budget musical sub

[littlemike]

So on balance,

the whole thread taken into consideration,

a compromise arrived at in view of everyone's input regarding my aims,

it's two NHT Foster amps and a pair of the peerless 10 inchers listed from PE assembled into a pair of sealed subs that, discounting the cost of wood and labor (since I already mentioned that twice now anyway) will bring me in under 150 for pretty much the most B for the B that can be had for low level, pure and simple, subterranean tonal satisfaction.

Am I close yet?

I'd love to enter the credit card numbers tonight and hit 'send'.

Sounds reasonable to me.

 

[peace brainerd]

then let me rephrase this just slightly..

Given that the Foster plate amp is presently a good value and that I'd like to, for simplicity's sake (I don't have a great deal of measuring equipement or expertise) go sealed,...

...what is presently the best >80USD driver available from any of the popular vendors to pair it with? Again, for anyone that has not read the whole thread...

this is for low spl, pure music, no HT, in an average (15w x 25l x 10h) living room?

 

[littlemike]

"Best" is such a subjective word. I do not know what is best for you. Honestly - I do not even know what is best for me, I have not found it yet (and I doubt I ever will).

The Peerless SLS 10 is a good driver, an excellent choice given the price. Shipping is free if you buy two.

I would consider running the two cabinets in parallel off a single amp, there is really no need for two amps unless you want another set of knobs to fiddle with.

 

[peace brainerd]

Ahh littlemike. I mentioned philosophy, but let's not take that seriously. I'm not impractical. Some amount of cash will certainly find the "best". But what fun would that be? There simply must be some stellar, stamped frame, respectable excursion, solidly constructed, rubber or pleated surrond, <80USD driver out there with sub duty TS parameters going for it.

What's a very good 12inch subwoofer that will mate up well with that Foster amp in a closed box for low level pure music?

Could someone describe a range of TS parameters I should be targeting for this particular approach? Does that Peerless 830634 10" SLS Woofer fit the billl with its.....
steel frame with generous ventilation and minimal airflow restriction; chamfered edge minimizes diffraction effects. 1-1/2" two-layer copper voice coil with 1" winding. Parameters optimized for equalized sealed enclosures. Buyout, limited quantities. Specifications: *Power handling: 110 watts RMS/220 watts max *VCdia: 1-1/2" *Le: 2.1 mH *Impedance: 8 ohms *Re: 6.7 ohms *Frequency response: 36-4,000 Hz *Fs: 36 Hz *SPL: 89.5 dB 1W/1m *Vas: 2.58 cu. ft. *Qms: 2.80 *Qes: 0.65 *Qts: 0.53 *Xmax: 8.5 mm *Dimensions: A: 10-3/8", B: 8-7/8", C: 5-1/4".

 

[Pallas]

So on balance,

the whole thread taken into consideration,

a compromise arrived at in view of everyone's input regarding my aims,

it's two NHT Foster amps and a pair of the peerless 10 inchers listed from PE assembled into a pair of sealed subs that, discounting the cost of wood and labor (since I already mentioned that twice now anyway) will bring me in under 150 for pretty much the most B for the B that can be had for low level, pure and simple, subterranean tonal satisfaction.

Am I close yet?

That sounds good. Then the two subs could be repurposed as secondary subs when you upgrade, with a bigger sub going in the corner.

Thanks for the input. Size constraints are somewhat limiting, but with some imagination... maybe the sub box could be a stand for the Fonkens.

Bad idea. Placement that's good for mids/highs is invariably awful for bass. Better to put the mains where they work best, and the subs where they work best.

Ahh littlemike. I mentioned philosophy, but let's not take that seriously. I'm not impractical. Some amount of cash will certainly find the "best". But what fun would that be? There simply must be some stellar, stamped frame, respectable excursion, solidly constructed, rubber or pleated surrond, <80USD driver out there with sub duty TS parameters going for it.

Here's one: Peerless SLS12.

Madisound appears to be a little more expensive, but in stock: Peerless SLS 830669 - 12" Woofer - Coated Paper Cone from Madisound

I don't know of anything in the same price range that is comparable.

Could someone describe a range of TS parameters I should be targeting for this particular approach?

Basically look for three things:
1) High xmax
2) Ratio of Le/Re of 1/2 or better.
3) Something in the specs indicating the presence of a shorting (Faraday) ring in the motor.

