See what I meant? There's no focus. 10 pages! See how fast it grows. Maybe this will overtake the mega thread <Beyond the Ariel> which has not come to a conclusion yet.
I like this:
http://www.diyaudio.com/forums/multi-way/90804-large-midrange-ob-scott-g-40.html#post1953221
I like this:
http://www.diyaudio.com/forums/multi-way/90804-large-midrange-ob-scott-g-40.html#post1953221
Haha all talk, no action ae. This is why I always recommend speakers that have been designed already...like the ones on humblehomemadehifi etc, for customers who dont know much about the technical side anyway.
Yes but look how much some people learned from the 2-way thread.
Lets get down some pertinent thoughts then.
Midrange clarity is most important so do we need a second order electrical high pass or the extra component for a third order electrical to get 4th order acoustic?
is roll-off on the woofer going to be first order, second order or strange and do we need a zobel?
Just of the back of my hand I would have said zobel on the midrange, with 3rd order electrical on the low side and second order at 2700hz But what do I know
Lets get down some pertinent thoughts then.
Midrange clarity is most important so do we need a second order electrical high pass or the extra component for a third order electrical to get 4th order acoustic?
is roll-off on the woofer going to be first order, second order or strange and do we need a zobel?
Just of the back of my hand I would have said zobel on the midrange, with 3rd order electrical on the low side and second order at 2700hz But what do I know
To keep the focus are we locking in the seas drivers.
I say yes.
What about crossing up a bit higher on the MID say around 5K to avoid the peaks between 1 & 4K on the HF drivers and the peaks on the MID curve?
I'd agree with the steeper slopes here
I say yes.
What about crossing up a bit higher on the MID say around 5K to avoid the peaks between 1 & 4K on the HF drivers and the peaks on the MID curve?
I'd agree with the steeper slopes here
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Ill just update you all on the drivers. I will have to get some more 27tdfc's in(these fly out the door as so many kits use them). But I would appreciate if those who are actually serious about this kit to come forth, so I can get a fiar idea of how many extra to order. I for one will build these, as a reference for others who view this thread after the initial orders have been made.
I've done a 2.5way with two 6.5" Seas W18EX and Millenium tweeter in a TL, I've seen a lot of jaws dropping with them, especially when they realise the subwoofer is switched off. 😀
Also a nice driver, I think the 91dB sensitivity is just a bit high for the mid.
My belief is to keep the XO as simple as possible, I would suggest 2nd order electrical for a start.
I'm doing 2kHz 2nd order XO on my speakers and it work perfectly, it is about the highest point before beaming start on the midrange driver.
For the woofer I would stay relatively close to bafflestep, we can simulate and see what is the lowest point that will work.
I won't vote on driver selection if you don't mind, the thread was and is a good idea but my new mortgage precludes me participating in a build at this stage.
It would be nice to know if the selected SEAS drivers are going to be around for a good while tho'
It would be nice to know if the selected SEAS drivers are going to be around for a good while tho'
The drivers will be available for a while im sure. Infact SEAS is bringing out a new driver soon. The U18RNXP, especially designed for TL's. SEAS are increasing their product range, and I think the prestige range will continue to grow more rapidly.
If a group buy is done through Madisound, I'm definitely in. (Also, on a slightly highjacking note, if there are any Australian's out there planning on an order from madisound in the next few months, would you like to split postage with me?)
Absolutely great woofer and a pity it's gone. I use the M22WR baby version. Someone mentioned the Jaycar carbon fibre and they were a cracker. Andy G has a pair in Gumby and some of the nicest quality bass I've ever heard.
Good 10"-12" woofers aren't as plentiful these days as they seem to have been replaced by sub drivers.
I copies this from Troels page on the poor mans Strad.Poor Man'
It looks useful re crossover freq and driver selection
"This first set-up was including the 27TDC tweeter and despite an apparent high level of transparency, there was something that didn’t sound good. The 27TDC with its rigid, coated fabric diaphragm needs the same cure as the T25 and a felt ring was added to the centre polepiece and the terrible polyester foam plug in the vent was replaced by some wool felt material. This helped somewhat, but before doing more surgery on the poor dome, the 27TDC was replaced by the 27TFFC and things started going in the right direction. Everything started sounding really good except for some vocals. Vocals are the litmus test on any speaker. So back to the LspCAD and some dozens simulations later it was finally decided to take the point of crossover between the mid and tweeter down to 3 kHz.
