chopped and Screwed" deep bass tracks, and it sounded great that way too.
I am asking if sensitivity has anything to do with the output for a speaker? I have talked with many people about this, and some say it doesn't matter that much, if at all. Others say it has a lot to do with the output that you want. I have also read that many of these sensitivity ratings are often inflated by companies. In the past(before early 2000's), it seemed that the sensitivity rating was a big deal when buying a speaker. Now it just seems that kids are into How much power a speaker can handle. I also read that many of these sensitivity ratings are measured when the subwoofer is playing a 1000hz tone, which is inaccurate/irrelevant, as most subs are played between 10hz-100hz. Many newer companies don't even list the DB rating for their subs, only their POWER handling.
Back in the day, I can recall that if your speaker had a QTS of .45-.8 then you would put it into a sealed box or 4th order BP. If your speaker had a QTS of .18 up to .4 then you placed it into a ported/vented box or 6th order BP. This was pretty iron clad... I can recall putting a higher QTS speaker like a Kicker Comp 12(that required a 1.75cu ft sealed box) into a large 2.75 cu ft ported box.. and the bass sounded really muddy, ringing, lacking punch, and sounded horrible because they were underdamped. Then I remember my friend got two CV XL 15's(a low QTS woofer that needed 4cu ft ported per), and put them into a 8 cu ft sealed box, and I can remember not hearing any low bass at all, as the FB and Fs was way too high and lacked output because it was way overdamped.
I take a break for a few years, and now I see all these subwoofers with HUGE surrounds like a DONUT! I see these massive looking cones with gigantic dust caps. I am used to seeing normal sized dust caps and surrounds. It seems as if the new kids on the block only care about Power Handling and XMAX with large structural features.
Now I see all these newer companies out. Many of these newer and of higher quality. However, I am seeing many companies are using high to very high QTS subwoofers being put into very large ported or 6th order boxes. I know that you can place a high QTS sub into a ported box, but it will not have the same snap and transient response as a low QTS in a ported box. What gives? Is it because people want very LOW bass, and would prefer the thick sound of a higher QTS sub in a ported box?
I sat inside a kid's VW Golf that had a 12 inch Kicker L7 sub in a 2 cubic foot box hooked up to 600 watts, and the sound was very loud, but the transient response is just ok. The Kicker L7 12 has a QTS of .692. I am very confused about today's use of high QTS subs in ported boxes??? I am finding that many companies are doing the same thing! I am looking at certain new Cerwin Vega subwoofers that have a much higher QTS than their older lines.. but still recommend ported boxes.
I have been playing around with enclosure modeling software, and that many of these newer speakers often will not fit into the boxes that their Thiele and Small parameters suggest. I often find that the speaker box is either gigantic, spot on, or extremely small/tiny.
I have been looking into Digital Designs (DD) subwoofers, as these subs seem to be regarded as great quality and of high SPL winning many comps. About 75% of their product line recommends that their speakers are to be placed in large ported boxes. So I am looking at their Redline 700, Redline 800, 9500, and 9900 series subwoofers. I can remember that Cerwin Vega XLs used to have a QTS between .27-.36 for their 8-15 inch subs, and they required ported boxes. So all of CV XL line were low QTS subs. With the CV XL subs, Even though the group delay from the port was apparent, the transient response of the CV subwoofer itself was almost the same as the Kicker Comp sub. Try playing the song by the Beastie Boys called "Paul Revere" on different types of subs. It seems that these other newer companies vary their QTS, VAS, and FS a great deal within their own line of speakers. I do not understand this. I notice that the 10 inch subs have a much lower QTS compared to their larger brothers. I'll give an example of the DD 9500 and Redline 700 line with corresponding QTS, FS, and VAS for each size:
9500 line:
DD 9518 QTS .716 FS 30hz VAS 97 liters
DD 9515 QTS .666 FS 39hz VAS 52 liters
DD 9512 QTS .662 FS 37hz VAS 26 liters
DD 9510 QTS .431 FS 37hz VAS 19 liters
Redline 700 line:
DD 718 QTS .523 FS 26hz VAS 170 liters
DD 715 QTS .537 FS 31hz VAS 70 liters
DD 712 QTS .434 FS 28hz VAS 39 liters
DD 710 QTS .321 FS 28hz VAS 21 liters
When I plug in the specs of the 700 line into software, I get the most massive box for the 18 inch sub at 9-14 cubic feet.... and then the tiniest box for the 10 inch sub at .35 to .5 cubic feet per sub. Another example is the 9518 18 inch sub needing 10-23 cubic feet of ported per sub. Then I plug the 9510 ten inch sub into software, and I get .7 to .85 cubic feet per sub?? What gives?