If those all fit, then you can add EQ later to tailor the ULF to taste.

 

[littlemike]

In all honesty, I think you'd be hard pressed to do much better within that price range. If one driver does not seem like it will be enough, use two, you're still under $80 for the two. You can always turn it down.

As far as displaced air/dollar, the SLS 10 is really hard to beat. It has the right parameters for a simple sealed enclosure. It is cheap. It is a Peerless driver, typically they are of relatively good build quality and have reliable specs.

Did I mention it is cheap?

The next level driver so to speak adds a significant digit to the price. In your range, you've got some good stamped-frame drivers and a lot of junk. The list really is pretty short. Not counting the car drivers, I saw 5 12" subs at PE under $80. One is the 12" SLS. The only other ones I'd consider are the Daytons and only if the SLS was not available. The rest are not worth the effort. The 10's are similar, with the addition of a Tang Band. At only 85 dB with one watt input, the TB is not efficient enough, so my recommendations would be the buyout SLS, the regular SLS, then either of the two Daytons, and only if the SLS were not available. Do I sound like a broken record yet?

Did I mention it is cheap?

Seriously, the buyout 10" SLS is 1/2 the price of anything comparable.

That means you can buy two (or four...)

 

[AdamThorne]

Thanks for the input. Size constraints are somewhat limiting, but with some imagination... maybe the sub box could be a stand for the Fonkens.

How's the weather in MN??? It was below zero in Bismarck this morning.

Oops, sorry mikje, just to let you know you commented in while I was composing. I was intending to be speaking to svejkovat. I'm afraid I don't know anything about your radio shack drivers. The info I threw out was for the peerless SLS10 drivers. I'm sure the Foster plate amp would be capable of doing them justice though.

Brisk here this morning, about 10 degrees. Looking forward to getting some snow, they say maybe tuesday and wednesday. It'll probably slide south and east of us though, like everything else has for the last couple years...

 

[peace brainerd]

littlemike, at the risk of sounding like I want too much for too little....

(wait a sec, that's exactly what I want! Otherwise why work this hard at it?)

...what I would be looking for in the 830634...

Parts-Express.com: Peerless 830634 10" SLS Woofer | Peerless P830634 10" driver SLS Woofer subwoofer bass mid midbass mtm 2-way Tymphany genelec 342-6001 2-way 3-way midrange mid vifa studio monitor active
Specifications: *Power handling: 110 watts RMS/220 watts max *VCdia: 1-1/2" *Le: 2.1 mH *Impedance: 8 ohms *Re: 6.7 ohms *Frequency response: 36-4,000 Hz *Fs: 36 Hz *SPL: 89.5 dB 1W/1m *Vas: 2.58 cu. ft. *Qms: 2.80 *Qes: 0.65 *Qts: 0.53 *Xmax: 8.5 mm *Dimensions: A: 10-3/8", B: 8-7/8", C: 5-1/4".

...is a driver for subwoofer application with the only compromise being the ability to dance party or recreate dinosaurs thundering through my attic. In other words, I'd like a driver to be able to to reproduce, albeit at low spl, most of the information that might be available in my (wide genre) music collection.

The 880634's brother at PE, the 830668, actually advertises itself as a subwoofer (oops, so does the 880634 now that I look closer)

Parts-Express.com: Peerless 830668 10" Paper Cone SLS Subwoofer | Peerless SLS 830668 10" Subwoofer bass woofer XLS Nomex Cone speaker lf Driver shorting ring copper cap tymphany09
Specifications: *Power handling: 110 watts RMS/220 watts max *VCdia: 1.5" *Le: 3.3 mH *Impedance: 8 ohms *Re: 5.6 ohms *Frequency response: 33.3-2,000 Hz *Fs: 33.3 Hz *SPL: 88.7 dB 2.83V/1m *Vas: 2.44 cu. ft. *Qms: 4.85 *Qes: 0.57 *Qts: 0.51 *Xmax: 8 mm *Dimensions: A: 10.35", B: 8.82", C: 4.85".

Is the 830668 worth the extra 14 dollars (pretty insignificant difference all considered)? Or are these drivers pretty much neck and neck in a sealed sub?

