Transmission Line Speakers using Peerless W3-LK76-PBK 3" Full Range Drivers

an update...

i doubled amount of damping in the line and there is remarkable improvement. the cabinet resonance that I was hearing has reduced a lot and the bass, although not much to start with, has not reduced. it is still the same and slightly cleaner now.

however, one observation is confirmed that this driver has a very high cone break up and will not work without a crossover. i don't want to put a crossover so the only option is to find a better 3" driver with a better frequency range.

surprisingly at low volumes the sound is not that harsh in the midrange as doubted from the driver. and the rolled off treble after the 10khz probably gives a smoother response in the high frequencies than a two-way systems. but, detailing does suffer. It is suitable for casual background listening. Full range driver has a lot of potential for a warm, pleasing sound.

Still reasonable for a 4k speaker system!
 
Last edited:
an update...

i doubled amount of damping in the line and there is remarkable improvement. the cabinet resonance that I was hearing has reduced a lot and the bass, although not much to start with, has not reduced. it is still the same and slightly cleaner now.

however, one observation is confirmed that this driver has a very high cone break up and will not work without a crossover. i don't want to put a crossover so the only option is to find a better 3" driver with a better frequency range.

surprisingly at low volumes the sound is not that harsh in the midrange as doubted from the driver. and the rolled off treble after the 10khz probably gives a smoother response in the high frequencies than a two-way systems. but, detailing does suffer. It is suitable for casual background listening. Full range driver has a lot of potential for a warm, pleasing sound.

Still reasonable for a 4k speaker system!

Just go ahead and build the cross-over and all the anomalies will vanish. You can easily raise the volume without the cone break-up. If you have an AVR, you can configure the AVR speaker as small and have the cross-over set at around 100Hz. Do not connect the sub-woofer and you can see the smoothness in the response with no cone break-up. Hence suggested the cross-over as it will also tame the high-freq above 10KHz also, as i have applied the home x-overs values to them.

Cheers,
 
The AVR is a good idea! Hadn't thought of that. Till now I was using the speakers mostly on the Integrated, which I think is giving high power through a wide frequency range than this driver can handle. I will configure the speakers as small on the AVR and see the results.
 
You can try S081E from peerless, it will work without any modifications to the enclosure (its 3.5") or the cross-over. This driver has a flat response in the pass-band as has a very good impedance curve too. The LK76 is very harsh in its mid-range and needs to be compensated for hi-fi usage. For a small project like this its not worth the effort to painfully calculate the values of the passive components to do the justice for a flat response in the higher-mid frequencies.

hi hari,
have you used S081E. i am planning to use it for mid between 1khz and 3.2khz. any idea abt its sound quality in this range?
 
hi hari,
have you used S081E. i am planning to use it for mid between 1khz and 3.2khz. any idea abt its sound quality in this range?

I have measured the resonating freq of this driver and it was close to 96Hz. Hence practically you can use it from 300Hz onwards till 7 KHz if your design permits as this driver roll-off is around 8KHz. Will need to compensate for the resonance peaks and take care to use it accordingly else there is a risk of metallic/plastic kind of sound. Otherwise its a good driver. I will suggest you should try using this driver from 350Hz till 8KHz and use a super tweeter above 8KHz.
 
I have measured the resonating freq of this driver and it was close to 96Hz. Hence practically you can use it from 300Hz onwards till 7 KHz if your design permits as this driver roll-off is around 8KHz. Will need to compensate for the resonance peaks and take care to use it accordingly else there is a risk of metallic/plastic kind of sound. Otherwise its a good driver. I will suggest you should try using this driver from 350Hz till 8KHz and use a super tweeter above 8KHz.

well for the design i have in hand, it only needs to handle between 1khz and 3.2khz. hopefully in this range i dont encounter any resonance peaks! my interest in this mid (or any other from peerless) is about its off-axis (say 30 deg atleast) response. thats the main reason to go for this smaller mid rather than 5.25" mids
 
well for the design i have in hand, it only needs to handle between 1khz and 3.2khz. hopefully in this range i dont encounter any resonance peaks! my interest in this mid (or any other from peerless) is about its off-axis (say 30 deg atleast) response. thats the main reason to go for this smaller mid rather than 5.25" mids
Why don't you consider the Peerless mid-range dome speaker? It will give a far better response than the S081E driver. The S081E is suitable for an extended response driver and would not be suitable for the specified frequency that you are mentioning.
 
Why don't you consider the Peerless mid-range dome speaker? It will give a far better response than the S081E driver. The S081E is suitable for an extended response driver and would not be suitable for the specified frequency that you are mentioning.

the midrange dome dm50an is out of stock!
which one would you suggest for the freq.range specified? if its peerless then it would fairly easy and cheap to get it rather than importing any exotic driver!
how about compression driver from ahuja. below model can be crossed at 1khz. i will be using LR4 active xover for this.
Ahuja Sound Solutions
 
the midrange dome dm50an is out of stock!
which one would you suggest for the freq.range specified? if its peerless then it would fairly easy and cheap to get it rather than importing any exotic driver!
how about compression driver from ahuja. below model can be crossed at 1khz. i will be using LR4 active xover for this.
Ahuja Sound Solutions

I can think of the K0100 and P081E drivers from peerless which can work as mid-range drivers too. They are 4" mid-woofers though but are paper cone and not titanium doped. I am not aware of the compression drivers from Ahuja. Ahuja caters to more of PA stuff and would not be refined enough for home hi-fi use. Also consider P-Audio drivers the seem to have a range of mid-range drivers that can be suitable for your use. Also check if Peerless is having a 4" Kevlar cone which he use to sell earlier that can also be a good choice for mid-range.
 
I can think of the K0100 and P081E drivers from peerless which can work as mid-range drivers too. They are 4" mid-woofers though but are paper cone and not titanium doped. I am not aware of the compression drivers from Ahuja. Ahuja caters to more of PA stuff and would not be refined enough for home hi-fi use. Also consider P-Audio drivers the seem to have a range of mid-range drivers that can be suitable for your use. Also check if Peerless is having a 4" Kevlar cone which he use to sell earlier that can also be a good choice for mid-range.

thanks for the suggestion Hari.
P-Audio is available in India!?
will check abt availability of K0100 and P081E. there might be several midwoofers available, but the originial project goal here is achieving good off-axis response until 3.2khz.
as far as i know, 2" or 3" mids have wider dispersion (correct me). also since xover point is 3200hz, that means 13504/3200=4.22", ie mid to tweeter (center-t-cetner)distance cannot be more than 4.22" (correct me here too), which mandates use of smaller mid, 2" or 3" being suitable.
 
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