Stuffing can lower Qtc by 10% maybe 15 or 20%.
Will you hear a difference? Maybe is all I can say but you will find that they give greater excursion per watt, so more efficient but lower power handling as Qtc drops below 0.9.
The steeper roll-off of a Qtc of 0.7 may make integration with a sub-woofer easier, but I really do not know if that would be an issue with your set-up.
I just think the bigger box sounds "better" what-ever that means.
Will you hear a difference? Maybe is all I can say but you will find that they give greater excursion per watt, so more efficient but lower power handling as Qtc drops below 0.9.
The steeper roll-off of a Qtc of 0.7 may make integration with a sub-woofer easier, but I really do not know if that would be an issue with your set-up.
I just think the bigger box sounds "better" what-ever that means.
How does stuff like 0.5 and 0.707 work ... in vented? No such thing? I do want the flattest sound, but I may not be able to always have my subwoofer on. If the speakers do go low enough themselves and sound good enough to produce bass down to an adequate level, I wouldn't even bother with the subwoofer most of the time.
From all the graphs I have looked at, it seems to show that 0.5 is the flattest response curve, then as it goes up to 0.7 you get a peak in the low end... does that mean my speaker would be coloured by this peak?
The last speakers I made sounded extremely flat to me in the bottom end, maybe it was my mistake because it was my first build, but then, they were also around only 4.5/5" in size... so I made the subwoofer to compensate.
From all the graphs I have looked at, it seems to show that 0.5 is the flattest response curve, then as it goes up to 0.7 you get a peak in the low end... does that mean my speaker would be coloured by this peak?
The last speakers I made sounded extremely flat to me in the bottom end, maybe it was my mistake because it was my first build, but then, they were also around only 4.5/5" in size... so I made the subwoofer to compensate.
Qtc = 0.7 is supposed to give the lowest F3, but there is an opinion that it is F10 that is more important and Qtc gives lowest F10 ( I think ) but as Q increases past 0.7 there is a rising "HUMP" or peak in response, Think big "Rock and Roll " speakers Lousy for classical music but R&R sounds great on these types, the higher the "Q" the higher and steeper this peak.
One note bass if the box is too small.
Many books I have read say to always er on the side of the bigger box, but for your application it appears that the maximum box size is fixed, but 15 liters sounds do-able and stuffed would be equivalent to 19/20 so I don't see a great difference in sound quality between the options, anything with a "Q" of .75 or less is probably OK
One note bass if the box is too small.
Many books I have read say to always er on the side of the bigger box, but for your application it appears that the maximum box size is fixed, but 15 liters sounds do-able and stuffed would be equivalent to 19/20 so I don't see a great difference in sound quality between the options, anything with a "Q" of .75 or less is probably OK
Where the frequency is down by 10 Db, F3 is 3 Db down
Are you getting what you need from this thread?
I am; so far the only one jumping in!!
Yep, I am about to ring and order the D27's, then make a trip to Bunnings and purchase some wood! 14 Litre looks like a good balance between bass and clarity, with the 0.65 Q. I'll go larger one day with a different design, something that isn't right beside my head for recording. Might make some listening speakers that are transient perfect after these, so I can switch between the two after mixing. Yeah, thanks for all your help. I've learnt heaps more for these speakers than I did for my last build.
I just ordered the 1 mid/woofer, and 1 tweeter, and bought a pile of 12mm MDF from bunnings. 6mm looked too flimsy and akward to try and sandwich against 12mm... and the 6mm peices of quad... eww... hahaha, then having to work on shaving it down to inset the drivers...
So I just got 2 x 12mm's... so it'll be 2 x 12mm for a 24mm sandwich, and I'll try and route a few mm off the face for a mild inset. The drivers being front mounted instead of inset seems to be cosmetic as far as what I can tell from reading up.
So I just got 2 x 12mm's... so it'll be 2 x 12mm for a 24mm sandwich, and I'll try and route a few mm off the face for a mild inset. The drivers being front mounted instead of inset seems to be cosmetic as far as what I can tell from reading up.
If you have a router and can flush mount do so especially for the tweeter, less ragged top end ( Ripple ) otherwise use a felt pad on the front baffle.
Two layers of 12mm MDF is much better than a single 19mm I feel that the glue layer does a reasonable job of damping vibration
What price did you get on the D27-45-06??
