peerless 12inch subwoofer new build

rajesh srinivas

rajesh srinivas

Active Member
Joined
May 30, 2015
Messages
370
Points
28
Location
hubli (karnataka)
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.
 

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hi, the build looks nice. congratulation. i am suspecting the amp is not having enough grunt to drive the driver.just my opinion.
 
krell said:
hi, the build looks nice. congratulation. i am suspecting the amp is not having enough grunt to drive the driver.just my opinion.
Click to expand...

hi krell,
Thanks for your comments,the amp is good its Plate Amp:*Forte 200 Watts amp at 4 Ohm,perfect match for the subs,since subs are 4ohms -250 watts.
i cant raise vol more than half,cone movement vibration is thr like my window glass panes vibrates in certain movies,what i need is punch/thump.

i suspect the port length i.e 12 inch is too long.

thanks
bi
 
hi saheb

amp is aperfect match to the sub,the idea is taken from one of hifivision post by
t.j anthony.i have given the links of his post in my theard.

you just check this link for sub and amp.

http://www.hifivision.com/diy/22681...ss-driver-available-locally-2.html#post317859

http://www.hifivision.com/diy/27432-group-diy-sub-build-peerless-driver-forte-200-watts-amp.html

There is full cone movement,vibration is also thr,coz in some hd movies my window glass panes vibrates.i suspect the port pipe length.

and also i had voice coil rubbing with the sub on one side,(bad courier transportation from mumbai) solved it by alingning it tightening the nuts so no issue.

dont know whr is the problem.

i use my htpc for feeding only hd 1080p movies (5.1),with projector epson.
using my wall with proper treatment will post you some pics later.

bi
 

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I used the same design but did not do ported, instead did sealed enclosure. The design had both the options. It works very well for me. I am driving with a 500 watt rated amp. Change the amp and check. Also close the port if you want to try something else.

Cheers.
 
anilva said:
I used the same design but did not do ported, instead did sealed enclosure. The design had both the options. It works very well for me. I am driving with a 500 watt rated amp. Change the amp and check. Also close the port if you want to try something else.

Cheers.
Click to expand...
Hi anilva,

Could I have your box dimensions and know what amp have you've used? Even I can close the port with socks to make it sealed and check; I checked with my 200watts Forti amp, it made no difference.

I will procure another amp say 300 or 400 watts of the same make and check.

Just need clarification from you.

1. Is my box size ok i.e (external h21xw15.5xd19.5) perfect for this driver, because win isd says 119 ltrs.
2. If ported is my port dia (3.5in) and length (12inch) right?
3. Is bracing ok or bitumen roofing sheets done by anthony better.
 
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Hello Rajesh,

A few things IMHO:

1. I simulated your setup in Bassbox pro, according to your box size and port, the box is tuned at 27.75 Hz, try tuning it little higher ~35Hz +.
2. you could change the port size say 4" dia and 7" length, you could gain a lot on acoustic power. that would tune our box at 37 Hz.
3. Your room size is big for a 12" woofer to pressurize that volume. also place the sub in the room corner to get better bass effect. lot of people say a sub could be placed anywhere in the room. but, place it in a corner you could hear the difference.
4. You really dont need to change the amp, 200W is enough to bottom out your woofer at some frequencies. by pumping more power you could damage the woofer, its just that you get more headroom by using a more powerful amp.

you did a great job actually building the sub, nice effort.:)

Regards,
Aniket
 
The chest thumping bass seems to be around 120-160Hz. As you are crossing at 80Hz, this need to be done by your main speakers. Try experimenting with higher crossover frequencies. One problem with the higher crossover is that the bass will become more directional and you might have to tweak the positioning of the sub w.r.t to your main speakers.

In my design, the port is tuned low to give more gain in the lower frequencies and a gradual roll off. It was intended to be crossed low to compliment the main speakers. If you are looking for more SPL you may need to tune high (between 33Hz to 38Hz). You can experiment by shortening the existing port.
 
Aniket said:
Hello Rajesh,

A few things IMHO:

1. I simulated your setup in Bassbox pro, according to your box size and port, the box is tuned at 27.75 Hz, try tuning it little higher ~35Hz +.
2. you could change the port size say 4" dia and 7" length, you could gain a lot on acoustic power. that would tune our box at 37 Hz.
3. Your room size is big for a 12" woofer to pressurize that volume. also place the sub in the room corner to get better bass effect. lot of people say a sub could be placed anywhere in the room. but, place it in a corner you could hear the difference.
4. You really dont need to change the amp, 200W is enough to bottom out your woofer at some frequencies. by pumping more power you could damage the woofer, its just that you get more headroom by using a more powerful amp.

you did a great job actually building the sub, nice effort.:)

Regards,
Aniket
Click to expand...

hi aniket,
thanks for sparing your time in finding out things for me.regarding your points.

1.my fronts as posted in the theard has a cutoff frequency of 80hz its a 12inch philips holland full range model no: AD1256M8, with a philips 4inch dome tweater ip908 has a matching xover pics enclosed,since my home theater setup is only for watching bluray untouched 5.1/7.1 movies or music,now at what frequency should i cross the sub your suggestion.
2.since i have completed the box,i cant change the diameter 3.5inch,only length can be changed, now what can be the length.
3. will place the sub near the side wall in front of my towers and check,if no
improvements than have to go for 2nd sub.
i have already acquired another 12inch peerless sub,hence i dont want to go wrong this time in its build for a perfectly calculated box.that will be placed as dual subs as in the picture

also interesting points i found for having 2subs on the net....

