I am on the point of ordering components for a tri-amped
Peerless 850146/CSX257 (closed box), Peerless P13W-H-00-08 (closed) mid and Vifa D27TG-45-06 tweeter.
Upon ordering from my supplier (in Australia) Im told the 850146 is no longer available and "superceeded" by the 830668.
Well, I couldnt find a whole lot on the web (or here, or LSDG) on that topic. Plugging the numbers in to Unibox I notice the 850146 requires a closed volume of 37L. The 830466 requires 66L. Now that's not what I call a direct replacement ?
On that topic I have two questions if anyone has any experience or opinions :
1) If I use heavy fill for the 830668 I can reduce the box volume to 40L. If, say, I can live with this is the 830668 really a reasonable replacement for the 850146 (which seemed to be respected for its good bass reproduction and 9mm Xmax) in other respects (so in time might I expect to see it in LSDG as a recommended woofer as the 850146 still is). Or should I just say "bad luck" and scrap my design, well the woofer, and start over again looking for a decent woofer for the same price as the 850146.
2) I also notice that according to Unibox the max input power to stay within Xmax is 45W with the 830668, versus 60W for the 850146 (presumably due to the 8mm Xmax versus 9mm respectively). Is that something I should be concerned about for normal living room listening, considering Xmax is only reached at around 60Hz and below for that input power ? I dont have much of a grasp for what that power input over that frequency range means in the real world.
But the differences highlighted by Unibox are big enough for me to ask the questions, even if Im disappointed to say the least to complete my design only to find a major component has become obsolete in the time itsd taken me to do it !
Of course once Ive built the project I will probably be able to answer all these question myself !
Terry.
Peerless 850146/CSX257 (closed box), Peerless P13W-H-00-08 (closed) mid and Vifa D27TG-45-06 tweeter.
Upon ordering from my supplier (in Australia) Im told the 850146 is no longer available and "superceeded" by the 830668.
Well, I couldnt find a whole lot on the web (or here, or LSDG) on that topic. Plugging the numbers in to Unibox I notice the 850146 requires a closed volume of 37L. The 830466 requires 66L. Now that's not what I call a direct replacement ?
On that topic I have two questions if anyone has any experience or opinions :
1) If I use heavy fill for the 830668 I can reduce the box volume to 40L. If, say, I can live with this is the 830668 really a reasonable replacement for the 850146 (which seemed to be respected for its good bass reproduction and 9mm Xmax) in other respects (so in time might I expect to see it in LSDG as a recommended woofer as the 850146 still is). Or should I just say "bad luck" and scrap my design, well the woofer, and start over again looking for a decent woofer for the same price as the 850146.
2) I also notice that according to Unibox the max input power to stay within Xmax is 45W with the 830668, versus 60W for the 850146 (presumably due to the 8mm Xmax versus 9mm respectively). Is that something I should be concerned about for normal living room listening, considering Xmax is only reached at around 60Hz and below for that input power ? I dont have much of a grasp for what that power input over that frequency range means in the real world.
But the differences highlighted by Unibox are big enough for me to ask the questions, even if Im disappointed to say the least to complete my design only to find a major component has become obsolete in the time itsd taken me to do it !
Of course once Ive built the project I will probably be able to answer all these question myself !
Terry.
Hi Terry,
There is a difference between the two drivers. The resonant frequency is higher and Vas is lower in the new one .
The simulation shows a difference but it is not 'too' different. In practice the difference might not be very audible (?).
The Red curve is the 850146 in a 34 liter box with no damping. The blue, green and grey lines are the 830668 . The grey line is in a 45 liter box with damping on all sides. The blue line is in a 34 liter box with no damping and the blue line is in a 34 liter box with damping on all sides.
Additionally the 'linear' travel for the 830668 is 24-8 = 16mm peak to peak . The 850146 is 23-8 = 15 mm peak to peak.
So do not bother about the small differences . Looks like the new drive is a shade better. We do not know how the 9mm was specified on the old driver as it does not say 'linear' or "max" .
The -3db points are different but I think the new driver will most probably sound as good in practice.
I'm just about to switch on my 850146 in a 34 liter sealed box .
