Well, they are what I have in this build so I can assure you they do actually exist and work well
lolI am confused by this comment...
18s have 'floppy cone effect'? That sounds like urban myth to me, which djk has seemingly alluded to in his 'whatever' comment. lol
I am also confused by this comment! You are saying my boxes are small and light? (and containing 10s??)
I wish they were small and light, they just about killed two of us getting them up the stairs, they are about 200lb each!
Well, they are what I have in this build so I can assure you they do actually exist and work well
I meant to post that in another thread, sorry for the redundancy.
Exactly, the shift would be fs=21hz, Qe=.33 Qt=.3, Qm=4.6 or so. making 92db bass to low 30s. not bad.
haha
I've not weighed them but my builder chap reckoned on 100kg each (!) with drivers fitted and the MDF calculated. I've not checked but they are liftable and carryable (is that a word?) by two reasonably fit blokes (although I just about had a heart attack being on the bottom as we carried them up the stairs lol).
They can be slid over carpet fairly easily as the big-ish footprint means a lower PSI than if the footprint was smaller, but they are indeed a deadweight with no easy way to pick them up other than from the bottom corners!
And yes, $159 for an 600wRMS rated 18" driver with c.23mm each-way xmax is a bargain in my books too! Made in China but apparently they are all tested by SI before shipping. So far I've not read much of failures so I am hopeful mine will last, especially when AVS people have been running them with similar power in similar box volumes for longer. They are far from stressed in day-to-day music (they barely move!) and movies at Reference still don't see that much cone movement. If I can sort EQ hopefully I will see some more and get more <20Hz output
They work out around £200 each imported (shipping and 20% VAT paid) which is still almost half the price of a UK-sourced Fi Q driver, IIRC
I've not weighed them but my builder chap reckoned on 100kg each (!) with drivers fitted and the MDF calculated. I've not checked but they are liftable and carryable (is that a word?) by two reasonably fit blokes (although I just about had a heart attack being on the bottom as we carried them up the stairs lol).
They can be slid over carpet fairly easily as the big-ish footprint means a lower PSI than if the footprint was smaller, but they are indeed a deadweight with no easy way to pick them up other than from the bottom corners!
And yes, $159 for an 600wRMS rated 18" driver with c.23mm each-way xmax is a bargain in my books too! Made in China but apparently they are all tested by SI before shipping. So far I've not read much of failures so I am hopeful mine will last, especially when AVS people have been running them with similar power in similar box volumes for longer. They are far from stressed in day-to-day music (they barely move!) and movies at Reference still don't see that much cone movement. If I can sort EQ hopefully I will see some more and get more <20Hz output
They work out around £200 each imported (shipping and 20% VAT paid) which is still almost half the price of a UK-sourced Fi Q driver, IIRC
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Quick update!
I ran The Art of Flight BD this morning at Reference but +9dB on the subwoofer trim on the AVR.
Peaks of 119dB at the MLP (around 10 feet from the stacked subs) and 126dB close-mic'd at the mouth of the slot of one of the subs.
I'm sure there is a lot more to give (the cones were barely moving, perhaps 5mm peak-to-peak) and I do need to check my gain structure and also EQ the very bottom end (miniDSP is on the way, as is a calibrated UMIK) but it was great to have a back massage while sitting on the sofa
I'm not sure the neighbours will be too impressed if I play it that loud regularly, but it's nice to know that I have plenty of headroom!
I ran The Art of Flight BD this morning at Reference but +9dB on the subwoofer trim on the AVR.
Peaks of 119dB at the MLP (around 10 feet from the stacked subs) and 126dB close-mic'd at the mouth of the slot of one of the subs.
I'm sure there is a lot more to give (the cones were barely moving, perhaps 5mm peak-to-peak) and I do need to check my gain structure and also EQ the very bottom end (miniDSP is on the way, as is a calibrated UMIK) but it was great to have a back massage while sitting on the sofa
I'm not sure the neighbours will be too impressed if I play it that loud regularly, but it's nice to know that I have plenty of headroom!
LLT is another alternative
There are a lot of myths about subwoofer drivers and vented enclosures. If you have a reasonable sized space to vent into, an LLT is a lower distortion candidate for a subwoofer (better than IB) and it reaches louder/much lower. Eventually, when I do my home theater, I will do one. Anyways, read this thread - it is enlightening:
IB makeover.......... - Home Theater Forum and Systems - HomeTheaterShack.com
Retsel
There are a lot of myths about subwoofer drivers and vented enclosures. If you have a reasonable sized space to vent into, an LLT is a lower distortion candidate for a subwoofer (better than IB) and it reaches louder/much lower. Eventually, when I do my home theater, I will do one. Anyways, read this thread - it is enlightening:
IB makeover.......... - Home Theater Forum and Systems - HomeTheaterShack.com
Retsel
Very Interesting
One fellow local audio club member has commented more than once, that even as good as my I.B. bass is, another club member's HUGE bass reflex is even better. Well, since my I.B. is now residing in the left rear corner, I thought I'd do a bass reflex in the right rear corner.
Thank you, Sir Retsel. I am way over due for some interesting reading. I have had HUGE bass reflex subs in the past; re-located and built I.B. subs now.
One fellow local audio club member has commented more than once, that even as good as my I.B. bass is, another club member's HUGE bass reflex is even better. Well, since my I.B. is now residing in the left rear corner, I thought I'd do a bass reflex in the right rear corner.
Will do! I'm not confident on measuring but hopefully it won't be too difficult with a USB mic and REW
Amp is a CV5000 running in 2Ohm stereo - so far I'm happy with it!
Ports quickly go into power compression unless they are quite large as in at least 70% of the area of the driver. Ports test great at milli-watt levels but press them up to like 95dB at the port frequency and output will not even be close to as expected from a small port. Passive radiators or very large ports are by far the best choice. This gets the required area. There are several papers is the AES addressing this specific subject which is always ignored in favor of low rumbling sounds of bad ports instead of notes.
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