Things are looking up!!!

[Rowdy S13]

Well after YEARS of not having a sub it looks like I will finally have bass again soon. Long story short many years ago I bought a KEF sub from a friend of mine, and it sounded good no complaints really. One day while watching a movie, specifically Boondock Saints (the part in the beginning where they come out of the church and the music starts) it made an odd (loud) humming noise and started smoking. It was not turned up loud at all and was not ever really abused, but something was surely wrong. Well not knowing any better I thought the speaker popped so I hooked up a 8" sub I had laying around and instantly fried that too. Then it was sent to the corner to sit while I tried to contact KEF for any hope of repair. Of course that never worked (still hasn't) and it just sat for a LONG time.

Fast forward to last week, where I found myself in the CEO's office. He is an electrical engineer who worked at Sherwood in the late 70's designing amps. I asked if he still gets to work on electronics from time to time to which he replied no but asked what I had. So I told him about the sub that has been sadly sitting in the corner and he lit up and told me he could fix it and bring it in. I brought it in last week and he quickly discovered that it was outputting 50VAC to the speaker terminals which explains the destroyed subs. A little more digging told him that a transistor was fried. He checked at home and had one that was close but not exact (so I ordered some for a whopping $7.76 shipped for 5). When he got that in today for testing only we found that a relay got taken out when that went (or when I tried the second sub), a quick jumper to see if everything else was good and we were in business. So I ordered 2 relays ($7.17 shipped) and now when the parts come in the amp is back to 100%.

I am thinking of replacing the blown sub with this. What does everyone think about it? I don't really have any specs on the amp or the sub, I have been trying to contact KEF to get that but still nothing. The enclosure is down firing and rear ported if that helps.

Anyway the point of all of this is that for a little less than $15 bucks I got the amp all fixed up, and for a total of about $85.00 Ill have a sub again!!! Not bad in these times of tight money if you ask me. Now this will NOT be my ultimate final sub, but it will hold me over until I can get my hands on a SVS Ultra PB13. OK enough rambling, I'm just excited to have BASS again!


Sean

 

[Mister House]

Congratulations sir! I hope your long waiting has paid off. You will be back in the groove with a sub in the room again.

 

[lsiberian]

Well after YEARS of not having a sub it looks like I will finally have bass again soon. Long story short many years ago I bought a KEF sub from a friend of mine, and it sounded good no complaints really. One day while watching a movie, specifically Boondock Saints (the part in the beginning where they come out of the church and the music starts) it made an odd (loud) humming noise and started smoking. It was not turned up loud at all and was not ever really abused, but something was surely wrong. Well not knowing any better I thought the speaker popped so I hooked up a 8" sub I had laying around and instantly fried that too. Then it was sent to the corner to sit while I tried to contact KEF for any hope of repair. Of course that never worked (still hasn't) and it just sat for a LONG time.

Fast forward to last week, where I found myself in the CEO's office. He is an electrical engineer who worked at Sherwood in the late 70's designing amps. I asked if he still gets to work on electronics from time to time to which he replied no but asked what I had. So I told him about the sub that has been sadly sitting in the corner and he lit up and told me he could fix it and bring it in. I brought it in last week and he quickly discovered that it was outputting 50VAC to the speaker terminals which explains the destroyed subs. A little more digging told him that a transistor was fried. He checked at home and had one that was close but not exact (so I ordered some for a whopping $7.76 shipped for 5). When he got that in today for testing only we found that a relay got taken out when that went (or when I tried the second sub), a quick jumper to see if everything else was good and we were in business. So I ordered 2 relays ($7.17 shipped) and now when the parts come in the amp is back to 100%.

I am thinking of replacing the blown sub with this. What does everyone think about it? I don't really have any specs on the amp or the sub, I have been trying to contact KEF to get that but still nothing. The enclosure is down firing and rear ported if that helps.

Anyway the point of all of this is that for a little less than $15 bucks I got the amp all fixed up, and for a total of about $85.00 Ill have a sub again!!! Not bad in these times of tight money if you ask me. Now this will NOT be my ultimate final sub, but it will hold me over until I can get my hands on a SVS Ultra PB13. OK enough rambling, I'm just excited to have BASS again!


Sean

Replacing sub drivers like you propose usually has disastrous results. However if you provide me with the parameters of your current box along with the thickness of the outside material. I can see if it will work.

 

[Rowdy S13]

Replacing sub drivers like you propose usually has disastrous results. However if you provide me with the parameters of your current box along with the thickness of the outside material. I can see if it will work.

What information do you need? I will get you what I can along with photos if need be.

Sean

 

[adwilk]

What information do you need? I will get you what I can along with photos if need be.

Sean

Just post up the dimensions, whether its ported or sealed and if ported, how big the port is.

He's right, usually you can't just throw another sub in a random box and get great results. BUT, you will have bass again. We can fairly easily see what you should expect and maybe recommend some modifications..

 

[Rowdy S13]

OK here is some bad pics with even worse MS paint dimensions.

