Pairing Drivers and Rest !

[Froggy T]

Hi and good day to all DIyers of HFV.
For some good quality time I have been lurking around this forums DIY section keenly reading almost all threads with vast detailed posts. But somehow I felt that there is something missing for noobs who want to make their own stuff ( speaker for start ) as things go too much technical or are plain simple disheartening for excited first timers. So I would appreciate if technical inputs are kept simple or basic so that layman can understand it.

Stage one : Driver pairing

Need few advice for pairing different speaker drivers with each others that can have impact of final sound quality ( taking liberty to discard XO at this stage ) of speakers of different basic material for cone/domes like silk/aluminum/ferrite tweeter with paper cone or kevlar mid/woofers.
Drivers are from same manufacturer namely Peerless India and will be sourced from Jeetubhai Sir ( Mumbai ).

So here is my list of driver choice which I have selected :

1. M13NH 5.25 Paper cone Midbass/ Woofer

M13NH 5.25 Paper Cone T/S Parameters : Company Measured @ 1-4K Hz Freqs of Main (free air ) Only.

RMSE free - 0.93 Ohm
Fs - 69.54 Hz
Re - 3.25 Ohm
Res - 21.34 Ohm
Qms 2.76
Qes - .42
Qts - .36
L1 / L2 - 0.15 / 0.43 mH
R2 -3.76 Ohm
Vas (SD) 7.77 Liters
Mms(SD) 8.55 gms
Cms(SD) 612 uM/Newton
BL(SD) 5.37Tesla-M
SPLref (SD) 89.8 dB(Re)
Aub Index 0.00
Method: fixed-Mmd ( 8.038 gms )
Area(SD)- 95.05 sq cm


2. M13KH 5.25 Kevlar Midbass / Woofer


M13KH 5.25 Kevlar T/S Parameters : Company Measured

RMSE free 0.49 Ohms
Fs 58.97 Hz
Re 3.44 Ohm
Res 67.61 Ohm
QMS 8.15
Qes 0.41
Qts 0.39
L1 / L2 0.17 / 0.27 mH
R2 5.76 Ohm
Vas (SD) 10.76 Liters
Mms (SD) 8.59 gms
Cms (SD) 848 uM / Newton
BL (SD) 5.14 Tesla-M
SPLref (SD) 89.1 dB(Re)
Rub Index 0.01
Method Fixed-Mmd -8.07 gms
Area(SD) 95.05 sq cm
DCR Mode : Fixed 3.44 Ohm


3. Tweeter TL25AN 1 Aluminum
http://diyaudiocart.com/Raw%20Drivers/Peerless%20Fabrikkerne(I)%20Ltd./Peerless-25mm-Aluminum-Dome-Tweeter-TL25AN

4. Tweeter TL25SN 1 Silk Neo low fs
http://peerlessaudio.com/prod_details.asp?id=130

5. Tweeter TL25SG - 1" Ferrite low fs
http://www.peerlessaudio.com/prod_details.asp?id=134

For starter I have used company provided T/S parameters to select drivers for basic 2 way BS or 3 way FS. As time goes on based on suggestions of forum members about + / - ves of each drivers with intended XO at around 2.5K-3K ( approx not confirmed so open to discussion ) i will measure parameters after i get hold of drivers based on published T/S values( taking 10 deviation either side from company measured T/S values ).


I would really like to keep this thread in Stage Format with regular updates of suggestions for making speaker for first timers like me.

This is my first thread in fact first ever post so kindly pardon me for any mistakes.
Eagerly waiting for replies.

Thanks !

 

[soundnovice]

performance of M13nh and m13kh are proven to be good sounding (otherwise why would Hari select them for krypton audio TLs!!). m13nh is believed to be similar/copy of to G R research's m130 midbass(both models are manufactured by Peerless India only). both low Fs silk domes are preferred in general over metal domes, as low Fs tweeters can be crossed low(so freedom to chose lower xover point). chosing lower xover point will required higher value inductor but at the same time allows better/more spacing between the drivers.

 

[grubyhalo]

I'd probably consider reading this thread fully to understand drivers and crossover designs. It was not the easiest of reads if you do not understand the basics, but this is the easiest tutorial that made sense to be a little...

 

[Froggy T]

Soundnovice - Thanks

Yes i checked GR research's M130 model which i guess is manufactured by Peerless India and by further reading MTM build of FM Antony i guess M13NH is good to go but my main query was which tweeter to pair with either kevlar M13KH or M13NH.

Aluminum based TL25AN has Fs in sub 700Hz and TL25SN ( silk dome ) has somewhat in 850-900 Hz.
What really confuses me is that will metal tweeters work best with paper or kevlar woofers or should i go with silk dome/ferrite based tweeters.

Will most probably use 2 order XO at Fxo ~ 2.5K-3K Hz region if possible may be further lower in 2k Hz.

Grubyhalo - Thanks for link , it was very first tutorial that read .

