How to choose correct Drivers for DIY speakers? need advice

[prosenjit]

just a question..I am a complete noob about speakers..checking corrson audio(indian site,in bangalore) site for diy speakers kits....are they worth the price of the kits..any idea about the parts..they have pre cut wood and drivers and crossover electronics..all.
example like a 5.1 full kit is around 40k...any member tested them..any idea..
thank you for help..

 

[spirovious]

There are some threads which may be helpful-
Peerless India drivers: old notes | dhandanought.org/tcpip
Another MTM with Peerless India drivers | dhandanought.org/tcpip
Loudspeaker, Loudspeaker powered Subwoofers, Raw Drivers sub Woofer, Raw Drivers Woofer
Peerless Fabrikkerne(I) Ltd. - Mumbai - Audio Video Products manufacturers and suppliers.

 

[spirovious]

few useful threads explaining about speaker material & there pros/cons-
http://www.stonessoundstudio.com.au/stone/diy_speaker_info/diy_driver_types_p3.htm
http://www.nutshellhifi.com/library/speaker-design2.html
Pro/cons to paper & aluminum cones?

 

[spirovious]

How can different companies have same speaker model/part no.( P13WH00-08 )?Even similar make too?

Scanspeak-
Madisound Speaker Store


Vifa-
Vifa P13WH-00-08 Mid Woofer

 

[VFM]

Hi,

Some of the older Vifa designs are now owned by scanspeak and vifa no longer manufacture those. If you go through the scanspeak range at Madisound, you will find couple of familiar looking Vifas.

Regards,
VFM

 

[spirovious]

Hi,

Some of the older Vifa designs are now owned by scanspeak and vifa no longer manufacture those. If you go through the scanspeak range at Madisound, you will find couple of familiar looking Vifas.

Regards,
VFM

Oh,Vifa is now owned by peerless I think.

 

[spirovious]

a good thread to understand the basics of crossover-
A Guide to Crossover Networks & Crossover Settings - Blu-ray Forum

 

[spirovious]

Which can be better?may this is good answer-
Drivers and the Myth of Tweeter Dome Materials | AxiomAudioBlog

 

[spirovious]

Few more projects-
https://sites.google.com/site/undefinition/diy
Small BS-
https://sites.google.com/site/undefinition/speedster
http://techtalk.parts-express.com/s...Carmody-s-Speedster-Build-Thread-with-a-Twist
http://techtalk.parts-express.com/showthread.php?223751-Overnight-Sensation-Build-Two-Sets

 

[koushik]

Ever since they put up the site diyaudiocart.com, the diy bugs are biting me every now and then.

Thinking of a sub woofer build and have a question in mind. Is it better to go single 12" or two 8". What is the advantages and disadvantages of there two designs? Want to go deeper and also louder.

 

[spirovious]

a Good link to know more about crossover-
Phase, Time and Distortion in Loudspeakers

 

[spirovious]

Some more speaker projects-
Magazine | Loudspeakerbuilding

 

[Santy]

Is it better to go single 12" or two 8". What is the advantages and disadvantages of there two designs? Want to go deeper and also louder.

In my person opinion (which may be incorrect);

Advantages of one 12"
- Efficiency is more (power loss is less due to single amp)
- Goes much deeper
- Lower distortion for same SPL
- Dynamics is much better
- Lesser footprint

Diadvantages of one 12"
- More expensive if you want it to be musical (tight and fast)

Advantages of two 8"
-Stereo integration is better
-Symmetry of your setup (if you place it that way)
-Linear response is better
-Fills up the room more evenly
-More headroom available due to multiple amps
-Faster and crisper bass (controlling excursions of two small cones is easier)
-Less likely to receive complaints from neighbours
-Buy one first and add one more when budget permits

Disadvantages of two 8"
- Doublt the effort (in case of DIY)
- Bass extension is limited
- Placement / setup / configuration might become a headache
- Needs a receiver with two preouts (preferably) which is going to be expensive again
- More power drawn
- More floor space needed

 

[Hari Iyer]

