Amplifier for passive Sub-woofer

Hi Sunil,

You don't need a separate crossover - just use the cross-over of your AVR. Set it to the frequency based on the frequency response of the other speakers in your system.

Get am amp - but try out before you invest a good sum on the amp.

Or you could put this speaker on one of the rear channels & direct all the LFE there. You should try this before spending money on the amp. Check if it is possible in your AVR.

Let us know the result.

Regards

Sanjay

Hi doc,

Thanks for the advise.

Ok so the crossover part can adjusted with the AVR, but how can i direct all the LFE to the rear channels. does SR4600 have any options. the only setting that i could find in the setup is speaker size (large / small) and crossover frequency (80 / 100 / 120 hz).

Also do i have to worry about phase control.

regards - sunil

Hi Sunil,

You could try what the Doc says, alternatively you could have posted this thread in the DIY forum. I am sure many of the DIY experts would have been more than eager to help you out.

All the best.

Behram.

Hi,

i will be more than happy to do what doc has suggested. But how do i direct the LFE to the rear channels.

I mean in an AVR all the LFE's are supposed to be directed to the sub-preout. now how do i make the signals redirect to the rear channel ????

As far as I can tell, thats not possible, but maybe Doc could clarify.

I think what he meant was to use that speaker as a passive sub in your AVR and set the crossover accordingly.

sunilyo, not all AVRs have a power amp in..so not sure how you will do that without an additional amp.

if not then the only solution is to buy a used amp preferably and use the LFE in into that. any of the local indian amps should be ok..BTW most 12" subs i have seen have a min 150W amp..so better to by an igher rated sub

You will need to Split the LFE out by means of an RCA splitter and feed both the inputs into the Amp and that into the speaker

BTW What is the power rating/freq response of the speaker ?
As you will know it will perform only in the region of its LF to the crossover setting in your AVR (usually between 80-120) hence if your speaker is biwirable, better to disconnect the midrange as it will be hardly used at all..only your 12" is going to be used.

Hi,

The construction of the speaker is very basic.

I bought from the local electronics market here in Delhi located near the Red Fort.

It only consists of the 3 drivers which i have already mentioned conected by some cheap cable and the drivers have been fitted into a heavy wooden cabinet. that's it. nothing else is in it.

Along with this speaker i had bought a local amp also but it produces a lot of buzzing / humming noise when connected to an AVR. might be due to the cheap construction of the amp.

Do i have to invest in a monoblock amp. if so then please suggest me something which is cheap and basic and does not produce any extra noise. and dont forget to mention the price.

Hi Sunil,

I checked in my SR-4500 but I could not find the option of directing the LFE to any particular speaker other than Sub. BUT you can try to set it up as follows:

-Sub = No
-All speakers = small except SB
-SB = one
-SB = Large
-LFE = 80 Hz
-Feed SB speaker output into your passive Sub
-You may disconnect the midrange drivers

Alternatively you can take Sub out and feed it to your local amp and connect that to the speaker. Regarding the buzzing, just check what's wrong the amp or speaker?

Regards

Sanjay

Thanks doc,

will try this one and let u know the results.

regarding the buzzing sounds it is definitly the amp.


Edit:
But i think if i am connecting it the SB channel then the only the surround effects will come out of it. i mean afterall the speaker is being connected to the surround channel.

what do u say?

in that case i am left with the option of buying an amp for this one.

regards - sunil

SUNILYO schrieb:

Do i have to invest in a monoblock amp. if so then please suggest me something which is cheap and basic and does not produce any extra noise. and dont forget to mention the price.

Monoblocks are pretty expensive.. get a locally made Stereo amp if you chose to go that route

Doc, does SB mean surround ? will this setup ensure that ALL LFEs will be sent to the single large speaker ?

SB = Surround Back Channel

Just try, it might work. If the AVR is intelligent enough it would send all the LFE to the single large speaker in absence of a Sub.

