peerless 12inch subwoofer new build

[rajesh srinivas]

Namskara Rajesh, hegithithra swami? A little trial and error may be needed to get the best out of your subs.

I note that your inductors are not placed at right angles to each other as is recommended. See the crossover here:
Bamberg Audio :: Speakers for Life

hi George Namakara,N?nu cenn?gidd?ne.

sorry for later reply.

yes it takes a lot of time and effort to get the things in its place,with my hifi friends support and feedback i can achieve it.

inductors are not placed at right angles to each other

You have already pointed out this issue in t.anthony's thread Re: My MTM stand mount loudspeakers.

will think over it once i finish with the sub/mains issue.

bi

 

[GeorgeO]

Good luck Rajesh. DIY is very rewarding and once you get it right gives you a lot of satisfaction.
Cheers

 

[rajesh srinivas]

hi antony,

once again sending you my test report,hope to receive your reply at the earliest.

As already mentioned i blindly believe/trust your suggestion,and will follow as you say. The observation you have done is exactly to the problem i am facing.

1. if nothing is working out i will try to swap the 2nd sub,but before that i once again checked my sub for any voice coil rub issue,i.e for free cone movement) looked to be decent as in the video link.

https://docs.google.com/file/d/0B3zA...Q3RlItTDQ/edit

Also if the driver is directly screwed to the mdf, I would suggest using t or d-nuts and matching allen bolts.

2. i have mounted the sub on the mdf using t-nuts as in video,the sub has no vibration perfectly well mounted, i mentioned vibration with respect to the window glass panes means when i play at a high vol,the glass panes vibrates to suggest i do get very low frequencies.

Coming to the box, for a ported design, I would say it's better not to change the dimensions and the port location

since the box is completed i cannot make any changes to its dimension,it is 100% air tight, i used fevicol with mdf sawdust (2 layers) to seal all the joints including the inner side of front panel where the sub is mounted. i made sure that my box vol did not change compared to your build,just added few ltrs for dowel displacement,

Please do a quick test of your sub as indicated below to see if the change in dimensions had any effect in the performance

i did check the Air coming out of the port,when playing a low bass track the feel of air is at max 2feet,as i go further no trace of it,only when in some action gun shot scenes or dts demo videos at one perticular time i can feel the air upto 10feet (at that time the amp goes in clipping stage)that's the major problem,your feedback required to solve this issue.

Matching the subwoofers with the main speakers needs a bit of tweaking.

you are absolutely right that matching the fronts with the subs is a very serious issue,needs lot of tweaking.i crossed my mains at 80hz

details for my front tower speaker AD1256M 12inch philips full range is in this link.

Philips AD 1256/M8 Fullrange Loudspeaker Measurements Data and Information Full Range

and also here

vintage 12" Philips AD 1256-M8 AlNiCo 8 ohm 30W dual cone full-range drivers in excellent condition (response range 45-16,000 Hz (98dB sensitivity) - some specs. show the upper limit as 17 KHz), made in Holland probably about 1969, for about NZ$400 from Eric Cross at Vintage Audio World. These drivers are quite rare nowadays and sought-after when in great condition. They are renowned performers, and have been described as "probably the best sounding full range driver ever". Eric promised me that they would sound great.
Larger drivers - e.g. 12" - lack high frequency response beyond 12-14Khz or so, hence they need a super-tweeter supplement.

My MTM design placed horizontally for the center channel is not a good idea as it will have lobing issues. You might want to consider moving the tweeter to the top edge similar to this design

yes i am planning to build shortly the center channel (MTM) as per your original design,placing the tweeter to the top,drivers have been bought already (m13nh midwoofer and TL25SN),the port will be placed at the rear ,MDF sheet yet to buy since waiting if you suggest to go in for a 2nd sub since my room size is 11x22.

By placing the center box horizontally ,i know it creates lobing issue any solutions to over come it,

any more information you require just mesg me.

thanks

 

[t.antony]

...As already mentioned i blindly believe/trust your suggestion,and will follow as you say

Will this statement expire at my next bad choice? . DIY involves a bit of trial and error some of which points you at the right direction, but never a guarantee on meeting all expectations. So please take everything with a pinch of salt.

i did a check on monday the Air coming out of the port,when playing a low bass track the feel of air is at max 2feet,as i go further no trace of it,required is around 10feet as you say,that's the major problem,your feedback required to solve this issue.

