dual 8" bass bins driver suggestions??

Limited by about 9" cabinet width since I am placing my mains on top and SAF

Will actively cross to my mains around 200hz

Will also have a seperate dedicated sub in the corner for LFE effects
so SQ is the goal

If someone has a succesfull build to share I don't mind not re-inventing the wheel

Seems like the Dayton RSS210 might be a candidate with 2 in series

Thanks
John
 

18Hurts

Member
2010-11-21 11:20 pm
How deep can the woofer/sub be?

9 inches wide and I'm assuming about 30 inches tall or taller since you must be using a very small speaker that it needs a 200 Hz crossover.

Assuming you'll use 1/2 inch plywood, your "inside" box volume would be about 2.5 cubic feet after removing the driver displacement (external measurements of 9 W x 30 H x 19.2 D) If SAF is your thing, you might cut them down to 13" deep or around 1.5 cubic feet.

The largest sub you can fit in a box that narrow would be the Tangband W8Q-1071F which is an 8 x 12" subwoofer. Rated Fs of 27 Hz and you could use dual 12" passive radiators on either side of the cabinet and tune them to your room. (Don't forget the cross braces!)

The inner basket frame is 7.925 inches so it will fit if you use 1/2" braced plywood. Be forewarned it is a 4 ohm speaker so take that into account.

What kind of speakers are you using for the mains that require them to be crossed that high?
 
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9" w x 16" d x about 30" tall sounds right

That TB speaker is one I had not noticed and would fit but I wonder about the SQ versus the Dayton RSS210's

The TB has a huge rising impedance

I should've mention I have planned to "step" the sides of the bass bins
from 9" at top to 10.5" so I will have the inside width for any 8" woofer.

Is there any issue with series connection of a pair of 4ohm?
 
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18Hurts

Member
2010-11-21 11:20 pm
You have about 2 cubic feet to work with--the Dayton pair and single TB are very close! Fs of the Dayton is 28 Hz but drop it to 27 Hz for two of them which equals the TB. The TB sensitivity is 88 but a pair of Daytons is close at 86.5 (single is low 83.5 dB) Vas of the Dayton is 1.14 cubic feet each with the TB requiring 2.47 cubic feet.

The TB has a larger Xmax but a pair of Daytons make up for that. Kind of a coin flip between the two unless cost is a concern. TB costs $88 for one and a pair of Daytons is about $194. If you're going to run high power, the Daytons might be the ticket.
 

18Hurts

Member
2010-11-21 11:20 pm
If you're going to run sealed, go for the Daytons

The .50 Qts really wants a sealed enclosure with the TB .34 Qts wanting ported. Since the 2 cu ft size of your box, the smaller Vas for a pair of Daytons would work better in a sealed box.

In theory, the Daytons should head into the 20's IF they are in a 2.28 cu ft enclosure--you will "gain" that with about 2 pounds of fill. They handle a ton of power so a mild bass boost at 30 Hz of 3dB shouldn't hurt anything (unless you are hitting them at 500 to 1000 watts)

Since you have chosen car subwoofers, I'm assuming you will hit them with quite a bit of power so a stuffed and sealed cabinet should give you added protection although I'd use a filter set at 20Hz or so to conserve amp power and prevent overexcursion of the dual 8's.
 

bobhowell

Member
2008-12-25 9:02 am
I have been considering a similar project and am looking hard a the Kevlar Usher 8" driver. Also, Madisound has Aurasound 8" 4ohm drivers for $20 each. Four would give you two sets of bins with 8ohm each and lots of cone area. Both will fit in my 9"wide 33L boxes. Might work for you.
 
What interests me at Madisound on sale is the LAT 700 as it would fit a narrow bass bin, but I can't find any comments in the DIY community. And they are still more expensive than two 8" drivers, but look so cool..


"Tymphany LAT700 8/8 ohm Subwoofer

Stereo 8 ohm or wire in parallel for mono 4 ohm or wire in series for mono 16 ohm.

The LAT 700 has the power of two 12" subwoofers in a sleek tube shaped transducer."



Those 8" Aurosound don't look like subs



Don't call those those RSS210's a car sub or I might loose interest, looking for SQ no boom:)
 
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shameless plug for one of mikes designs -- sounds like it's exactly what you are looking for.

Reed Exodus Anarchy 25hz Tapped Horn - AVS Forum

It feels oddly sacrilegious correcting jbell on tapped horn matters, since much I know about TH's and other tapped resonators I learned from him.

However, as the OP already stated, I don't think this design will be good up to 200Hz (quite a high xover imo... is it a small fullranger on top?).

In my experience a TH will cover about 2 octaves. So, depending on how low you want to get, a TH might still be a reasonable option. Will only get down to 50Hz though.

At what frequency are you thinking about crossing over to your corner subwoofer? Or do you intend to run the bass bins all the way down, with additional subwoofer?
 

jbell

Member
2003-04-02 4:34 am
.
It feels oddly sacrilegious correcting jbell on tapped horn matters, since much I know about TH's and other tapped resonators I learned from him.

However, as the OP already stated, I don't think this design will be good up to 200Hz (quite a high xover imo... is it a small fullranger on top?).

In my experience a TH will cover about 2 octaves. So, depending on how low you want to get, a TH might still be a reasonable option. Will only get down to 50Hz though.

At what frequency are you thinking about crossing over to your corner subwoofer? Or do you intend to run the bass bins all the way down, with additional subwoofer?

Here's mike's 2pi measurements. Yea it's not ruler smooth from 100-200, but with a 150 cross on the sub to tame the 150-200 peak, and a 200cross on the tops, should be very acceptable.
Anarchy%20TH%20SPL%20and%20THD.jpg


A tower with 4 mcm 55-2421 would also be a cheap option, although not ruler flat to 30 hz like mikes design....
 
I plan to run the bass bins with active crossover around 200hz to make my stereo pair full range. Corner sub is to add low effects only for HT

Not totally satisfied with the bass from my standmount speakers which are otherwise wonderfull, So I'm making them 3 way

Right now I am just running them as small and using my HT reciever to crossover to a pair of home brewed mono subs under the standmounts but the current subs are based on 2-12's with 15" wide cabinets and are not found to be attractive, hence the mandate to build something no wider than my standmounts

I own all the amps and crossovers so just need to pick the best 8" woofers
 
Right now I am just running them as small and using my HT reciever to crossover to a pair of home brewed mono subs under the standmounts but the current subs are based on 2-12's with 15" wide cabinets and are not found to be attractive, hence the mandate to build something no wider than my standmounts

Are you standmounts exactly 9 inches wide? From a proportion and aesthetic point of view, the bass bins should be slightly wider than the width of the speakers sitting on them, to give a good proportion of larger base and stability. Unless you are shooting for a parallel sides look where everything is the same width from the top to bottom. Would also gives you a bit more volume to work with for the bass bins.