So my T34B saga continues. Now that my back chambers are re-attached, there is a new issue.
Today, listening to the tweeters with a 1V sine wave sweep, I can hear some fuzz around the area under 1.5k on one of the driver's.
It sounds like a rubbing VC, so I ran quick impedance sweeps on the DATS test setup. Low and behold, it looks like a rubbing VC. The TSPs are also a bit different which shouldn't be on a matched pair of drivers, unless they're only matched for FR and not overall parameters.
My question is, has anyone with these tweeters measured them as a pair and how did they look?
Today, listening to the tweeters with a 1V sine wave sweep, I can hear some fuzz around the area under 1.5k on one of the driver's.
It sounds like a rubbing VC, so I ran quick impedance sweeps on the DATS test setup. Low and behold, it looks like a rubbing VC. The TSPs are also a bit different which shouldn't be on a matched pair of drivers, unless they're only matched for FR and not overall parameters.
My question is, has anyone with these tweeters measured them as a pair and how did they look?
Attachments
even more evidence to show they should have covered repair and shipping costs. gonna keep sticking to companies with competent customer support.
Sorry I can't help you with plots.
Just curious.. did removing the rear chamber affect the diaphragm positioning? Does the screw torque have an effect? Could there be damping material rubbing?
Just curious.. did removing the rear chamber affect the diaphragm positioning? Does the screw torque have an effect? Could there be damping material rubbing?
What a deflating saga. They absolutely should send you a replacement, at their expense. For that kind of money, and the level of performance expected, and advertised, this shouldn't even be a thing. I hope that this can be worked out for you. Glenn.
Check your mail, and thanks again!
Check your mail, and thanks again!
@AllenB Possibly when I got them with the chamber detached in shipping. Who knows how hard they were thrown around. We have the worst delivery drivers here in AZ. Nobody cares about this stuff. I'm just done with boutique drivers. First this, then a bad brand new Manger MSW straight from the box. I'm so done with all this crap.
Last edited:
We'll see what Stanislav has to say after I emailed him with the pictures and measurements. I doubt this will be resolved easily without drawing more blood.
The impedance curve on the bad driver looks like there's an air leak at the chamber, but i tried some blue masking tape to seal around the gap between the magnet and chamber - no luck. The rough peak is an indication of a mechanical issue in the moving assembly.
I honestly believe these Bliesma drivers are top notch. I just can't get a break with this bad luck. Everything from SB, Seas, Vifa, Scanspeak, Peerless, etc has been flawless. Even Eminence has their product design and manufacturing down after many years of durability and fit / finish issues. It just seems after the whole green packaging movement eliminating Styrofoam from everything is causing alot of problems with shipping damage. I know Styrofoam is bad for the environment, but what else can you practically use?
I honestly believe these Bliesma drivers are top notch. I just can't get a break with this bad luck. Everything from SB, Seas, Vifa, Scanspeak, Peerless, etc has been flawless. Even Eminence has their product design and manufacturing down after many years of durability and fit / finish issues. It just seems after the whole green packaging movement eliminating Styrofoam from everything is causing alot of problems with shipping damage. I know Styrofoam is bad for the environment, but what else can you practically use?
if this gets worked out, I'll probably be selling the replacement drivers at a loss. I'm sticking to companies with US distributors from now on.
I wanted to buy these tweeters from a US dealer, but Solen was the closest and they were out of stock. The other issue ordering from them is having to pay import duties despite coming from Canada, so it made sense to order them from Europe. I got beat up by people on here for allegedly being cheap and purchasing from an online European vendor. I just ordered from a dealer who had them in stock. Price was secondary but an incentive nonetheless. I had no clue this would turn into such a mess.
I wanted to buy these tweeters from a US dealer, but Solen was the closest and they were out of stock. The other issue ordering from them is having to pay import duties despite coming from Canada, so it made sense to order them from Europe. I got beat up by people on here for allegedly being cheap and purchasing from an online European vendor. I just ordered from a dealer who had them in stock. Price was secondary but an incentive nonetheless. I had no clue this would turn into such a mess.
Can you take a screenshot (using Windows Key, Shift, S) to further elucidate the differences? Also, perhaps have the Zmax as 30 ohms, or something like that, so we have a zoomed view.
The differences may be there, but they actually might not make a practical difference, particularly since its not in the passband where you will typically use these tweeters.
I'm not apologizing any discrepancy, but what I'm trying to reassure you is that what happens in the impedance trace above Fs is certainly much more important what happens below Fs.
I was once checking one of my tweeters, which had a odd dual impedance peak. Specified Fs is 600Hz, but this one had something going on higher.
