Repair: REL Q100E foam damage

Elcs

Novice Member
Hello all

Whilst being dragged around a car boot sale at yon time of a weekend morning, prior to breakfast and wake up juice, I managed to land a deal on a REL Q100E 12" sub to replace my 6 year old HTIB Onkyo 8" sub which didn't do much no matter how many bits of sound advice I followed.

Now the only caveat is that the foam surround of the Q100E has some damage. The rest of the sub is absolutely perfect and is like comparing Messi to the Sunday league player, it's so much better.

I'd like to fix it and AVForums has always set me in the right direction so I started here. DIY is not my forte but I am willing to give a go at a repair/replacing the foam myself and a repair centre is not out of the question if one is local.

Any suggestions? Pictures attached

Dropbox - Damage1.jpg
Dropbox - Damage2.jpg
 
Last edited:

snaithg

Well-known Member
Hello all,

Whilst being dragged around a car boot sale at yon time of a weekend morning, prior to breakfast and wake up juice, I managed to land a deal on a REL Q100E 12" sub to replace my 6 year old HTIB Onkyo 8" sub which didn't do much no matter how many bits of sound advice I followed.

Now the only caveat is that the foam surround of the Q100E has some damage. The rest of the sub is absolutely perfect and is like comparing Messi to the Sunday league player, it's so much better.

I'd like to fix it and AVForums has always set me in the right direction so I started here. DIY is not my forte but I am willing to give a go at a repair/replacing the foam myself and a repair centre is not out of the question if one is local.

Any suggestions? Pictures attached


Pictures Faulty!


Graham.
 

Elcs

Novice Member
Pictures Faulty!
Graham.
The forum, my phone and Dropbox hate me. I've been trying since i posted the OP to get them to work.
 

Elcs

Novice Member
I have had a repair quote for £60 plus postage costs on top to replace the foam surround. This seems to be quite steep considering the foam surrounds are often just £10-15 on their own.

They also advised that running the subwoofer at all in it's current state would damage it, eventually causing irreparable damage to the drive unit. Would I be okay running the subwoofer at a very low volume? At 50% and running Audyssey my AVR set it to -12 dB's and I've temporarily dropped the volume to minimum on the back of the sub.
 

Elcs

Novice Member
Does this help?
I'm not sure :) I managed to add proper links, just not the embedded picture like that.

What would really help is a bit of advice if anyone has it :D Time is on my side anyway.
 

IronGiant

Moderator
The drivers they put in those REL units weren't very expensive could you get them to quote for sending you a new driver? It might be cheaper due to much lower shipping costs.

Otherwise something like this? Eminence Beta 12C 4 ohm £55.48 IN STOCK (1 Jul 2014) You'd need to dig out the Thiele parameters for the Q100e to check they are comparable.
 

Elcs

Novice Member
The drivers they put in those REL units weren't very expensive could you get them to quote for sending you a new driver? It might be cheaper due to much lower shipping costs.

Otherwise something like this? Eminence Beta 12C 4 ohm £55.48 IN STOCK (1 Jul 2014) You'd need to dig out the Thiele parameters for the Q100e to check they are comparable.
Something like this? REL Q100E Replacement

For £40 it sounds very cheap, considering the REL Q100E's pedigree.

As I'm also the leaqrning type, what the 'Thiele parameters' and where am I likely to find the answers, beyond hitting lucky on the Gogglematron?

Thanks IronGiant.
 

IronGiant

Moderator
No question about it I'd get that driver from BK when they come back in stock :) As I said, despite their reputation at the time the drivers in the REL Q100e were not very expensive... In fact REL Q100e copies were being made by us DIYers at the time using drivers and amp panels sourced from, you guessed it: BK.