Le/Re is a better ratio on the 830634 with slightly more xmax, but the 830668 seems to have a slightly better (lower) freq response and Fs. Are all these too close to matter? Do they share the same motor structure? Is a Nomex cone anything to get hot and bothered about? (rimshot)


Thanks so much all of you for entertaining these questions.

 

[peace brainerd]

Hey, doing a diyaudio search for the 830668 I discovered a link to a downfiring sealed sub design by Linkwitz for use with his Pluto speakers. Guess that's endorsement enough for the quality this driver might be capable of?

 

[mikejennens]

Hey, doing a diyaudio search for the 830668 I discovered a link to a downfiring sealed sub design by Linkwitz for use with his Pluto speakers. Guess that's endorsement enough for the quality this driver might be capable of?

svejkovat,
I Googled the Peerless driver, but didn't find the sub design to which you're referring. Can you post a link or details?
Thanks,
Mike

 

[gibbed]

I suggest a 38 hz tapped horn, as seen here:
http://www.diyaudio.com/forums/subwoofers/155219-38-hz-tapped-horn-volvotreter.html

(mine is on page 2)

 

[peace brainerd]

Certainly,

Pluto + subwoofer

Whew!! Reading Mr. Linkwitz' webpages is not for the faint of heart. The attention to detail is a little forbidding to the novice. It challeges any assumption I might have of integrating a sub with any ease.

To lighten the demands on the woofer/midrange driver a 100 Hz crossover frequency would be necessary with a LR4 acoustic filter response. The relatively high crossover frequency then requires that the radial distances from each subwoofer and tweeter to the listener should differ by less than 2 feet (60 cm).

An impedance measurement of the driver in the sealed box can yield the the important parameters f0 and Q0 for the 2nd order electro-mechanical filter that controls the acoustic highpass response at low frequencies. In this case f0 = 74.3 Hz and Q0 = 1.57 as calculated by using the formulas in f0Q0.gif.

To extend the low frequency response these two parameters will be changed to a target of fp = 20 Hz and Qp = 0.5 by using a biquad equalizer. Values for standard components are calculated by using the pz-eql.xls spreadsheet.

R1 = 5.62k, R2 = 1.96k, R3 = 75k
C1 = 1000 nF + 390 nF, C2 = 100 nF, C3 = 100 nF
which gives
f0 = 76 Hz, Q0 = 1.59, fp = 21 Hz, Qp = 0.49
Adc = 22.2 dB

some of the low frequency content of the input signal must be shifted away from PLUTO so that it is reproduced by the subwoofer instead. This task is not as straight forward as it may seem, because PLUTO's acoustic low frequency response is that of a 2nd order highpass filter with -3 dB corner at 60 Hz. Cascading this filter with any standard 100 Hz electrical crossover filter highpass section will not result in a 100 Hz acoustic crossover. PLUTO's response determines the missing electrical filter response, that when added leads to the desired LR4 acoustic crossover response. The block diagram of the w-ASP shows the necessary circuit elements for crossover filters and equalization of both PLUTO and its subwoofer PLUTO+.

To obtain the desired 100 Hz LR4 acoustic crossover behavior for the subwoofer it is merely necessary to cascade an electrical LR4 lowpass filter (U4) with the biquad equalizer (U5B). The LR4 acoustic highpass filter for PLUTO, though, requires more effort since that speaker's low frequency response has a 2nd order roll off below 60 Hz. This must be equalized - again with a biquad (U2A) - to become an acoustic highpass with fp = 100 Hz and Qp = 0.7 to form one of the two LR4 crossover highpass filter stages. The other stage (U1B) then uses the standard electrical LR4 filter topology.

R1 = 10k, R2 = 16.2k, R3 = 3.48k
C1 = 330 nF + 390 nF, C2 = 100 nF, C3 = 1 uF + 1 uF

The complete 100 Hz LR4 electrical highpass filter for PLUTO is shown below. Together with subwoofer equalization and lowpass filtering it can be easily implemented on the w-ASP printed circuit board. The pcb has a general topology that makes it useful for any woofer and its crossover.

Holy $hit. So much for slapping the 10" peerless inna box and wiring up the ol' Foster amp, eh? Or is this Nth degree of perfection just that? An Nth degree that won't be too great a loss to most of us? The quotes above certainly do some abuse to the suggestion by AdamThorne earlier in this thread that...