Tweeters still have a lot of output between 1-2 KHz, so this was a real problem.
It took awhile to figure this out and fix it...
The differences may be there, but they actually might not make a practical difference, particularly since its not in the passband where you will typically use these tweeters.
I'm not apologizing any discrepancy, but what I'm trying to reassure you is that what happens in the impedance trace above Fs is certainly much more important what happens below Fs.
I was once checking one of my tweeters, which had a odd dual impedance peak. Specified Fs is 600Hz, but this one had something going on higher.
Tweeters still have a lot of output between 1-2 KHz, so this was a real problem.
It took awhile to figure this out and fix it...
Last edited:
None of my other dome tweerers I tested had any wrinkles like this or were this different across the range, even if they weren't matched. The big discrepancy is under Fs if you compare both and its not acceptable for this price range.
I did once have a set of Morels that had faint VC buzz at lower frequencies on one tweeter. That one eventually failed and upon inspection of the VC, there was a crease in the VC former and a shiny spot on the windings which shorted on the upper pole piece.
My philosophy on HF drivers is to only purchase the ones with user serviceable VCs, otherwise you have no way to deal with a failed driver other than sending the drivers to the manufacturer for repair or throwing them in the trash. As much as I like SB acoustics stuff, the HF domes are mostly not serviceable. Thats not good business IMO.
I did once have a set of Morels that had faint VC buzz at lower frequencies on one tweeter. That one eventually failed and upon inspection of the VC, there was a crease in the VC former and a shiny spot on the windings which shorted on the upper pole piece.
My philosophy on HF drivers is to only purchase the ones with user serviceable VCs, otherwise you have no way to deal with a failed driver other than sending the drivers to the manufacturer for repair or throwing them in the trash. As much as I like SB acoustics stuff, the HF domes are mostly not serviceable. Thats not good business IMO.
Sorry, what do you expect from Bliesma ?
You try to repair the Tweeters by your own and now they have differences, don't match 100% , ...
Now you are going to blame the manufacturer, in such a case my answer would be 🖕
I've used in the last years several Bliesma Chassis in 5 diff. Projects, everytime without any issue.
You try to repair the Tweeters by your own and now they have differences, don't match 100% , ...
Now you are going to blame the manufacturer, in such a case my answer would be 🖕
I've used in the last years several Bliesma Chassis in 5 diff. Projects, everytime without any issue.
I take it you aren't aware of the history this user has with the company. They sent him damaged units and didn't do a thing to try and fix it for him.
I'd sell em or pitch em, this company clearly doesn't care about op. Seems to be the case with most of these silly priced driver manufacturers.
What I remember from the past discussion :
- he has ordered the tweeters from a dealer in Europe
- This dealer is usually responsible to take care about guaranty issues
- Bliesma has offer to repair, but Profiguy don't what to take the shipping costs and want to repair the tweeters by DIY
But Bliesma didn’t send him the units.
When you buy product from retailer, I usually take it back to retailer for service/support.
That’s why the 40-50% margins are built in there. That’s the traditional way of doing business.
If I buy 100 units from Stanislav as an OEM, and I have a failure rate of 1-2%, I wear it. You feed it back to the company and they work to resolve/improve the process. It’s in mutual best interests for this to happen.
In the past when I’ve purchased from Madisound, on the rare occasion that something was DOA; after a few email exchanges they promptly sent a replacement. I wonder why the retailer didn’t offer this.
When you buy product from retailer, I usually take it back to retailer for service/support.
That’s why the 40-50% margins are built in there. That’s the traditional way of doing business.
If I buy 100 units from Stanislav as an OEM, and I have a failure rate of 1-2%, I wear it. You feed it back to the company and they work to resolve/improve the process. It’s in mutual best interests for this to happen.
In the past when I’ve purchased from Madisound, on the rare occasion that something was DOA; after a few email exchanges they promptly sent a replacement. I wonder why the retailer didn’t offer this.
I've bought dayton audio stuff from other dealers and dayton still covered them under full warranty no problem. What'd bliesmas excuses here?
bought some kali lp6 v2 used and they had the bad amp firmware problem. kali sent me out two new amps and covered shipping for the news and to send the old ones back.
yall need some standards or something. it's called supporting your products and customers.
To me, this issue is about (mis)communication and managing levels of expectations and entitlement, and talking to the right people that can affect the necessary changes.
You judge me without even remotely having the facts to substantiate it.
I only reattached the rear chambers. I didn't touch the diaphragmscor any other components. What I did wont cause what is happening now. Please dont contaminate my thread with your accusations.
- Status
- Not open for further replies.