Details of DIY Ultra WAF in Wall System with TL SUB

TLS Guy

TLS Guy

Audioholic Slumlord
So as I promised I would give you the details of my DIY in wall system in our new home.

I might as well come clean now. I have a period of enforced idleness. I had a prostate biopsy on Monday at Mayo. Since I'm an old bloke passed my cell by date, prostate cancers are part of the turf. I should have the results in the next few days. So I await to see the grade. The probability of cancer being present is high. However a lot of superannuated guys like me die with prostate cancer, but not from prostate cancer. Anyhow what is will be.

So since I have ordred idleness for a couple of weeks, it is a good time to post details of the three system here.

For background here is a link to the build thread.

We have to be mindful of aesthetics. An ugly cobbled system is not pleasing however good it sounds. Making a system pleasing to the eye has to be part of a project.

My wife liked our system in our Eagn town home but hated the look of it. I don't blame her.



That was not an elegant system. However we knew our ownership if that property would be relatively short. It turned out to be 11 years. So we did not want to make major structural alterations.

In our new home, I had not considered putting a major system in the main living area of the lower great room. However my wife wanted one. She did not want any "boxes" in the room and it had to be as unotrusive as possible. She wanted it to sound at least as good as the system she was used to.

She had no idea what a tough challenge this would be. It seemed to me an in wall system would be mandatory.

Now this is a huge space.

Living room.



It is contiguous with the kitchen, dinning room, stairs to the upper level and the entry way and a passage way to laundary and other areas.







So you can see that is a big space to fill. Since the space is so open, I thought a 3.1 system would be optimal. Actually a 2.1 could probably fit the bill, but I wanted to design a three way center.

So I thought I would build the system in wall by building out the fireplace breast.

Obvioulsy the speaker system needed to handle significant power and significant power provided.

The elctronics would be a 65" Panasonic plasma from the Benedict AV room, a Marantz 7701 from the Eagan townhome, an Intel NUC, a Panasonic BD player, Comcast TV unit connected to the one in the studio which is the master, an APC Smart UPS, and two Quad 909 power amps providing 1000 watts of power all channels driven.

So my biggest concern was getting adequate uniform bass coverage, given the space avialable. There would only be room for one sub. However experience has tought me that TL speakers are highly efficiant and can can uniformly cover a large area due to the encircling nature of pipes. So an in wall TL sub was designed and built to carry out this task. You can see the deatials of the build in the build thread.

For the left and right mains and center high powered drivers were required. For many reaons, space and integration I thought selaed spekaers would be best for the task. I wanted and F3 of around 80 Hz to make for easy integration with the sub. This did not quite work as planned due to the in wall location. I knew not to provide baffle step compenstion as being in wall there is no half space/full space transition. However I thought the gain from the flat wall would be hard to calculate and so it proved
The feeds for FM TV and Internet come down from the studio chase in Tech Tubes. Tech Tunes also link the ancillaries, pre/pro and power amps.

So I chose for the bass mids six Morel 6" 638 Bass mids were selected for the three speakers. Each bass/mid is in its own enclosure. This is best practice for sealed designs to prevent drivers from driving each other. They are therfore acoustically isolated. For the right and left speakers Scanspeak 1" soft dome D2608-913000 were selected.

For the mid range of the center this small but potent Morel EM 428 was selected. It is in its space with the tweeter.

The tweeter for the center selected was a 3/4" softdome Eton 19 SD-1. This tweeter is pretty much an exact copy of the old Dynaudio D 21 AF. Sadly the Eton tweeter is discontinued. However I'm pretty sure I can adapt the design for the Hiquaphon 3/4" dome if anyone wants to build this system.

The sub driver is the: -
Dayton Audio RSS265HO-4 10" Reference HO Subwoofer 4 Ohm

This is the model for theTL Sub.



I have linked the box and crossover models.

So how did it turn out? There were some issues. The wall reinforcement of the bass mids necessitated the crossover from the speakers to sub be 40 Hz and not 80Hz. Even so there is still reinforcement around the sub crossover, causing slight coloration, and I mean slight on voices, and makes the system slightly warm, which is not unattractive.

So here is the impedance curve of the right and left mains.



