Dayton WWMT problems

[Rick Craig]

I received an email from a local builder who complained about some problems with the sound of the WWMT project found here. Anyone else unhappy with the results? At one time I heard there were some quality issues with the tweeter? I'll be measuring them and will report back if anyone is interested.

[Jed]

I'd first be inclined to check over his wiring of the crossovers and drivers to see if anything is out of phase. It only takes one little error to make a poor sounding speaker- but of course I'm sure he checked it over and over again.

Which crossover design did this individual use and what is the specific problem?

Jed

[Rick Craig]

I'd first be inclined to check over his wiring of the crossovers and drivers to see if anything is out of phase. It only takes one little error to make a poor sounding speaker- but of course I'm sure he checked it over and over again.

Which crossover design did this individual use and what is the specific problem?

Jed

Harshness with vocals / trumpets / sax and borderline sibilance. I'll check the crossovers (Dennis Murphy's design) first to make sure that everything is correct. It doesn't sound like a phase problem.

[cjd]

Two things I see sometimes: these are sensitive to stuffing and general box treatment in the mids. And, people aren't used to how harsh these instruments actually are.

I also personally find Dennis doesn't quash the breakup as much as I prefer, which I find adds a bit of edge to these same instruments...

Verify wiring. Mess with stuffing on the mid. And make sure the right tweeter was used - the RS28A and RS28A-S aren't as interchangeable as we might like.

C

[Jim Holtz]

Harshness with vocals / trumpets / sax and borderline sibilance. I'll check the crossovers (Dennis Murphy's design) first to make sure that everything is correct. It doesn't sound like a phase problem.

Hi Rick,

I built the 27TBFC version of that speaker way back when it first came out and it's very musical. There were a couple including mine at the 2006 Iowa DIY event and was only edged out by Curt's design. My money says the crossover isn't right, the source components are finally being heard or simply the CD's are not well recorded.

If it's the RS28 version, I can't comment because I've not heard it.

How are things? You seem to be very, very busy these days. That's a good thing! :T

Merry Christmas to you and your family!

Jim

[jkrutke]

Hi Rick,

There were some RS28's that had issues though I haven't tested any in a year. With those I found that the rub and buzz is not very obvious with music but just comes across as annoying and edgy. But it stands out like a sore thumb when I swept a tone through the audible range.

Mark K, if you are around, how are RS28's these days? If you remember those defective ones I sent you, I notice PE now has replacement domes... I bet you could pop a couple of those in there and they'd be good. PE should give those out for free to anyone who needs them.

All that said, my money's also on screwed up crossover assembly. All it takes is one component out of place or not connected. Or worse yet, a cap lead overheated with solder - very difficult to troubleshoot. I bet designers underestimate how easy it is for a DIY'er to mess up a complicated crossover.

[ThomasW]

I received an email from a local builder who complained about some problems with the sound of the WWMT project found here. Anyone else unhappy with the results? At one time I heard there were some quality issues with the tweeter? I'll be measuring them and will report back if anyone is interested.

Rick,

There was a problem with some of the tweeters quite a while ago. PE instituted a QC program, now all the tweeters have an inspection sticker on them. The problem was a slight misalignment of the VC. It was easily fixed by loosening the screws and shifting the VC.

Other factors to consider are his playback equipment and room treatments (or lack there of...)

The fix maybe as simple as padding down the tweeter a little.

[chasw98]

Rick, it might be as simple as he didn't swap the polarity on the midrange or messed up '+' and '-' on another driver. I built a pair using the 27TBFC just like Jim and have not had any problems. They have been A/B'd with some Stratus Gold's and the owner of the Gold's liked the WWMT's better.

[fjhuerta]

Two things I see sometimes: these are sensitive to stuffing and general box treatment in the mids. And, people aren't used to how harsh these instruments actually are.

I remember the first time you told me that. And you are still right! ;x(

[Rick Craig]

Hi Rick,

I built the 27TBFC version of that speaker way back when it first came out and it's very musical. There were a couple including mine at the 2006 Iowa DIY event and was only edged out by Curt's design. My money says the crossover isn't right, the source components are finally being heard or simply the CD's are not well recorded.

If it's the RS28 version, I can't comment because I've not heard it.

How are things? You seem to be very, very busy these days. That's a good thing! :T

Merry Christmas to you and your family!

Jim

It's been crazy lately. Merry Christmas to the Holtz family as well!

[Rick Craig]

Thanks to everyone for your suggestions. After I check out the speakers I'll post my findings.

[Jed]

So Rick,

What was the issue with the speaker? Did you get around to measuring?

Jed

[Spanky Ham]

They have been A/B'd with some Stratus Gold's and the owner of the Gold's liked the WWMT's better.

That is a flat out lie and slanderous!



Oh wait, I have already sold the Golds. Yeah it is true. :B

[Rick Craig]

So Rick,

What was the issue with the speaker? Did you get around to measuring?

Jed

I've been away and already have several projects in the loop. I hope to know something in a few weeks.

[digital desire]

(In voice of sweaty convict) Any word from the governor?

[cjd]

What tweeter was used?

I need to do more in-depth checks but the new Seas tweeters may not quite be what they should...

[Rick Craig]

(In voice of sweaty convict) Any word from the governor?

I'm working on a possible visit this weekend and will report back.

[Rick Craig]

What tweeter was used?

I need to do more in-depth checks but the new Seas tweeters may not quite be what they should...

Dayton tweeter.

[Jed]

What tweeter was used?

I need to do more in-depth checks but the new Seas tweeters may not quite be what they should...

Chris, this has my interest. Hopefully there isn't lesser performance from batch to batch?

[cjd]

Well, were it just my tweeter measurements I'd not be concerned. But I've had a lot of folks finding some harshness and sibilance with the MTM's lately, making me really wonder. It's a broad peak leading up to around 5200 (up about 3dB). This equates pretty well to the distance between the tweeters and my screen so I think it probably is NOT the tweeters, but for the sibilance I clearly heard listening to these without the screen...

The dome material is very clearly NOT the same as the tweeters I used to build my MTM's.

C

[augerpro]

Chris are you saying that you have newer TDFC's that have a different dome than some older ones?

[cjd]

Yes. The domes they (TDFC's) have now are not the same as those I purchased a few years ago. Different color, different texture.

C

[Rick Craig]

Looks like I won't be working on the speakers. The owner had already installed and soldered the crossovers. I proposed measuring the drivers without the crossover in place and he didn't want to remove everything.