Hi, Thanks in advance for anyone taking the time to read the drivel below.
I am in the process of modernising the speakers and amp an old 1960's radiogram. I'm powering the speakers with an old Quad 34 & 306 combo. I have put in a pair of tweeters and some 5 inch drivers with a 2 way crossover, all bought off the shelf. I have now worked out how I can also get a pair of 8" drivers in the cabinet as well, ( in the bottom facing down). The 5" ers do sound nice but some help lower down would be good. My crossover has 2 pairs of outputs for the lower frequencies(below 3k), is it just a case of putting a resistor and capacitor of the correct values on each of these circuits, I've seen a couple of images on google, resistor after the + output, then after that a capacitor linking the + and - outputs then off to the speaker. I may have misunderstood this though. Seems a waste to get another crossover if its a simple mod, i dont mind soldering. can anyone recommend a good crossover point and an easy way to calculate the components needed, and also if my poorly explained method is correct.
thanks for reading
I am in the process of modernising the speakers and amp an old 1960's radiogram. I'm powering the speakers with an old Quad 34 & 306 combo. I have put in a pair of tweeters and some 5 inch drivers with a 2 way crossover, all bought off the shelf. I have now worked out how I can also get a pair of 8" drivers in the cabinet as well, ( in the bottom facing down). The 5" ers do sound nice but some help lower down would be good. My crossover has 2 pairs of outputs for the lower frequencies(below 3k), is it just a case of putting a resistor and capacitor of the correct values on each of these circuits, I've seen a couple of images on google, resistor after the + output, then after that a capacitor linking the + and - outputs then off to the speaker. I may have misunderstood this though. Seems a waste to get another crossover if its a simple mod, i dont mind soldering. can anyone recommend a good crossover point and an easy way to calculate the components needed, and also if my poorly explained method is correct.
Code:
5" speaker
TECHNICAL DATA:
Impedance (Z) 8 Ω
Resonant frequency (fs) 45 Hz
Max. frequency range f3-10,000 Hz
Music power 80 WMAX
Power rating (P) 50 WRMS
SPL (1 W/m) 89 dB
Suspension compl. (Cms) 1.23 mm/N
Moving mass (Mms) 10 g
Mech. Q factor (Qms) 5.54
Electr. Q factor (Qes) 0.32
Total Q factor (Qts) 0.30
Equivalent volume (Vas) 15.5 l
DC resistance (Re) 6 Ω
Force factor (BxL) 7.5 Tm
Voice coil induct. (Le) 0.75 mH
Voice coil diameter 35.5 mm
Voice coil former Kapton
Linear excursion (XMAX) ±3.25 mm
Eff. cone area (Sd) 95 cm2
Magnet weight 550 g + 17 g
Weight 1.52 kg
tweeter
TECHNICAL DATA:
Impedance (Z) 8 Ω
Resonant frequency (fs) 1,200 Hz
Max. frequency range fx-22,000 Hz
Rec. crossover freq. (12 dB) 2,500 Hz
Music power 80 WMAX
Power rating 40 WRMS
SPL (1 W/m) 90 dB
Voice coil diameter 25 mm
Magnet diameter 70 mm
Mounting cutout Ø 72 mm
Mounting depth 40 mm
Dimensions Ø 100 mm
Weight 610 g
crossover
TECHNICAL DATA:
General Information 2-way
Output impedance 8 Ω (bass also 4 Ω)
Crossover frequency 3 kHz (B = 4 Ω : 1.7 kHz)
Slope/oct. 6 dB/18 dB
Max. input power 350 W
Dimensions 125x32x110 mm
Weight 0.4 kg
8"
TECHNICAL DATA:
Impedance (Z) 8 Ω
Resonant frequency (fs) 28 Hz
Max. frequency range f3-4,500 Hz
Music power 120 WMAX
Power rating (P) 80 WRMS
SPL (1 W/m) 90 dB
Suspension compl. (Cms) 0.89 mm/N
Moving mass (Mms) 37 g
Mech. Q factor (Qms) 4.65
Electr. Q factor (Qes) 0.41
Total Q factor (Qts) 0.38
Equivalent volume (Vas) 54 l
DC resistance (Re) 6.2 Ω
Force factor (BxL) 9.9 Tm
Voice coil induct. (Le) 0.75 mH
Voice coil diameter 50 mm
Voice coil former Kapton
Linear excursion (XMAX) ±4.75 mm
Eff. cone area (Sd) 207 cm2
Magnet weight 840 g + 50 g
Weight 2.8 kg
Another huge research project for the tireless system7! 