I paid $56- each last year
If you get them really close together you may want to put a small brace at right angles on the inside of the front baffle, the weakest point would be at that junction not much wood there.
Two layers of 12mm MDF is much better than a single 19mm I feel that the glue layer does a reasonable job of damping vibration
What price did you get on the D27-45-06??
I paid $56- each last year
If you get them really close together you may want to put a small brace at right angles on the inside of the front baffle, the weakest point would be at that junction not much wood there.
D27TG-45-06 was ... $42.50. I have a computer business, which will hopefully be a computer/design business, I hope... as soon as I finish my Visual Communications Degree. ... majoring in Digital Industrial Design. I wanted to team up with a few people who knew more about speakers than I do, and make a home made CNC... and start something good going eventually, maybe. Only thing is, my ears as accurate as they are, I only have 40% hearing in one ear, and about 75% in the other. I have to adjust the left/right balance with everything I do to suit my stupid partial deafness. But that all said, I can still pick the difference between good and bad audio. I've just lost a bit of the top end. My ears seem to have a notch filter or low pass around 18k. lol
And I think all of that was completely off topic, haha. oh well.
I don't own a router. Doh. Maybe I should get one in a few weeks. I'll complete them as much as I can, then flush mount after I get a router. Might be three more pays before then. lol. Yay being broke is fun.
And I think all of that was completely off topic, haha. oh well.
I don't own a router. Doh. Maybe I should get one in a few weeks. I'll complete them as much as I can, then flush mount after I get a router. Might be three more pays before then. lol. Yay being broke is fun.
So with the faceplates being 169 & 104mm respectfully, and getting them as close together as possible the C2C distance is ~137mm so 360000 / 137 give a cross-over frequency of 2700Hz.
Looking at the factory graph for impedance/F I would be tempted to start with a coil in series with the woofer calculated for 11R at 2500 Hz.
First approximation, you will be better off using a good program to help with XO.
Looking at the factory graph for impedance/F I would be tempted to start with a coil in series with the woofer calculated for 11R at 2500 Hz.
First approximation, you will be better off using a good program to help with XO.
I dont know any good programs for crossover calculation. But it looks like I will need to use the D27's recommended parallel compensation as seen in the PDF, it says I will need it for High Power? I dunno what they consider High Power, but my amp is a Yamaha M-65 Power Amp, 170watt per channel.
Also have to add the chosen crossover with an attenuation for the tweeter of about -2 or -3db. They recommend a crossover of 3500hz, but looking at the graphs from what I can tell, 2700 will be just as good. I can't see any peaks or issues with 2700hz. If I'm looking at it correctly. I calculated around 2700hz as well.
Also have to add the chosen crossover with an attenuation for the tweeter of about -2 or -3db. They recommend a crossover of 3500hz, but looking at the graphs from what I can tell, 2700 will be just as good. I can't see any peaks or issues with 2700hz. If I'm looking at it correctly. I calculated around 2700hz as well.
50 Watt RMS Fader - Mono - Jaycar Electronics
L-pad with variable volume, constant ( ?? ) impedance of a nominal 8R
Thanx for PDF, never understood the need for that parallel circuit when crossing that high, I wonder if the Zobel in also needed?? Or even if it is needed at all when using 3rd order XO?
Weems uses an L-pad with 4.7uF and 0.45mH ( with no Zobel or trap circuit )
L-pad with variable volume, constant ( ?? ) impedance of a nominal 8R
Thanx for PDF, never understood the need for that parallel circuit when crossing that high, I wonder if the Zobel in also needed?? Or even if it is needed at all when using 3rd order XO?
Weems uses an L-pad with 4.7uF and 0.45mH ( with no Zobel or trap circuit )
An adjustable L-Pad would be useful? Looks odd to have something you can adjust on the speaker... I've never heard of such a thing.
I spent the day in the shed today. Built one cabinet... front/sides and top/bottom, out of the one 12mm thickness. Will sand it till it's smooth as... then glue another 12mm panel onto each panel maybe tomorrow.
Speakers turned up this morning... damn fast. I ordered them 4:40pm last night, they arrived here 8am this morning.
I spent the day in the shed today. Built one cabinet... front/sides and top/bottom, out of the one 12mm thickness. Will sand it till it's smooth as... then glue another 12mm panel onto each panel maybe tomorrow.
Speakers turned up this morning... damn fast. I ordered them 4:40pm last night, they arrived here 8am this morning.
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