The AT drivers are 4 ohms and 93 dB too.
You dont think the Faster AT 10" drivers will sound better ?
The AT have 8.6 mm x max , .22 qts 133 L vas 21 fs 102mm VC 4 ohm 93.5db
Volts 5.5 mm , .39 qt , 172 L vas 32 fs 75 mm vc 8 ohm 93 db
Small box for the AT drivers is nice and small too
From looking at those specs Do you think the 15 "Volts will do the job better than 10" AT ?
cheers
You dont think the Faster AT 10" drivers will sound better ?
The AT have 8.6 mm x max , .22 qts 133 L vas 21 fs 102mm VC 4 ohm 93.5db
Volts 5.5 mm , .39 qt , 172 L vas 32 fs 75 mm vc 8 ohm 93 db
Small box for the AT drivers is nice and small too
From looking at those specs Do you think the 15 "Volts will do the job better than 10" AT ?
cheers
Now I know you don't like "HUGE" boxes it is obvious the At drivers are the best choice. Actually I could not find the spec you have quoted for these better 10" but instead found another 10" with a lower spec. If you stick to the usual alignments they will suggest a small box size of around 1.5-2ft" tuned to approx 40Hz for the 2 drivers. I would use around 3ft" (or even 4ft") tuned to 30Hz. This alignment is an extended bass shelf which does have around 1.5dB negative pass band ripple, that is you lose 1.5dB of sensitivity below 100Hz. However as you are using two drivers your sensitivity will be 93db +3dB (for second driver) - 1.5dB (neg. pass band ripple) so you will still have a healthy 94.5dB sensitivity with an f3 of around 34Hz (referenced to 100Hz -crossover frequency). What I would do in your position is built a couple of test boxes (quickly and cheaply!) in particle board, and try both box sizes, side by side, and ultimately let your ears be the judge. The location in the room where you test is important, set up where you will eventually use the speakers. Like I said before, I always prefer lower qts. drivers, (as long as fs is low) they do sound "faster" and more informative to me, even though this idea of "faster" is a little contentious here on diy Audio!
Yes 4.4ft" for 2 drivers is in the right ball park. This alignment gives around 3dB negative pass band ripple, giving an overall sensitivity of 93.5dB for 2 drivers. Referenced to 60Hz you will now have 27Hz @-3dB, very nice! In effect in this alignment you have traded some sensitivity for extended bass response, but still with ample power handling. This alignment is close to the one I use and will produce tight bass that will never sound boomy or uncontrolled. You can use a 4" port, 6" will probably too long unless the cabinet is very deep.
It is essential to create a box with minimal panel resonance, I have used 25mm HDF, double thickness front panel, braced extensively, with no more than 4-5" between each hardwood/HDF brace, together with 200 2" screws and glue. I intend to finish the cabinet by covering with 8-10mm marble, or something similar. At present each box with drivers is around 200Lbs (90kg), but will end up around 260-300lb.
It is essential to create a box with minimal panel resonance, I have used 25mm HDF, double thickness front panel, braced extensively, with no more than 4-5" between each hardwood/HDF brace, together with 200 2" screws and glue. I intend to finish the cabinet by covering with 8-10mm marble, or something similar. At present each box with drivers is around 200Lbs (90kg), but will end up around 260-300lb.
Okay so I m on the right path .
what tuning freq. do you recommend ?
I m happy with the smaller box for the two 10s .
I will be using the birch ply for construction myself .
I could go bigger but is it beneficial ?
box is 16 " deep so dual 4" ports will do or better do a flat port flared ?
I do not want 200 lbs cabinets that is very heavy and hard to move around.
cheers
what tuning freq. do you recommend ?
I m happy with the smaller box for the two 10s .
I will be using the birch ply for construction myself .
I could go bigger but is it beneficial ?
box is 16 " deep so dual 4" ports will do or better do a flat port flared ?
I do not want 200 lbs cabinets that is very heavy and hard to move around.
cheers
So you will have to decide whether to go for 3ft" or 4.4Ft" for your box, any smaller than 3ft" would entail higher tuning than 30Hz. Above 4.4ft" size you will achieve a little more of the bottom octave but at the expense of overall efficiency. In either case I suggest tuning to around 30Hz using a 4" diameter pipe. I think a flared port is less important in this case because mach air speeds will not be too high. One advantage of a round section port (water pipe!) is that it is fairly easy to change if you want to experiment with different port tunings. It is possible to fit a small baffle or rim to the outside diameter of the port, say 8" diameter, on the end of the port inside the speaker box. This measure can help air flow symmetry, balancing positive and negative air flow through the port. For 30Hz tuning 5" long pipe for the 3ft" box and 10" long pipe for the 4.4ft" box should be fine. I use birch ply for my PA boxes but a decent amount of bracing is still essential. I usually allow around 10% extra cabinet volume to allow for the space taken up by bracing, which should be hardwood or similar.
One 4" pipe is fine in this application for two drivers together in one enclosure, which I always advocate to be front facing. I don't know if you have access to any speaker design programs but you will find that if you specify a 6" port or even 2 4" ports, they will be too long to fit into the enclosure or box, hence why I have specified a single 4" port.
Those AT drivers are definitely awesome, no corners have been cut here! Two 3" ports will reduce the air mach speed somewhat, but remember they will have to be longer than a single 4" pipe. Also always allow at least the diameter of the pipe in between the end of the pipe and the inside back of the enclosure to ensure airflow.
Got it thank you .
I ll do a 4 with a nice flare on both ends
I have to agree no corner cuts there at AT . even the Focal Audiom woofs look less impressive and a tad too tight to give low bass.
I think the AT woofs will do bass nicely even at low loudness .
Worth every penny indeed
I wonder how their mids are ???? any comments ?
I ll do a 4 with a nice flare on both ends
I have to agree no corner cuts there at AT . even the Focal Audiom woofs look less impressive and a tad too tight to give low bass.
I think the AT woofs will do bass nicely even at low loudness .
Worth every penny indeed
I wonder how their mids are ???? any comments ?
i had 4-way speakers using Volt BM2500.4 along with ATC 3'' dome (now the ATC is replaced by FR cone driver) and i believe the BM2500.4 is very useable up to 1,400hz while being at his best between 70hz and 700hz.
That driver never sounds annoying so i'm not surprised some people are using it in 2-way speakers or monitors.
Thinking would the Audax TW034X0 tweeter be a good match for the Volt @ 1500-1600 Hz 3rd or 4th order on the tweeter?
Simon
Simon
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