A. "2 Subs are always better than 1, purely because of Room modes. every room has a null or peak and by by adding 2 subs in opposing corners of the room helps eliminate the null or peak in the room . So irrespective where you are in the room . the bass will sound even . So basically smoothening the sound in the room irrespective which part of the room you are in .
Adding the second sub does not double the output- the overall output will increase by 3db"

B."Large overall space: Bass from a single sub tends to get lost in large overall spaces, so if you have a large room or an open floor plan (i.e. no walls between the living room, kitchen, and/or hallways, etc.), two subs are almost a requirement for realistic bass quality and low bass extension."

C. Having 2 subs is not to have them play different frequencies. it is to take care of room modes. let both play the same fq range lets say 80hz down

4. you are perfectly right no need more then 200w for this sub,and also since building a similar sub for the rear,that will take care of the empty space.

still better suggestions is welcome from all.
 
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t.antony said:
The chest thumping bass seems to be around 120-160Hz. As you are crossing at 80Hz, this need to be done by your main speakers. Try experimenting with higher crossover frequencies. One problem with the higher crossover is that the bass will become more directional and you might have to tweak the positioning of the sub w.r.t to your main speakers.

In my design, the port is tuned low to give more gain in the lower frequencies and a gradual roll off. It was intended to be crossed low to compliment the main speakers. If you are looking for more SPL you may need to tune high (between 33Hz to 38Hz). You can experiment by shortening the existing port.
Click to expand...

hi anthony,
i am very much thankful for your diy posts/threads its becoz of them i am able to design my hometheater speakers,you are my mentor,even i am going to build mtm for my single center channel based on your below link ...
http://www.hifivision.com/diy/16612-my-mtm-stand-mount-loudspeakers.html

Drivers are purchased m13nh midwoofer and TL25SN) box design is pending,i will post a theard later,it is for center channel need your feedback that we can discuss later.

regarding your view points,as already mentioned my setup is only for home theater and at present my mains are crossed at 80hz or should i cross it still below,i will rule out the thumping bass since you say bass sound will become directional above 80hz,so at what frequency should i setup my plate amplifiyer and for port tunning now should i make any changes,diameter is ruled out (3.5inch) since i have completed my box, only length i can change.

i made a mistake in calculating the width for the front panel my width is 15.5inch,should have been around 18inch since it says that .

"Try not to place the speaker on the very edge of the enclosure. If possible, keep the speaker and ports three to four inches away from the edges and walls".

so anthony please guide me what best for the sub i can do to get the best out of it for my present setup.

enclosing xover pic of my front towers,its been designed as per the drivers specs and for my front ht requirement.

thanks.
 
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Hello Rajesh,

You could decrease the port length to 6", that will tune your box to 35Hz, with considerable increase in the acoustic power. try crossing your sub ~125Hz, the punch lies from 80Hz-150Hz, below that is thump ;). also what are you using as your source, a blue ray player or a PC ?

as you have already acquired another peerless sub, i would have rather gone for a single 15" or 18" pro audio sub. these are very efficient. with proper enclosure and tuning they could produce really high spl with good tonality.

Regards,
Aniket
 
There is full cone movement,vibration is also thr,...
Click to expand...

... and also i had voice coil rubbing with the sub on one side,(bad courier transportation from mumbai) solved it by alingning it tightening the nuts so no issue
Click to expand...

There is a possibility that the basket could be deformed due to the poor handling by the courier guys. Since you have another driver with you, can you swap your current driver with it and see if there is any reduction in the vibrations or improvement in overall performance. Also if the driver is directly screwed to the mdf, I would suggest using t or d-nuts and matching allen bolts.

Coming to the box, for a ported design, I would say it's better not to change the dimensions and the port location. Please do a quick test of your sub as indicated below to see if the change in dimensions had any effect in the performance.

Stand directly in front of the port while playing a low bass track (there should be decent cone movement). Are you feeling the air coming out of the port? It will be similar to the bursts you get from an enfield exhaust. If you are feeling the bursts of air, move back to see how far you could experience these. With the original design, you could probably feel these up to about 10ft.

Post your observations here. If you have any specs on your main speakers, please share them as well. Matching the subwoofers with the main speakers needs a bit of tweaking.

am going to build mtm for my single center channel based on your below link ...
http://www.hifivision.com/diy/diy/diy/16612-...dspeakers.html
Click to expand...

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 - https://www.madisoundspeakerstore.c...io-za5.3c-center-channel-single-with-cabinet/
 
Last edited:
Aniket said:
Hello Rajesh,

You could decrease the port length to 6", that will tune your box to 35Hz, with considerable increase in the acoustic power. try crossing your sub ~125Hz, the punch lies from 80Hz-150Hz, below that is thump ;). also what are you using as your source, a blue ray player or a PC ?

as you have already acquired another peerless sub, i would have rather gone for a single 15" or 18" pro audio sub. these are very efficient. with proper enclosure and tuning they could produce really high spl with good tonality.

Regards,
Aniket
Click to expand...

hi aniket. after reading all the useful post given by you and others,i giveup the punch now prefer the thump as u mentioned which is very much prefered for ht.

since as mentioned by you my box is tuned at 27.75 Hz,will keep the same or will try to go still lower around 20hz (sub fs is 25hz), i have also checked the port velocity the feel of air coming out of port is max 2feet,after that i hardly get the air pressure,shld be more to get better SQ/SPL.

so now what do u feel is it the port length or box vol.

you mentioned earlier that my room size is big for a 12" woofer to pressurize that volume.should i go in for the 2nd sub????
 
hi antony,
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 have checked my sub performance for any voice coil rub issue,i.e the cone movement) looked to be decent as in the video link.

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

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 said:
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./QUOTE said:
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.

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 /QUOTE said:
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 details you require about my setup,just mesg me.

thanks
Click to expand...
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