Modest cost 8" woofer

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#41
hifijim said:
Since this will be a sealed box design, I would like an Fs of less than 36 Hz and a Qts in the range of 0.34 - 0.45
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You are saying that there is going to be a DSP involved as well as being a sealed box, so Qt is not really important because of this. Since that can all be compensated for. (within certain limits obviously)

I need a bit more context, what the purpose is going to be, what the other drivers are going to be as well as the total budget?
But my idea would be to find something with plenty of xmax yet still be able to cross around 300Hz.
Although this is a point where the other parts become important, why the 300-500Hz range?

Instead of a single 8 inch, a double 6inch could work as well.
Or obviously a 10 inch.

I assume you want things be available in the US?
Because I see plenty of options here in this topic, but all from EU stores.
Also plenty of option that are far more than $40-$60.

If it has to fit very tight within this budget within this volume, I think I would go for this;
https://www.parts-express.com/GRS-8...-Excursion-Subwoofer-4-Ohm-292-816?quantity=1

Fits fine within 15-20 liter.
Needs about 80-100W at most
Plenty of xmax (10.5mm), f3 around 35Hz or so.
Crossing around 300Hz would not be a problem, although in an active system you probably are fine around 200Hz, depending on the mid-range.
Can always get the f3 higher to gain more SPL /less distortion.

Otherwise the SD215A-88, although f3 would be around 45-50Hz instead.
Only 6mm xmax.

edit:
There is also the Dayton DCS205-4, with 8.8mm xmax.
Slightly over budget.
 
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#42
tktran303 said:
Dayton really knocked this one out of the park when they designed it.
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Great woofer, 100% agree!

Funny part; there is a little speaker shop in Germany, Omnes Audio.
They used to have the exact same driver, just a different name and slightly different cone color.

Which makes me think that Dayton didn't design this woofer by themselves.
Doesn't really matter, great woofer, although I don't think I would use it for this purpose.
 
#43
carstenan said:
for DSP/Digital-X-over, there are certain options in ASR or Digital-Line.

But I found one Analogue Active-X-over pretty good, the TIPD134 from Texas Instruments. Though it's designed for 2-way. In Taiwan, one finished board (print, have someone to install the SMD things on it) is around $40 USD. If you refer its simulation software, one should be able to modify for 3-way designs. I installed it with TPA3221 board and they works great.
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I never found any of those analog active filter boards very usable.

Usually one needs at least a shelving filter and a param EQ (or two ideally).

I have been working on a good one for a while.
If people are interested let me know.
It's basically finished, was trying to get a extensive manual together, but I think I will just release it as is.
Otherwise it's just so much additional work.

This board is also semi modular so one can bypass or add certain sections.
 
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#46
AdamThorne said:
I have a pair of the SDS-160F25PR01 they seem to be pretty good swept vol per dollar. I've got them in I forget exactly 10 -15 liters or so, sealed. That models down to some 80 Hz or so (model suggests they could get pretty low ported), but in-room measurements (RTA) suggest I'm not quite getting there. The woofer's fault, or my room? I dunno, they take some boost to make up the difference with no complaint, and can get down far enough to hand off to my sub.
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I had a piece of Dual Peerless SDS-160F25PR01 (8 ohm) into one Isobaric design. They sound all-right. Though in ported 15L box and with TIPD134 analogue X-over and TPA3221. Probably not the best design.

sorry the speaker wire is not well attached in the pic
isobaric_peerless.JPG
 
#47
Fast Eddie D said:
The 225-8 replaced a very similar woofer in the Dayton lineup. It is an improvement; the biggest improvement is the taming of pesky midrange peaks.

I would have to look it up. I've had them for about six years. For all I can remember, they have the same designation.
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I have no idea what driver you are referring to. The RS225 has been around for 20 years now. When these came out, there were no hifi Dayton woofers like there are today, save for the Euro series.
 
#48
wolf_teeth said:
I have no idea what driver you are referring to. The RS225 has been around for 20 years now. When these came out, there were no hifi Dayton woofers like there are today, save for the Euro series.
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Possibly he is referring to the RS225S? If memory serves, there were initially shielded versions of the RS drivers. I built an EBS tower with them some 20 years ago, and the required cabinet size was maybe 2x larger than the current rs225
 
#50
I would have to take one of the woofers out, and they are hanging from the ceiling.

I distinctly remember looking them up for specs, and Parts Express didn't list them for sale any more, but I was able to access the specs. They might be an older version for all I know. I also distinctly remember that some of the specs were a little different, and the frequency response graph is different. They look exactly like the 225-8 and are definitely the same series of Dayton woofers.
 
#52
@Pida

Do they have round frames?

@hifijim
Some test data of the early RS225 vs Silver Flute 8” vs others

https://web.archive.org/web/20141101050507/http://www.audioheuristics.org/measurements/Testing/Woofer2/8 inch woofer test.htm

This driver was internally referred to as “RS250 prototype” and was a prerelease sample of the what would be later as sold as the RS225. It was first model of what would later expand to include different sized drivers. It was 8 ohm, and had slightly more x-max than later (and current) releases. It had the bucking magnet, which some ultra DIYers removed @5th element
 
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#54
Fast Eddie D said:
Probably, and they do require a bigger cabinet. I really don't remember if it's Q or Vas or both that's different. I know I did equalize to work in the sealed cabinets. Plenty of xmax and they really hit hard.
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Okay, that makes sense. I was reading it like it wasn't an RS225 at all and was similar. Shielded version I would understand....
 
#55
The way I deal with truncated frames is to countersink them on the baffle using closed cell neoprene foam of same flange thickness. This way you only have to use with a razor blade to chase the basket outline and remove the traced material under the driver flange. The closed cell foam only causes very little FR ripple compared to open cell foam. The other options are rear mounting the driver or using a thin top mounted 1/8th inch baffle cover once the driver has been mounted using a simpler round countersink underneath. Laser cutting a decorative baffle is another option.after the drivers were top mounted.

I like the look of the higher density neoprene foam sheet on the front baffle.
 
#56
Visiton, Multicomp, and GRS had not been on my radar, so thanks for making me aware of those. I knew of Silver Flute and HiVi, but I was unsure of their reputation, so again thanks for confirming that these are viable options.

I am still in the very early stages of planning, so I only have a vague concept at this point for a compact active 3-way with an 8 inch woofer. This discussion has helped clarify to me what the potential woofers might be at various price points.

I probably need to start a new thread if I am going to discuss this project itself, rather than just low cost woofers...

j.
 
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#57
Again, I haven't used the MCM, but there are some people that consider them on equal footing to the RS225

From this thread https://diy.midwestaudio.club/discussion/1690/mcm-10-and-12-sleepers

"I highly recommend the MCM 55-5670 eight inch woofers. They are not good, they are VERY good. Normal price is just $39 (I got mine on sale for only $26). I personally feel they sound and perform better than the Holy grail Dayton RS225-8 drivers"
 
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#58
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#59
Some of us have been aware of that MCM 55-5670 8” woofer for a couple of years, (as well as the 6.5” one) but never seen independent measurements.

Apparently they have a copper in the motor and low Le, and healthy 7.5mm excursion based on traditional motor geometry (VC height - gap height)) / 2.
But the impedance at 20Khz is higher than the RS series.

It’s a bold claim that it as good or better!

I would like to see that woofer measured and compared to the Reference. Certainly the price is right.

@shrub0
Have you come across this driver? If/when you are planning another round of comparative testing please PM and perhaps I can have them drop shipped to you.
 
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