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Post by eeyore on Jul 24, 2006 8:45:47 GMT -7
While I agree that 12mm is at the lower limits I would point out that the Dayton IB is about 14.3mm and the AE IB15 is about 15.4mm. A difference but not huge. One must also consider that you could nearly buy eight of these for the price of 4 of the Dayton's and get a much better bargain. I think that price has been what has kept a large number of potential IB users away. These may push a few over the edge. Had these been around when I was looking for drivers I would have bought them without hesitation. If selling my AE IB15's and whipping up a huge manifold was easy enough I would do it right now. If not for an improvement certainly for the fun and to satisfy my curiousity. Hopefully this inspires another AE IB15 (8 ohm version) user to sell his to me.  |
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Post by Darren on Jul 24, 2006 8:54:12 GMT -7
Yeah, if I didn't have to cut another hole I'd buy 4 just for fun and play with them but I gotta stop somewhere  Maybe my garage needs an IB for my little 20 watt receiver... nah. As far as comparing the value of these 18" drivers to the AE IB and the Dayton IB specs I'd say yes, the 18" drivers are my choice for sure! How can you go wrong. For $50 I was considering building a box sub out of one for giggles, that would have to be one big box though. |
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Post by mazeroth on Jul 24, 2006 8:57:02 GMT -7
One thing you guys need to also keep in mind is the cost to ship these speakers. I got a quote from Mach 5 to ship to Columbus, OH and it came out to $37.82 per 18" driver. That's $89.81 per driver, shipped. Still a stellar deal, but I made the misconception of getting a $52 18" driver, when in reality, it's really a $90 18" driver.
I'm still debating whether or not to give 2 of them a try. I already have four Dayton RS315HFs that I was going to use in stereo dipole subs, but with the cost of these I could get twice the displacement for what I paid for the Daytons. Albeit, the H-frames will be a LITTLE bit bigger!
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Post by Darren on Jul 24, 2006 9:19:50 GMT -7
Yeah, I noticed the shipping seemed a bit steep. I just shipped 4 15" drivers for $91 to MI from WA and I ensured them for 150 each.
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Post by ThomasW on Jul 24, 2006 10:12:57 GMT -7
There is probably a Canadian version of Parcel Post. Much slower than 1st class (a couple weeks from Canada) but it should be very cheap....
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Post by chrisbee on Jul 24, 2006 10:36:08 GMT -7
What do you really think of these Thomas?
4 x 18" would slot straight in place of the IB15s.
8 x 18" is getting into serious displacement and still costs less overall than my UK distributor, B-stock 4 x AE IB15s including European freight charges.
With half the VAS it suits those with limited rear volume enclosures.
The 18" paper cone should offer SQ advantages over the polycone AE IB15s.
A nice opposing driver manifold to keep them compact and avoid wall flexure.
Sell the IB15s to help fund the freight charges to keep my wife sweet?
Or sneak them in while my wife is gardening and wonder if she'll notice...? ;D
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Post by ThomasW on Jul 24, 2006 12:11:56 GMT -7
What do you really think of these Thomas? 4 x 18" would slot straight in place of the IB15s. 8 x 18" is getting into serious displacement and still costs less overall than my UK distributor, B-stock 4 x AE IB15s including European freight charges. With half the VAS it suits those with limited rear volume enclosures. The 18" paper cone should offer SQ advantages over the polycone AE IB15s. A nice opposing driver manifold to keep them compact and avoid wall flexure. Sell the IB15s to help fund the freight charges to keep my wife sweet? Or sneak them in while my wife is gardening and wonder if she'll notice...? ;D The post is a joke right? If it's not you need professional help..  |
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Post by mrogowski on Jul 24, 2006 13:26:30 GMT -7
I agree Thomas, he needs help. There's absolutely no way he could get past the wife without the radar setting off an alarm...  |
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Post by chrisbee on Jul 24, 2006 14:19:20 GMT -7
Humour alert! Lighten up Thomas! That's why we have these: ;D Do you seriously think I could sneak these drivers past my wife? The idea is completely absurd. That's why it's funny. (IMO of course) I'd still be interested in hearing your expert opinion on replacing AE IB15s with these 18" drivers. I'm sure a number of other IB owners using inexpensive 15" drivers would also value your opinion on these drivers. These !8" drivers do have a high Fs but you have repeatedly mentioned that this does not matter with EQ. Xmax is modest but acceptable, I think. What should we not like apart from the freight charges? 
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Post by chasw98 on Jul 24, 2006 14:32:07 GMT -7
Mark:
I went to place an order today and "wow", the shipping was $180.00 and the drivers were $210.00. Is there any way to ship by parcel post as Thomas suggested?, Otherwise, I will bite the bullet and dig into my pockets. Thanks.