I find this so confusing. However, their recommendation for the size of their boxes increase at a small linear rate as the subwoofer gets bigger. However, all sorts of modeling software shows a drastic difference between their smallest to largest sub. It seems that their 12 and 15 inch subs are the only two needing a normal sized box.
I am looking into large ported boxes, but mainly 6th order series bandpass boxes because of the type of car that I may be buying like the Lexus SC300 or Nissan Skyline R33 GTR.
So what is the story now days? What changed in the last 20 years? I used DD Audio as an example. Are there any other newer sound companies out there that produce a subwoofer similar to the old Cerwin Vega XL's or V-Flex that have a lightweight cone, low QTS, low FS, etc..?
Sorry for being so long winded. I've had 20 years of questions.. and I needed to put the background of where I came from in the picture.
Brad
Back in the early to mid 1990's, it seemed that very large ported and moderately large bandpass boxes were the king and queen in the car audio community. Many of the cars that these subwoofers were going into were older cars from the 1960's up until the early 1990's. These older cars often had very large trunks. Also 25-30 years ago, I can remember amplifier power costed between $2-$5 per watt. Due to the high cost of amplifier power, it seemed that speaker companies were putting out subwoofers that had a very high sensitivity ratings that often required large ported or bandpass boxes in order to get more spL.
In the early to mid 1990's, I can recall two companies that often reported very high sensitivity ratings for the subwoofers, and they were JBL and Cerwin Vega in the range of 92db-98db for their 8, 10, 12, and 15 inch subs. Most of my knowledge from speakers came from those early Crutchfield catalogs, and what was in online forums. It seemed that Kicker and Cerwin Vega put out the best subwoofers in those catalogs at that time. I remember if you wanted great transient response or so called "tight" bass you went with the Kicker Competition line. If you wanted very high output with a given wattage output, then you went with the Cerwin Vega XL subs. I can remember that the Kicker Comp subs requiring a moderately sized sealed boxes and the Cerwin Vegas needing large ported boxes.
Then something happened in 1996. I was reading a car audio magazine, and Kicker introduced the Solobaric line which mimicked the loaded Isobaric type subs. These subs doubled their cone mass and increased motor strength allowing them to go into boxes half the size of their Kicker COMP line. At the same time, POLK audio introduced their DB line of subs that also went into very small sealed boxes. These newer heavy massed cone subs were put on the market because trunk space was getting smaller with newer cars, and also amplifier power cost dropped in price as well. It seemed that these new very small sealed box subwoofers had a very very LOW sensitivity rating compared to regular subs. It seemed that the market was ripe for customers wanting to put subs into their tiny trunks... or just will not put a larger box in the trunk.