The active c/o is not ready yet.
Cheers.
Edit:I've deleted the Plots .
The plots are incorrect for the 830668. I'll rework it and post it a bit later.
There is a difference between the two drivers. The resonant frequency is higher and Vas is lower in the new one .
The simulation shows a difference but it is not 'too' different. In practice the difference might not be very audible (?).
The Red curve is the 850146 in a 34 liter box with no damping. The blue, green and grey lines are the 830668 . The grey line is in a 45 liter box with damping on all sides. The blue line is in a 34 liter box with no damping and the blue line is in a 34 liter box with damping on all sides.
Additionally the 'linear' travel for the 830668 is 24-8 = 16mm peak to peak . The 850146 is 23-8 = 15 mm peak to peak.
So do not bother about the small differences . Looks like the new drive is a shade better. We do not know how the 9mm was specified on the old driver as it does not say 'linear' or "max" .
The -3db points are different but I think the new driver will most probably sound as good in practice.
I'm just about to switch on my 850146 in a 34 liter sealed box .
The active c/o is not ready yet.
Cheers.
Edit:I've deleted the Plots .
The plots are incorrect for the 830668. I'll rework it and post it a bit later.
Here are the response plots.
Red plot 830668 in a 37 lit box with a Q of 0.764 and with no damping in the box.
Green is 830668 in a 48 liter box with Q of 0.709 and no damping.
Blue is the 850146 in a 37 liter box with a Q of 0.69 and no damping.
I think you can go ahead with the 830668 driver. It should be just as good with some minor changes in the box dimensions or the same 37 lit box filled with damping material.
Red plot 830668 in a 37 lit box with a Q of 0.764 and with no damping in the box.
Green is 830668 in a 48 liter box with Q of 0.709 and no damping.
Blue is the 850146 in a 37 liter box with a Q of 0.69 and no damping.
I think you can go ahead with the 830668 driver. It should be just as good with some minor changes in the box dimensions or the same 37 lit box filled with damping material.
Attachments
I measured the Q of the 850149 in my 37 liter box. No absorbent . The box has a small hole for the speaker cable at the moment. So it isn't ideally sealed.
Fb = 50 Hz ( simulated 48 Hz)
Qc = 0.76 ( simulated 0.69 ). This should change a bit when the box is properly sealed .
I can also use an absorbent to reduce Q a bit.
Actual listening might take a while unless I can get my breadboarded active crossover working .
Cheers.
Fb = 50 Hz ( simulated 48 Hz)
Qc = 0.76 ( simulated 0.69 ). This should change a bit when the box is properly sealed .
I can also use an absorbent to reduce Q a bit.
Actual listening might take a while unless I can get my breadboarded active crossover working .
Cheers.
Thanks for your replies ashok - and the plots. They do seem similar in the simuation, although I do wonder why they've changed the driver with no huge improvements obvious.
Im still a bit puzzled by the apparent significant difference in max input power to keep within Xmax - although perhaps Im using the wrong figures having entered 9mm for the 850146. If I use your figures should I be putting something like 7.5 into Unibox (although the data was preloaded in Unibox) ? If I did that they'd look similar in max power before Xmax is exceeded.
And if the drivers are that similar in reality I guess my concern about reaching Xmax below 60Hz is not warranted, only because so many people use the 850146 and nobody complains about it hitting Xmax ! Im not sure I get why though, 45W doesnt seem like a lot of power to me .....
Terry
Im still a bit puzzled by the apparent significant difference in max input power to keep within Xmax - although perhaps Im using the wrong figures having entered 9mm for the 850146. If I use your figures should I be putting something like 7.5 into Unibox (although the data was preloaded in Unibox) ? If I did that they'd look similar in max power before Xmax is exceeded.
And if the drivers are that similar in reality I guess my concern about reaching Xmax below 60Hz is not warranted, only because so many people use the 850146 and nobody complains about it hitting Xmax ! Im not sure I get why though, 45W doesnt seem like a lot of power to me .....
Terry
Forget about the xmax limitations in the software as playing music is completely different. If the software was correct, my walls should be splattered with driver cones. Use it as a guide and also when comparing drivers.
