Unpleasant noises from my IB

Hi toecheese,

If it were me, I'd probably try to recreate the problem with REW. See if it will happen with pink noise or tones or a sweep at a low volume. I would probably prefer tones, but a sweep will give you an idea of what tone might cause the problem, and pink noise will cast the widest net. Start turning it up (within reason, of course) until you hear it. If you can, good. Now try to figure out what's rattling!

Also, presuming that it could be a driver, you could disconnect one driver, and then the other, to see if the problem follows one.

Good luck!

Check the mounting screws, be sure the drivers are secure. Next check all the joints on the manifold to be sure none have separated, you might want someone to play some test tones while you are at the manifold and see if you can isolate the noise.

I just got an email from the guru of IB (Thomas) and he suspects damaged voicecoils... time for some tests. :-((

Well, one of the two has a rubbing sound when I push it in. Grrrr!

Looks like they're doing the tempests again: http://www.acoustic-visions.com/~acoustic/products/subwoofer_drivers/tempest_classic/

Anything beat them price/performance-wise for an IB? I went to the link off the cult forum and there are 18" Canadian drivers for cheap... hmmm.

Yes.

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=295-190

Yeah, those are listed on the cult driver page: http://www3.sympatico.ca/bonaz/IB-Sub/IBdrv-01.htm

The xmax numbers don't match up to what's in the spreadsheet though...

You might consider doubling the drivers to 4 so you don't have the same issue again.

Yes, if I don't get an exact replacement, I'll have to rebuild my manifold anyway- so I'd make it a 4-way.

toecheese said:

Yeah, those are listed on the cult driver page: http://www3.sympatico.ca/bonaz/IB-Sub/IBdrv-01.htm

The xmax numbers don't match up to what's in the spreadsheet though...

Click to expand...

Thats cause they actually aren't on the the cult driver page, for whatever reason.

:rubeyes:

What are the economics of driver voicecoil replacement if that is the problem?

Not sure- yet. I'll see if they sell a rebuild kit.

toecheese said:

Looks like they're doing the tempests again: http://www.acoustic-visions.com/~acoustic/products/subwoofer_drivers/tempest_classic/

Anything beat them price/performance-wise for an IB? I went to the link off the cult forum and there are 18" Canadian drivers for cheap... hmmm.

Click to expand...

http://www.mach5audio.com/product_info.php?products_id=38&osCsid=25d1f8bf41adcb1052b928ce4f67e177



I assume you will want to replace them asap. I am currently working with a reseller in MD which will result in cheaper shipping costs for many. They won't be made available for at least a month tho...

Best,
Mark

mr.ogowski, That is awesome news! the only thing holding me back from purchasing a driver were shippings costs...(yes all, I am THAT cheap).

toecheese thats strange, I was definitely going to consider tinsel slap as a possibility. If you're noticing something rubbing its probably not tinsel slap. Have you had a chance to try each driver free-air?

Perhaps the Cult's advice on 2 x 15" as a start pack is just too optimistic?

4 x 15" or 4 x 18" offers a safety net for those dangerous moments in films when you watch them for the first time and don't know what to expect.

Exocer said:

mr.ogowski, That is awesome news! the only thing holding me back from purchasing a driver were shippings costs...(yes all, I am THAT cheap).

toecheese thats strange, I was definitely going to consider tinsel slap as a possibility. If you're noticing something rubbing its probably not tinsel slap. Have you had a chance to try each driver free-air?

Click to expand...

I don't think you can consider your decision cheap when the shipping doubles the cost of the driver , it is good news that shipping charges will come in line with normal expectations. Too bad it costs so much from Canada.

I use the Mach5 MJ-18 drivers and they can dish out more than I can take. But keep in mind that the x-max on the MJ-18 is pretty low for an 18". For a fair comparison I say it's 4 x MJ-18 vs. 2 x Other 18" drivers. They're still a bargain if they give you enough output. Sounds like you might be pretty bass hungry though...

Actually 4 of those 18" drivers is equivilent to only two RL-P 15 15" drivers in displacement. A great bargain nonetheless for those who are budget minded. I found that the higher XMAX drivers produced a more natural sounding bass at higher levels. When using a 14mm XMAX driver I found the bass to be "one note-ish" and kind of hollow.

The one-notish sound quality you heard is not from the excursion of the driver, but rather the charateristics of the design and the enclosure the driver was in (if it was in an enclosure at all of course).

Best,
Mark