So you can see the speakers are 4 ohm. There is one peak of impedance for the sealed alignment, and a peak just above the crossover point of 2.5 KHz. The phase angles are benign. The low pass crossover is first order and the high pass second order. However this makes for a composite fourth order crossover when driver roll offs are added.

This is the on axis FR at 2 meters.



That is a very satisfactory FR and impulse response.

Now the horizontal off axis responses. 15, 30, 45 and 60 degrees.



The green trace is 60 degrees. That is excellent dispersion.

The center impedance curve.



Agian there is one tuning peak. There are some swings of the phase angle, but the negative swings are where impedance is high. The impedance does drop to 3.5 oms at the 400 Hz crossover point. Electically the crossover are second order at 400 and 4000 HZ. So the entire speech discrimination band is handled by the midrange driver, which really aids voice clarity.
These are the dispersion characteristics. However there is little change in voice clarity whether just the right and left speakers are used or the center as well. Speech is marginally clearer with a 3.1 source.

The center speaker FR



Now this shows the biggest issue. The black trace is the axis response and the FR improves as you move off axis. This dip is due to an out of phase condition between the mid and woofers at crossover. However reversing the polarity of the mid causes a bigger problem in that it then puts the midrange out of phase with the left and right bass/mids over a large frequency region and was not pleasant at all. Fortunately the problem resolves off axis and the total system resonse is satisfactory and this is not a severe problem.

Now to the sub.

Here is the impedance curve.



You can see one peak of impedance showing that the line is correctly damped. You can see that the pipe is supporting the driver into the 15 to 20 Hz range. The driver is not fully decoupling from the line until 15 Hz.

This is the FR of the sub.



You can see that maximum output is at fp just below 40 Hz. You can see the pipe is supporting the driver over a full two octaves from 20 to 80 Hz. So the TL is working as it should and giving much broader support to the driver than a conventionally ported sub.

Here are the far field FRs of the system. I measured all off the listening positions, and also took one over in the dining room and one at the kitchen cook top where the left speaker is not even visible. This latter is the green trace.



As you move away from the speakers, there is a fall off in the higher end as there should be. If this is corrected the sound is not natural.

There is a rise at the sub/speaker crossover at 40 Hz, which gives slight warmth to the system. The sub is so effient Audyssey puts it 12 db down compared to the other speakers.

So how does it sound. Very good. So in a TL one 10" driver does fill the space. This is a huge space open to the house, and the bass is plentiful and unclored. Organs are reproduced with great authority. So you don't need large numbers of subs, huge drivers and insane amounts of power to fill a very large space, open to a large stairway.

I have caught my wife cranking the system very loud, without distress. She by the way is thrilled with this system of which she has taken over total ownership.

Voice clarity and speech intelligibility is excellent. In fact you can here dialog easily on the upper landing wihtout the system playing loud. It just sounds like someone talking downstairs.

I can listen to any music or program I want on this rig without complaint. So I have to report the system a succesful design.

If anyone wants to build it, then I have all the speakers in computers at the cabinet shop in Albany MN. So we could crank out a flat pack in literally minutes for anyone interested.

The speakers are all 4 ohm, and the center has a drop below 4 ohms where there is significant power. The Quad 909s though have run cool, and never triggered the fans to come on which are under thermostatic contriol. The power amp case has never got over 3 C above ambient temperture. However Quad current dumpers run cool, which is just one of the reasons I favor them.

Whether a receiver would tolerate this speaker system I do not know. If not pushed hard I suspect it would. Decent power amps however would be the safer choice.

I will report on the other two systems in further threads. Also I did a system for the owners of our former lake home using Elac speakers and I did get a few measuements. Stay tuned.
 

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ryanosaur

ryanosaur

Audioholic Spartan
So as I promised I would give you the details of my DIY in wall system in our new home.

I might as well come clean now. I have a period of enforced idleness. I had a prostate biopsy on Monday at Mayo. Since I'm an old bloke passed my cell by date, prostate cancers are part of the turf. I should have the results in the next few days. So I await to see the grade. The probability of cancer being present is high. However a lot of superannuated guys like me die with prostate cancer, but not from prostate cancer. Anyhow what is will be.

So since I have ordred idleness for a couple of weeks, it is a good time to post details of the three system here.

For background here is a link to the build thread.