This is not necessarily an issue that compromises your sub. You can try the following tweak and see if the the power handling of the woofer is improved at low frequencies. Stuff the port with a bundle of plastic straws(use good quality ones). Tape the straws together and make a bundle that fits snugly in the port. You can experiment by Variying the density of the bundle and length of the straws. While tuning the port this way look for reduction in the "boominess".

One cause for the tonal imbalance you are experiencing could be from the mismatch between the sensitivities of your mains and your sub. You would probably need active equalization to bring things under control. With a matched enclosure, a 12' driver like Philips ad 1256/M8 could provide the "chest thumping" mid-bass punch. Your current sub cabinet seems to be suitable for this driver. IMHO try the Philips in your sub enclosure, and try the straw method mentioned earlier. If the results look promising, stuff the cabinet lightly with poly-fill(half a pillow should be sufficient). Post your observations here.

... waiting if you suggest to go in for a 2nd sub since my room size is 11x22.

Yes, two subs are always better than one. Before cutting any mdf I would suggest first test with Philips as mentioned above.

 

[rajesh srinivas]

As per your earlier suggestion, I replaced the sub with new one,and after the test the result was outstanding,i am getting the real thump desired.

Hence your experiment with plastic straw was ruled out but certainly will give it a try if come across boominess.

My Philips AD1256M with Philips 4inch dome tweeter is enclosed in a 85.73 ltr (external H48XW14XD10.5) box was designed using its graph and t/s specs,is specifically used for my fronts with a suitable xover (crossed at 80hz) the pics of both is shown in this thread,though earlier the box was ported for stereo music,now since using it mainly for my ht purpose so sealed it,the performance is remarkable,only thing required is proper tunning/matching with my sub for which i need your help???

The earlier sub was indeed bad,as already told voice coil rub issue,when i tap the cone i get knock noice not the usual dull thump,but will give it a try to remove the rub as per these below methods.

1. rotating the driver 180 degree The spider can sag due to the mass of the cone overtime and can cause the imbalance to balance out again.

2. remove the dust cap and shim the voice coil just as you would if you were doing a re-foam. Then spray the spider with acetone enough to get them pretty damp. Then turn the speaker upside down with the cone facing down towards the floor. Supposedly by relaxing the spider and shimming the coil the speaker might fall back into it's original position. Then all you need to do is replace the dust cap.

One cause for the tonal imbalance you are experiencing could be from the mismatch between the sensitivities of your mains and your sub. You would probably need active equalization to bring things under control.

How to achieve the above,your detailed procedure required so that my subs can take over my mains all the details i have provided to you for the sub and fronts.

After this issue is solved i will proceed to build my center will update you later.

Yes, two subs are always better than one. Before cutting any mdf I would suggest first test with Philips as mentioned above.

i feel having one sub is not filling my room with even bass,what would you say should i go for another sub/amp of the same make,or one is sufficient for ht or it should not be too much bass i am confused.

 

[anilva]

My advice is to use the Philips full range system for stereo and not for HT. They are not meant for HT and will not have sufficient low mid strength. Get yourself a nice HT set and then add the Sub. BTW I have the same Philips full range set but mounted in a open baffle. Good for stereo and definitely not for HT.

 

[rajesh srinivas]

My advice is to use the Philips full range system for stereo and not for HT. They are not meant for HT and will not have sufficient low mid strength. Get yourself a nice HT set and then add the Sub. BTW I have the same Philips full range set but mounted in a open baffle. Good for stereo and definitely not for HT.

hi anilva,
was busy so late in replying,as you say

The Philips full range are not meant for HT and will not have sufficient low mid strength,

i fully agree to your quote hence i have other options,i have another set of speakers for which i need your advice to make a proper choice that can match my sub.

1. Philips full range 8inch (2415 264 48001 20W Pmax 4- Ohms)
pics enclosed.

one pair currently using for my surround (pic with stand shown), another pair is laying with me thought for 7.1 setup,can i use them for my fronts??

2. i also own a pair of Philips 8inch woofer IP-949 (257 46511-40 watts Rms) with Philips Dome Tweeter 4inch IP-908-4 Ohms ).

kindly give your feedback to make a proper choice..

 

[anilva]

hi anilva,
was busy so late in replying,as you say



i fully agree to your quote hence i have other options,i have another set of speakers for which i need your advice to make a proper choice that can match my sub.

