Hi everyone,
I made an account here after being a long time lurker.
I have a problem in that i am trying to create a sub enclosure for an SP-400HT and can't find a lot of info. The info that i find, i don't know if it is correct, but is as follows:
Impedance: 8 ohm
1 W / 1 m: 98 dB
fs: 21 hz
Vas: 410 l
Qms: 6.55
Qes: 0.25
Qts: 0,24
Re: 6,4 ohm
Sd: 855 cm²
Le: 1,6 mH
Rms: 1,7
Mms: 85 g
B * l: 16.9 Tm
When i give this in winisd, i get an enclosure of around 100L but the -3db is above 50hz 😱
Right now it is in an old enclosure i made when i was a teenager, around 140L and two short big ports, really not optimal, but it was on a serious budget 🙂
But it plays... not bad, and certainly lower than 50hz -3b, it goes down to 30hz pretty easily.
Maybe this is a sub made especially for PA and thus doesn't get really low?
I was wondering if someone with more knowledge here could help me out, thanks in advance! 🙂
I made an account here after being a long time lurker.
I have a problem in that i am trying to create a sub enclosure for an SP-400HT and can't find a lot of info. The info that i find, i don't know if it is correct, but is as follows:
Impedance: 8 ohm
1 W / 1 m: 98 dB
fs: 21 hz
Vas: 410 l
Qms: 6.55
Qes: 0.25
Qts: 0,24
Re: 6,4 ohm
Sd: 855 cm²
Le: 1,6 mH
Rms: 1,7
Mms: 85 g
B * l: 16.9 Tm
When i give this in winisd, i get an enclosure of around 100L but the -3db is above 50hz 😱
Right now it is in an old enclosure i made when i was a teenager, around 140L and two short big ports, really not optimal, but it was on a serious budget 🙂
But it plays... not bad, and certainly lower than 50hz -3b, it goes down to 30hz pretty easily.
Maybe this is a sub made especially for PA and thus doesn't get really low?
I was wondering if someone with more knowledge here could help me out, thanks in advance! 🙂
The Qts is a little on the low side, but you should be able to use a bigger box and tune lower to get more LF extension.
Going too far results in a peaky alignment, but a gentle slope down before the LF rolloff is okay.
Chris
Going too far results in a peaky alignment, but a gentle slope down before the LF rolloff is okay.
Chris
Thanks Chris for your reply, how big would you go on this without making it too "laggy" and inefficient? Size is not really a concern, i have a decent sized room for it.
Thanks,
Steven.
Thanks,
Steven.
If you got room for a large 6th order bandpass then this would give you 97 dB/w/m response at 20 Hz plus room-gain (which can add upwards of 10 dB under the right conditions). The large midbass peak will compensate for the increasing room gain in the deep part of the bass spectrum, and it will add a good physical punch to all midbass. Great for hometheater explosions and such.
An adventure with 8th order BP
Se Grecs build in the thread linked to above for a possible layout.
An adventure with 8th order BP
Se Grecs build in the thread linked to above for a possible layout.
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Thx Circlomanen,
My experience with bandpass is somewhat limited, but i was under the impression that it is somewhat laggy and, as you said, peaky on a specific frequency, making it somewhat boomy.
But I will certainly look into this 🙂 thanks!
Is it possible to not have this delay when dealing with bandpass? and the reason you don't see many commercial bandpass systems, does this have to do with its size?
Sorry for all these questions 🙂
Best regards,
Steven.
My experience with bandpass is somewhat limited, but i was under the impression that it is somewhat laggy and, as you said, peaky on a specific frequency, making it somewhat boomy.
But I will certainly look into this 🙂 thanks!
Is it possible to not have this delay when dealing with bandpass? and the reason you don't see many commercial bandpass systems, does this have to do with its size?
Sorry for all these questions 🙂
Best regards,
Steven.
Hi Steven, all
Your numbers, T/S parameters don't make sense. From where did you take them? To light a cone(?) and a very low frequency and BL don't seem correct. Actually there must be a problem with fine measurement of the t/s parameters for a correct alignment and dimensioning.