I have had various subwoofer systems in my 1986 Buick Somerset in the late 90's. I had four CV XL's 12 inch subs in 2 cu foot a piece tuned to 36hz hooked up to an Autotek 90 Mean Machine at 400 watts. The CV XL's power handling was about 250-300w RMS. I absolutely loved the sound of my Vegas. My buddy had a 1986 Dodge Lancer Hatchback with two Kicker Comp 15's in a 6.8cu ft. box powered by an Autotek 90 bridged at 2ohms(the amp wasn't 1ohm stable and he had problems with it). The sound from those 15's were amazing, so I sold my CV 12's and got two Kicker Comp 15's. However, I didn't take into account that his hatchback was a lot different from my coupe in terms of sound transfer function. IMO, it seemed that the Kicker 15's lacked a "Full" forceful sound, and that they sounded "Hollow" to me. I can remember wishing to myself that CV would come out with a version of their XL's that would handle a lot more power. In 1996, CV came out with their Vega V-Flex sub, which is my favorite speaker of all time. It seemed like they added a little more mass to the cone dropping the sensitivity rating by 2db, but also dropped the Fs rating too. It seemed like those 12 inch CV Vega V-Flex subs could keep up with or flat out outperform any other 15 inch speaker out there. I tested this by using my Autotek 90 bridged at 4ohms for the Kicker 15 and the CV V-Flex 12. The Kicker in 3.5cubic feet sealed and the Vega V-Flex in 2.2 cubic feet ported. The CV Vega V-Flex was a lot louder, sounded deeper, and fuller. It also seemed to "almost" have the same transient response of the Kicker 15. Then I had two CV Vega/V-Flex 12's in 2.75 cubic feet a piece(28hz tuned), which increased their deep bass between 25-45hz, but very little above 55hz. Then I thought, if the 12 inch Vega could be louder than any other 15, then their 15 inch CV Vega/V-Flex would be just as loud as an 18inch from another company. So I then put two Vega/V-Flex 15's in a 9 cubic foot ported box with a 96 cubic inch port area tuned to 28hz. I then hooked up a US 400 X Exterminator Amp rated at 1600w at 4ohms bridged, but probably put out 2100w from what other sources said. I was going after the loudest and deepest trunk system in the area, and I achieved that hitting around 149-151db at certain times/frequencies. I can remember plugging up the port if I wanted to play any "Chopped and Screwed" deep bass tracks, and it sounded great that way too.
I am asking if sensitivity has anything to do with the output for a speaker? I have talked with many people about this, and some say it doesn't matter that much, if at all. Others say it has a lot to do with the output that you want. I have also read that many of these sensitivity ratings are often inflated by companies. In the past(before early 2000's), it seemed that the sensitivity rating was a big deal when buying a speaker. Now it just seems that kids are into How much power a speaker can handle. I also read that many of these sensitivity ratings are measured when the subwoofer is playing a 1000hz tone, which is inaccurate/irrelevant, as most subs are played between 10hz-100hz. Many newer companies don't even list the DB rating for their subs, only their POWER handling.
Back in the day, I can recall that if your speaker had a QTS of .45-.8 then you would put it into a sealed box or 4th order BP. If your speaker had a QTS of .18 up to .4 then you placed it into a ported/vented box or 6th order BP. This was pretty iron clad... I can recall putting a higher QTS speaker like a Kicker Comp 12(that required a 1.75cu ft sealed box) into a large 2.75 cu ft ported box.. and the bass sounded really muddy, ringing, lacking punch, and sounded horrible because they were underdamped. Then I remember my friend got two CV XL 15's(a low QTS woofer that needed 4cu ft ported per), and put them into a 8 cu ft sealed box, and I can remember not hearing any low bass at all, as the FB and Fs was way too high and lacked output because it was way overdamped.
I take a break for a few years, and now I see all these subwoofers with HUGE surrounds like a DONUT! I see these massive looking cones with gigantic dust caps. I am used to seeing normal sized dust caps and surrounds. It seems as if the new kids on the block only care about Power Handling and XMAX with large structural features.
Now I see all these newer companies out. Many of these newer and of higher quality. However, I am seeing many companies are using high to very high QTS subwoofers being put into very large ported or 6th order boxes. I know that you can place a high QTS sub into a ported box, but it will not have the same snap and transient response as a low QTS in a ported box. What gives? Is it because people want very LOW bass, and would prefer the thick sound of a higher QTS sub in a ported box?
I sat inside a kid's VW Golf that had a 12 inch Kicker L7 sub in a 2 cubic foot box hooked up to 600 watts, and the sound was very loud, but the transient response is just ok. The Kicker L7 12 has a QTS of .692. I am very confused about today's use of high QTS subs in ported boxes??? I am finding that many companies are doing the same thing! I am looking at certain new Cerwin Vega subwoofers that have a much higher QTS than their older lines.. but still recommend ported boxes.
