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macantley

American bass VFL-8" woofer depth?

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Most people would call that 5". If the egde of the mag is hitting but the pole vent still has about an inch I'd run it.


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id have to redo alot of the box to put the woofer in it, or make a custom mounting ring for it, if i had better tools to build with id make a nice custom ring.  I installed a tang band 8" woofer with the neo magnet, its several years old but i've only used it as a backup for my home surround sound subwoofer. its not as loud as the VFL8d4 but since it was only playing the tighter bass that my VFL 12 couldnt hit  it should be fine.   

right now i have to look up the box specs for the VFL8d4 now to figure out if i want to run sealed or ported.  It looks like i'm going to have about 1.2 CF of room to work with in the truck,  

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41 minutes ago, macantley said:

id have to redo alot of the box to put the woofer in it, or make a custom mounting ring for it, if i had better tools to build with id make a nice custom ring.  I installed a tang band 8" woofer with the neo magnet, its several years old but i've only used it as a backup for my home surround sound subwoofer. its not as loud as the VFL8d4 but since it was only playing the tighter bass that my VFL 12 couldnt hit  it should be fine.   

right now i have to look up the box specs for the VFL8d4 now to figure out if i want to run sealed or ported.  It looks like i'm going to have about 1.2 CF of room to work with in the truck,  

The vfl 8 is ported only, don't put it in a sealed box. 


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Remove material to gain depth. Router out 1/2" worth. A small 5x5 section with only 1/4" thick wood won't hurt rigidity. 


Kenwood KDC-X597 head unit, Alpine R-S65C.2 comps, RF P300.2 amp, Pioneer TS-W3003D4 sub i(1.5cf @ 40hz), JBL GTR-1001 amp, Knukonceptz fuse blocks/wiring, Stinger 4k series rca's. 

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On 1/24/2019 at 9:22 PM, THATpurpleKUSH said:

The vfl 8 is ported only, don't put it in a sealed box. 

every sub calculator i've checked says they are ported or sealed..... so far i've found absolutely zero specs from american bass on what the sub is recommended for.   as of right now the new box i'm building for it is going to be 1.1 CF sealed on estimate, *IF* i can get alittle more out of the box i may try ported if it doesnt sound great. I've been running my 2001 model VFL 1222 in a 1cf sealed box for 19 years now. I know the designs have changed over the last 19 years though. 

 

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10 minutes ago, macantley said:

every sub calculator i've checked says they are ported or sealed..... so far i've found absolutely zero specs from american bass on what the sub is recommended for.   as of right now the new box i'm building for it is going to be 1.1 CF sealed on estimate, *IF* i can get alittle more out of the box i may try ported if it doesnt sound great. I've been running my 2001 model VFL 1222 in a 1cf sealed box for 19 years now. I know the designs have changed over the last 19 years though. 

 

There are tsp specs all over for that sub, it has a high ebp of about 76 indicating that it should go in a ported box. 


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10 minutes ago, THATpurpleKUSH said:

There are tsp specs all over for that sub, it has a high ebp of about 76 indicating that it should go in a ported box. 

https://www.diyaudioandvideo.com/Calculator/SealedVsPortedSpeakerBox/

this was the site i used, it does put it closer to the ported side, but says it will work on either.  i listen to all types of music but probably rap/hiphop the least, but i do enjoy some EDM which can hit low.   The funny thing is i have a pair of Tang-Band 8x12 woofers (they are no longer made) that sound great but i really dont want to put an oval sub in my truck because they look strange and i have no grill for it. 

 

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If you want the sub to perform correctly and optimum id try to listen and understand the why people are telling you what they are... 1st off learn how tsp's indicate driver preference and use modeling software to find what is best in your application... then use a calc. A calc is only as good as your info from modeling can make it imo.

https://www.eminence.com/support/understanding-loudspeaker-data/

My .02


JVC KD-X350BTS, RE Sx-18d4 9ft3 36.86hz, Synergy 3K@ 2 ohm, RF 500s, Polk DB comps, Cache Preamp/EQ

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I'm having difficulty using the calculators to attempt to figure out how much space and port length i would need for a ported box for a single VFL 8   I've been a novice when it comes to optimum box size for years.   My audi wagon has a 12" sub on the drivers side wheel well area with 1CF of airspace after the basket size, and my passenger side has a tang-band Neo 8" sub with .4 CF of space.   the Tang band is driven by an orion cobalt 500.1, and the VFL 12 is being driven by a memphis "big bell" sub channel. 

my pickup truck is still yet undetermined on the amps i'm going to use, i have a dozen or so different ones i can choose from, but i'm considering  using an HCCA275r for the sub at 2 OHM, and two HCCA 225's for the front/rear door speakers.  Those amps put out amazing SQ. 
 

