DIY subwoofer/speakers (1 Viewer)

[GeorgePCY]

Hi, I've had this home theatre set called the Creative Gigaworks S750 7.1. The electronics in the subwoofer have become faulty and creative wouldn't repair due to warrenty period expiring. I have opened the subwoofer and taken some pictures of the internals:


http://img248.imageshack.us/g/pic1oa.jpg/


I unsoldered the driver to get it out of the box. It says 8ohms. I am not able to repair the electronics. I have a multimeter but they have glue all over the boards and I could probably only test the amp part which I think is the part with two copper coils. However I am not very comfortable in doing so. I also unsoldered the power in wires and broke the switch and power in cable terminal out of the woofer box lol.


I have noticed the sub driver uses 3 pairs of red and black wires that go from the driver to an electronic board. Could someone explain why it would use 3 and not 2. If I use the same subwoofer box and driver could I make a seperate woofer by just buying some new wires and terminals. I would like to try. My main concern is the following:


1. I do not have an external amplifer.

2. If I were to buy an external amp then I need it to power 7 satalite speakers and the woofer. Therefore I would need to understand about power consumption and how I could connect this up.

3. If this involves any kind of crossover designs or some other kind of electronics that I see inside the woofer. I probably would not be able to do this.


Spec

Total Power 700 Watts Satellite RMS Power /ea 70 Watts Subwoofer RMS Power 210 Watts Frequency Response 25Hz - 40,000Hz Signal to Noise Ratio(SNR) 99 dB

Any basic information on building my own woofer would be nice so that I could try to apply that to this.

 

[Robert_J]

Rebuilding the Creative subs are a lost cause. It's a lot of proprietary equipment that is a pain to work with. If you want to build a speaker or sub from scratch then I can help.

 

[GeorgePCY]

Okay. That sounds nice. I live in the UK. Could you give me a ruff estimation on the cost of building my own theatre subwoofer and if possible a name of a non-overpriced amplifier that can be used for 7+ speakers as well. I still have 7 satalite speakers. So some sort of amp could accomodate for both the subwoofer and them? I am really not experienced with power consumption. For example I don't know why woofers have internal amps rather than plugging a driver into an external amp if possible.

 

[Robert_J]

The cost of building a sub is directly related to your goals. If you want 10hz at 120db then you are looking at thousands of dollars at the minimum.


What is your budget for a receiver? Are these 7 speakers from the Creative system?

 

[GeorgePCY]

Yes those 7 speakers are from my creative system. I do not want to spend thousands. The idea is to buy a 7.1 amp and upgrade those speakers when I am able to? That is my first goal then we can see about the sub. However I am not sure about amps/recievers and whether that amp/reciever accomodates a subwoofer etc. I would not spend over about 500USD? Maybe same goes for the sub.

 

[Robert_J]

The UK should have the same manufacturers available as we do. Pioneer, Denon, Onkyo, etc. You can get some over here for as low as $200. They all support powered subs. The Creative speakers may or may not work with a regular receiver. I have zero information about them. At minimum, what is the impedance?


Same with subs. I don't know what you guys have available over there. I know you have car audio available over there. What manufacturers? A lot of "car subs" will work just fine in a home environment if you design the enclosure correctly. Then you power it with a sub amp or a pro audio amp.

 

[GeorgePCY]

Subwoofer power (RMS): 210 Watts RMS (Rated @ 8 ohms @ 0.2% THD @ 70Hz, Single Channel Loaded)

Speaker power (RMS): Satellites and center speaker: 70 Watts RMS per channel (Rated @ 8 ohms @ 0.1% THD @ 1kHz, Single Channel Loaded)


Signal-to-noise ratio: 99 dB

Frequency response (+/- 3 dB): 25Hz to 40kHz

Tweeter (diameter): 1 inch

Transducer type: Cone

Directionality: Monopole


I would have no trouble in designing the enclosure apart from calculating volume etc. Materials side I could use a few sheets of MDF and some sort of join such as dovetail.

 

[Robert_J]

Before we go any further, do you have pictures of this Creative system or maybe a link to a site with pictures and a description?

 

[GeorgePCY]

Here is the link. Thank you.

http://sg.creative.com/products/product.asp?category=4&subcategory=789&product=9306&listby=usage

 

[Robert_J]

Look for an inexpensive 7.1 receiver from a big name like Pioneer, Onkyo, Denon. That will drive the 7 speakers as long as you don't crank the volume, set the speakers to small in the receiver and set the crossover at 120hz.


I don't recommend using the sub at all. Being in the UK, you are limited in the DIY products that are available compared to us so we will need to look at car audio subs. Check out the drivers from http://www.bladeice.com/ and see what fits your budget.

 

[GeorgePCY]

[COLOR= rgb(0, 0, 0)][SIZE= 12px]Hey, [/COLOR][/SIZE] [COLOR= rgb(0, 0, 0)][SIZE= 12px]I've been looking at recievers. This is my current list in this order:[/COLOR][/SIZE]
[COLOR= rgb(178, 34, 34)]Onkyo TX-SR608[/COLOR] - http://www.onkyousa.com/model.cfm?m=TX-SR608&class=Receiver&p=i

[COLOR= rgb(178, 34, 34)]Denon AVR-1911[/COLOR] - http://usa.denon.com/US/Product/Pages/Product-Detail.aspx?Catid=3d9614d1-8000-4106-ab91-8192242cab83&SubId=40b5820d-83c2-4e93-9909-60aae60e0bdd&ProductId=75e77041-c488-4707-a874-c045157bed9b

[COLOR= rgb(178, 34, 34)]Pioneer VSX-1020 - [/COLOR]http://www.pioneerelectronics.com/PUSA/Products/HomeEntertainment/AV-Receivers/PioneerReceivers/ci.VSX-1020-K.Kuro


I'm not sure about:

Pre-out sub connection. I don't see this on the Pioneer or denon but I dont know if I would connect a sub directly to my PC for example.

crossover adjustment.