There was a really good discussion on this recently in the fullrange forum.
BTW, none of the new Peerless drivers are direct replacements and are only a suggested alternative.
There was a really good discussion on this recently in the fullrange forum.
BTW, none of the new Peerless drivers are direct replacements and are only a suggested alternative.
Hi Terry , Rabbitz is correct about the drivers being "suggested" replacements.
About the X max. The cones are capable of much more movement than "linear Xmax" which is a bit higher in the new driver.
Linear X max for 850146 is 7.5mm . Max safe X max is probably 9mm .
That works out to be 20% over the 'linear Xmax'.
For the 830668 , "linera Xmax " is 8mm and so 20% higher is 9.6mm .
In Bass Box Pro , they use 50% of linear Xmax to get the physical Xmax !
In the physical Xmax condition the coil will be partly out of the magnetic circuit ! Happens in real use and not noticeable unless it gets to be too much.
At 60Hz the 830668 probably will be slightly better than the 850146 .
The driver was probably changed as they have changed the basic basket design and possibly some changes to the cone / coil assembly. However the rubber surround and spider appear to be similar. Coil length has gone up a bit and so that's a good thing .
I doubt if you will find any significant difference between the drivers . Just go ahead and use it. For X max you can put in 9.6mm or 13.5mm as BassBox does !! Maybe 10mm is a safe bet. I've driven the cone at 10mm using 20Hz signals and I heard no terrible noises. But then this is supposed to be only applicable for short duration signals ( like music ) and not continuous sine waves.
Cheers.
About the X max. The cones are capable of much more movement than "linear Xmax" which is a bit higher in the new driver.
Linear X max for 850146 is 7.5mm . Max safe X max is probably 9mm .
That works out to be 20% over the 'linear Xmax'.
For the 830668 , "linera Xmax " is 8mm and so 20% higher is 9.6mm .
In Bass Box Pro , they use 50% of linear Xmax to get the physical Xmax !
In the physical Xmax condition the coil will be partly out of the magnetic circuit ! Happens in real use and not noticeable unless it gets to be too much.
At 60Hz the 830668 probably will be slightly better than the 850146 .
The driver was probably changed as they have changed the basic basket design and possibly some changes to the cone / coil assembly. However the rubber surround and spider appear to be similar. Coil length has gone up a bit and so that's a good thing .
I doubt if you will find any significant difference between the drivers . Just go ahead and use it. For X max you can put in 9.6mm or 13.5mm as BassBox does !! Maybe 10mm is a safe bet. I've driven the cone at 10mm using 20Hz signals and I heard no terrible noises. But then this is supposed to be only applicable for short duration signals ( like music ) and not continuous sine waves.
Cheers.
Thanks for all the info. I suspected I was dwelling on theory too much, but then until I build, listen and adjust that's all I can do !
I confess to trying to get away with just Unibox for my first initiative, especially given its triamped, for just one speaker project shelling out for some of these packages is prohibitive. But even so, its all about understanding the drivers in the real world too.
So, thanks for the advice, the order has gone in ! Now I cant wait to build it all
.
T
I confess to trying to get away with just Unibox for my first initiative, especially given its triamped, for just one speaker project shelling out for some of these packages is prohibitive. But even so, its all about understanding the drivers in the real world too.
So, thanks for the advice, the order has gone in ! Now I cant wait to build it all
.T
simulations ?
Ok, Im now looking at the box design on more detail having chosen and ordered the drivers. Im using UniBox 4.04. But I get some quite different numbers than ashok does ?