I have been playing around with enclosure modeling software, and that many of these newer speakers often will not fit into the boxes that their Thiele and Small parameters suggest. I often find that the speaker box is either gigantic, spot on, or extremely small/tiny.
I have been looking into Digital Designs (DD) subwoofers, as these subs seem to be regarded as great quality and of high SPL winning many comps. About 75% of their product line recommends that their speakers are to be placed in large ported boxes. So I am looking at their Redline 700, Redline 800, 9500, and 9900 series subwoofers. I can remember that Cerwin Vega XLs used to have a QTS between .27-.36 for their 8-15 inch subs, and they required ported boxes. So all of CV XL line were low QTS subs. With the CV XL subs, Even though the group delay from the port was apparent, the transient response of the CV subwoofer itself was almost the same as the Kicker Comp sub. Try playing the song by the Beastie Boys called "Paul Revere" on different types of subs. It seems that these other newer companies vary their QTS, VAS, and FS a great deal within their own line of speakers. I do not understand this. I notice that the 10 inch subs have a much lower QTS compared to their larger brothers. I'll give an example of the DD 9500 and Redline 700 line with corresponding QTS, FS, and VAS for each size:
9500 line:
DD 9518 QTS .716 FS 30hz VAS 97 liters
DD 9515 QTS .666 FS 39hz VAS 52 liters
DD 9512 QTS .662 FS 37hz VAS 26 liters
DD 9510 QTS .431 FS 37hz VAS 19 liters
Redline 700 line:
DD 718 QTS .523 FS 26hz VAS 170 liters
DD 715 QTS .537 FS 31hz VAS 70 liters
DD 712 QTS .434 FS 28hz VAS 39 liters
DD 710 QTS .321 FS 28hz VAS 21 liters
When I plug in the specs of the 700 line into software, I get the most massive box for the 18 inch sub at 9-14 cubic feet.... and then the tiniest box for the 10 inch sub at .35 to .5 cubic feet per sub. Another example is the 9518 18 inch sub needing 10-23 cubic feet of ported per sub. Then I plug the 9510 ten inch sub into software, and I get .7 to .85 cubic feet per sub?? What gives?
I find this so confusing. However, their recommendation for the size of their boxes increase at a small linear rate as the subwoofer gets bigger. However, all sorts of modeling software shows a drastic difference between their smallest to largest sub. It seems that their 12 and 15 inch subs are the only two needing a normal sized box.
I am looking into large ported boxes, but mainly 6th order series bandpass boxes because of the type of car that I may be buying like the Lexus SC300 or Nissan Skyline R33 GTR.
So what is the story now days? What changed in the last 20 years? I used DD Audio as an example. Are there any other newer sound companies out there that produce a subwoofer similar to the old Cerwin Vega XL's or V-Flex that have a lightweight cone, low QTS, low FS, etc..?
Sorry for being so long winded. I've had 20 years of questions.. and I needed to put the background of where I came from in the picture.
Brad
Cliff notes version:
Why are high QTS(.45-.9) subwoofers often used in vented/ported or 6th order bandpass today compared to restricting their use in sealed only boxes of 20-30 years ago?
Is sensitivity of a subwoofer measured in dB's at 1w at 1 meter of use today, when I 've heard that they often measure this at 1000hz, even though the very high sensitive low QTS subwoofers often sound louder with better transient response?
If you need background to this, refer to the post above. Thanks Brad
Why are high QTS(.45-.9) subwoofers often used in vented/ported or 6th order bandpass today compared to restricting their use in sealed only boxes of 20-30 years ago?
Is sensitivity of a subwoofer measured in dB's at 1w at 1 meter of use today, when I 've heard that they often measure this at 1000hz, even though the very high sensitive low QTS subwoofers often sound louder with better transient response?
If you need background to this, refer to the post above. Thanks Brad
Well, I have a Kicker 08S15L74 in a negative flare tapped horn (BP6S) for home theater. I have a Coustic Power Logic HT612 in a BP4 in my 2000 Toyota Solara SEV6 (FWD Lexus SC300).