Thiele parameters are the physical characteristics of the driver and are responsible for the way a driver performs in a given box. The ones for the Eminence driver are:
THIELE & Small Parameters
  • Resonant Frequency (fs) 45.5 Hz
  • DC Resistance (Re) 3.47
  • Coil Inductance (Le) 0.75 mH
  • Mechanical Q (Qms) 9.57
  • Electromagnetic Q (Qes) 0.49
  • Total Q (Qts) 0.46
  • Compliance Equivalent Volume (Vas) 115.0 liters
  • Peak Diaphragm Displacement Volume (Vd) 128.0 cc
  • Mechanical Compliance of Suspension (Cms) 0.279 mm/N
  • BL Product (BL) 9.46 T-M
  • Diaphragm Mass inc. Airload (Mms) 43.9 grams
  • Efficiency Bandwidth Product (EBP) 93.4
  • Maximum Linear Excursion (Xmax) 2.37 mm
  • Surface Area of Cone (Sd) 538.9 cm%uFFFD
  • Maximum Mechanical Limit (Xlim) 11 mm
There are Thiele parameters available for most drivers if the manufacturer cares to release them. However if BK have gone to the effort of sourcing a compatible driver, they've done that job for you :)
 

Elcs

Novice Member
No question about it I'd get that driver from BK when they come back in stock :) As I said, despite their reputation at the time the drivers in the REL Q100e were not very expensive... In fact REL Q100e copies were being made by us DIYers at the time using drivers and amp panels sourced from, you guessed it: BK.
<snipped a bit>

You should be renamed GentleGiant :) Very newbie friendly and I'm feeling less intimidated when I visit AV Forums because of responses like this.

Many thanks <bookmarks that BKE page and waits patiently>

Final question: Would I be able to use my Q100E in it's current condition if I use it at low sound levels (AV side) and low output volume (at the sub itself)? I don't want to risk losing the driver or damaging anything else if BKE if they're slow to get the replacements back in stock.
 

IronGiant

Moderator
Thanks :)
It's a relatively small area of damage. If you can get a small piece of duct tape over the hole to reinforce/protect it I would have thought you'd be OK so long as you don't drive it very hard. However, I'd prefer to have a few others agree with me before I actually recommend you go ahead.
 

Paul Smith

Well-known Member
I wouldn't recommend it. Foam surrounds only last so long and it has probably reached it's sell by date.
You'll probably find it is rather weak by now, with a tendency to tear/crumble and touching it more will probably just make matters worse.

If the foam is no longer properly supporting the cone it may allow the voice coil to rub and can cause itself damage if left to rub away, but really it has to be pretty bad to get that far!

If it was me I'd probably pick up some replacement foams from china, the US or somewhere for a tenner or so and refoam it - I like keeping things alive and hate throwing away repairable stuff.
Though you'd need appropriate glue as well, some kits include it some don't (I have some glue left over from previous refoaming jobs so it would be less expense for me).
But it's a fairly straight forward job really.

If doing it yourself and saving a few bob doesn't take your fancy then those replacement cones seem like a no brainer! And with a rubber surround you'll never need to worry about foam rot. ;)

Paul.
 

Elcs

Novice Member
I wouldn't recommend it. Foam surrounds only last so long and it has probably reached it's sell by date.
You'll probably find it is rather weak by now, with a tendency to tear/crumble and touching it more will probably just make matters worse.

If the foam is no longer properly supporting the cone it may allow the voice coil to rub and can cause itself damage if left to rub away, but really it has to be pretty bad to get that far!

If it was me I'd probably pick up some replacement foams from china, the US or somewhere for a tenner or so and refoam it - I like keeping things alive and hate throwing away repairable stuff.
Though you'd need appropriate glue as well, some kits include it some don't (I have some glue left over from previous refoaming jobs so it would be less expense for me).
But it's a fairly straight forward job really.

If doing it yourself and saving a few bob doesn't take your fancy then those replacement cones seem like a no brainer! And with a rubber surround you'll never need to worry about foam rot. ;)

Paul.
I managed to apply some masking tape over the damaged area. Of course I made the foam surround a little worse in that area but all gaps are now covered and I'm playing the sub on a really low level, avoiding the 'Slam' setting and my Audyssey setup with the sub at 50% vol set my AVR to -12dB on the sub so yeah, it's vibrating gently and producing some bass but not punching or moving violently so I'll likely avoid any more damage that causes me concerns.

The main allure of the 40 quid pack from BKE is that it's an all-in-one package supplied by the makers/owners of all things REL Q100E so they've made a replacement pack. No risk of me buying the wrong size foam/rubber or having to find the right glues :)

However, I am all for saving money so I'm more than willing to pick up a foam/rubber ring and fit it myself... which is kinda where I was hoping to go from the very start.

My biggest issue is... do I go foam to preserve the original sound as much as I can or do I go rubber for the longevity? Plus there's a million and one different 12" surrounds so I have no idea which one is going to fit properly, preferably without modification.