Regards

Sanjay

Try a local Indian amp like Pulz, Norge, Torvin, DNM, Sonodyne etc that delivers at least 50W continuous per channel. It will handle your bass effectively. Lithos has a passive sub, which can be powered through an amp. You can imitate them and get very powerful bass.

Thanks Neutral,

I went on the site of sonodyne and was looking at the specs of their power amplifier, model SPA 202.

Description : Two channel power amplifier
Inputs : 2 line level inputs via. gold plated RCA sockets
2 line level balanced inputs via. Female XLR sockets
Outputs : 2 speaker outputs via gold plated binding posts
Front Panel Switches : 1 push type power switch
Front Panel Indicators : Power ON, Fault/ Protection
Output at Clipping: 8 Ohms : 2 x 120 watts
Output at Clipping: 4 Ohms : 2 x 200 watts
Bridged mode power output into 8ohms : 400 watts, 4 ohms bridging not recommended
Distortion @ Rated Power
THD : Better than 0.05%
IMD : Better than 0.05%
Freq Response (-3dB) : 15 Hz ~ 80 kHz
Slew Rate : 40 V /uS
Damping Factor : > 150 (8 Ohms) 1 kHz
Channel Separation (1 kHz) : Better than 70 dB
Sensitivity : 775 mv (at rated power, 8 ohms)
S/N Ratio unweighted : 105 dB
Input Impedance : 30 Kohms balanced,
4.7 Kohms unbalanced
Power Requirement : 230 V AC 50 Hz
Power Consumption : 575 VA max.
Dimensions (H x W x D) mm : 107 x 440 x 400 max
Net Weight : 11.5 Kg

Any idea how much does this model cost ?

also wanted to know what is bridge mode ?

Can this also be used as a stereo amp with my DVD/CD player ??


regards - Sunil

Hi Sunil,

Bridge mode is when the two channels of the power amp are interconnected converting it into a mono-block and increasing it's power to 1.5-2 times.

If your CDP / DVD has a volume control then you can connect it directly to the power amp otherwise you need a pre-amp.

Regards

Sanjay

Thanks doc,

Yes my DVD player has a volume control built-in.

Hey Abhi,

Would need ur inputs on this amp. u seem to have gone underground .

Have u reviewed this model from sonodyne.


regards - Sunil

Yes my DVD player has a volume control built-in.

Which DVD Player is this ?

Is the volume control a front panel knob ?

If not, it lowers the volume by throwing away bits of data !

That is Phoo Phoo for audiophile applcations, and would certainly not fully exploit the rest of the system components, including the Power Amp that you are considering....

Amp_Nut schrieb:

Yes my DVD player has a volume control built-in. Which DVD Player is this ? Is the volume control a front panel knob ? If not, it lowers the volume by throwing away bits of data ! That is Phoo Phoo for audiophile applcations, and would certainly not fully exploit the rest of the system components, including the Power Amp that you are considering....

adding to that..if you connect the power amp directly you can only use the DVDs volume control and the AVRS volume would need to be around at Maximum !! i would definitely not recomment it.

Why dont you just conncet the LFE output to the amps pre in in a non bridged mode (1 channel only). the LFE output level can be lowered/increased from the AVR itself/ most of them have individual level controls for each channel.

So Arj,

So you are suggesting that I connect the power-amp to the AVR and control the volume thru the AVR.

That means any increase or decrease in the AVR will result in an increase or decrease of the sub also ???

Dear Sunil,

Can you explain what are you intending to do? If you plan to use the power amp to drive your passive sub in your existing HT then just take the Sub line out from the AVR and feed it into th one of the channel of power amp and take the output of that channel to your Sub. The sub level can easily be adjusted in the setup menu of AVR and after this setup the volume knob of the AVR will control the volume of the sub also.

BTW are you planning to buy a power amp just to try how the passive sub works? I would adivce please try it BEFORE you buy it. And I think that you can get a decent Active Sub for the price of a power amp.