Any heating issues.


While Denon AVR-1911 looks good, its power rating is less and offers less connections compared with the Onkyo TX-SR608. However I have read some people having problems with particular Onkyo models regarding heating issues. However this model has a fan but I am not sure how reliable it would be.

I do not really care for extra features such as dolby or sound effects etc. My understanding is it would be worth the money to get a reciever rather than a stand-alone amp.


For the sub:


I was looking at the website you gave me. This is my list:


The 15" £325. http://www.bladeice.com/havoc.php (1250W)

The 18" £275. http://www.bladeice.com/chaos.php (800W)

The 18" £279. http://www.bladeice.com/ssdseries.php (1000W)

The 10" £259. http://www.bladeice.com/qseries.php (800W)


I might not like the Qseries because it says they are for reference music, which I think is a flat sound? I don't want a boomy loud sound either. I would like nice deep sound, maybe achieved by larger cones? That brings me on to say with a price point of about 300, would it be better to get the 18" or the 12" from the two different types of woofer. I am also worried about cost of power e.g. PSU to driver it.

I'm siding with the Havoc 15" but there is no way for me to know what it will sound like and it might be slightly too powerful.


Thanks.

 

[Robert_J]

Receivers - I'm a fan of Pioneer. My home theater receiver is the VS-1014. 6 years old and running perfectly. My office receiver is another Pioneer. 18 years old and again, running perfectly. The VSX-1020 has a sub pre-out.

That is a nice selection of subs. How big can your enclosure be? That will determine the one that works the best.


A larger cone does not guarantee deeper bass. 90% of the output is determined by the enclosure design. If you went with four 18" subs, they would still not overpower your other speakers if the system is properly calibrated. I'm guessing that you don't want something large enough to hide inside so I recommend something like the SSD 10". The 10" will play a little higher without breakup allowing them to blend in better with your satellite speakers. As for powering it, a Behringer EP-2000 is inexpensive and provides a lot of power.

 

[GeorgePCY]

Hi,


If I were in the furture to buy some bookshelf speakers would the Pioneer be able to drive those power-wise. For example,

http://www.bowers-wilkins.com/Speakers/Home_Audio/600_Series/686.html


What does the Pioneer spec mean by:


Power Output: Watts per Channel (1kHz @ 8 ohm) 110 Power Output: Watts per Channel (20Hz-20kHz@8ohm) 80
in comparision:


Onkyo 1kHz & 20Hz-20Hz = 100W

Denon 90W


The cables at the moment for my satalite are Phono to bare wire. How do I plug the phono into the amp or do i buy bare wires on both ends to go around the red and black knobs. I also don't know how to go to my PC because its got no HDMI, only different coloured jacks.


I don't think theres an audio return channel in the Pioneer so u need to use another wire for the TV?


Thanks.

 

[Robert_J]

Ignore the power ratings on receivers and speakers. Unless your speakers are rated extremely low (like 10w) or you are going to power them with a 1,000w amp then the ratings are useless.


The Pioneer and all of the other receivers have more then enough power to push the B&W speakers to dangerous SPL levels.


Post a picture of the connection to the satellite speakers. If they have push terminals in, then you are correct in that all you need is regular speaker wire. Or you can just cut the phono ends off the existing wire.


The different colored jacks on the PC mean something. I have 4 audio output jacks on my PC. I use 1/8" stereo to RCA cables to get 7.1 audio from my PC. One jack is center and sub. One jack is left and right main. One jack is right and left surround. One jack is the rear surrounds.


If you use your TV's internal tuner then you need a line level connection from the TV to the receiver.

 

[GeorgePCY]

Yes I would need to cut the wire but thats fine. Where do the 4 RCA cables go into the amp? The single side stereo jack would go into the PC and the double male side? On the back i see Audio(zone 2 out) with a phono then DVR/BDR in/out, DVD, CD, TV/SAT, VIDEO IN, CD IN, CD-R/TAPE IN OUT and a line of coaxials underneath.


http://www.avland.co.uk/aasp/pioneer/1020/vsx1020/rearlrg.jpg


Cheers

 

[Robert_J]

The VSX1020 doesn't have a multi-channel pre-amp in. That's what I get for assuming since my 1014 does.


Do you have a digital audio output on your computer? A quick Google search shows some cards with digital out for about $30.

 

[GeorgePCY]

No because it's an onboard sound card from 5 years ago. I might buy a new motherboard because i'm having problems with it now anyway. I tend to stick with Asus. I am not sure what kind of sound card would be nice. Would there be difference between latest onboard sound card and a bought one? I normally go for boards which have most options on there already.

 

[Robert_J]

Some of the external cards like the ones from M-Audio are studio quality. They will also allow you to use programs like Room EQ Wizard with a calibrated, professional mic.