Tb W4-1052sa

[smbrown]

I've seen recent threads on these. I picked up a pair that arrived from Parts Express just the other day. Today I stuck them in a BR box that is 980 in3 and has a 2.5" x 0.75" vent. I put about 25% stuffing in it. So far they sound pretty good, but a couple problems and I'm looking for some help. When I play my test CD and measure the SPL from sitting position, I get nice and flat down to 63 hz, and 50hz is -7 db. So the bass is not too bad. The top end seems to have good presence and is all there without too much harshness. But the problem is in the lower midrange. I get a bit drop out between 250 and 400hz. We're talking about -5 to -8 db. This causes everything to sound kind of thin. Any ideas about what I might tweek? There is no BSC at this time but I think that might just make it worse. Sure appreciate any ideas you all might have -- these seem to have lots of potential. Not as airy as the Fostex's I've tried, but much better impact and bass. Thanks,
Steve

[smbrown]

Well, having seen no replies, I took matters into my own hands. I remodeled the Tang Band W4-1052SA's on WIN ISD and ended up with a box that is 620 in3, and a 2" by 5" port. I also added a bit of BSC - just a 1mh + 4ohm resistor I had laying around. Later I'll see if that's even in the ball park.

My mid bass problem is much better and the speakers easily get down into the 50's now. Wow, great imaging, very nice dynamics. I still think the Fostex's I've heard are a bit faster. But these seem to have smoother treble than some of the Fostex I've had and don't seem to need hundreds of hours of break in time.

So far I'm pretty impressed with these little guys!

[MarkMcK]

Go to:

http://diyaudio.com/forums/showthrea...threadid=24030

There is more information there about this driver.

Too much treble will also cause a loudspeaker to sound "thin." The 1052 has a bump shelf in the low to mid treble that must be equalized. Your "BSC" is close, but not ideal.

Also, the 250 to 400 Hz problem may be room or location. It could be a box problem, but in quasi anechoic testing I have never seen a problem in this range with this driver in comparable sized boxes.

Data base searches are not perfect, but if you search the "1052sa" the other thread will appear.

Mark

[454Casull]

Give MarkMck's 1052 mods a try (found in the thread he linked to). Unfortunately, mod #2 hasn't been posted on his site yet.

[smbrown]

Thanks for the thread reference. I changed my BSC to the filter shown by MarkMac (don't know if you'd call this BSC with the added cap so correct if I'm wrong). At any rate, even without the glue modification it sounds and measures much better. I am still getting the big drop around 400 - 500 hz, however. Wondering if it was room placement (my box is rear ported), I moved it closer to the back wall. Seems to not make much difference - I tried it about 2' and at about 4'. The latter sounds much better for sound stage. I just picked up a bottle of Gem Tac at Michael's, a crafts store. I'll give it a try as well.

I had my son listen to these, he has much better HF hearing than I do now. He heard a bit of upper treble tizziness. About a handfull of more stuffing behing the driver cured this without making the box sound overstuffed. Any other ideas on the 400 hz dropout (still about -7 db) would be appreciated. Box is currently 626 in3 with a 2"x5" rear facing port.
Thanks a bunch!!