Sharkwoofer Re-design - bringing back bass and amplification for the 928
04-27-2016, 07:15 PM
#46
Rennlist Member
Thread Starter
Roger.
No, I am going to use the 8ohm driver. 8ohm is an easier load for the amplifier to drive, so it will run cooler. The effective power rating of the amp will be reduced roughly by half to ~250w. This is ideal for the power handling of the driver as well.
You may think that reducing the output of the amp to 250w would make a significant difference in output, but in reality power/output is logarithmic, and by decreasing the power by half only will reduce the maximum output by 3db.
Regards,
Hans
No, I am going to use the 8ohm driver. 8ohm is an easier load for the amplifier to drive, so it will run cooler. The effective power rating of the amp will be reduced roughly by half to ~250w. This is ideal for the power handling of the driver as well.
You may think that reducing the output of the amp to 250w would make a significant difference in output, but in reality power/output is logarithmic, and by decreasing the power by half only will reduce the maximum output by 3db.
Regards,
Hans
04-28-2016, 12:52 AM
#47
Archive Gatekeeper
Rennlist Member
Rennlist Member
Took the GTS out for a spin tonight, got to remind myself how great Hans' setup is. This is a JBL MSA-1004 in 3 channel mode, driving Hans' door speakers (crossovers in the door panels) and a Wavecor 8.75" SW223BD01. All hidden by a Rob Budd cargo mat without the rubber backing on the factory mat. Pleixglass cover is off so I could tweak crossover settings a while back.
04-28-2016, 03:09 AM
#48
Burning Brakes
No, I am going to use the 8ohm driver. 8ohm is an easier load for the amplifier to drive, so it will run cooler. The effective power rating of the amp will be reduced roughly by half to ~250w. This is ideal for the power handling of the driver as well.
You may think that reducing the output of the amp to 250w would make a significant difference in output, but in reality power/output is logarithmic, and by decreasing the power by half only will reduce the maximum output by 3db.
You may think that reducing the output of the amp to 250w would make a significant difference in output, but in reality power/output is logarithmic, and by decreasing the power by half only will reduce the maximum output by 3db.
Thanks,
Roger
04-28-2016, 11:20 AM
#49
Rennlist Member
Thread Starter
I am a little behind schedule, but took the day off last night from the social agenda, and was able to model the Alpine PDX-V9 including all the electrical connections so I can properly carve out a cable path in the enclosure.
Years ago when I started this project, Mark Benton surgically removed the spare tire well from a car for me so I can test fit on the bench. I am going to go get that out of storage this weekend and make sure I get the optimal location for the amp before modeling the rest of the enclosure. Depending on how Sunday looks, this may be ready to send out for bids on Monday.
Thanks
Hans
Years ago when I started this project, Mark Benton surgically removed the spare tire well from a car for me so I can test fit on the bench. I am going to go get that out of storage this weekend and make sure I get the optimal location for the amp before modeling the rest of the enclosure. Depending on how Sunday looks, this may be ready to send out for bids on Monday.
Thanks
Hans
05-11-2016, 09:47 PM
#51
Race Car
Pretty cool, friendly bump. I inherited a nasty tangle of wires and cables connected to an amp in the spare tire well from the p/o. I'm tamping down on new work/improvements while I and others are hung up on a couple stubborn minor faults, but might be tempted to tidy that up.
05-11-2016, 10:25 PM
#53
Drifting
Hans is one of a kind…..cant believe he is so good at so many things….I have his twin fan plus shroud just waiting to install at the next stock failure…..
can't wait to order this for the completion of my ultimate 928
can't wait to order this for the completion of my ultimate 928
05-12-2016, 01:11 PM
#54
Rennlist Member
Thread Starter
Work on this project to a minor stall. SB-Acoustics was going to send me a 3D model of the driver, so I didnt have to re-create it to make an optimal enclosure, and they didnt get it finished before heading out an industry show in Germany.
I hope to have the data/model soon, or I will just start doing it myself. Since its a fairly organic design, its a bit of a pain, so was hoping to get the model from them instead.
I have my test "tub" pulled out of storage and ready to go,
I hope to have the data/model soon, or I will just start doing it myself. Since its a fairly organic design, its a bit of a pain, so was hoping to get the model from them instead.
I have my test "tub" pulled out of storage and ready to go,
05-15-2016, 01:21 PM
#56
Racer
05-15-2016, 09:01 PM
#57
Rennlist Member
Put me down for a set.
A good sound system is the only thing missing from my 84 928. Would also like to upgrade from the original speakers as well.
Great stealth setup as well!
A good sound system is the only thing missing from my 84 928. Would also like to upgrade from the original speakers as well.
Great stealth setup as well!
05-17-2016, 02:14 PM
#58
Rennlist Member
Thread Starter
SB-Acoustics just sent over the solid model of the driver. I will get the rest of the enclosure designed this week.
Initial calculations show that a 15L sealed enclosure will yield a native F3 of about 53hz. With a headunit capable of parametric EQ or even adjustable bass-boost, a filter set at approximately 25hz at 3db of gain and Q of ~1.4 coupled with the subsonic filter of the alpine amp set at approximately 15 (maybe a tad higher since its a 24db slope) should yield an F3 down in the high 20's (tough to estimate the effect of the reflection of hatch glass). Max ouutput should be around 107db, which to put things in perspective is noticeably louder than your THX equipped mulitplex cinema, which should not exceed 105db. An average loud concert down front is about 110db.
Everything is looking really nicely for this driver, it should have plenty of low extension and output in a small sealed enclosure with the power delivered by the Alpine.
Initial calculations show that a 15L sealed enclosure will yield a native F3 of about 53hz. With a headunit capable of parametric EQ or even adjustable bass-boost, a filter set at approximately 25hz at 3db of gain and Q of ~1.4 coupled with the subsonic filter of the alpine amp set at approximately 15 (maybe a tad higher since its a 24db slope) should yield an F3 down in the high 20's (tough to estimate the effect of the reflection of hatch glass). Max ouutput should be around 107db, which to put things in perspective is noticeably louder than your THX equipped mulitplex cinema, which should not exceed 105db. An average loud concert down front is about 110db.
Everything is looking really nicely for this driver, it should have plenty of low extension and output in a small sealed enclosure with the power delivered by the Alpine.
05-17-2016, 02:28 PM
#59
Archive Gatekeeper
Rennlist Member
Rennlist Member
Hans, please put me down for one of the new sharkwoofers. Thanks!
05-17-2016, 04:52 PM
#60
Rennlist Member
...
Initial calculations show that a 15L sealed enclosure will yield a native F3 of about 53hz. With a headunit capable of parametric EQ or even adjustable bass-boost, a filter set at approximately 25hz at 3db of gain and Q of ~1.4 coupled with the subsonic filter of the alpine amp set at approximately 15 (maybe a tad higher since its a 24db slope) should yield an F3 down in the high 20's (tough to estimate the effect of the reflection of hatch glass). ...
Initial calculations show that a 15L sealed enclosure will yield a native F3 of about 53hz. With a headunit capable of parametric EQ or even adjustable bass-boost, a filter set at approximately 25hz at 3db of gain and Q of ~1.4 coupled with the subsonic filter of the alpine amp set at approximately 15 (maybe a tad higher since its a 24db slope) should yield an F3 down in the high 20's (tough to estimate the effect of the reflection of hatch glass). ...