 

[soundnovice]

i am using TL25SG and they are good. have tried crossing at as low as 1600hz! both silk and metal domes will match well will paper or kevlar mids but chosing correct xover point is very important. any midbass of size 5.25" would be good to be crossed at less than 2khz although they have flat response until 5khz. in most of the datasheets what they dont publish is the distortion graphs! so to be on the safer side crossing as low as possible would be a good idea. 1.8k or 2khz seems to be an optimized point for m13nh or m13kh.

 

[Froggy T]

thanks soundnovice


So went ahead and purchased M13NH along with TL25AN06 ( Low Fs ) as wanted to keep cost little low considering hunt for XO parts will burn 40-50% of total system budget and this being my 1st experiment so I am happy to have solid drivers to play around.

Stage 2 :Enclosure Type

My initial plan is to make TMM or MTM bookshelf with total volume of box being near about 20 Liters with height being about ~18-20 inches and keeping Fbox to 54 Hz.( Just like that number so not finalized yet about box freq but that is target I am aiming for )

I read that MTM sounds better than TMM which is famously documented as DApolitto configuration but almost 90% commercial consumer grade FS I see in market are in TMM configuration ..any reason why ?

Apart that fired up BasBox pro and WinISD softwares to see what model I can get from given T/S parameters. Surprise Surpriseboth gave me final parameter values which matched with Peerless supplied values. Now comes the bummer in BassBox as whenever I try to keep Fb 54Hz either total volume ( Vb ) of box goes to enormous sub 30 liters with F3 in 90-95 Hz region while changing either gives me port length that is too big to even think of considering the box size..
So now what should I do to keep F3 at or near 60 Hz or what is optimum value for F3 for given woofer ( M130NH ) when Fb is kept 54 Hz.

Or

What tuning freq of box should I aim for along with F3 value keeping final volume of box to 20L(max) . 18L (ideally ) 16L(most desirable ) ?

Or Should I go for Floor standers in place of BS ?

 

[soundnovice]

thanks soundnovice


So went ahead and purchased M13NH along with TL25AN06 ( Low Fs ) as wanted to keep cost little low considering hunt for XO parts will burn 40-50% of total system budget and this being my 1st experiment so I am happy to have solid drivers to play around.

Stage 2 :Enclosure Type

My initial plan is to make TMM or MTM bookshelf with total volume of box being near about 20 Liters with height being about ~18-20 inches and keeping Fbox to 54 Hz.( Just like that number so not finalized yet about box freq but that is target I am aiming for )

I read that MTM sounds better than TMM which is famously documented as DApolitto configuration but almost 90% commercial consumer grade FS I see in market are in TMM configuration ..any reason why ?

Apart that fired up BasBox pro and WinISD softwares to see what model I can get from given T/S parameters. Surprise Surpriseboth gave me final parameter values which matched with Peerless supplied values. Now comes the bummer in BassBox as whenever I try to keep Fb 54Hz either total volume ( Vb ) of box goes to enormous sub 30 liters with F3 in 90-95 Hz region while changing either gives me port length that is too big to even think of considering the box size..
So now what should I do to keep F3 at or near 60 Hz or what is optimum value for F3 for given woofer ( M130NH ) when Fb is kept 54 Hz.

Or

What tuning freq of box should I aim for along with F3 value keeping final volume of box to 20L(max) . 18L (ideally ) 16L(most desirable ) ?

Or Should I go for Floor standers in place of BS ?

check GR research website. i think any box model used there for m130 could be used for m13nh too! box plans are available for free download

 

[keith_correa]

...Apart that fired up BasBox pro and WinISD softwares to see what model I can get from given T/S parameters. Surprise Surpriseboth gave me final parameter values which matched with Peerless supplied values....

Don't understand this. How did BassBox & WinISD "give" you final parameters? Both require that you either input the parameters or you select the driver from their database and it loads up the parameters for you from what is in their database.

...Now comes the bummer in BassBox as whenever I try to keep Fb 54Hz either total volume ( Vb ) of box goes to enormous sub 30 liters with F3 in 90-95 Hz region while changing either gives me port length that is too big to even think of considering the box size..
So now what should I do to keep F3 at or near 60 Hz or what is optimum value for F3 for given woofer ( M130NH ) when Fb is kept 54 Hz

In BassBox - what does the "Suggest" say?

 

[GeorgeO]

I have three MTM designs( am not personally familiar with the TMM or MMT), two designed by Dr Joe D'Appolito himself-the AriaR and the Audax HT speakers( I have exchanged emails with him on the e latter project).Both have given me many hours of enjoyable listening.

 

[Froggy T]

Soundnovice : Checked GR research BS plans , all are having port at back.I need front port plan for either BS or FS.

Keith_correa : What i meant is for new driver info, i supplied basic T/S parameters given by Peerless / JeetuBhai in both BassBox & WinSID to get other values which matched final calculated values from both s/w's and peerless .Then cross checked again and it was same or near about same.

In BassBox - what does the "Suggest" say?