Regards

Sanjay

yes..i'd be interested to know whcih dvd player has a volume control implemented ?

Sunil..which dvdp is it ?

manek.

dr saab has a point..should not end up buying a dog since you have aleady have a leash

SDhawan schrieb:

Dear Sunil, Can you explain what are you intending to do? If you plan to use the power amp to drive your passive sub in your existing HT then just take the Sub line out from the AVR and feed it into th one of the channel of power amp and take the output of that channel to your Sub. The sub level can easily be adjusted in the setup menu of AVR and after this setup the volume knob of the AVR will control the volume of the sub also. BTW are you planning to buy a power amp just to try how the passive sub works? I would adivce please try it BEFORE you buy it. And I think that you can get a decent Active Sub for the price of a power amp. Regards Sanjay

The Sonodyne amp you mentioned is a monster
Mine just puts out 60W/ch. Buy an amp rated at around 50W/ch as I told you for between 5 to 10 thousand. Not a Godzilla that will cost around 20K (meant for driving 30K+ speakers like Avant).

Better to use the AVR's vol control. The DVD player's vol control will lose fidelity at low vol. Alternatively, get a power amp with its own vol control.

..should not end up buying a dog since you have aleady have a leash

Dear Arj,

I like that

Regards

Sanjay

Hi,

I have the Onida DFX-5100P as my DVD player. It has this volume level on the remote which i used to use with my first HTS package.

So are you guys telling me that there is no such thing as volume control in a DVD player .

So then how does such kind of volume controller work ???

Doc:

All i am trying to do is use my 12inch driver to some good use (use it as my sub) instead of investing in a new a sub. and my so called 'old' 12 driver is not that old its hardly one year since its purchase and i have only used it 5 - 6 times (around 25 hours of total usage time). that is why i want to invest in a decent power amp like sonodyne. because that is (i think) is the only indian brand which i can get in delhi and also that i cannot afford any international brand. Any idea how much does it cost or do u have any other suggestions on indian brand which are available in delhi.

Hi Sunil !

All I meant was that you should first try the setup you are planning to have lest you should feel disappointed in the end.

A large 12" driver doesn't neccessarily mean that it is best suited for low frequencies. There are many other design factor to be taken into account to optimize a driver to efficiently reproduce low frequencies.

I think that the Sonodyne Power Amp is in the range of about 15-17 K (not sure). Why don't you buy NAD C320BEE (Marantz PM-4001)for about 20 K and try only the power amp section. In case you are not happy with you ingenious Sub, you could still use the amp for a stereo setup.

Regards

Sanjay

Thanks doc,

I think for that price i can easily get a powered sub.

SUNIL,

I asked the question about volume control becuase most dvdp's dont come with a volume control feature. Lucky you found one.

manek.

SUNILYO schrieb:

Hi, I have the Onida DFX-5100P as my DVD player. It has this volume level on the remote which i used to use with my first HTS package. So are you guys telling me that there is no such thing as volume control in a DVD player . So then how does such kind of volume controller work ??? Doc: All i am trying to do is use my 12inch driver to some good use (use it as my sub) instead of investing in a new a sub. and my so called 'old' 12 driver is not that old its hardly one year since its purchase and i have only used it 5 - 6 times (around 25 hours of total usage time). that is why i want to invest in a decent power amp like sonodyne. because that is (i think) is the only indian brand which i can get in delhi and also that i cannot afford any international brand. Any idea how much does it cost or do u have any other suggestions on indian brand which are available in delhi.

Sunil, A Norge amp costs Rs 6,000 and it will be shipped to you in Delhi for free from Bombay. My friend has a 12" driver and a 3" driver and I am searching out an amp of around 60W for between 5,000 to 10,000. I suggest you too do the same. My take is that we can get more bass out of two 12" drivers than a single 10" driver in a commercial powered subwoofer. (Technical-minded folks, do correct me if I am wrong.) And that too for less than half the cost

I have this local-made amp with me. The only problem with this one is that there is a lot of humming noise in it. i dont think that there is any problem with my earthing because no such humm's or buzz's come out from any other system/speaker.

do we get any kind of device which i can connect between the amp & speaker which can suppress or filter out such sounds.

i dont think that there is any problem with my earthing because no such humm's or buzz's come out from any other system/speaker.

