Thoughts on DIY-ing Sub-woofer.

[TAM]

I would like to know your opinion regarding the Ahuja -15 inch+8 ohm,sub-woofers,Are they good?
Can you suggest few budget sub-woofers ,15inch in size and 8ohms,which has good frequency response,and price comes within 15k max ?
Does sub-woofer-driver quality affects the low frequency "colouration" ???

Please guide me.
Thanks in advance!

 

[rwnano]

@ketansethi1987

 

[Sumanta]

I would like to know your opinion regarding the Ahuja -15 inch+8 ohm,sub-woofers,Are they good?
Can you suggest few budget sub-woofers ,15inch in size and 8ohms,which has good frequency response,and price comes within 15k max ?
Does sub-woofer-driver quality affects the low frequency "colouration" ???

Please guide me.
Thanks in advance!

If space is not a problem, and you can make cabinet with your local carpenter, I would suggest use two Ahuja AS-15 to make a Ripole. OB bass is hard to beat.

 

[ketansethi1987]

I would like to know your opinion regarding the Ahuja -15 inch+8 ohm,sub-woofers,Are they good?
Can you suggest few budget sub-woofers ,15inch in size and 8ohms,which has good frequency response,and price comes within 15k max ?
Does sub-woofer-driver quality affects the low frequency "colouration" ???

Please guide me.
Thanks in advance!

Ahuja AS15 is a professional subwoofer. It needs punchier and heavy amplifier. Will sound like a DJ setup. I would suggest go for subwoofer with rubber surrounds and lose spider which can produce better low frequencies at home.

 

[diyaudio]

Instead of looking for hard to find 15" driver, take two 12" drivers and mount them on opposite side enclosures, you will get better performance. Pioneer car subwoofers have healthy coil size, Xmax, Qts, Fs. This will surpass xmax, vas and Fs of Ahuja driver by a wide margin

 

[Sumanta]

Ahuja AS15 is a professional subwoofer. It needs punchier and heavy amplifier. Will sound like a DJ setup. I would suggest go for subwoofer with rubber surrounds and lose spider which can produce better low frequencies at home.

Well, for everyone's information, I play it with a mere 12WPC class D amplifier, and it does not sound like DJ for sure. I would suggest us to listen them in proper design implementations. Name, brand, intents of the PA makers are not the last word for a driver to perform. T/S parameters, Physics and appropriate design compromises can create true OB/CB speakers out of commercial drivers too. Let's open our mind.

 

[ketansethi1987]

Well, for everyone's information, I play it with a mere 12WPC class D amplifier, and it does not sound like DJ for sure. I would suggest us to listen them in proper design implementations. Name, brand, intents of the PA makers are not the last word for a driver to perform. T/S parameters, Physics and appropriate design compromises can create true OB/CB speakers out of commercial drivers too. Let's open our mind.

One can definitely do that
I was just sharing my experience and opinion

 

[Sumanta]

Instead of looking for hard to find 15" driver, take two 12" drivers and mount them on opposite side enclosures, you will get better performance. Pioneer car subwoofers have healthy coil size, Xmax, Qts, Fs. This will surpass xmax, vas and Fs of Ahuja driver by a wide margin

I haven't looked into car subwoofers of 12 inch size, thanks a lot for this direction. Do you have any handy link or information comparing Qts of AS-15 of Ahuja with any higher spec Pioneer ones? I know you haven't indicate Qts as higher in Pioneer, but just incase you know one.
Thanks in advance.
XMax will be very much higher than Ahuja ones, and I do not want higher xmax, but Pioneers having higher Qts will be a good option. Higher Qts will demand higher Vas as well, so that'll be interesting to see too.

Generally I read, lower Qts drivers will not be a good one for Ripole or OBs, and unfortunately I haven't yet tried to make OBs with lower Qts LF drivers, so can't confirm.

And one more important point, Ripole will take care of lowering Fs of a driver, so we can take the full benefit of low Xmax, high Qts, low cone mass, good motor strength, good enough coil size of Ahuja drivers (speciall AS-15) in a Ripole design. Supposedly, Ripole can lower Fs by 5 to 10 Hz as it is claimed by others online. I am not a measurement guy, I felt it is true but did not care of its actual value of lowering.