You basically stated the reasons...amplifier power is cheap and space is a premium in newer cars so manufacturers build inefficient high Xmax drivers that play low, require a lot of power, and play in small enclosures.
You basically stated the reasons...amplifier power is cheap and space is a premium in newer cars so manufacturers build inefficient high Xmax drivers that play low, require a lot of power, and play in small enclosures.
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thank you for the reply. I knew that these high xmax, heavy cone, and inefficient subs were to be played in small sealed or BP4 boxes....
Kicker stated that you never put a Solobaric sub into a ported or BP6 box.
So is it that these newer companies found ways to build a sub similar to a Solobaric... but now tweaked the build to put them into ported and BP6 boxes?
Kicker stated that you never put a Solobaric sub into a ported or BP6 box.
So is it that these newer companies found ways to build a sub similar to a Solobaric... but now tweaked the build to put them into ported and BP6 boxes?
'Physics, it's the LAW' 
, so in theory, no and from just looking at some Solobaric driver specs they probably were just saying it for marketing purposes. That, or for potential motor cooling problems.
Regardless, with the advent of high SQ performing DSP at reasonable prices to go along with ever increasing [peak] power handling, doesn't matter how bad the box alignment response is, only need to build in [set of] digital frequency shaping filters to choose from, so designing for smallest box at 'X' peak power @ desired SPL, Fb seems a reasonable way to do woofers nowadays.
GM
, so in theory, no and from just looking at some Solobaric driver specs they probably were just saying it for marketing purposes. That, or for potential motor cooling problems. Regardless, with the advent of high SQ performing DSP at reasonable prices to go along with ever increasing [peak] power handling, doesn't matter how bad the box alignment response is, only need to build in [set of] digital frequency shaping filters to choose from, so designing for smallest box at 'X' peak power @ desired SPL, Fb seems a reasonable way to do woofers nowadays.
GM
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I found a Kicker Solobaric PDF owner's manual from January 1997 stating never to put Solos into ported or dual reflex 6th order bandpass boxes. You are right. Back then when the Solos first came out, they were trying to market the original Solobaric for small sealed or 4th order BPs to the people with space issues. The T/S specs today didn't change all that much from 20 years ago. It's probably because my thinking is still stuck in a time capsule from 25 years ago.
But I guess times have changed and people experimented and found that the higher QTS drivers that were once required for sealed in the past have today now found use in vented, dual reflex 6th BP, T-lines, and horns.
A Somerset Regal? With the little pod-radio and separate cassette with external tuner/amp? Where did you find 8 cubic feet in a Somerset?
Plenty of installers back then paid no attention to Mfr suggestions and just crammed what they wanted where they could fit it and tried to straighten it out with crossover, EQ, and power. Not so much different from now, just lowly analog filters.
I found about 13 cubic feet total with about 10 cu feet of usable space for a box. I cut out the rear supports of the backseat. Then I took out the front passenger seat. Then I installed a 9 cubic foot box in through the front, then right into the trunk. I then sealed off the backseat from the trunk. Had two Vega 15's firing into the cabin directly. I also installed two extra batteries as well back there. That trunk's dimensions could fit an external box of about 38 inches wide by 18 inches tall and 29 inches deep... which internally after bracing came out to a little over 9 cubic feet!
I removed the mini radio box. Then I cut a rectangular hole underneath the heater buttons. I put an Alpine CD player in there.
I did pay attention the the manufacture recommended airspace. The CV Vega/V-Flex 15's called for 4 cubic feet per sub. I put a 9.1 cubic foot box instead because every Vega I ever had preferred an extra 12-25% more airspace than what they called for. I tuned the box to about 27 hertz, using a large rectangular port. They were 8 ohm subs, then I wired them to a US 400X amp bridged 4 ohm mono. US Amps said it put out 1600w in bridged mode, but some tested at 2100w total. The box took up the whole trunk... but did I ever have the loudest and deepest hitting trunk system in the Pittsburgh area circa 1999. Those Vegas had a 96dB sensitivity rating. I wish I could find speakers similar to those now today!