A quick recommendation on the glue would be nice too, unless I can use some UHU glue which I have around the house.

I know I'm being a bit hand-holdy here but old sub + new to the repairing subs part makes me very nervous from a picking the right parts perspective. Once I get them in my hands and start taking the guts out, I'll be fine.
 

Paul Smith

Well-known Member
Of course the £40 woofer will have postage on top of that, but it's certainly the most straight forward option (even with new holes needing to be made).

As for a replacement surround.
I personally always replace like for like, the original was foam so I would go for that, but I don't mind that it will only last another 15-20 years before needing to be done again.;)
Though having said that the type of surround (foam or rubber) normally has more influence on the top of the driver's operating range, so for use in a sub it probably doesn't matter and won't result in any noticeable difference in output.

The fit is fairly simple, most good replacement surround sellers list the sizes of their rings. The measurements refer to the diameter of :- the outer mounting edge - the outer edge of the roll surround - the inner edge of the roll surround - the inner mounting edge. So just four figures that you can measure on your current driver and match up to get the right fit.
One other thing that is sometimes specified is whether the cone edge is flat or angled, in your case it would be angled I believe. And it looks like it gets glued to the edge underneath the cone - a little more awkward to clean and fit but with a bit of patience it shouldn't be a problem.

Normally some form of PVA based glue is what is used on speakers, nothing particularly special really.

I hope this helps.
 

Elcs

Novice Member
The fit is fairly simple, most good replacement surround sellers list the sizes of their rings. The measurements refer to the diameter of :- the outer mounting edge - the outer edge of the roll surround - the inner edge of the roll surround - the inner mounting edge. So just four figures that you can measure on your current driver and match up to get the right fit.
One other thing that is sometimes specified is whether the cone edge is flat or angled, in your case it would be angled I believe. And it looks like it gets glued to the edge underneath the cone - a little more awkward to clean and fit but with a bit of patience it shouldn't be a problem.

Normally some form of PVA based glue is what is used on speakers, nothing particularly special really.

I hope this helps.
Very helpful indeed :)

Looks like I might be subless for a while because I know that if I take the driver out to take my measurements that the foam is just going to disintegrate :) Unfortunately that despite the REL Q100E seemingly being a very popular sub back in it's heyday and for some time after there appears to be scant information on the ground about specifics especially the driver.

Maybe next weekend I'll pop it out, see what's on the other side and order what I need.

PVA glue you say? I have some of that as well as a couple of flavours of UHU. I'll know more when I peek inside this unit and decide whether or not to play it ultra safe and buy some 'subwoofer foam surround glue' :)
 

Elcs

Novice Member
After finding out that the foam surround I wanted would cost me around £25 inc postage I decided to grab the replacement driver pack from BKE for £40 inc postage.

A little bit more on the pocket but I'm sure that replacing the driver will be more fun in a way :D
 

The Eggman72

Active Member
I had the same issue with an aging Q50 sub I ended up putting a JBL driver in it...if anything its an improvement.
 

Paul Smith

Well-known Member
It's quite likely a newer drive unit would improve things.
Though you've got me wondering now, what happens to all these drivers that needed refoaming?
 

Elcs

Novice Member
New driver in the house. I'll snap some pics and message IronGiant so that he can kindly post them up here properly :D

Then I'll get my drill out, get my Google on and see if I have a soldering iron and solder handy and get hooking it up some time this afternoon.
 

Elcs

Novice Member
Okay, the whole process wasn't too fun.

The cables inside the enclosure gave me about an inch wiggle room to play with so desoldering wasn't easy and soldering the new one on required the assistance of my Dad.

Other than that it wasn't too bad... despite the fact that they were silly enough to not bother to include instructions so it's a damn good job that I reasonably knew what I was doing before I stuck my hands in and a bit of Facebooking with an audio friend across in the Scandinavian countries gave me the only bit of additional support I required.

The problem now is getting it all tuned in :) I've been using the high level connection quite a bit for most of my stuff to get the nice, blended low hz (my Revolver R33's going down to 45hz) and I'm getting good sound so far.

Dropbox - CameraZOOM-20140717135046609.jpg

Tweaking tomorrow... hopefully a job well done!
 
Probably gonna cost a tenner for a new surround, or..

REL Q100E Replacement

I wonder if that driver is improved over the Q100E.
 

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