 

[Sumanta]

One can definitely do that
I was just sharing my experience and opinion

Ahuja drivers in general has quite high SPL, in the range of 95+, hence mere 1 WPC amps can also play them with very good control.

 

[diyaudio]

I haven't looked into car subwoofers of 12 inch size, thanks a lot for this direction. Do you have any handy link or information comparing Qts of AS-15 of Ahuja with any higher spec Pioneer ones? I know you haven't indicate Qts as higher in Pioneer, but just incase you know one.
Thanks in advance.
XMax will be very much higher than Ahuja ones, and I do not want higher xmax, but Pioneers having higher Qts will be a good option. Higher Qts will demand higher Vas as well, so that'll be interesting to see too.

Generally I read, lower Qts drivers will not be a good one for Ripole or OBs, and unfortunately I haven't yet tried to make OBs with lower Qts LF drivers, so can't confirm.

And one more important point, Ripole will take care of lowering Fs of a driver, so we can take the full benefit of low Xmax, high Qts, low cone mass, good motor strength, good enough coil size of Ahuja drivers (speciall AS-15) in a Ripole design. Supposedly, Ripole can lower Fs by 5 to 10 Hz as it is claimed by others online. I am not a measurement guy, I felt it is true but did not care of its actual value of lowering.

@Sumanta , the OP has not asked for OP/Dipole/Ripole, so I assume he is talking about sealed or ported. The car audio driver from reputed brands like Pioneer/JBL have strong motors so their Qts is below 0.5, good for sealed as well as ported. They are designed to be driven by less power so their sensitivity designed to be above 89dB. My old Pioneer had a very good Qts of 0.38 indicating high BL integration of the magnetic filed into the coil, I can see coil overhang of 10mm atleast visually. That driver is not available anymore as its very old driver. I believe these drivers are available everywhere but not given a serious thought.

The relation between Qts and Vas is not a strong one. Most of the high Qts drivers are designed by having a weak motor ie lower BL, you can achieve the same effect by putting a resistance in series as this too produces lesser electrical damping needed for high Qts or by just equalizing the frequency response, there are many roads to Rome. And there are plenty of drivers with high Qts from sweton/doogesound and probably others, most of Indian brands have started using Chinese materials giving good aesthetics but use a weaker magnet to save costs.
Also low cone mass may not be a necessarily a good thing, it means the cone will flex more when loaded, it may need big enclosure for sealed/ported use, will work fine on OB/dipole but Ripole I am not sure duet to extra air mass loading will be difficult to handle by a weak cone.

I am not a fan of Dipole/Ripole/OB for two reasons, one there is a serious drop of SPL, the dynamics are lost in bass heavy passages, and second the figure 8 radiation pattern, this one is a complete no-no, the rear sound makes the placement real-estate intensive. I cant leave 3 feet of space behind the speaker or subwoofer. I have to stick the speaker to the wall, so figure 8 pattern has to be avoided.
I am building cardioid bass section now from 50Hz to 200Hz into my speakers where the room modes are and separate subwoofer ion the corner for 20Hz to 50Hz where there are no room modes. I have complete placement freedom with this setup. I change houses very often so this freedom is a must hence I am building cardioid

 

[diyaudio]

Ahuja drivers in general has quite high SPL, in the range of 95+, hence mere 1 WPC amps can also play them with very good control.

This is at higher frequencies, just compare at 25Hz with a home subwoofer or car audio subwoofer, the situation changes

 

[diyaudio]

The point I was making is this,
lets compare B&C 100TBX100, excellent LF driver with 95dB sensitivity, give 100 watts and see the SPL at the ported tuned 25Hz, in 40 litres, gives about 103dB

Now, lets take a home driver in same box/tuning, it has sensitivity of 87dB only, it gives about 100dB

Vast difference in sensitivities (8dB) but very less difference in real use case at 25Hz, just 3dB. 3dB for bass is almost nothing.
I am not against pro audio drivers usage above Fs, I know they shine where the real sensitivity helps it a lot but for subwoofer the advantage wears out.
Warm Regards,
Diyaudio