I built TL SPeakers : Need help to address some probs

[sudhirbhosale]

Hi all,
I built my TL speakers with 2 way drivers from Peerless. 6"' woofer + tweeter
Not used any crossover but added capacotor in between.
Not yet properly damped inside

I am getting good basss and trable.

Need help to address following issues:

1. Getting very harsh effect in Mid frequencies. Music with many instruments gives noise. Does in because of lack of damping or anyting else
2. Damping cause effect/improvement on which frequencies? All / Low / Mid ?
3. Need tips on relation between various values of capacitors and crossing freq (uF vs at what frequency it will cross). I read tips in this forum like (At 2.5 uF it will cross near 12 kHz)
4. What options available from market if i want to add crossover
5. Waht material from home i can use as damping material? Normal foam sheet, thick towels etc.
6. How to test damping capacity of material"?
7. What is resonance?

Thanks in advance.

 

[jetlag]

Sudhir
Is it your own design? Did you consider the Fs of the Mid driver. In my opinion, just a capacitor would not work as a good xover.
There are too many issues to be handled. I suggest that you start from the cabinet design. Damping also plays a big role. The cabinet should be totally dead .

Start your analysis and come out with one thing at a time.

Maybe this helps.

That said, there are some design giants here in the forum who can also pitch in.

Later
Peace
Jetlag

 

[Prasad Karpe]

Hi Sudhir,
Here are just my 02 cents.
1) Use "Polyfill" as damping. By polyfill I mean the material used in pillows, commercially called as"Decron" or "Recron". The damping will damp down high frequencies emenating from the woofer.
2) If the mid frequencies are what giving you the trouble then use "baffle stage correction" circuit.
3) Use first order crossover.
4) Moreover I will suggest that just use the woofer first & after finalising with it start afresh with the tweeter & crossover.
5) lastly if you are getting good results then dont go into the Resonance & other juggalary. If you insist i will suggest you some reading material

regards
Prasad

 

[doors666]

TL is not suitable for each and every driver. some favour TL, some dont.

you need a crossover. u need either proper datasheet or measurements to design a crossover. at the minimum, graphs and/or TS params are required for that.

whats that overhang of wood... front is supposed to be flat, unless its taken care of design.

cabinet size, TL size etc are all dependant on the TS parameters of the drivers. How did u come up with the cab size.. is it something that you chose based on convenience. thats not going to work.

in future, its better to ask for help first and then make the speakers rather than first make something and then ask for help. it will save u a lot of money. I am sorry to say but you are back to drawing board.

Oh, and it looks like prasad also needs to do a lot of reading. barring his first comment, all others are irrelevant.

 

[Prasad Karpe]

@doors666

When somebody has made the speakers with furnished cabs it is understood that he must have known the TS parameters.

As regards TL one needs to design the line for bass response as the vocals & bass which is very difficult to reproduce.

The OP is getting good bass & treble from his design & is having a problem with mid frequencies.

The whole idea of using a TL speaker is to have cleanest sound without any crossover ckt. Afterall the original design by "bailey" did not have any cross overs.

Further once somebody has already finished making the speakers there is no point in getting back & researching on "Resonance". He can research for his next project.

Tons of material is available on merits & demerits of different kind of crossovers.
So somebody must not doubt on anybody's design principles.

Lastly it will be better you suggest some methods to salvage his speakers without discouraging him.
Prasad

 

[doors666]

@doors666

When somebody has made the speakers with furnished cabs it is understood that he must have known the TS parameters.

that is an assumption... anyway, all drivers are not suitable for tl, ts params will tell you which ones are and which ones are not.

As regards TL one needs to design the line for bass response as the vocals & bass which is very difficult to reproduce.

The OP is getting good bass & treble from his design & is having a problem with mid frequencies.

The whole idea of using a TL speaker is to have cleanest sound without any crossover ckt. Afterall the original design by "bailey" did not have any cross overs.

most of the music lies in the mids. who told you tl doesnt need a crossover. just because bailey did it with some drivers, doesnt mean it can be done with all drivers. anyway, they are two totally different things. crossover is between the two drivers (say between 1500hz to 3000hz in this case), TL is for bass response.

You are asking him to implement baffle step correction to fix mid frequencies, please read what is that before you suggest that.
You are also asking for a first order crossover. Very very few driver combos are suitable for that and the xo point has to be chosen very carefully. noise will be too high otherwise.

Further once somebody has already finished making the speakers there is no point in getting back & researching on "Resonance". He can research for his next project.

Tons of material is available on merits & demerits of different kind of crossovers.
So somebody must not doubt on anybody's design principles.

and why not? if a design principle is bad, shouldnt that be corrected.

Lastly it will be better you suggest some methods to salvage his speakers without discouraging him.
Prasad

I am not discouraging him. he needs to go back to the drawing board, figure out if his tl is good or not and fix the cabinet if need be. design a xo and implement that. just adding some foam/wool/whatever is not going to fix his problem. at the minimum he needs to post his cabinet internals, sizes, lining etc, what xo is he using, t/s parameters/graphs etc if he expects people to help him.

 

[Prasad Karpe]

@doors 666

A TL basically is for a single fullrange driver. Other drivers can be added after finalising the line.How can you quote that other people have not read the material before posting here? Who told you that first order crossovers are a bad design.

Anyway you have some serious differences with my ideology. Let the OP decide which way to go. There is no point in arguing more about this.

This issue is closed from my side.

Prasad

 

[doors666]

@doors 666

A TL basically is for a single fullrange driver. Other drivers can be added after finalising the line.How can you quote that other people have not read the material before posting here? Who told you that first order crossovers are a bad design.

Anyway you have some serious differences with my ideology. Let the OP decide which way to go. There is no point in arguing more about this.