We have to be mindful of aesthetics. An ugly cobbled system is not pleasing however good it sounds. Making a system pleasing to the eye has to be part of a project.

My wife liked our system in our Eagn town home but hated the look of it. I don't blame her.



That was not an elegant system. However we knew our ownership if that property would be relatively short. It turned out to be 11 years. So we did not want to make major structural alterations.

In our new home, I had not considered putting a major system in the main living area of the lower great room. However my wife wanted one. She did not want any "boxes" in the room and it had to be as unotrusive as possible. She wanted it to sound at least as good as the system she was used to.

She had no idea what a tough challenge this would be. It seemed to me an in wall system would be mandatory.

Now this is a huge space.

Living room.



It is contiguous with the kitchen, dinning room, stairs to the upper level and the entry way and a passage way to laundary and other areas.







So you can see that is a big space to fill. Since the space is so open, I thought a 3.1 system would be optimal. Actually a 2.1 could probably fit the bill, but I wanted to design a three way center.

So I thought I would build the system in wall by building out the fireplace breast.

Obvioulsy the speaker system needed to handle significant power and significant power provided.

The elctronics would be a 65" Panasonic plasma from the Benedict AV room, a Marantz 7701 from the Eagan townhome, an Intel NUC, a Panasonic BD player, Comcast TV unit connected to the one in the studio which is the master, an APC Smart UPS, and two Quad 909 power amps providing 1000 watts of power all channels driven.

So my biggest concern was getting adequate uniform bass coverage, given the space avialable. There would only be room for one sub. However experience has tought me that TL speakers are highly efficiant and can can uniformly cover a large area due to the encircling nature of pipes. So an in wall TL sub was designed and built to carry out this task. You can see the deatials of the build in the build thread.

For the left and right mains and center high powered drivers were required. For many reaons, space and integration I thought selaed spekaers would be best for the task. I wanted and F3 of around 80 Hz to make for easy integration with the sub. This did not quite work as planned due to the in wall location. I knew not to provide baffle step compenstion as being in wall there is no half space/full space transition. However I thought the gain from the flat wall would be hard to calculate and so it proved
The feeds for FM TV and Internet come down from the studio chase in Tech Tubes. Tech Tunes also link the ancillaries, pre/pro and power amps.

So I chose for the bass mids six Morel 6" 638 Bass mids were selected for the three speakers. Each bass/mid is in its own enclosure. This is best practice for sealed designs to prevent drivers from driving each other. They are therfore acoustically isolated. For the right and left speakers Scanspeak 1" soft dome D2608-913000 were selected.

For the mid range of the center this small but potent Morel EM 428 was selected. It is in its space with the tweeter.

The tweeter for the center selected was a 3/4" softdome Eton 19 SD-1. This tweeter is pretty much an exact copy of the old Dynaudio D 21 AF. Sadly the Eton tweeter is discontinued. However I'm pretty sure I can adapt the design for the Hiquaphon 3/4" dome if anyone wants to build this system.

The sub driver is the: -
Dayton Audio RSS265HO-4 10" Reference HO Subwoofer 4 Ohm

This is the model for theTL Sub.



I have linked the box and crossover models.

So how did it turn out? There were some issues. The wall reinforcement of the bass mids necessitated the crossover from the speakers to sub be 40 Hz and not 80Hz. Even so there is still reinforcement around the sub crossover, causing slight coloration, and I mean slight on voices, and makes the system slightly warm, which is not unattractive.

So here is the impedance curve of the right and left mains.



So you can see the speakers are 4 ohm. There is one peak of impedance for the sealed alignment, and a peak just above the crossover point of 2.5 KHz. The phase angles are benign. The low pass crossover is first order and the high pass second order. However this makes for a composite fourth order crossover when driver roll offs are added.

This is the on axis FR at 2 meters.



That is a very satisfactory FR and impulse response.

Now the horizontal off axis responses. 15, 30, 45 and 60 degrees.



The green trace is 60 degrees. That is excellent dispersion.

The center impedance curve.



Agian there is one tuning peak. There are some swings of the phase angle, but the negative swings are where impedance is high. The impedance does drop to 3.5 oms at the 400 Hz crossover point. Electically the crossover are second order at 400 and 4000 HZ. So the entire speech discrimination band is handled by the midrange driver, which really aids voice clarity.
These are the dispersion characteristics. However there is little change in voice clarity whether just the right and left speakers are used or the center as well. Speech is marginally clearer with a 3.1 source.