For the 830668 :
For a Qtc of .764, no fill, no leaks, Unibox says 51.6L versus your calcs of 37L.
and Qtc of .709, no fill, no leaks, 69.1L.
something isnt right here. Im assuming its me, but Im lost to what Im doing wrong. Here's what Im using :
Drive Unit Parameters
Peerless 830668
Fs 33.30 Hz
Re 5.60 Ohm
Qms 4.85
Qes 0.57
Sd 335.0 cm2
Vas 69.3 l
Xmax peak 8.00 mm
(Le) 3.30 mH
(Le2) 0.00 mH
(Re2) 0.00 Ohm
Nominal Power 45.7 W
External Components
Rs 0.00 Ohm
(Lco1) 0.00 mH
(Rco1) 0.00 Ohm
(Cco1) 0.00 uF
(Lco2) 0.00 mH
(Rco2) 0.00 Ohm
(Cco2) 0.00 uF
Parameters of Single Unit
SPL at 1 W 1 m 88.4 dB
SPL at 2.83 Vrms 1m 90.0 dB
Max SPL at 45.7 W 105.0 dB
Qts 0.510
Effective Qts 0.510
Mms 51.96 g
Cms 0.440 mm/N
Rms 2.241 kg/s
Bl 10.33 Tm
Ref. efficiency, n0 0.432 %
Efficiency, n 0.432 %
Applied voltage 16.00 Vrms
Drive Unit Nondirectional Range
Piston range 532 Hz
Box Type
Suggested box type Closed
Down fire application 0.97
Which gives :
Vb 53.6 l
Fb 50.44 Hz
F3 50.44 Hz
Qtc 0.707
Response peak 0.00 dB
Max power input 45.7 W
Design by Vb and Q
Physical Vb 69.1 l
Absorption, Qa 120
Leakage, Ql 30
Alpha, a 0.990
Vb 70.0 l
Fb 46.97 Hz
F3 46.56 Hz
Qtc 0.709
Response peak 0.00 dB
Peak at none
Ok, Im now looking at the box design on more detail having chosen and ordered the drivers. Im using UniBox 4.04. But I get some quite different numbers than ashok does ?
For the 830668 :
For a Qtc of .764, no fill, no leaks, Unibox says 51.6L versus your calcs of 37L.
and Qtc of .709, no fill, no leaks, 69.1L.
something isnt right here. Im assuming its me, but Im lost to what Im doing wrong. Here's what Im using :
Drive Unit Parameters
Peerless 830668
Fs 33.30 Hz
Re 5.60 Ohm
Qms 4.85
Qes 0.57
Sd 335.0 cm2
Vas 69.3 l
Xmax peak 8.00 mm
(Le) 3.30 mH
(Le2) 0.00 mH
(Re2) 0.00 Ohm
Nominal Power 45.7 W
External Components
Rs 0.00 Ohm
(Lco1) 0.00 mH
(Rco1) 0.00 Ohm
(Cco1) 0.00 uF
(Lco2) 0.00 mH
(Rco2) 0.00 Ohm
(Cco2) 0.00 uF
Parameters of Single Unit
SPL at 1 W 1 m 88.4 dB
SPL at 2.83 Vrms 1m 90.0 dB
Max SPL at 45.7 W 105.0 dB
Qts 0.510
Effective Qts 0.510
Mms 51.96 g
Cms 0.440 mm/N
Rms 2.241 kg/s
Bl 10.33 Tm
Ref. efficiency, n0 0.432 %
Efficiency, n 0.432 %
Applied voltage 16.00 Vrms
Drive Unit Nondirectional Range
Piston range 532 Hz
Box Type
Suggested box type Closed
Down fire application 0.97
Which gives :
Vb 53.6 l
Fb 50.44 Hz
F3 50.44 Hz
Qtc 0.707
Response peak 0.00 dB
Max power input 45.7 W
Design by Vb and Q
Physical Vb 69.1 l
Absorption, Qa 120
Leakage, Ql 30
Alpha, a 0.990
Vb 70.0 l
Fb 46.97 Hz
F3 46.56 Hz
Qtc 0.709
Response peak 0.00 dB
Peak at none
Drat ! Looks like I can only think for 30 mins. then I cant edit my post ! Here's the revised version, please disregard the last :
Ok, Im now looking at the box design on more detail having chosen and ordered the drivers. Im using UniBox 4.04. But I get some quite different numbers than ashok does ?
For the 830668 :
For a Qtc of .764, no fill, no leaks, Unibox says 51.6L versus your calcs of 37L.
and Qtc of .709, no fill, no leaks, 69.1L versus you 48L ?