This issue is closed from my side.

Prasad

sorry man, it wasnt my intention to offend you. i didnt say first order crossover are a bad design. they require usually very low noise drivers which are usually very expensive (or you need a huge overlap in the driver's frequencies). With 'normal' drivers, the noise is very prominent. if one can successfully pull of first order crossover it probably will give you the best sound (after full rangers). But i dont think these relatively cheaper drivers will give you that kind of performance.

 

[kapvin]

Hi all,
I built my TL speakers with 2 way drivers from Peerless. 6"' woofer + tweeter
Not used any crossover but added capacotor in between.
Not yet properly damped inside

I am getting good basss and trable.

Need help to address following issues:

1. Getting very harsh effect in Mid frequencies. Music with many instruments gives noise. Does in because of lack of damping or anyting else
2. Damping cause effect/improvement on which frequencies? All / Low / Mid ?
3. Need tips on relation between various values of capacitors and crossing freq (uF vs at what frequency it will cross). I read tips in this forum like (At 2.5 uF it will cross near 12 kHz)
4. What options available from market if i want to add crossover
5. Waht material from home i can use as damping material? Normal foam sheet, thick towels etc.
6. How to test damping capacity of material"?
7. What is resonance?

Thanks in advance.

harshness seems to be becuase of crossover issues. could be cone breakup or the tweeterplaying below it's usable limits. typically if this happens, you need sharper slopes not shallower slopes.

accentuated or "honky"midrange could indicate the need for Baffle step compensation.

which peerless drivers are you using? did you meaure them for specs?

how did you arrive at the dimensions for your box?

on what basis are you deciding that the enclosure needs damping. not clear to me? anyway definitely not thick towels.

suggest you give these details if you want coherent answers. otherwise all answers will be a bit subjective.

have fun.

 

[kapvin]

@doors 666

A TL basically is for a single fullrange driver. Other drivers can be added after finalising the line.How can you quote that other people have not read the material before posting here? Who told you that first order crossovers are a bad design.

Anyway you have some serious differences with my ideology. Let the OP decide which way to go. There is no point in arguing more about this.

This issue is closed from my side.

Prasad

it's not a question of ideology, but of basic design principles. you contention that a TL is only for a single full range driver is a bit off.

sorry man, it wasnt my intention to offend you. i didnt say first order crossover are a bad design. they require usually very low noise drivers which are usually very expensive (or you need a huge overlap in the driver's frequencies). With 'normal' drivers, the noise is very prominent. if one can successfully pull of first order crossover it probably will give you the best sound (after full rangers). But i dont think these relatively cheaper drivers will give you that kind of performance.

"Doors666, you are absolutely on the right track. the "sonic" benefits of first order slopes are to be weighted against driver behaviour with those slopes. Typically there are many trade offs caused by driver misbehaviour; which is why in most cases cost crossover parts = cost of drivers (or more).

@doors666

When somebody has made the speakers with furnished cabs it is understood that he must have known the TS parameters.

As regards TL one needs to design the line for bass response as the vocals & bass which is very difficult to reproduce.

The OP is getting good bass & treble from his design & is having a problem with mid frequencies.

The whole idea of using a TL speaker is to have cleanest sound without any crossover ckt. Afterall the original design by "bailey" did not have any cross overs.

Further once somebody has already finished making the speakers there is no point in getting back & researching on "Resonance". He can research for his next project.

Tons of material is available on merits & demerits of different kind of crossovers.
So somebody must not doubt on anybody's design principles.

Lastly it will be better you suggest some methods to salvage his speakers without discouraging him.
Prasad

the thought is that the cost of drivers is more than the cost of enclosures. and the enclosure in photo has just been put together and not finished.

might be most cost effective to do another enclosure.

anyway, best not to get so snippy. i think doors666 is only trying to help. if you are the expert, then it might be nicer to be a bit more tolerant.

 

[Prasad Karpe]

@ kapvin
I am not claiming to be an expert. However the most challenging job i found in making

speakers is the woodwork. It might not be a costly affair but for that you have to be

dependent on somebody else.

Thanks for pointing out henceforth i will be more tolerant while posting here.

regards
Prasad

 

[kapvin]

@ kapvin
I am not claiming to be an expert. However the most challenging job i found in making

speakers is the woodwork. It might not be a costly affair but for that you have to be

dependent on somebody else.

Thanks for pointing out henceforth i will be more tolerant while posting here.

regards
Prasad

Hey Prasad,

On this, I've "been around the block" a couple of times, and IMHO, tweaking the crossover is the most challenging job. there was a thread somewhere here on how simple changes to the crossover made such huge impact to the sound.

box is complicated if you don't have the tools or skills. but outsourcing this is relatively cheap.

just my two bits.

 

[doors666]

I think the first and the easiest step would be to get rid of the 'extra wood' on the front baffle edges.

 

[kanwar]

Cool down guys,

I am yet see an acknowledging reply from the thread starter in relation to TL.


@ Sudhir,

By looking at your queries it looks like you haven't even done you basic homework of cross-over networks with relation to driver TS-parameters. A simple search on Google can teach you very much about the basics. Spoon feeding shouldn't be expected everytime.

 

[kapvin]

Cool down guys,

I am yet see an acknowledging reply from the thread starter in relation to TL.


@ Sudhir,

By looking at your queries it looks like you haven't even done you basic homework of cross-over networks with relation to driver TS-parameters. A simple search on Google can teach you very much about the basics. Spoon feeding shouldn't be expected everytime.

@ Kanwar. No one is stressed. It is a relatively peaceful discussion.

But you are absolutely right. OP has gone into hibernation. Maybe he was hoping for simple answers- yes use blankets, it will give a 35% improvement in sound.