For the side shot if you couldn't tell, the Grey bar is the divider with the 9-3/4" hole in it, the white outline is the port (end of flare to end of flare), and the blue on the top is the little brace.

The whole box is 3/4" MDF including the brace and the divider. It also has some fiberglass batting in it that I took out for the pictures. Let me know if there is anything else needed to pick a sub.


Thanks,
Sean

 

[Rowdy S13]

OK I also found out that it has an internal volume od 1.3 cubic feet if that helps.

Sean

 

[fredk]

That last number was very useful. How long is the port?

Do you know how much power the amp puts out?

 

[Rowdy S13]

The port is 10" long, and the amp is "100" watts. I dont know if that is RMS or peak, and I still dont know what OHM the speaker is. Once the new parts are in the amp he is going to take it and run some test on it to figure out the exact output and what OHM so I can be sure I dont overload the amp. Also he said that it was 50v something (I cant remember what). I know that when it was blown that it had 50VAC on the terminals for the speaker.

Sean

 

[Rowdy S13]

Come on guys, where are the suggestions?

Sean

 

[TLS Guy]

Come on guys, where are the suggestions?

Sean

This is a huge problem working drivers backwards. You can't pull it out of the back of the neck.

This driver is your only hope. If you have the original driver get it reconed.

This driver should fit in your box, but the port has to be lengthened.

Name: Tang Band WT-1427G 10" Neo Sub
Type: Standard one-way driver
Company: Tangband
No. of Drivers = 1
Fs = 25 Hz
Qms = 3.42
Vas = 38.23 liters
Cms = 0.219 mm/N
Mms = 189.6 g
Rms = 8.471 kg/s
Xmax = 9.5 mm
Xmech = 14.25 mm
P-Dia = 211.1 mm
Sd = 350 sq.cm
P-Vd = 0.333 liters
Qes = 0.311
Re = 3.2 ohms
Le = 0.69 mH
Z = 4 ohms
BL = 17.35 Tm
Pe = 120 watts
Qts = 0.29
no = 0.185 %
1-W SPL = 85 dB
2.83-V SPL = 88.8 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box
Shape: Prism, square
Vb = 1.3 cu.ft
Fb = 30.49 Hz
QL = 7
F3 = 28.08 Hz
Fill = minimal
No. of Vents = 1
Vent shape = round
Vent ends = one flared
Dv = 3.25 in
Lv = 16.49 in

You will have to add a curved extension to the port, as it won't fit otherwise.

You will have to enlarge the hole a bit as this driver needs an opening of 9.17 inches.

Vent velocity is 18 m/sec and I think the sub will work comparably to how it did before. You will never find a drop in replacement. You will always have to mod. Choices of drivers that will tune and fit in that box are slim to non existent. The driver I have found is as close as you will get. So do it or chuck it.

 

[Rowdy S13]

I understand that it is not easy, and I appreciate the effort. How much and what will I be giving up if I go with the driver I mentioned without modding? This is only a temporary deal, and I cant crank it up really at all so some trade off (depending what it is) is acceptable to me. Or we can go this route, out of these subs which is the best without modding?
Option 1
Option 2
Option 3
Option 4

Thanks again for all of the help guys!

Sean

 

[TLS Guy]

I understand that it is not easy, and I appreciate the effort. How much and what will I be giving up if I go with the driver I mentioned without modding? This is only a temporary deal, and I cant crank it up really at all so some trade off (depending what it is) is acceptable to me. Or we can go this route, out of these subs which is the best without modding?
Option 1
Option 2
Option 3
Option 4

Thanks again for all of the help guys!

Sean

I looked at every single driver that could possibly fit on PartsExpress and the driver I selected is the only one that can possibly work. With the others you won't even have a sub. This is very exacting work. You don't have a clue what is involved, so don't argue with someone who has done the work and given you a gift horse.

I'm not doing any more work on this. What I have done is well beyond the call, and I don't get paid for it. So now you are on your own.

And yes, you do have to do the minimal mods I outlined, or the sub will not work. If this is too much work, take the sub to the recycling center.

 

[Rowdy S13]

I looked at every single driver that could possibly fit on PartsExpress and the driver I selected is the only one that can possibly work. With the others you won't even have a sub. This is very exacting work. You don't have a clue what is involved, so don't argue with someone who has done the work and given you a gift horse.

I'm not doing any more work on this. What I have done is well beyond the call, and I don't get paid for it. So now you are on your own.

And yes, you do have to do the minimal mods I outlined, or the sub will not work. If this is too much work, take the sub to the recycling center.

Whoa settle down there guy. Someone needs to step down off their high horse for a little while.

Sean

 

[walter duque]

Whoa settle down there guy. Someone needs to step down off their high horse for a little while.

Sean

TLS Guy is just trying to help you out. Trust me if it's not the exact same driver the sub will not work. Just recently I replaced my $100.--(Goldmund) driver with the Aurasound NS12 (549.--) and let me tell you it does not work.