Some salesman at Best Buy in Robinson Twp, Pittsburgh(who then sold CV) told me that I would never be able to supply the airspace needed for the Vega 15's. Then he also said I would never be able to supply enough power. Then I installed my whole setup.....and returned to the store..... I showed him my trunk... and said heres 9.1 cubic feet and 1600w of power. He didn't say a damn word to me, and stared in disbelief.
Yep that engine wasn't any good at all. Esp with all my equipment in the trunk. That car was very slow! You would think with a 2.5 liter inline 4... which is equivalent in size to a stroked out Honda K24/K20 Frankenstein... like 2.6... that the Iron Duke with it's overbore 4 inch bore... it should have put out HP, since it was half of a 5.0 engine!
I never short change the airspace on any subwoofer. In fact, I often use too much. I once put in two Kicker Competition 15's(the 2nd gen ones from the mid 90s) in 8 cubic feet... when Kicker said that 3 cubes per sub was good enough. I wanted to try a lower Qtc... so I used 4 cubes with the box very loosely filled to just over half with Polyfill... I didn't like the sound that much compared to the four Vegas I had, as I didn't like the low Qtc sound. I pay attention to Hoffman's Iron Law.. in that I will often use as much airspace as possible in order to get efficiency and low extension! I would rather put an 8 inch subwoofer into 1.4 cubic foot ported box than try to stuff a 12 in there like many others do. I had a buddy who saw my setup with the oversized 5.6 cubic foot box for two Vega 12's... and he put them into 1.5 cubes a piece... Sounded terrible... I told him he was suffocating them.
It was a hell of a lot easier to find the room for four CV 12's than those two 15's because I split the 12's up into two boxes. 2 cubes a piece each. CV called for 2 to 2.2 cubic feet a piece. Two in the back firing upwards, and then two in the front firing into the cabin. That def worked. Many guys running their two 15 inch MTX Thunderpros were in disbelief and shock that my system hit harder and sounded better with me running less than half of the power they were running. Those four CV XL 12's were the best overall and most efficient system I have ever had! Low QTS, somewhat low Fs for the time, and very high sensitivity rating. Damn I wish I could find some PA subs or something like these now!
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Well, maybe. That's like the old "Linkwitz Transform" but much more sophisticated-in theory you can measure the transient response and even if a mess I guess you can deconvolve (or is it reconvolve? I forget) all the data stream to get something lovely. Except for the part that the speakers' performance changes with drive level. Is anyone running that level of correction?
For a SPEAKER, to oversimplify the sensitivity and power handling will add up to maximum output IF neither spec is baloney.
For a SUBWOOFER the sensitivity spec is pretty meaningless, because again to oversimplify that figure is a midband spec. For the ACTUAL sensitivity you have to use an accurate model like LEAP or whatever has supplanted it. Things that will change the midband sensitivity may not increase the sensitivity at low frequencies etc etc.
The tiny box trend, yeah I was working in product planning for a gigantic audio company. MANY dealers and reps were like "we want to use these premade boxes by Obcon, Q-Logic, etc" so I went and designed subs that were perfect for those. Literally a standing ovation from the sales reps upon product introduction
. There are two things that happen: more mass lowers the resonance frequency in the box, and then you need a lot more magnetic force to tame the resonance down to a reasonable lack of boominess (at least at that time...tastes change, and the prevalent hip-hop these days some might feel is better served with boom).
A lot of your questions can be answered by doing full simulations comparing output. WinISD for instance shos cone excursion and SPL with a given power.
These days insane power is available, so if space is the problem, power overcomes.
I am actually looking for drivers with high VAS and higher Fs for use on BP-4 home sub. The high Vb is needed to keep the port ength short enough.
These days insane power is available, so if space is the problem, power overcomes.
I am actually looking for drivers with high VAS and higher Fs for use on BP-4 home sub. The high Vb is needed to keep the port ength short enough.
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