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Old 29th May 2013, 09:55 AM   #21
ODougbo is offline ODougbo  United States
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I was thinking here: 15 Watt Mono L-Pad | 50-090 (50090) | Distributed By MCM at least the tweeter level can be brought down.
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Old 29th May 2013, 10:28 AM   #22
PB2 is offline PB2  United States
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He already stated that he was using an L-pad on the tweeter.
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Old 29th May 2013, 12:03 PM   #23
Dissi is offline Dissi  Switzerland
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Parts Express provides a measurement of the woofer:

http://www.parts-express.com/pedocs/...-info-3665.pdf

A measurement of the tweeter is here:

Measurements: Pyle cheap horn tweeter PH25 (272-104 $6.93)

Both drivers do not behave well in the upper frequency range.
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Old 29th May 2013, 12:33 PM   #24
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A notch filter at arond 4K on the woofer looks like a good starting point. that should tame it a little, and may allow (with suitable tweeter) a cross at somewhere between 2 and 3 Khz.

Having been through an exercise of trying to deal with a driver that presented a similar response (though not as peaky) and coming out with a good result, it is surprising what you can actually achieve (though I will certainly not claim it is easy!!).

Below I've attached a response plot (in box) of my MW144's which are not dissimilar to the OP's woofers SPL curve in a lot of respects. I've attached these to show what is possible even when things look bad. Second pic is the tweeter that was mated with it (a DMS37), and third pic is the final result. Completely passive crossover. But designed with good measurements and simulation.

So what might at first look terrible can be bent into shape, and at least in my case it does sound good. crossover is at 2.8Khz 4th order bessel.

Having said that I think the chances of getting the tweeter in the first post to work with the woofer are extremely low!! Out of the two I'd be keeping the woofer

Tony.
Attached Images
File Type: png 1M MW144's only.png (63.0 KB, 116 views)
File Type: png 1M DMS37 only.png (64.7 KB, 114 views)
File Type: png horizontal_polar.png (45.1 KB, 91 views)
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Last edited by wintermute; 29th May 2013 at 12:34 PM. Reason: minor edit
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Old 29th May 2013, 02:05 PM   #25
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There is also the possibility of using a good 3inch driver to cover the treble, no problem crossing most of those down low enough and SLP/watt usually close enough above 300 or 400Hz, just need to use a small sealed cup behind the driver

eg

Visaton FRS8-8 3.3" Full-Range Speaker 8 Ohm 292-524
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Old 29th May 2013, 02:09 PM   #26
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Quote:
Originally Posted by wintermute View Post
A notch filter at arond 4K on the woofer looks like a good starting point. that should tame it a little, and may allow (with suitable tweeter) a cross at somewhere between 2 and 3 Khz.

Having been through an exercise of trying to deal with a driver that presented a similar response (though not as peaky) and coming out with a good result, it is surprising what you can actually achieve (though I will certainly not claim it is easy!!).

Below I've attached a response plot (in box) of my MW144's which are not dissimilar to the OP's woofers SPL curve in a lot of respects. I've attached these to show what is possible even when things look bad. Second pic is the tweeter that was mated with it (a DMS37), and third pic is the final result. Completely passive crossover. But designed with good measurements and simulation.

So what might at first look terrible can be bent into shape, and at least in my case it does sound good. crossover is at 2.8Khz 4th order bessel.

Having said that I think the chances of getting the tweeter in the first post to work with the woofer are extremely low!! Out of the two I'd be keeping the woofer

Tony.
Thanks very much for taking the time to respond. If one was to impulsively purchase these tweeters after getting his manhood handed to him in an audio forum, could you offer some crossover advice? Also, is there any way to salvage my original (PE reco'd) sealed cabinet volume, or will I have to increase volume and port to have any hope of fixing this mess?

Cheers.
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Old 29th May 2013, 05:04 PM   #27
system7 is offline system7  United Kingdom
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Having had a play with the similar Visaton W170 woofer ( a parcel shelf car woofer....) and a TW-70, I fancy the 4" Goldwood GT-25 cone tweeter.

It all works rather well. The Woofer gets a typical 6" woofer's 5kHz notch. Lots of bafflestep for bass and a gentle rolloff. Crossover's a tidge lower than I would like ideally, but I don't think it'll sound too bad in a cubic foot or so. You adjust the attenuator on the treble so it stays around 9 ohms overall on a 6 ohm DC tweeter to get the treble level about right, but it won't be far off anyway. This tweeter is so cheap, what have you got to lose?

BTW, I assume it's a sealed unit, otherwise you build a tiny little box for it.
Attached Images
File Type: png Goldwood_Guesstimate_ConeTweeter.PNG (7.9 KB, 89 views)
File Type: png Goldwood_Guesstimate_FR.PNG (20.1 KB, 88 views)
File Type: png Goldwood_Guesstimate_Phase.PNG (22.6 KB, 15 views)
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Old 29th May 2013, 10:04 PM   #28
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You might be able to do something with the tweeter by using a small cap on it (maybe 2uF or less + an lpad with the series resistor bypassed (with perhaps a 1uf cap) That could flatten it out a bit. Then try crossing it at say 2.5K. Without seeing an impedance measurement of it, and power handling (I know it says 60W but they normaly qualify that with a X point and slope) it is a bit hard to tell if that would be doable though.

If I have time (a big if) I'll spltrace it and have a bit of a play in speaker workshop.

Tony.
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Old 30th May 2013, 11:58 AM   #29
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Note that above comment was wrt the original tweeter, not the pioneer. Without any graphs of the pioneer very difficult to say anything.

As was suggested earlier the woofer (if you want bass) would probably best be put in a vented enclosure. I modeled it sealed and vented in 22L (your 0.79 cubic feet) If tuned to around 48-50 Hz you might get something ok. But it will not handle much power (sealed won't either under 100Hz)

You may need to put in a high pass at 50Hz. It could probably handle about 20W if you did.

Anyway attached is graph comparing vented to sealed. bothwere using your cabinet size, vented tuned to 48Hz., sealed heavy stuffing.

I also realised that without an impedance plot of the tweeter doing any sims to try and work out something that could flatten it out a bit is probably a bit pointless. I could substitute in another tweeters impedance plot to get an idea, but it would be largely academic.

Tony.
Attached Images
File Type: gif goldwood.gif (22.7 KB, 16 views)
File Type: gif VB Excursion gooldwood 206_8.gif (22.6 KB, 14 views)
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Old 30th May 2013, 12:52 PM   #30
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ok as I said pretty academic (I used my dms37's impedance curve) but the attached is what I came up with very quickly. Note phase has not been extracted from the spl trace.

The red target is 3rd order butterworth at 2.5Khz idea being that if the woofer were tamed a bit with a notch and given a similar accoustic target the nature of the butterworth would fill in the hole in the response a bit. I've not don anything with the woofer.

I dropped the tweeter down to 85db which allows for 3db of baffle step correction on the woofer. Not all is as bad as it first seems

Blue is the original tweeter response curve.

Tony.
Attached Images
File Type: png tweeter_correction.png (29.1 KB, 23 views)
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