Something isnt right here. Im assuming its me, but Im lost to what Im doing wrong. Here's what Im using :
Drive Unit Parameters
Peerless 830668
Fs 33.30 Hz
Re 5.60 Ohm
Qms 4.85
Qes 0.57
Sd 335.0 cm2
Vas 69.3 l
Xmax peak 9.00 mm
(Le) 3.30 mH
(Le2) 0.00 mH
(Re2) 0.00 Ohm
Nominal Power 100.0 W
External Components
Rs 0.00 Ohm
(Lco1) 0.00 mH
(Rco1) 0.00 Ohm
(Cco1) 0.00 uF
(Lco2) 0.00 mH
(Rco2) 0.00 Ohm
(Cco2) 0.00 uF
Parameters of Single Unit
SPL at 1 W 1 m 88.4 dB
SPL at 2.83 Vrms 1m 90.0 dB
Max SPL at 100 W 108.4 dB
Qts 0.510
Effective Qts 0.510
Mms 51.96 g
Cms 0.440 mm/N
Rms 2.241 kg/s
Bl 10.33 Tm
Ref. efficiency, n0 0.432 %
Efficiency, n 0.432 %
Applied voltage 23.66 Vrms
giving :
Closed Box
Standard Design
Vb 53.6 l
Fb 50.44 Hz
F3 50.44 Hz
Qtc 0.707
Response peak 0.00 dB
Max power input 57.8 W
Design by Vb and Q
Physical Vb 69.1 l
Absorption, Qa 120
Leakage, Ql 30
Alpha, a 0.990
Vb 70.0 l
Fb 46.97 Hz
F3 46.56 Hz
Qtc 0.709
Response peak 0.00 dB
Peak at none
Now being somewhat puzzled, Ive put the same parameters into WINISD. That suggests a box of 77L for Qtc .71, presumably no fill no leaks. Its acceptably close to Unibox's 69L (in fact WinISD suggests 69L gives a Qtc of .72), its not remotely close to the figures you quoted ?
WinIsd params as follows :
Driver : Peerless 830668
Vas : 69.3
Qts : 0.51
Fs : 33.30
SPL : 88.70
Number of drivers : 1
Box type : Closed
Box size : 69.1 l
Where have I left the path of sanity !! ?
Terry.
Ok, Im now looking at the box design on more detail having chosen and ordered the drivers. Im using UniBox 4.04. But I get some quite different numbers than ashok does ?
For the 830668 :
For a Qtc of .764, no fill, no leaks, Unibox says 51.6L versus your calcs of 37L.
and Qtc of .709, no fill, no leaks, 69.1L versus you 48L ?
Something isnt right here. Im assuming its me, but Im lost to what Im doing wrong. Here's what Im using :
Drive Unit Parameters
Peerless 830668
Fs 33.30 Hz
Re 5.60 Ohm
Qms 4.85
Qes 0.57
Sd 335.0 cm2
Vas 69.3 l
Xmax peak 9.00 mm
(Le) 3.30 mH
(Le2) 0.00 mH
(Re2) 0.00 Ohm
Nominal Power 100.0 W
External Components
Rs 0.00 Ohm
(Lco1) 0.00 mH
(Rco1) 0.00 Ohm
(Cco1) 0.00 uF
(Lco2) 0.00 mH
(Rco2) 0.00 Ohm
(Cco2) 0.00 uF
Parameters of Single Unit
SPL at 1 W 1 m 88.4 dB
SPL at 2.83 Vrms 1m 90.0 dB
Max SPL at 100 W 108.4 dB
Qts 0.510
Effective Qts 0.510
Mms 51.96 g
Cms 0.440 mm/N
Rms 2.241 kg/s
Bl 10.33 Tm
Ref. efficiency, n0 0.432 %
Efficiency, n 0.432 %
Applied voltage 23.66 Vrms
giving :
Closed Box
Standard Design
Vb 53.6 l
Fb 50.44 Hz
F3 50.44 Hz
Qtc 0.707
Response peak 0.00 dB
Max power input 57.8 W
Design by Vb and Q
Physical Vb 69.1 l
Absorption, Qa 120
Leakage, Ql 30
Alpha, a 0.990
Vb 70.0 l
Fb 46.97 Hz
F3 46.56 Hz
Qtc 0.709
Response peak 0.00 dB
Peak at none
Now being somewhat puzzled, Ive put the same parameters into WINISD. That suggests a box of 77L for Qtc .71, presumably no fill no leaks. Its acceptably close to Unibox's 69L (in fact WinISD suggests 69L gives a Qtc of .72), its not remotely close to the figures you quoted ?