BassBox Box Properties tab ->Box Design :

Vented Box design, when i keep design as high fidelity i get following
Vb of 4.715 L
Total volume of 5.621 L
Fb -72.47hz
QL -7
F3 -86.65hz

Dimension External - HxWxD = 6.331 x 6.331 x 8.558 Inch
Port( One Flush end ) :
Dia = 2 Inch
Lenght = 8.471 Inch

So When i change dimension to - 10(H) x 8(w) x 9(D) Inch , i get following :
Vb- 10.89 L
Total volume - 11.8 L
Fb- 58.18 hz
QL-7
F3-61.14 hz

Port( One Flush end ):
Dia = 2 Inch
Lenght = 5.034 Inch


So now my query is :
1. What Fb / F3 should i look for ?
2. The volume presented by BassBox is for one driver right then for 2 driver of 5.25 Inch i have to add total volume ?
3. Published Fs of M13Nh is 69.54Hz ...so how low can i go for Fb & F3...should i choose low Fb of 45 or so...then what about F3 value ?
4. What is ideal way of choosing Fb / F3 by taking account Fs of driver/box size (volume) and how to manage both with total box size of 16-18 L ?
5. Why is F3 always higher than Fb ?



GeorgeO : thanks for those designs but i am looking for front port based MTM or TMM designs due to space crunch.
If i go for back port based plan...how far do i need to keep speakers from wall ?
Would appreciate more plans.

Cheers !

 

[soundnovice]

i think putting the port to front (instead of back as in GR research plans) should not effect the sound. experts need to confirm though. i personally prefer sealed box which gives tight accurate bass but at lower efficiency. since 5.25" drivers anyway cant produce good bass below 60hz, using sealed cabs should be fine as anyway u will need to augment the lows with a dedicated sub/woofer.

 

[keith_correa]

...2. The volume presented by BassBox is for one driver right then for 2 driver of 5.25 Inch i have to add total volume ?...

Configuration Tab-->You specify the # of drivers and the configuration of the drivers here. BassBox should [will?] then take this configuration into account for the recommended enclosure.

 

[Froggy T]

Anyone for following ?

1. What Fb / F3 should i look for ?
2. Published Fs of M13Nh is 69.54Hz ...so how low can i go for Fb & F3...should i choose low Fb of 45 or so...then what about F3 value ?
3. What is ideal way of choosing Fb / F3 by taking account Fs of driver/box size (volume) and how to manage both with total box size of 16-18 L with max height of 20 Inches ?
4. Why is F3 always higher than Fb ?
5.Does port re-arrangement from Back to Front interfere or effect sound quality ?
6.How to get Speaker Impedence of 8 Ohms from 4 Ohm drivers ?

Being a 4 Ohm driver each ( TL25SN & M13NH ) , how do I wire ( Series / Parallel ) them up to make final 8 Ohm impedence ? Do I need to add a resistor to get final value of 8 Ohm but that will lead to power waste ..isnt it ?

I am toying with the idea of using 2 woofers and 1 tweeter per speaker in an MTM design similar to some of the designs on Dr.K MTM build (partsexpress) and other places. But I noticed that they use two 8 ohm woofers wired in parallel crossed over before getting to the speaker so you only need one crossover; and one 4 ohm tweeter. But that means they would have to wire them in series to get back to 8 ohms .

Another question , do we really need the necessity of having the same impedance for each driver - is it necessary? Even if the effective impedance of the woofers is 4 ohms, the power will be split between the two of them, right? So you would need twice as much power to drive the woofer to the same excursion and spl as single woofer. But since there are twice as many woofers, you get the same splOr am I playing with driver that will soon burst into flames or roasted amplifier if I dont take care of this impedence problem ?

 

[Froggy T]

Anyone with any advice ?

 

[soundnovice]

Being a 4 Ohm driver each ( TL25SN & M13NH ) , how do I wire ( Series / Parallel ) them up to make final 8 Ohm impedence ? Do I need to add a resistor to get final value of 8 Ohm but that will lead to power waste ..isnt it ?

assuming u r planning for MTM, two m13nh in series will give 8ohm. u should have selected 8 ohm tweeter! diff.impedance drivers will lead to complex xover design. otherwise i think u can add one more tweeter on the back panel and wire it in series with the front tweeter.

Another question , do we really need the necessity of having the same impedance for each driver - is it necessary? Even if the effective impedance of the woofers is 4 ohms, the power will be split between the two of them, right? So you would need twice as much power to drive the woofer to the same excursion and spl as single woofer. But since there are twice as many woofers, you get the same splOr am I playing with driver that will soon burst into flames or roasted amplifier if I dont take care of this impedence problem ?

if the amp is capable of working at lower impedance, then 4ohm speakers would be ok.

 

[Froggy T]

Well trying to live with what i have right now so going to wire woofers in series and then wire it in parallel with tweeter.

Will use L-pad for tweeter which will bring sensitivity to level of woofer's.It will also keep a tab for tweeters impedance.

XO - Plan to cross around 2000 Hz in 2'nd order or Use Series XO ( Acoustic reality xo ).