Chuck
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Post by ThomasW on Jul 24, 2006 15:16:04 GMT -7
I'd still be interested in hearing your expert opinion on replacing AE IB15s with these 18" drivers. I'm sure a number of other IB owners using inexpensive 15" drivers would also value your opinion on these drivers. These 18" drivers do have a high Fs but you have repeatedly mentioned that this does not matter with EQ. Xmax is modest but acceptable, I think. What should we not like apart from the freight charges? Sorry, today has been spent battling a migraine, so my sense of humor is somewhat lacking..... The Fs and lower Xmax are no big deal given the ability of a driver to play lower than's it Fs and since 18"s have a huge Sd. Beyond this I can't comment since it would be just speculation on my part. |
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Post by mrogowski on Jul 24, 2006 18:12:50 GMT -7
Chuck, pm me and provide your shipping addy - I'll see what I can do.
Best,
Mark
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ryans
Full Member
Posts: 132
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Post by ryans on Jul 24, 2006 18:59:03 GMT -7
Its great to finally see some hands on experience with this.
Here's some displacement numbers to consider:
PE IB15 - 2.34L
Dayton DVC 15 - 2.44L
Old Adire Tempest - 2.56L
Mach 5 MJ18 - 2.47L
So the Mach 5's fall right in line with some familiar 15's. I think the big difference is that they'll be capable of a lot more in the mid bass (above 40Hz) than some of these other woofers. Just consider the 93dB sensitivity.
When I model them they definitely look like they'll want a lot of boost down low (or cuts up high). But if you're planning to use EQ anyway, who cares?
Similarly, they could probably use some EQ even in a ported box. But you could do a reasonable sized box if you weren't trying get sub-20Hz output (and if you are then maybe choose another woofer). 5 - 6 cuft tuned to 25Hz looks good. 116dB @30hz with 500 watts. Or 113dB if you think 250 watts is a safer bet with such an inexpensive woofer.
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Post by ThomasW on Jul 24, 2006 20:23:02 GMT -7
Here's some displacement numbers to consider: PE IB15 - 2.34L Dayton DVC 15 - 2.44L Old Adire Tempest - 2.56L Mach 5 MJ18 - 2.47L For Canadian buyers this is a no brainer given the huge difference in price importing drivers from the US. US buyers need to factor shipping from Canada |
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Post by jackgilvey on Jul 25, 2006 4:29:42 GMT -7
Ah-HAA! So it is too good to be true! I wouldn't be put off by a low price. The high Xmax and thermal capacity of many drivers is expensive, neither of which these have or need for our purposes. Mark, the listed Sd for your drivers seems low compared to others of the same diameter, are you just being more conservative? Do you have an Le spec handy? |
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Post by mrogowski on Jul 25, 2006 5:16:45 GMT -7
Hi Jack,
Sd is a bit lower on account of the larger foam surround the MJ-18 has over other units. I did measure it by hand, so yeah, you can say its a bit conservative.
I measured 5.5mH on the coil. Its a bit high, but tolerable.
Best regards,
Mark
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Post by jackgilvey on Jul 25, 2006 5:37:18 GMT -7
Did you include any of the surround? I think DUMAX specifies 1/3.
Got it, thanks.
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Post by Darren on Jul 25, 2006 6:33:35 GMT -7
I think I understand what you were saying above but it might be confusing to some others...
We do indeed want high XMAX, 12mm is at the bottom of what we'd want from everything I've read. If you want good home theater bass without destroying your drivers you will need lots of drivers or a reasonable amount of higher excursion drivers. These drivers are priced right for using many to accomplish what you want, if they had higher xmax they'd be more $$ like you state.
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Post by mrogowski on Jul 25, 2006 7:53:57 GMT -7
Did you include any of the surround? I think DUMAX specifies 1/3. Yes I did. Best, Mark |
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Post by osuhog on Jul 25, 2006 7:55:22 GMT -7
Just consider the 93dB sensitivity. You know, that's another thing I forgot to mention. The gain on my amp is only turned a few clicks past half way with these two 18's and my LFE out is set to 0. With my 15's to get the same volume the amp was 3/4 of the way up. Then again I did have a few small cut filters on my BFD, but even before the BFD it was about 3/4 I believe. When I model them they definitely look like they'll want a lot of boost down low Again, these things have the exact same dip at 20 hz that my 15's did, and my 15's have an FS of 23.5. I don't know why that is. Maybe my meter? I may buy a newer meter and see what I get later this week. I really don't think these will need any boost when you figure in room gain, but I'm no expert. Also, I did some more listening last night to make sure I wasn't crazy, and all I can say is wow all over again! These things are so impressive for the money. I really still can't believe it. Again, I can't wait for someone else to get a pair and back up my findings. By the way, my 15's are now for sale as I am keeping these 18's permanantly. Luckily I don't have to pay shipping since I already have the woofers. Thanks again Mark!!! |
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