1. Philips full range 8inch (2415 264 48001 20W Pmax 4- Ohms)
pics enclosed.

one pair currently using for my surround (pic with stand shown), another pair is laying with me thought for 7.1 setup,can i use them for my fronts??

2. i also own a pair of Philips 8inch woofer IP-949 (257 46511-40 watts Rms) with Philips Dome Tweeter 4inch IP-908-4 Ohms ).

kindly give your feedback to make a proper choice..

None of the above are good for HT. They are not low/mid drivers but full rangers with paper surround. Modern HT mid/bass drivers have a foam/rubber surround for the excursions required to reproduce realistic bass for movies. Sorry to disappoint you, but do not plan to use any of these philips drivers for HT. You may use them if there is no option, but do not expect room shaking experience of a typical HT setup.

Regards

 

[rajesh srinivas]

None of the above are good for HT. They are not low/mid drivers but full rangers with paper surround. Modern HT mid/bass drivers have a foam/rubber surround for the excursions required to reproduce realistic bass for movies. Sorry to disappoint you, but do not plan to use any of these philips drivers for HT. You may use them if there is no option, but do not expect room shaking experience of a typical HT setup.

Regards

hi anilva,

The Philips model no: IP-949 (257 46511)40 watts Rms is a 8inch woofer-
power handling -40 watts Rms (8 ohms) and it has foam surround you can see in the below picture,but unfortunately i dont have its manufacture specs (t/s parameters) i also dont know its frequency response.

i designed the box on assumption.

I feel it can act as a low/mid driver with the dome tweater (IP-908-4 Ohms) with suitable xover.

what do you say, If yes where can i get its specs for both the woofer and dome tweeter.

i agree to your point that full range speakers are no for front channel,that is the reason i am using this Philips full range for the surround.

thanks

 

[anilva]

hi anilva,

The Philips model no: IP-949 (257 46511)40 watts Rms is a 8inch woofer-
power handling -40 watts Rms (8 ohms) and it has foam surround you can see in the below picture,but unfortunately i dont have its manufacture specs (t/s parameters) i also dont know its frequency response.

i designed the box on assumption.

I feel it can act as a low/mid driver with the dome tweater (IP-908-4 Ohms) with suitable xover.

what do you say, If yes where can i get its specs for both the woofer and dome tweeter.

i agree to your point that full range speakers are no for front channel,that is the reason i am using this Philips full range for the surround.

thanks

The mid/bass driver with surround you are referring to is a Philips India driver and not a Philips Holland model (if I remember right). In my opinion it is not a great driver. In those days, Philips could palm them off giving all kinds of unrealistic wattage figures. They have popularized PMPO etc. Use them as along as you can manage, but do not plan a long term solution with these drivers. Go and get yourself a decent set of drivers from Peerless and make nice fronts and centre. Then you can make dipole like surrounds.

Regards

 

[t.antony]

One cause for the tonal imbalance you are experiencing could be from the mismatch between the sensitivities of your mains and your sub. You would probably need active equalization to bring things under control.

How to achieve the above,your detailed procedure required so that my subs can take over my mains all the details i have provided to you for the sub and fronts.

Bass is not only dependent on the sub. Your main speakers also play an important role in handling the transients at the lower mid-bass and mid-bass. The crossover frequencies, gain and phase correction between individual drivers & speaker units, relative position of the speakers in the room, wall & floor reflections, room treatment... all these are important in sound perception.

To fine tune the system, you need to understand the current frequency response in your room and apply corrections needed. REW is a good tool to analyze and optimize the acoustics of your HT setup - REW - Room EQ Wizard Room Acoustics Software. A bit of learning is required for using REW. Here is a link to start with - REW YouTube Tutorial - Home Theater Forum and Systems - HomeTheaterShack.com. There are lots of posts in home theater shack regarding the setup and use of REW. REW Forum at Home Theater Forum and Systems - HomeTheaterShack.com

With your current set of drivers you need to consider acquiring a good equalizer. A word of warning here... If the Philips doesn't provide sufficient grunt at the low mids as anilva pointed out, don't expect a big change even with equalizer.

here are couple of useful links.
Subwoofer Setup and Calibration for Best Bass | Audioholics
How to master your equalizer for the perfect sound | Digital Trends

feel having one sub is not filling my room with even bass,what would you say should i go for another sub/amp of the same make,or one is sufficient for ht or it should not be too much bass i am confused.