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Bass Box Pro is the most accurate and best program to use. 

Winisd will get you close but it doesn't predict cabin/room gain so it's not accurate below 50hz. 

 

Putting that vfl 8 in a sealed box will seriously choke its performance. 


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I'm not gonna pay for bass box, but i put all the parameters that i knew into WINISD and it says ported box, with  0.86 CF and a 4 inch port  approx.24 inches long. or a 4x4 rectangle port at 32 inches long.   Pretty sure i'm gonna go with a round port at 30 inches long. and it says tuned to 39hz

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4 hours ago, macantley said:

I'm not gonna pay for bass box, but i put all the parameters that i knew into WINISD and it says ported box, with  0.86 CF and a 4 inch port  approx.24 inches long. or a 4x4 rectangle port at 32 inches long.   Pretty sure i'm gonna go with a round port at 30 inches long. and it says tuned to 39hz

port seems a little long for .86 cf net @39hz 4" round? was that a little over 4"? if just 4" i got around 35hz if not flared. Maybe i looked at it wrong idk? I paid for bass box pro and I am glad i did port length has been spot on, there is a difference between winisd port length and bbp depends on how you're doing the port.  Excursion seems more accurate to me anyway. I've had a couple of subs that I've modeled and according to winisd  they should be over excursion but not on bbp  went with bbp without issues. Group delay is different then winisd as well as vent velocity. Other stuff like impedance etc, seem close idk but yeah that length seems long if going for 39hz in that volume. If you're going with a 4'" personally I wouldn't worry about flaring seems like plenty of port area at that volume u can just smooth the edges imo but i am no expert. Also 4 looks like it'll be a little more boomy then a 3 but the 4 will give ya a little more output near tune. personally with a single 8 I'd go for as much output as you can get.


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work truck 2017 international pro star Alpine ute62 hu. Amps RF t1000.5ad 4 ch mode infinity k1000  sa 15 3.5 @ 30hz or 2 type s12 6.3 @ 41 hz  or jbl s3 1.5 42hz. or nvx  vcw 10 1.1 @ 32hz  2 8 " eminence pro woofers. 2" Dayton rs52fn midrange. 1 1/8 Dayton dc28f silk dome tweeters.

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if i go with a 3 inch port it wants 12.5 inches long

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If you are feeding the sub a true 400rms it will max out acceptable port velocity with a 3 inch port. As far as box size, I would keep it in the range of .5-.75cf. The larger the box size the more you will have an undesirable spike in group delay around 50hz. I had to reinstall windows on my laptop and I'm having issues printing to pdf so I can't post my graph from Bass Box Pro. 


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44 minutes ago, THATpurpleKUSH said:

If you are feeding the sub a true 400rms it will max out acceptable port velocity with a 3 inch port. As far as box size, I would keep it in the range of .5-.75cf. The larger the box size the more you will have an undesirable spike in group delay around 50hz. I had to reinstall windows on my laptop and I'm having issues printing to pdf so I can't post my graph from Bass Box Pro. 

so is that your way of telling me that i should keep a 4 inch port?  I have a 4" port now but its only 8 inches long, so i'll either have to  extend it, or build a slot port of some sort.  After i put some internal bracing in my box to keep it stiffer it will probably be around the .75CF  after accounting for basket size and what the port itself removes from the box. 

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53 minutes ago, macantley said:

so is that your way of telling me that i should keep a 4 inch port?  I have a 4" port now but its only 8 inches long, so i'll either have to  extend it, or build a slot port of some sort.  After i put some internal bracing in my box to keep it stiffer it will probably be around the .75CF  after accounting for basket size and what the port itself removes from the box. 