The center speaker FR



Now this shows the biggest issue. The black trace is the axis response and the FR improves as you move off axis. This dip is due to an out of phase condition between the mid and woofers at crossover. However reversing the polarity of the mid causes a bigger problem in that it then puts the midrange out of phase with the left and right bass/mids over a large frequency region and was not pleasant at all. Fortunately the problem resolves off axis and the total system resonse is satisfactory and this is not a severe problem.

Now to the sub.

Here is the impedance curve.



You can see one peak of impedance showing that the line is correctly damped. You can see that the pipe is supporting the driver into the 15 to 20 Hz range. The driver is not fully decoupling from the line until 15 Hz.

This is the FR of the sub.



You can see that maximum output is at fp just below 40 Hz. You can see the pipe is supporting the driver over a full two octaves from 20 to 80 Hz. So the TL is working as it should and giving much broader support to the driver than a conventionally ported sub.

Here are the far field FRs of the system. I measured all off the listening positions, and also took one over in the dining room and one at the kitchen cook top where the left speaker is not even visible. This latter is the green trace.



As you move away from the speakers, there is a fall off in the higher end as there should be. If this is corrected the sound is not natural.

There is a rise at the sub/speaker crossover at 40 Hz, which gives slight warmth to the system. The sub is so effient Audyssey puts it 12 db down compared to the other speakers.

So how does it sound. Very good. So in a TL one 10" driver does fill the space. This is a huge space open to the house, and the bass is plentiful and unclored. Organs are reproduced with great authority. So you don't need large numbers of subs, huge drivers and insane amounts of power to fill a very large space, open to a large stairway.

I have caught my wife cranking the system very loud, without distress. She by the way is thrilled with this system of which she has taken over total ownership.

Voice clarity and speech intelligibility is excellent. In fact you can here dialog easily on the upper landing wihtout the system playing loud. It just sounds like someone talking downstairs.

I can listen to any music or program I want on this rig without complaint. So I have to report the system a succesful design.

If anyone wants to build it, then I have all the speakers in computers at the cabinet shop in Albany MN. So we could crank out a flat pack in literally minutes for anyone interested.

The speakers are all 4 ohm, and the center has a drop below 4 ohms where there is significant power. The Quad 909s though have run cool, and never triggered the fans to come on which are under thermostatic contriol. The power amp case has never got over 3 C above ambient temperture. However Quad current dumpers run cool, which is just one of the reasons I favor them.

Whether a receiver would tolerate this speaker system I do not know. If not pushed hard I suspect it would. Decent power amps however would be the safer choice.

I will report on the other two systems in further threads. Also I did a system for the owners of our former lake home using Elac speakers and I did get a few measuements. Stay tuned.
Very cool. ;) Thank you for sharing!
I hope we get the chance to revisit our conversation from last year; I am still eager to learn more about designing a TQWT Sub for myself. Unlike last year, I now have most of the tools in place.
Best,
R
 
S

snakeeyes

Audioholic Ninja
Wow! What a beautiful home.

Are those photos with the speaker grills removed? (Hard to tell on my small phone) I was thinking they probably disappear nicely with grills that match the wall paint.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Wow! What a beautiful home.

Are those photos with the speaker grills removed? (Hard to tell on my small phone) I was thinking they probably disappear nicely with grills that match the wall paint.
The picture in this thread is with grills on. The grills are black. The lower cabinets have white painted frames, and the speakers plated aluminum frames to match the TV surround.

If you go to the build thread you can see pictures without the grills.
 
Last edited:
Swerd

Swerd

Audioholic Spartan
I might as well come clean now. I have a period of enforced idleness. I had a prostate biopsy on Monday at Mayo. Since I'm an old bloke passed my cell by date, prostate cancers are part of the turf. I should have the results in the next few days. So I await to see the grade.
Hope that it all comes to Gleason 3+3 = 6. For those who aren't familiar, a Gleason score is a pathologist's diagnosis of prostate biopsy tissue. The score indicates the prognosis. A Gleason 6 is the lowest available score, basically good news.

Thanks for the photos and details on the new home. It looks great.
 