Choosing drivers depends also on the following factors,
1. Is it going to be 2 way or a 3 way speaker system.
2. Type of cross-over - 1st order , 2nd order, 3rd order, 4th order.
3. Type of enclosure - sealed, bass-reflex, TL etc.
4. Room size - due you require that much throw for a big 12" woofer. Remember 12" does not really mean deep bass. For low bass, TS parameters like Resonating freq of the woofer and Vas is important to consider for low freq extension.
5. Placement of speakers in the room also plays important role and cannot be considered in isolation.
6.Two 8" drivers in parallel or series can cause challenges in designing the cross-over too as impedance of the woofer will change vis-a-vis cross-over.
7. Two 8" drivers can cause cancellation between common frequency if both of them emit the same freq. You need to align both the drivers properly in time to prevent cancellation effect.
8. Efficiency of the drivers will be reduced if the cross-over does not level matched to the two 8" driver.
9. Proper damping of the enclosure is required to prevent back pressure from both the drivers interacting inside the cabinet. A dual chamber for isolation at the back for both drivers could resolve the issue if your design permits.
10. A 12" driver can reduce most design challenges and the only area where you need to consider will be the cross-over freq between the lows and the mids.
Cheers

 

[kapvin]

In my person opinion (which may be incorrect);

Advantages of one 12"
- Efficiency is more (power loss is less due to single amp)
- Goes much deeper
- Lower distortion for same SPL
- Dynamics is much better
- Lesser footprint

Diadvantages of one 12"
- More expensive if you want it to be musical (tight and fast)

Advantages of two 8"
-Stereo integration is better
-Symmetry of your setup (if you place it that way)
-Linear response is better
-Fills up the room more evenly
-More headroom available due to multiple amps
-Faster and crisper bass (controlling excursions of two small cones is easier)
-Less likely to receive complaints from neighbours
-Buy one first and add one more when budget permits

Disadvantages of two 8"
- Doublt the effort (in case of DIY)
- Bass extension is limited
- Placement / setup / configuration might become a headache
- Needs a receiver with two preouts (preferably) which is going to be expensive again
- More power drawn
- More floor space needed

Hey Santy, none of this is correct emperically.

all of this is contextual to which 8" and which 12" is being compared. In each size you get drivers that would directly contradict what you said.

generally the only thing that one can say empirically, is that an 8" allow for a slimmer baffle, and theoretically allows you to cross over at higher level without lobing issues coming up (smaller CTCs) also dual woofers can address floor bounce issues when placed appropriately at different hts on the baffle. and used as X.5 (2.5 way or 3.5way) can provide baffle step compensation, without the need of a BSC circuit.

when you run 2 woofers together in parallel, you also get a +6db gain.

 

[kapvin]

6.Two 8" drivers in parallel or series can cause challenges in designing the cross-over too as impedance of the woofer will change vis-a-vis cross-over.
7. Two 8" drivers can cause cancellation between common frequency if both of them emit the same freq. You need to align both the drivers properly in time to prevent cancellation effect.
8. Efficiency of the drivers will be reduced if the cross-over does not level matched to the two 8" driver.

Cheers

mostly true, Hari.

but there are somethings that you said that are very puzzling. can you explain what you mean? I am assuming that the standard practice of choosing a driver, measuring the frd on baffle & enclosure and then designing the crossover is employed

point 6? - i am assuming the same model of woofer. you'd get either 1/2 the impedance or double. so where is that a problem?

point 7? - are you taking about lobing? isn't that irrelevant at the typical frequencies that a woofer handles?

point 8? - your point being?

 

[Santy]

all of this is contextual to which 8" and which 12" is being compared. In each size you get drivers that would directly contradict what you said.

Is it not obvious? Going by the title of this thread, I thought the comparison was mainly for DIY decision making, wherein the quality and design of driver, amplifier, crossover, enclosure all remaining same, what happens when only the size changes. Not a comparison of X model of 8" driver costing 500 USD and Y model of 12" driver costing 50 USD.

 

[Santy]

Hey Santy, none of this is correct emperically.

If possible, can you drill down to each point, assuming all parameters are same except the driver size?

 

[Santy]

There seems to be lack of clarity. Hari is comparing two small drivers in single enclosure vs one large driver in same enclosure; while I was answering a query about one sub with a large driver vs two subs with smaller drivers. hyeah:

 

[kapvin]

If possible, can you drill down to each point, assuming all parameters are same except the driver size?

All parameters being the same would be an identical driver but I understand your question. Pm me your number and we'll talk.

I did not actually realise that you were talking about a sub, my bad. But the points I made remain as valid, except, you'd need not worry about baffle step.

Generally speaking, I'd look at motor strength & MMs as well while defining a sub..there is a strong argument made for larger Sd and lower excursion on the premise that linearity will be better. Of course, as always, this is nothing that a well engineered motor & suspension will not solve.

As a general rule, state your requirements, and which of the iron laws you want to hold onto, and a whole range of appropriate drivers will present themselves.

Eventually choice would boil down to what box alignment you are planning and what application.

But let's talk, I'll be happy to address what little I know towards answering any queries you may have.





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