This can happen as the bass get directional as your crossover point is at 80hz, in this case two subs are better than one as they will provide more convincing directional bass by acting as an extension to your stereo mains.

 

[Hari Iyer]

If you fail to get well centred and we'll imaged bass then it has to be issued with phase setting and subwoofer level. Phase and level setup has always been and will continue to be the most challenging part of any sub-sat setup. There aren't any quick solutions too, the links provide by TAnthony is a good starting point though.

 

[rajesh srinivas]

The mid/bass driver with surround you are referring to is a Philips India driver and not a Philips Holland model (if I remember right). In my opinion it is not a great driver. In those days, Philips could palm them off giving all kinds of unrealistic wattage figures. They have popularized PMPO etc. Use them as along as you can manage, but do not plan a long term solution with these drivers. Go and get yourself a decent set of drivers from Peerless and make nice fronts and centre. Then you can make dipole like surrounds.

Regards

hi anilva,

The mid/bass driver i am referring to is as shown in the picture below,its a
philips 40W rms 8ohms Woofer with Foam and not full range.

Since DIY approach is also to see that we make maximum utilization of the available components, in my case my front tower i.e its driver,cabinet,xover wherein if any additions or correction/alteration can be done.

hence my query as below:

Since the 12inch Philips AD1256 lacks low/mid strength as shown in the graph, then is it possible that if i add my philips 8inch woofer or a new peerless mid/bass driver as suggested by you to the existing front cabinet (AD1256 & 4inch Philips dome tweeter) as in picture with a suitable 3 way xover,dont you feel the issue can be solved.

For surround i am using at present as already told you philips 8inch fullrange as in picture.Dipole is a very good option if you are watching only movies,certainly will go for it when my front setup issue is solved.

For my centre as already told in this thread will be a MTM design,peerless M13NH & TL25SN,drivers are acquired,xover is ready drawback is lobing issue as pointed out by t.anthony will take his suggesition to overcome it.

regards

 

[tnvijay]

Hi Rajesh,
I once had the same problem. I found a nice solution which worked so well. Take two polyfill pillows and rip off the poly fill. stuff the entire cabinet with poly fill. Then play your bass test tracks and adjust by removing / adding through the port hole. I did all modifications to my 8 inch dig sub,but none where fruitful. At last the polyfill stuff worked and I get chest thumping bass. Try it.

 

[rajesh srinivas]

Hi Rajesh,
I once had the same problem. I found a nice solution which worked so well. Take two polyfill pillows and rip off the poly fill. stuff the entire cabinet with poly fill. Then play your bass test tracks and adjust by removing / adding through the port hole. I did all modifications to my 8 inch dig sub,but none where fruitful. At last the polyfill stuff worked and I get chest thumping bass. Try it.

hi vijay,

My issue is with front channel (towers),sub issue is solved,
have posted my queries awaiting for a suitable reply.

regards

 

[rajesh srinivas]

If you fail to get well centred and we'll imaged bass then it has to be issued with phase setting and subwoofer level. Phase and level setup has always been and will continue to be the most challenging part of any sub-sat setup. There aren't any quick solutions too, the links provide by TAnthony is a good starting point though.

hi hari iyer,

i welcome you for joining my thread and sharing your viewpoints,

My only concern is for a proper build/setup for my front channel (towers) that can compliment with my 12inch peerless sub.

As i think you have already gone through my thread and to summaries again,
for my 2way front towers i am using Philips holland full range driver AD1256M with 4inch philips dome tweeter enclosed in a sealed 85.73 ltr mdf box (external dimision H48XW14XD10.5) with a matching xover ,though earlier i was using it as a ported for stereo listing,pics are enclosed in page 2.

As pointed out my anilva the 12inch philips fullrange is not meant for HT and will not have sufficient low mid strength,i am enclosing its original F/R graph
and also provide you additional links for sharing your suggestion.




my query is.

1.Looking at the F/R GRAPH enclosed here, you feel the 12inch driver lacks low mids.

2. If it lacks low mids,can i add a suitable peerless midrange driver to the existing setup making it a 3 way design again with a matching 3 way xover.

3. or should i totally build a new one with the existing box.