Drivers are these:
Monacor 8" Kevlar SPH-200KE 8 ohmsMONACOR - Products - SPH-200KE
Monacor 5" Kevlar SPH-135KEP 8 ohmsMONACOR - Products - SPH-135KEP
Monacor DT-109 Titanium 1" 92dB domeMONACOR - Products - DT-109
Crossover is Monacor DN-2618 two way 8 ohm
DN-2618
I just ran this through a simulator with any old 5" plus 1": Software | Visaton
Not a complete train-wreck, and the bump at 1.3kHz is a Visaton W130S issue, But actually this sort of crossover works much better with a 4 ohm bass.
Your classic three way looks like this:
http://www.troelsgravesen.dk/3WClassic.htm
That won't be an off the shelf solution, IMO. But this one might be in the ball park:
http://www.visaton.de/en/products/crossovers/hw-3130-ng-8-ohm
Drivers are these:
Monacor 8" Kevlar SPH-200KE 8 ohmsMONACOR - Products - SPH-200KE
Monacor 5" Kevlar SPH-135KEP 8 ohmsMONACOR - Products - SPH-135KEP
Monacor DT-109 Titanium 1" 92dB domeMONACOR - Products - DT-109
Crossover is Monacor DN-2618 two way 8 ohm
DN-2618
I just ran this through a simulator with any old 5" plus 1": Software | Visaton
Not a complete train-wreck, and the bump at 1.3kHz is a Visaton W130S issue, But actually this sort of crossover works much better with a 4 ohm bass.
Your classic three way looks like this:
http://www.troelsgravesen.dk/3WClassic.htm
That won't be an off the shelf solution, IMO. But this one might be in the ball park:
http://www.visaton.de/en/products/crossovers/hw-3130-ng-8-ohm
Attachments
It's a good point about potential downfiring bass sag causing non-linearities. People have anecdotally ruined bass units by storing them for years face down.
The bafflestep diffraction analysis shows diffraction starts to become an issue at around 300Hz too.
There's two ways to go on this.
Persevere with the two way with a more appropriate, say, 1.8mH coil and 5.6uF shunt and maybe attenuate the tweeter a bit more. In the radiogram case. Bit more bass.
Or do the proper three way like Troels' classic three way style. With those Monacor drivers, a potentially very good regular speaker. Fair bit of work, of course. You'd need to assess how much change from Troels' idea is necessary, based of a comparison of the drivers to his SEAS ones.
3 ways usually have simple enough circuits to give you a reasonable chance of an acceptable result with other well behaved drivers.
The bafflestep diffraction analysis shows diffraction starts to become an issue at around 300Hz too.
There's two ways to go on this.
Persevere with the two way with a more appropriate, say, 1.8mH coil and 5.6uF shunt and maybe attenuate the tweeter a bit more. In the radiogram case. Bit more bass.
Or do the proper three way like Troels' classic three way style. With those Monacor drivers, a potentially very good regular speaker. Fair bit of work, of course. You'd need to assess how much change from Troels' idea is necessary, based of a comparison of the drivers to his SEAS ones.
3 ways usually have simple enough circuits to give you a reasonable chance of an acceptable result with other well behaved drivers.
Hi ,Thanks for the replys, I've read up , watched dear old youtube and downloaded several programs, I have some 3 way crossovers in the programs to play with but before i make any i was wondering if the idea of putting the 2 attached circuits onto the outputs of my existing crossover would work , quicker and cheaper. I dont need it to be perfect , just alright. There is a lot of work to do on the conversion of the radiogram , but i would like to listen to it whilst it gets done.
The crossover has 2 outputs for below 3k so i was wondering if i can just put 1 circuit on each output , splitting the frequency below 3K between the 8" and 5".or will this affect the crossover itself.
Thanks
The crossover has 2 outputs for below 3k so i was wondering if i can just put 1 circuit on each output , splitting the frequency below 3K between the 8" and 5".or will this affect the crossover itself.
Thanks
An externally hosted image should be here but it was not working when we last tested it.
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