I dont understand...

Can you elaborate ?

In your case, the Hum is probably due to :

1. A defective interconnect between your CD PLAYER and amplifier.

Try replacing the interconnect.

2. If your Amp has a 2 pin Mains plug, try reversing (flipping it Left to right) it.

3. MOST Likely this is a Power Supply Fault. ( If the hum is there in BOTH Channels, this is Most likely the culprit ) Get it fixed.

Hi,

Interconnect i think is not the culprit because i am using the same between by DVDp and AVR and is working perfectly fine.

May be i will try the other suggestions and then let u know.

But i still am not satisfied as to all my other components are working fine and i am not facing any problems with regard to humming.

Can a lousyly assembled circuit also create such defects??

Hi Sunil,

There is a shop in Malviya Nagar on the Shivalik Road called "The Diplomat's Gallergy" which stocks second hand equipment. You could try finding an amp there.

Do you have one or two large speakers that you want to convert to Subs?

Regarding the humm, try connecting your speaker to a different amp (may be your AVR) and also try a different speaker on this amp in question. You may be able to figure out whether speaker. the amp or the combination is the culprit.

Regards

Sanjay

Thanks doc,

I have only speaker which i plan to convert.

This shop what types/brands does it deal in ?
Have you bought something from this shop?

Also if you could give me the address / phone number.

Can a lousyly assembled circuit also create such defects??

OFCOURSE !

Amp Nut,

From my observation, even cheap multimedia speakers do not come with a humming sound. Quality in Indian products is fairly good. Maybe a manufacturing defect could cause this problem. Unlikely to be a design flaw.

Hey..since we are not using 7.1 the remaining 2 amps in the avr remains useles.Is it not possible to re-route the LFE out to an analog input,using the inbuilt crossover in the avr? Cant we run the sub in a multiroom multisource configuration with independant volume control...? this way we can use the last 2 amps ..:. .im am going to try this one....

neono schrieb:

:) Hey..since we are not using 7.1 the remaining 2 amps in the avr remains useles.Is it not possible to re-route the LFE out to an analog input,using the inbuilt crossover in the avr? Cant we run the sub in a multiroom multisource configuration with independant volume control...? this way we can use the last 2 amps ..:. .im am going to try this one....

Hi !

None of these two options is possible at least in SR-4500. You cannot re-route the LFE to any specific spkr other than Sub. And multi-room setting the Spkr B will get the same signal as the fronts in the main room.

What can be done is to use this as single surround-back spkr (6.1 config.) and specify it as large & Sub as none. You will get a rear surround effect with some more bass.

ATLAST

now everybody knows who doc is

nice picture doc I think forgot to say cheeeeeez

Thanks

Yesterday the picture was a bit different..there was a name plate...

Sunilyo,may be its not possible with sr4500.But the sr5500 has multiroom,with multisource feature.so the lfe[from the receiver itself] can be fed to the CD analog input using a Y splitter.the multiroom source will be set as CD.the amplified signal at the surround back speaker terminals can be fed to a passive sub. ..Recycling..

sr5500 has multiroom,with multisource feature.so the lfe[from the receiver itself] can be fed to the CD analog input using a Y splitter.the multiroom source will be set as CD.the amplified signal at the surround back speaker terminals can be fed to a passive sub. ..Recycling..

If it works, it will be great.

Yesterday the picture was a bit different..there was a name plate...

I increased the amplification, reduced the THD and used high pass filter to bring out the mid & the high ...Extrapolating....

SDhawan schrieb:

I increased the amplification, reduced the THD and used high pass filter to bring out the mid & the high ...Extrapolating....

perchance is that the audio equivqlent of Photoshop functions doc