Once i have the correct drivers for the front channel i can do the necessary active equalization/REW as suggested by anthony to get the best performance from my front ht setup.

kindly let me have your clear suggestion step by step to proceed further in building my center channel, i am stuck here.

regards.

 

[amit46]

Driver:*Peerless 12" Driver. 4 Ohm and 250 Watts.*
Plate Amp:*Forte 200 Watts amp at 4 Ohm*
followed t. anthony's build for 12inch peerlesss subwoofer,
his threads/posts is as below
http://www.hifivision.com/diy/22681-diy-sub-using-peerless-driver-available-locally-2.html
http://www.hifivision.com/diy/19965-my-ported-subwoofer.html
http://www.hifivision.com/diy/19965-my-ported-subwoofer-6.html

T/S PARAMETERS FOR THE SUB from varsha electronics from diyaudiocart
*Fs : 24.94 Hz RMSE - Free 0.43 Ohms
> Re : 3.68 ohms Fs 25.01 Hz
> Qms : 1.17 Re 3.68 Ohms
> Qes : 0.45 Res 9.69 Ohms
> Qts : 0.32 Qms 1.17*
> Le : 0.53 mH Qes 0.45*
> Vas : 256.35 liters Qts 0.32*
> Mms : 59.71 gms L1 0.53 mH
> Cms : 678 L2 1.11 mH
> BL : 8.80 R2 6.09 Ohms
> SPL : 94.7 dB RMSE - Load 1.01 Ohms
> Sd : 518.75 cm2 Vas (SD) 256.35 Liters
Mms (SD) 59.71 Grams
Cms (SD) 678 uM/Newton
BL (SD) 8.80 Tesla-M
SPL ref (SD) 94.7 dB [Re]
Rub -Index 0.14*
Area (SD): 518.75 Sq.Cm
Impedance 4 Ohms
Frequency response 26 - 220 Hz
Method: Mass loaded - Mmd (100 Grams)
DCR Mode: Fixed (3.68 Ohms)

After adding the specs into WinISD database and done calculation. It recommends:
119.4 ltr. Outer diameter
H = 21 inch
W = 18 inch
D = 19 inch
Vent = 4.02 inch Dia, 5inch Length.
tunning frequency 31.61 hz

But built the box as per anthony's volume 73.34 ltrs
My built external box dimension
H 21 X D 19.5 X W 15.5, internal volume comes to around 77.17 ltrs, adding vol for 1inch dowels bracking on all sides,whereas anthony's is 73.34 ltrs he used fiberglass/putty
My problem is being my room size of 11x22inch ht room
I am not getting much thump/punch I mean it shld make me feel, crossing 200w forte plate amp, filter (80hrz) and eq & vol at 12 'o' clock (half).other wise to much of eq and vol amp starts clipping.
I want the air punch in my chest, I want to feel the power of the bass
need suggestion in this regard if my box vol is correct or port dia and length is correct, or need different box dimension or if 2 subs are needed for my room (already i have bought 2nd sub 12inch peerless).
or I have made a mistake placing dowels instead of bitumen sheets or my box vol is wrong or port length/dia

my port size is 3.5inch, pvc flared both side length is 12inch (end to end of the pvc pipe,or should the length of flare outer diameter of both the radius to be considered for port length calculation,

can somebody help me where did I go wrong.

pics of my enclosure and box bracing is shown.

I built a sub woofer vented cabinet using a 12 inch JBL sub-woofer powered by a 150 watt RMS Rockford Fosgate amplifier. It was powered by a 40 amp 12 volt LED smps supply easily available through ebay.in or any local electronic parts supplier.
Remember that at low frequencies the sub woofer will draw huge current, therefore the power supply should at double the power rating at least!! My sub gives clean chest thumping bass at even 50% volume of the Denon AVR-X510BT.
The sub amplifier gain is on level 3 only.

 

[amit46]

I built a sub woofer vented cabinet using a 12 inch JBL sub-woofer powered by a 150 watt RMS Rockford Fosgate amplifier. It was powered by a 40 amp 12 volt LED smps supply easily available through ebay.in or any local electronic parts supplier.
Remember that at low frequencies the sub woofer will draw huge current, therefore the power supply should at double the power rating at least!! My sub gives clean chest thumping bass at even 50% volume of the Denon AVR-X510BT.
The sub amplifier gain is on level 3 only.