Ported Sub to Tapped Horn. Few questions before starting

[Viennatom_new]

Hey - great idea if you are using batteries to store sun energy. So you are independent on the power net. But I can't really see why one would need to use "turntables" in the 21st century, the century of CD, MP3 and Internet streaming etc..

 

[freddi]

THAM12 RCF MB12N351 - 40V hits xmax - nice little cabinet

 

[suparub]

freddi, always here. Thx u so much again you make me save a lot of time with the learning curve of the app.

 

[freddi]

here's the comparison you wanted - that 15 has 9mm xmax vs 5,5 for the 12, not onsidering heating effects and compression

 

[suparub]

ok the comparison was more between this mb12n351 in a sealed enclosure vs it in a THAM12 (but also very interesting comparing the 2 types of drivers in the THAM series)

 

[freddi]

sorry about that - here's that RCF 12 in THAM12 vs a one cubic foot sealed box

 

[suparub]

king (really) ! And to finish in beauty, here my decisive question before building the boxes / choosing the drivers :

Alright, I am now debating on the choices of the mid-range drivers. Regarding the fact that I'm interested only in the frequency range from 150Hz to 1Khz, which driver will sound louder in this range ? I'm curious how to do the calculations in advance instead of going to a shop. I know also that the sensitivity is per Watt, but I also know that most of the Watts are needed for the low frequencies (which I will not use in this case). No problems about the amplifier, it has much enough juice to power them both (I'm applying a limiter on my dsp in order to not burn the drivers)

- RCF MB12N351 - 12" Mid Bass 99 dB sensibility / 650W RMS
- RCF MR10N301 - 10" Sealed Basket 102 dB sensibility / 300W RMS

As don't plan to use the MB12N351 for bass frequencies, I still wanna figure out if they will sound louder in the midranges than the MR10N301. Hope I'm not too much off topic from the original post ^^

 

[freddi]

looks to me that midrange using an active 300Hz 4th order highpass, would handle 40 volts peak to hit its 1mm xmax. Can THAM12 work well to 200Hz?

btw, I had to fudge Vas vs the 2 liter published figure to get their mmd

The passive filter is "off" in the first and second pictures. "On" in the third where it gives a bit of "boost" from pulling
the impedance down. With that particular passive filter, the excursion is ~2.3mm @210Hz @40v input.

Which amplifiers are you going to use? I'm curious about battery power for a party.

 

[suparub]

looks to me that midrange using an active 300Hz 4th order highpass, would handle 40 volts peak to hit its 1mm xmax. Can THAM12 work well to 200Hz?

Pm for the amp Havent mention that I want to compare the MB12 in a sealed box, not in a THAM12

 

[freddi]

explain what you want compared and I'll try to simulate it.

In the US, Eminence's 10" sealed back midrange is inexpensive. It has a high qtc, and less motor than the RCF - but still could be useful

 

[suparub]

explain what you want compared and I'll try to simulate it.

You are right, Im not accurate enough. So I want to compare, at 600W power and between 150Hz and 1,5Khz frequency range :
1 x MB12N351 in a sealed enclosure with a volume of ~ 20 Liter
1 x MR10N301 with no enclosure (doesnt need it)

In a less technical way, I wanna know which one sounds louder giving the same juice.

 

[freddi]

the 10" is a bit louder - but at 600 watts nominal drive, its 1.4mm Xmax is exceded below ~500Hz when using a 4th order 160Hz highpass filter. The 12" woofer with 5.5mm spec is "ok" although that's a lot of cone movement. In practice Ik doubt if 600 watt peaks would be there but I'm ignorant as to PA work.and speakers in general. FWIW I think the 12" midbass looks better for this application.

(I thought its xmax was 1mm - still 1.4mm is hit around 400Hz)

maybe 2 less expensive speakers in parallel could outperform these (?)

 

[suparub]

perfect, thank x 1000. Yeah I plan to use one ot these drivers in pair and in //

 

[suparub]

Also, I was wondering : can i use the ROAR designs with a midbass driver and hope to cover the frequency range from 40Hz to 1Khz with only one enclosure / driver or it's too risky ?

I saw that THAM is not an option in this fashion, but the ROAR seems to be "linear in it's variations" from 300Hz. There is "only" this drop between 170Hz-250Hz that concerns me at my level

 

[suparub]

Lastly, would it be possible to compare the RCF LF15N401 - 15" Woofer in a vented / bass reflex enclosure (with the volume giving the best SPL) vs a THAM15 ?

I really need to learn Hornresp !

 

[suparub]

Any help ?

The idea is to put in parallel two same drivers in two different enclosures in order to get both :
- powerful bass frequency on the tapped horn enclosure
- a linear curve from 200hz to 800hz in the vented/closed enclosure

Is this a good idea ?

Thanks again !

 

[suparub]

Hi again I answered myself and decided to stay for now with a vented enclosure and a 2 way system and with this design (even if I will build this THAM15 at some point !) : http://www.lean-business.co.uk/SPEAKER_PLANS/CIARE 15.00 SW DUAL REFLEX.pdf

Regarding the drivers, I hesitate between these two as the main goal is to get the most linear response from 40Hz to 800Hz :
RCF LF15N401 - 15" Woofer
RCF MB15N401 - 15" Mid Bass

Problem is Im getting 2 different sims when I design the enclosure on BassBoxPro and WinISD
freddi maybe you can help me this ? I wanna send 800W and don't know if I should listen to BassBox (and go with the MB15N401) or WinISD (and go with LF15N401 as the difference between the 2 drivers is not significant)




Thanks !

 

[weltersys]

I wanna send 800W and don't know if I should listen to BassBox (and go with the MB15N401) or WinISD (and go with LF15N401 as the difference between the 2 drivers is not significant)

Compare output levels at Xmax- comparing woofers and midrange drivers without considering the linear output won't give you much useful information.

 

[suparub]

Compare output levels at Xmax-

on BassBoxPro, everything is ok over 40Hz and at 850W


green = lf15n401 (Xmax = +-8)
blue = MB15N401 (Xmax = +-6)



So is the custom amplitude right ? Why WinISD is giving me something different ? Dunno who to trust ^^

 

[GM]

Time to learn Hornresp .

GM