Despite the ability of the MCA15 to run up to 6 kHz without trouble, it shan’t. 4 kHz is very much the middle treble area and despite a nice performance from measurements, the sound wasn't right. Getting the point of crossover down to 3 kHz was the cure and the phase tracking between mid and tweeter all of a sudden fell into place too."
And i guess we should start thinking about the box too
It looks useful re crossover freq and driver selection
"This first set-up was including the 27TDC tweeter and despite an apparent high level of transparency, there was something that didn’t sound good. The 27TDC with its rigid, coated fabric diaphragm needs the same cure as the T25 and a felt ring was added to the centre polepiece and the terrible polyester foam plug in the vent was replaced by some wool felt material. This helped somewhat, but before doing more surgery on the poor dome, the 27TDC was replaced by the 27TFFC and things started going in the right direction. Everything started sounding really good except for some vocals. Vocals are the litmus test on any speaker. So back to the LspCAD and some dozens simulations later it was finally decided to take the point of crossover between the mid and tweeter down to 3 kHz.
Despite the ability of the MCA15 to run up to 6 kHz without trouble, it shan’t. 4 kHz is very much the middle treble area and despite a nice performance from measurements, the sound wasn't right. Getting the point of crossover down to 3 kHz was the cure and the phase tracking between mid and tweeter all of a sudden fell into place too."
And i guess we should start thinking about the box too
My design was going to be a 270mm wide, 350mm deep, and 1250mm high made from 25mm MDF well braced. I hadn't decided on a final midrange enclosure size, but my lower chamber for the woofers was going to end up roughly 50litres (once bracing and port was taken into account) and tuned to about 35hz. The width of my cabinet design is only just wide enough for a 10" woofer, unless you side mounted.
It's been a while since i've updated it, I should have the latest design done in the next week (newborns are rather time consuming), but you can see what direction I was going in here, http://www.diyaudio.com/forums/multi-way/149247-design-my-own-do-you-know-design-3.html#post1920470 The latest version is 100mm shorter then shown in that thread. Also all the drivers have there centre's 165mm from one side and 105mm from the other side and the tweeter centre is 75mm down from the top. I was going to scollop out the bottom of the tweeter so that the mid to tweeter centre dimension was within one wavelength of the expected xover freq range.
It's been a while since i've updated it, I should have the latest design done in the next week (newborns are rather time consuming), but you can see what direction I was going in here, http://www.diyaudio.com/forums/multi-way/149247-design-my-own-do-you-know-design-3.html#post1920470 The latest version is 100mm shorter then shown in that thread. Also all the drivers have there centre's 165mm from one side and 105mm from the other side and the tweeter centre is 75mm down from the top. I was going to scollop out the bottom of the tweeter so that the mid to tweeter centre dimension was within one wavelength of the expected xover freq range.
And I just thought Id mention, I just priced up this with madisound and including shipping you would have to pay $712AU.
Yeah I was looking through your site again yesterday and the prices you have are great, when I buy the mids and tweets for my project I'll definitely be buying from you.
Thats really good to hear Luke. I match my competitors prices, where I can, and you save because of lower shipping costs. Shipping the drivers for this project would cost around $70nz, instead of $144us!
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How much influence does a small dealer like yourself have with the manufacturers?
I really prefer 16 R drivers if I am using multiple mids and woofers, perhaps it is because i have amplifiers that work best with 8 Ohm loads.
I have often argued that using triple 16R woofers is the best solution to a lot of small problems like Baffle-step, of course that may work out to be nominal 24 Ohm but that is an 8 ohm load for the amplifier and relatively easier to drive.
There may be some out there who would like to build this as a 3.5 and there is a good argument for doing so but placing the .5 woofer on the rear face of the tower.
Regards
Ted
I really prefer 16 R drivers if I am using multiple mids and woofers, perhaps it is because i have amplifiers that work best with 8 Ohm loads.
I have often argued that using triple 16R woofers is the best solution to a lot of small problems like Baffle-step, of course that may work out to be nominal 24 Ohm but that is an 8 ohm load for the amplifier and relatively easier to drive.
There may be some out there who would like to build this as a 3.5 and there is a good argument for doing so but placing the .5 woofer on the rear face of the tower.
Regards
Ted