OK. I'm not sure why BK think that it was necessary to sim a 3rd-order as opposed to 2nd-order filter for the low-pass, maybe they made a mistake. 140Hz is almost two octaves away from 40Hz so the influence is minimal.
Alternatively you could probably bypass the fixed 140Hz filter, or change that to 40Hz and bypass the adjustable one.
Alternatively you could probably bypass the fixed 140Hz filter, or change that to 40Hz and bypass the adjustable one.
The amp should still be fine for a simple and cheap project. The problem with crossing so high is that the response will be lacking in bass. What we are doing is cheating a little - using a lower fc for the lowpass gives us a better looking response on the bottom end. The only problem with this is that you may be lacking in gain to pull this off. With just that fixed filter set at 140 Hz you get an F3 at that point. Combined with the lowpass set at its highest, you get an F3 at 120 Hz. The problem with this is that for it to work, you would need a lot of bass boost to bring up the bottom end. F3 is 53 Hz!
If I were you I'd do a temporary compromise - run the sub up to around 80 Hz or so (set by variable lowpass set at 40 Hz). This gives you F3 @ 27 Hz - not bad. There might be a bit of a gap in between the sub and mains. There isn't a simple way to fix this with that driver and amp, without messing with the amp and I'm not sure you want to do this.
Rather than do this, I suggest live with a compromise here until you make some DIY mains. Then it's quite simple - make a DIY bookshelf speaker with a 6.5" midbass in a sealed box and you will get natural roll off that will match the 80 Hz -3db point of the sub with the lowpass at its lowest setting.
If I were you I'd do a temporary compromise - run the sub up to around 80 Hz or so (set by variable lowpass set at 40 Hz). This gives you F3 @ 27 Hz - not bad. There might be a bit of a gap in between the sub and mains. There isn't a simple way to fix this with that driver and amp, without messing with the amp and I'm not sure you want to do this.
Rather than do this, I suggest live with a compromise here until you make some DIY mains. Then it's quite simple - make a DIY bookshelf speaker with a 6.5" midbass in a sealed box and you will get natural roll off that will match the 80 Hz -3db point of the sub with the lowpass at its lowest setting.
What do you think of this amp http://www.lautsprechershop.de/english/index_hifi.htm think its worth the extra money also how much watts would it be in 8ohms could only see value for 4 ohms in the spec
thanks guys
thanks guys
hi guys and thanks again for all the help got a few more question
1. do you think the 150 watt to 4ohms amp http://www.lautsprechershop.de/hifi/det150 en.htm will be powerfull enough for the 10" peerless xls or do you think i should go for the 300 version (its a bit over my budget) i have attached a screen of predicted SPL with 75watts (worst case i think)
2. Should i put Damping Material in my box
thank guys
craig
1. do you think the 150 watt to 4ohms amp http://www.lautsprechershop.de/hifi/det150 en.htm will be powerfull enough for the 10" peerless xls or do you think i should go for the 300 version (its a bit over my budget) i have attached a screen of predicted SPL with 75watts (worst case i think)
2. Should i put Damping Material in my box
thank guys
craig
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Given the 8 ohm impedance you get less than 150w. The more powerful amp would be advisable, but it depends on budget. It's not a huge SPL difference (3dB), but the difference is clipping is more likely on the lower powered amp.
You should check:
* have you modelled all the filters included on the plate amp?
* check apparent amplifier load - it shows the actual load the amplifier will see and while you input 75 watts, it may actually require 500 watts due to the effects of impedance and eq
* check driver excursion that xmax is not exceeded at any point
You should check:
* have you modelled all the filters included on the plate amp?
* check apparent amplifier load - it shows the actual load the amplifier will see and while you input 75 watts, it may actually require 500 watts due to the effects of impedance and eq
* check driver excursion that xmax is not exceeded at any point
do you guys think i would be better buying the peerless XXLS 10" which is 4 ohms http://www.madisound.com/pdf/peerless/830842.pdf as this would be cheaper than buying a bigger amp and seems to be similar in winisd to the 8 ohms xls or if you could point out a good 4ohms driver for a small sealed box
thanks
thanks
Hi
I was wondering what would be best to seal of the hole where the speaker wires come through i was think silicone would that work?
thanks
I was wondering what would be best to seal of the hole where the speaker wires come through i was think silicone would that work?
An externally hosted image should be here but it was not working when we last tested it.
thanks
For a small box, a powerful Car Subwoofer with a large magnet and coil would sound good and give you big bass. Plus 4 ohms gets you more power than 8 ohms if your amp can push it.
I'm only using a small 1.25 cu ft box, and I have a 12" inch Sony Xplod 5 sided subwoofer, and the lows can be heard outside at moderate volumes, and at high power, you can hear it very well.
You can get the Sony Xplod at Walmart or Circuit city.
You could get a high quality 10" or 12" car sub that would do great for a subwoofer in the house. But don't get a cheap sub, cheap subs get loud, but don't play good down low, and don't last long at high volumes. A good sub should be able to do 20 or 25hz well.
I'm only using a small 1.25 cu ft box, and I have a 12" inch Sony Xplod 5 sided subwoofer, and the lows can be heard outside at moderate volumes, and at high power, you can hear it very well.
You can get the Sony Xplod at Walmart or Circuit city.
You could get a high quality 10" or 12" car sub that would do great for a subwoofer in the house. But don't get a cheap sub, cheap subs get loud, but don't play good down low, and don't last long at high volumes. A good sub should be able to do 20 or 25hz well.
Overall, 4 ohms is better for a sub driver as you get more power out of the amp, but the XLS impedance drops down quite low at its top end. This isn't a problem for those who cross low at 40 - 60 Hz but in your case, you want to run it up high where the impedance is low. I'm not sure its a good idea to use the 4 ohm version and run it up that high from an amp point of view. Risk of overdriving your amp to the point of failure increases.
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