Another reason you might not see a lot of write ups on builds like this is that there isn't much to doing it.

With respect to AdamThorpe, I do understand what he's saying actually. And I hope that it indeed turns out to be the case... in this case.

And with regard to Mr. Linkwitz, it's extremely encouraging to see that this thread has led to his doorstep. I believe that with regard to the criteria I've described above for my personal subwoofer requirements, he seems sympathetic. That's not bad company.

 

[AdamThorne]

The quotes above certainly do some abuse to the suggestion by AdamThorne earlier in this thread that...

With respect to AdamThorpe, I do understand what he's saying actually. But then again.....

Well, to be fair, the Pluto+ subwoofer is not exactly your average budget sub...

 

[littlemike]

littlemike, at the risk of sounding like I want too much for too little....

(wait a sec, that's exactly what I want! Otherwise why work this hard at it?)

- SNIP -

Is the 830668 worth the extra 14 dollars (pretty insignificant difference all considered)? Or are these drivers pretty much neck and neck in a sealed sub?

Le/Re is a better ratio on the 830634 with slightly more xmax, but the 830668 seems to have a slightly better (lower) freq response and Fs. Are all these too close to matter? Do they share the same motor structure? Is a Nomex cone anything to get hot and bothered about? (rimshot)


Thanks so much all of you for entertaining these questions.

For what you initially described, they are functionally identical. Between these two, I would choose based on price. Both drivers will work fine, but if I can buy 2 for the price of one, I'll choose the cheaper ones.

As far as the complexity - Linkwitz's stuff is exceptional, but certainly would not be described as either "simple" or "budget". It is possible to complicate anything if one tries hard enough. It is also possible to simplify things to the point where they lose value. You can make things as simple as, or as complicated as you'd like. Personally, I'd start simple.

"Make everything as simple as possible, but not simpler."
-- Albert Einstein

"Any fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
-- Albert Einstein

 

[littlemike]

BTW - since the internet may not catch my tone - I meant no offense to anyone with those quotes.

Einstein was a far, far smarter man than I, I occasionally find guidance in his quotes.

Back to your regularly scheduled discourse.....

 

[badman]

Just a heads up, since this is budget oriented: Zalytron has a very nice sale on their inexpensive sub drivers.

Zalytron

 

[Pallas]

Is the 830668 worth the extra 14 dollars (pretty insignificant difference all considered)? Or are these drivers pretty much neck and neck in a sealed sub?

The only thing that might make the stock model "worth more" than the Genelec buyout is that if it breaks it's a stock model, so you can replace it with the exact same thing. But then again, sealed subs are fairly tolerant, and they do use the same basket/screw hole locations, so if you buy the 38 dollar one and it breaks, replacing it with the stock model will be just fine.

So in short, buy the cheaper one while they're still out there.

Do they share the same motor structure?

I haven't compared coil lengths, but for simple cost reasons one would expect them to share a motor structure. The Genelec buyout might have a slightly different cone/coil/surround, but for subwoofer use that's not a big issue.

Is a Nomex cone anything to get hot and bothered about? (rimshot)

No. Well, maybe if you build your box out of metal and your house catches on fire.

 

[BP1Fanatic]

This looks looks REAL nice for $15.00 a piece on sale!
Zalytron Model #800PL, 8.0 in, 7.88 ohm, fs = 32hz .QTS = .45, VAS = 55 liters, Xmax = 7.9mm, stamped basket, rubber surround, 88 db @ 1w/1m, List = $45.00.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[TheSeekerr]

Pluto + subwoofer

EDIT: Oops, for some reason my browser didn't load the second half of the thread, so I'm a bit behind the times!

 

[mightydub]

I put this 8" Dayton subwoofer Parts-Express.com: Dayton RSS210HF-4 8" Reference HF Subwoofer 4 Ohm | subwoofer Rss210hf-4 8" subwoofer dayton reference rs sub dayton loudspeaker in a sealed cube 12" on a side, double thick front, with a homebuilt plate amp and crossover/EQ. I got the driver for $80 when PE had it on sale. EQ was necessary because of the small sealed box, it does the job very nicely. Has enough oomph at the low end to scare the cat when watching movies, though my main use is for bass extension for a pair of homebuilt small 2-ways.