WinIsd params as follows :
Driver : Peerless 830668
Vas : 69.3
Qts : 0.51
Fs : 33.30
SPL : 88.70
Number of drivers : 1
Box type : Closed
Box size : 69.1 l
Where have I left the path of sanity !! ?
Terry.
I checked out the calculations again. You needn't worry.
It's just a matter of different parameters being used in the different software.
For example my calculations showed box losses Ql as 6.9 . How that figure appeared I do not know. However when changed to Ql=30 ( as you have ) the box size goes up to 66.3 liters.
Additionally if you include some absorption ( Qa=120 ?) the box size will come down. In my case I only have a choice of none, minimal , typical , heavy for absorbent. I can't input any numerical values.
So it appears you just need to get a box made and test the unit. You have my box size as a guide. 37 liters calculated and Q of 0.76 .
If I change Ql to 30 then the predicted Qc=0.743 in a 37 liter box!
I measured 0.76 in the box.
Yours is 66 liters ( for Qc=0.707) calculated in BB with Ql=30. So both programs are not far off.
Bass Box also predicts with Ql=30 and a box filled with absorbent you can get a Qc of around 0.7 in a 37 liter box.
So I guess you can pick any box size between 37 and 66 liters and tune it with absorbent to get 0.707 .
Try simulating with Ql=30 and plenty of absorption and check the box size in your program.
Maybe you can wait a bit......................
Here are my driver specs .............measured and ( data sheet value )
850146.
Fs 29.58 (22.6 )
Qms 6.51 (2.56 )
Vas 61.6 ( 144 )
Cms 0.45 ( 0.96 )
Qes 0.51 (0.4 )
Qts 0.473 ( 0.35 )
Sens 88.7 db/2.83 V ( 88.2 db )
So you can expect quite a variation I think , unles they have improved their accuracy with the new drivers .
Fs can go down a bit and Cms can go up and affect all other values after some burn in.
Cheers,
Ashok.
It's just a matter of different parameters being used in the different software.
For example my calculations showed box losses Ql as 6.9 . How that figure appeared I do not know. However when changed to Ql=30 ( as you have ) the box size goes up to 66.3 liters.
Additionally if you include some absorption ( Qa=120 ?) the box size will come down. In my case I only have a choice of none, minimal , typical , heavy for absorbent. I can't input any numerical values.
So it appears you just need to get a box made and test the unit. You have my box size as a guide. 37 liters calculated and Q of 0.76 .
If I change Ql to 30 then the predicted Qc=0.743 in a 37 liter box!
I measured 0.76 in the box.
Yours is 66 liters ( for Qc=0.707) calculated in BB with Ql=30. So both programs are not far off.
Bass Box also predicts with Ql=30 and a box filled with absorbent you can get a Qc of around 0.7 in a 37 liter box.
So I guess you can pick any box size between 37 and 66 liters and tune it with absorbent to get 0.707 .
Try simulating with Ql=30 and plenty of absorption and check the box size in your program.
Maybe you can wait a bit......................
Here are my driver specs .............measured and ( data sheet value )
850146.
Fs 29.58 (22.6 )
Qms 6.51 (2.56 )
Vas 61.6 ( 144 )
Cms 0.45 ( 0.96 )
Qes 0.51 (0.4 )
Qts 0.473 ( 0.35 )
Sens 88.7 db/2.83 V ( 88.2 db )
So you can expect quite a variation I think , unles they have improved their accuracy with the new drivers .
Fs can go down a bit and Cms can go up and affect all other values after some burn in.
Cheers,
Ashok.
Ashok thanks again for your replies. Its really good to have someone take the time to check calcs and ideas, as presumably you did before your first big one ! (Ive only done a Shiva powered subwoofer to date) .....