Your numbers, T/S parameters don't make sense. From where did you take them? To light a cone(?) and a very low frequency and BL don't seem correct. Actually there must be a problem with fine measurement of the t/s parameters for a correct alignment and dimensioning.
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Check out the Devastators over on avsforum.com. They all have similar curves to Circlomanen's model for the exact same reasons he stated, "The large midbass peak will compensate for the increasing room gain in the deep part of the bass spectrum, and it will add a good physical punch to all midbass. Great for home theater explosions and such." RedFive is constantly modeling new versions. Your 15" should work in 1 his enclosures.
Hi Inductor,
Do you want me to measure the height of the surround? Thats what that R looks like to me.
Also, i took them from a german forum somewhere, i might be able to find it again. Also there it appears there are 2 versions of this woofer, the ones in your attachment don't match mine. Mine is more orange, not yellow, and the back is different sticker. I made an attachment with picture.
@BP1Fanatic, yea will do! thanks 🙂 I guess latency doesn't really matter that much for movie content 🙂
Do you want me to measure the height of the surround? Thats what that R looks like to me.
Also, i took them from a german forum somewhere, i might be able to find it again. Also there it appears there are 2 versions of this woofer, the ones in your attachment don't match mine. Mine is more orange, not yellow, and the back is different sticker. I made an attachment with picture.
@BP1Fanatic, yea will do! thanks 🙂 I guess latency doesn't really matter that much for movie content 🙂
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Right you are! 😉
In the same thread as those posted above: Boxenvolumen, Unterschied von 30 Liter was stimmt nun?, Lautsprecher - HIFI-FORUM posts # 7, 8:
From a 1999 Monacor catalog and at least closer to reality based on Mms, BL in that they line up near enough perfect with T/S, though with a very low 760 cm^2 [Sd] [typo?] makes me wonder if it's the same driver, so agree for the need to check [Sd] :
GM
This peak in frequency domain affect phase and is near crossover frequency. System has to be considered as a whole. It make crossing harder, how much, and how important it is depend a lot of hardware. It's a compromise I would do for my computer monitors since it's easy to deal with filter with computer. But not for my audio system.
This peak can compensate for a low-mid way that lack of juice. It's no more only a "subwoofer", but a low-mid helper that will start to get localisation and placement issues, while it will probably get mono signal.
Circlomanen promote really interesting projects with this kind of curve. It took me some time to understand that i wasn't agree with him only because he answer with this specific case target in mind, to every case here.
A bit off-topic, about room gain, i don't remind having read anything about it effect on phase. Do someone have some reading to point me ?
Check out the Devastator threads. They are all using amps with built in dsp or using Mini DSP for time alignment.
Thanks Inductor for your time on this 🙂
So in the second piece are the correct numbers you get with my measurements.
Is there anything else i can do to make this more precise, what data can i provide? 🙂
I could try to do a sweeptest, tho only mic i have is one from the setup of my AV receiver.
If anyone could point me to a good program, if this would be at all helpful, thanks.
best regards,
Steven.
So in the second piece are the correct numbers you get with my measurements.
Is there anything else i can do to make this more precise, what data can i provide? 🙂
I could try to do a sweeptest, tho only mic i have is one from the setup of my AV receiver.
If anyone could point me to a good program, if this would be at all helpful, thanks.
best regards,
Steven.
You are very welcome.😀
Your measurements should be pretty fine close to the originals it gave me about Sd: 840 cm². The same original numbers should be used by the persons that measured the first time and the second time to give the same results that I doubt so far, then Sd: 855 cm².
After all this is the only measurement we have that was verified and checked...
The second one was an impedance test/measurements and also then T/S parameters.
I make the impedance test with a German software and CD (or DVD) for the 20Hz to 20kHz frequency sweep. You can use also the PC.
Links1 Software > Speaker Design : Comprehensive list of Recommended Design Tools
Links2 Dayton Audio DATS V3 and software link from PE
Links3 Dayton Audio DATS V3 from Amazon
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