G

Grandzoltar

Full Audioholic
Very impressive from the aesthetics to performance. Fr response like that shows very well design TL’s with well designed crossover network. All that without using Audyssey. :)

Implementing a 4000hz xo on the center you must have carefully chosen that midrange driver. Assuming the xo slope is -12db Why did you choose the crossover at 40hz? Being that the sub is most impactful at 40hz.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Hope that it all comes to Gleason 3+3 = 6. For those who aren't familiar, a Gleason score is a pathologist's diagnosis of prostate biopsy tissue. The score indicates the prognosis. A Gleason 6 is the lowest available score, basically good news.

Thanks for the photos and details on the new home. It looks great.
The path report was ready for me this morning. It is Gleason 3 + 4 = 7. So I'm wating for Mayo to advise on the next steps. The MRI showed a probable tumor in the left lobe. The only biopsies positive were from this lesion and the transition zone. So at this time the adenocarcinoma is confined to this immediate area.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Very impressive from the aesthetics to performance. Fr response like that shows very well design TL’s with well designed crossover network. All that without using Audyssey. :)

Implementing a 4000hz xo on the center you must have carefully chosen that midrange driver. Assuming the xo slope is -12db Why did you choose the crossover at 40hz? Being that the sub is most impactful at 40hz.
Well I deigned the crossover to be 80 Hz. The F3 of the speakers is calcualted to be 80 Hz. Since they are sealed then roll of is 12 db second order. The prepro high pass receiver crossover is also 12 db second order. Added that is 24 db roll off fourth order. Now the low pass filter of the pre pro is 24 db fourth order so in theory you then have a perfect fourth order crossover.

The problem is the in wall design. This is causing sgnificant gain in the low bass and altering the calcualted roll off in a major way. So if you cross at 80 Hz then there is massive excess energy in that region, which really made for poor speech clarity. It was very "chesty". If you tuned down the sub then you lost low bass. Funnily enough Audyssey knew the correct crossover was 40 Hz and indeed it is.

The sub is set 12 db below the other speakers. This is a relection of how efficinet pipes are. You can see from my FRDs, there is large reinforcement of the 10" driver in the last two octaves.

Yes, I did choose the mid driver with care. If you are going undertake the huge hassle of designing a three way speaker then you had better get the advantage of having a single driver cover the speech discrimination band, or don't bother. The vast majority of commercail three way designs are a waste of time and effort and have only disadvantage over good two ways.
 
Swerd

Swerd

Audioholic Spartan
The path report was ready for me this morning. It is Gleason 3 + 4 = 7. So I'm wating for Mayo to advise on the next steps. The MRI showed a probable tumor in the left lobe. The only biopsies positive were from this lesion and the transition zone. So at this time the adenocarcinoma is confined to this immediate area.
I'll take that as good news, at least, good enough news.

To put these Gleason scores into some context, my own prostate cancer has two growths, both confined to the right lobe. One is Gleason 3 + 3 = 6 and the other is 3 + 4 = 7. My urologist, as well as everyone else I asked, said this is low-grade, low-risk prostate cancer. It's my call what I want to do next. I chose active surveillance. That meant visit the urologist 3-4 times yearly, draw blood for PSA tests to see if it rises, and have a biopsy every 2 years. If the PSA rises to near 20, it would be time to take more active steps. Apparently, in many similar cases, more active steps are never required.

In my case, the recent diagnosis for AS, a form of rheumatoid arthritis, made me rethink things, as I discussed in my Steam Vent thread. AS treatment involves potent anti-immune drugs that may possibly allow some cancers to progress. So in my case, I am opting for surgery soon, in April and then start the AS therapy.

Just for grins, I looked for what robot surgery looks like. I will be having that. When I saw one, it was shockingly scary looking. As I imagined myself under the blue shroud, it looks like an ASS CNC machine :oops:. I'll be completely anesthetized, so I'll never see it.
1582324704516.png
 
ryanosaur

ryanosaur

Audioholic Spartan
Just for grins, I looked for what robot surgery looks like. I will be having that. When I saw one, it was shockingly scary looking. As I imagined myself under the blue shroud, it looks like an ASS CNC machine :oops:. I'll be completely anesthetized, so I'll never see it.
Don’t they use those to build Teslas, too? ;)
 

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