I have plenty of time given Ive only just oredered the drivers and still have 2 amps and to active filters to build before the boxes And on that topic :
OK I guess anything up to maybe WINISD's 69L would be OK, or is that too big ? In fact perhaps Im better off making it slightly too small and using absorbent to correct/fine tune rather than the other way round when I cant compensate ?
In fact I was originally imagining a floor standing design to blend in as furniture from the wife's perspective (I do a fair bit of woodwork so whe's fine with it if it looks nice). But 37L is going to be a bit small for floor standers as far as I can see.
So that's making me think I might just line the box walls for a 61L enclosure. Maybe its my calcs but 61L seems to be halfway between a floor stander at around 60/65 cm tall ? Even if I take out 2L for the midrange enclosure it doesnt make much difference. I imagined a floor standing design at perhaps a metre tall. Have I miscalcuated is is this a consequence of choosing drivers I like and then worrying about the box ?
What enclosure design is your box, presumably stand or bookshelf mounted etc ....
T
I have plenty of time given Ive only just oredered the drivers and still have 2 amps and to active filters to build before the boxes
And on that topic :OK I guess anything up to maybe WINISD's 69L would be OK, or is that too big ? In fact perhaps Im better off making it slightly too small and using absorbent to correct/fine tune rather than the other way round when I cant compensate ?
In fact I was originally imagining a floor standing design to blend in as furniture from the wife's perspective (I do a fair bit of woodwork so whe's fine with it if it looks nice). But 37L is going to be a bit small for floor standers as far as I can see.
So that's making me think I might just line the box walls for a 61L enclosure. Maybe its my calcs but 61L seems to be halfway between a floor stander at around 60/65 cm tall ? Even if I take out 2L for the midrange enclosure it doesnt make much difference. I imagined a floor standing design at perhaps a metre tall. Have I miscalcuated is is this a consequence of choosing drivers I like and then worrying about the box ?
What enclosure design is your box, presumably stand or bookshelf mounted etc ....
T
Hi Terry,
My box is meant to be a sub but as I am not sure how good it will be because my crossover frequency is quite low.
My main speakers are a pair of Missions ( 701 ) which are in reflex cabinets. When I seal them I get a Fc of 66Hz and Q of about 0.8 .
Now that makes it a second order HPF.
I can use a 4th order Linkwitz Riley filter for this system. A second order HPF for the Missions and a 4th order LPF for the sub. The Missions are book shelf units ( 2 way with 6 inch bass driver ) .
So my sub has to be short ! Keeping the sub separate is a good thing as I can use it with other bookshelf speakers which I have . I'll have to make sure that the crossover filters have switchable Fc and Q. My bookshelf units are on sand filled stands.
I'll send you pictures and more details later. My sub enclosure is about 19.5 inches tall , 12.5 inches wide and 13 inches deep. Walls are all 19 mm MDF. This was originally a test box ( has a duct which is now sealed ) . I will not get around to making a new box as I have very little free time. So I just have to use this and tweak it if required to get what I want.
Cheers,
Ashok.
My box is meant to be a sub but as I am not sure how good it will be because my crossover frequency is quite low.
My main speakers are a pair of Missions ( 701 ) which are in reflex cabinets. When I seal them I get a Fc of 66Hz and Q of about 0.8 .
Now that makes it a second order HPF.
I can use a 4th order Linkwitz Riley filter for this system. A second order HPF for the Missions and a 4th order LPF for the sub. The Missions are book shelf units ( 2 way with 6 inch bass driver ) .
So my sub has to be short ! Keeping the sub separate is a good thing as I can use it with other bookshelf speakers which I have . I'll have to make sure that the crossover filters have switchable Fc and Q. My bookshelf units are on sand filled stands.
I'll send you pictures and more details later. My sub enclosure is about 19.5 inches tall , 12.5 inches wide and 13 inches deep. Walls are all 19 mm MDF. This was originally a test box ( has a duct which is now sealed ) . I will not get around to making a new box as I have very little free time. So I just have to use this and tweak it if required to get what I want.
Cheers,
Ashok.
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