I would rebuild the box allowing the space for a properly designed port. You'll probably have to do a slot port to incorporate a long port. What amp are you planning on using?


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*IF* i can move my seat forward enough in the back of the truck i'm going to attempt to build an amp rack behind it to fit all 3 old school (mid 90's) orion HCCA amps, i'll use an HCCA 275R for the single 8" sub  according to the manual its 600W RMS at 2 ohm mono.   Although i'll be honest, i dont want to use the orion amps, I'd much rather have a single 5 channel amp to run everything.   I've got a memphis "big bell"  5 channel amp in my audi wagon and it does a great job. The HCCA 225's that i have could run my 4 doors and the 275 on the sub, but it seems extreme.  I've also got an american bass XD 1800 (early 2000's i think) and an american bass SQ900 (not sure what it's 2 ohm mono rating is)  i've got quite a few other amps but i dont think any of them are up to the task.    but lets just use the orion as the example for now.     The box i'm building is approx. 28 inches in length (26.5 internally)   its custom for the pickup truck so rebuilding it isnt really the best option, i could shorten the box some but then i wouldnt have the best length for a round port and i'd have to go with a slot.   *IF* i go with a round port it will be ported out the side of the box under the passenger rear seat (i dont see this being an issue as it will have about 20" or so of room between the port and the passenger rear door)  from what i'm reading i need about 4" of room between the port  and the inside wall of the box  so that i'lll have plenty of room for air movement.  so given that recommendation from box desing, i can be no longer than  23.25 inches on my port length.   although it does seem that the larger the box, the shorter my port length is.   I guess i need to finish building the box and get the 100% accurate measurement of the airspace inside of it then remove what space the port will be taking up. 

 

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finished building the box other than cutting the hole for the round port, I estimated that a 4 inch port at 20 inches long is approx. 0.15 cubic foot of air space, the box itself is 1.05 CF, and the subwoofer takes up 0.10 CF, so if i port the box it will be 0.80 CF of space, *IF* i tune the box to 37HZ i can add a few more inches to the port and the box will be approx. 0.76 CF of air space  which i think would be optimum  from what i'm reading, almost every sub box i've viewed on Youtube that runs the american bass VFL subs is between 0.75 and 0.80 CF per sub. and they are ported. 

 

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10 minutes ago, macantley said:

finished building the box other than cutting the hole for the round port, I estimated that a 4 inch port at 20 inches long is approx. 0.15 cubic foot of air space, the box itself is 1.05 CF, and the subwoofer takes up 0.10 CF, so if i port the box it will be 0.80 CF of space, *IF* i tune the box to 37HZ i can add a few more inches to the port and the box will be approx. 0.76 CF of air space  which i think would be optimum  from what i'm reading, almost every sub box i've viewed on Youtube that runs the american bass VFL subs is between 0.75 and 0.80 CF per sub. and they are ported. 

 

Are you using sch 40 pvc for the port? 

A 20inch long port thats flush with the side of the box and made from sch40 pvc is .0787cf. 

.5-.75 is optimal for that sub, the larger you go the boomier it will sound and the faster it will reach its max excursion. It sounds like it will be slightly under to right around its rms power with any of the amps you have. 

In general, the larger the box size the shorter the port will need to be when cross section area stays the same. 


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3 minutes ago, THATpurpleKUSH said:

Are you using sch 40 pvc for the port? 

A 20inch long port thats flush with the side of the box and made from sch40 pvc is .0787cf. 

.5-.75 is optimal for that sub, the larger you go the boomier it will sound and the faster it will reach its max excursion. It sounds like it will be slightly under to right around its rms power with any of the amps you have. 

In general, the larger the box size the shorter the port will need to be when cross section area stays the same. 

thanks, i just realized i forgot to take in account that schedule 40 pipe is actually 4.5" in diameter due to the thickness of the pipe which also affects my cubic feet.  I'm going to have to measure to double check that i can fit a 4.5" pipe inside the box through the brace i made inside of it, i'm pretty sure i can, but i mostly accounted for 4.125" and was planning on screwing some screws through the pipe then cutting off the access of the screws. so the pipe will be rigid inside the box. Either way it's gonna wait till tomorrow, its damn cold outside now. 

 

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