Woofer suggestions for MTM

Hi everybody

I'm planning a set of speakers for 50/50 HT/music use.

Fairly sure I'll be using the Vifa XT25TG but I'm having trouble find a nice woofer to compliment it without blowing my budget.

I was considering the Vifa M18WO because I've heard its close to the quality of SS without the price tag. However the crossover point would need to be pretty low wouldn't it? Is the M18 worth the extra over the P17WJ which seems to allow for a greater range of crossover points?

I looked at the Hi-Vi M8a but the enclosures would be bigger than I'd like.

I was also looking at the Adire extremis 6.8 but its low sensitivity wouldn't match the tweeter too well.

Can anyone suggest a good woofer for around $60USD that would blend nicely with the XT25 and be relatively noob friendly to design a crossover for?

Also any suggestions on crossover design would be appreciated.

Thanks,
Anonymoose
 
There is a general consensus that the P17's bass capabilities are lackluster; it's more of a large-format midrange driver. Just by looking at the specs, the M18 would have better bass, but would not not work well at all above 1kHz. The dip in response from 1kHz to 1.6 and the double peak from 2.5 to 5kHz are the result of cone breakup. For better matches to the XT25, look at the PL18, MG18, and Peerless HDS series. In fact, the Peerless would probably be your best option as it has a very smooth response and a low distortion motor. As far as the Extremis goes, it has pretty uneven response and I wouldn't like to deal with it. Besides, it might be a little too pricey.

Another problem is that the XT25 is not a forgiving tweeter in terms of crossovers. Despite its low resonance, it doesn't like crossover points below 3kHz. There are other good tweeters in the price range that go much lower, like the Morel MDT30 and the Usher 9950. If you don't yet have the XT25, I wouldn't bother with it.
 
I would not call the Adire FR graph very even. From 90Hz to 5kHz, it fluctuates by about 8dB. Plus, don't forget that the curve is smoothed, so the actual response would be worse. It's pretty clear that this woofer needs some corrective filtering, and I would't try that without measuring equipment. It may be a great woofer, but it is definitely not for beginners.
 

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dmitriy167 said:
I would not call the Adire FR graph very even. From 90Hz to 5kHz, it fluctuates by about 8dB. Plus, don't forget that the curve is smoothed, so the actual response would be worse.

But the response at 90 Hz would be impacted by the enclosure, and all manufacturers graphs are smoothed.
I guess what I'm looking at is the lack of large breakup excursions above 2kHz such as you see with Scan-Speak drivers for example. I have a major aversion to notch filters, and I thought you could get away without one using the Extremis.
 
audiobomber said:


I guess what I'm looking at is the lack of large breakup excursions above 2kHz such as you see with Scan-Speak drivers for example.


The Extremis lacks the breakup peaks above 2k because it has a flimsier poly cone and not an ultra-stiff carbon fiber or Kevlar one, but that's probably what's causing the broad peak from 400Hz to 1k and the dip right after it. If you look at the SS FR curves, none of them have those midrange fluctuations. Also, the SS curves have much less smoothing than the Adire ones, and all the peaks and dips are probably worse in the Extremis than they seem. But the only way to know for sure is to measure.