ThorstenL, interesting. Any (construction/technical) details? Regards.
Last edited:
Hi,
I like the "should have". However, outside Harman's custom build rooms you may find more variation that you may like.
Also, Harman where you cite the is basically Floyd Toole. His view is just one and not entirely without detractors.
It may surprise you that not only am I very familar with Dr. Toole's work (there is a lot of good stuff in it), I do not necessary "buy" it in it's entirety. Professional Bodies including the IRT and the BBC when it still did proper research have their own large bodies of research and not all of this is in agreement with what Dr. Toole contends.
Maybe you need to broaden your horizons a little, past the writings issued by companies who would like to sell their products and more to independent sources.
Ciao T
I like the "should have". However, outside Harman's custom build rooms you may find more variation that you may like.
Also, Harman where you cite the is basically Floyd Toole. His view is just one and not entirely without detractors.
It may surprise you that not only am I very familar with Dr. Toole's work (there is a lot of good stuff in it), I do not necessary "buy" it in it's entirety. Professional Bodies including the IRT and the BBC when it still did proper research have their own large bodies of research and not all of this is in agreement with what Dr. Toole contends.
Maybe you need to broaden your horizons a little, past the writings issued by companies who would like to sell their products and more to independent sources.
Ciao T
Hi,
First, what has this got to do with the price of tea in china (even if it was true).
Good morning. Did you happen to read what I wrote earlier on the topic. It is one of the reasons I suggested a 3-Way system.
Ideally we could make the system to have a flat response and a flat directivity index of at least 6dB at all frequencies.
With the budget the OP suggested for drivers and other constraints this is not going to be possible, hence we are shooting for the second best thing, a DI that smoothly increases with frequency. Anyway, read my original post on that.
Ciao T
First, what has this got to do with the price of tea in china (even if it was true).
Good morning. Did you happen to read what I wrote earlier on the topic. It is one of the reasons I suggested a 3-Way system.
Ideally we could make the system to have a flat response and a flat directivity index of at least 6dB at all frequencies.
With the budget the OP suggested for drivers and other constraints this is not going to be possible, hence we are shooting for the second best thing, a DI that smoothly increases with frequency. Anyway, read my original post on that.
Ciao T
Hi,
Okay. So they will in effect operate rather well coupled with rear walls. Almost too well.
As doug20 said, this means you are sitting right in a node of probably several room modes. TO precise, your sofa is in an ANTI-NODE, meaning there will very little bass output at any frequencies where the room has an eigentone.
You can see the effects of such things as speaker directivity and placement in room with a nice little on-line calculator:
hunecke.de | Loudspeakers Calculator
Have a look and see for yourself where you may best start placing the sofa and speakers. This calculator used to include the option to add room treatment as well, sadly this has been removed.
Try the Tannoy System 15 DMTII as speaker. This will share quite a few of the traits in the LF region with the kind of alignment I am proposing.
When it comes to room acoustics the site of Herr Huenecke has a number of further quite interesting calculators and articles.
No problem, if at all it will help.
You probably want to consider shifting the sofa a little, maybe to 18.5ft from the front wall (not 20 or 10, avoid such even divisions as halves, quarters of thirds, though thirds are better than quarters) as starting point. I find some fine tuning is usually beneficial.
Ideally you want to couple the listening position to all room modes in such a way that the frequency response is minimally disturbed by the room modes. This can be quite tricky to achieve, but it is possible. You may also want to consider some room treatment for higher frequencies, but with room modes you cannot really do much other than by physical arrangements.
Ciao T
Okay. So they will in effect operate rather well coupled with rear walls. Almost too well.
As doug20 said, this means you are sitting right in a node of probably several room modes. TO precise, your sofa is in an ANTI-NODE, meaning there will very little bass output at any frequencies where the room has an eigentone.
You can see the effects of such things as speaker directivity and placement in room with a nice little on-line calculator:
hunecke.de | Loudspeakers Calculator
Have a look and see for yourself where you may best start placing the sofa and speakers. This calculator used to include the option to add room treatment as well, sadly this has been removed.
Try the Tannoy System 15 DMTII as speaker. This will share quite a few of the traits in the LF region with the kind of alignment I am proposing.
When it comes to room acoustics the site of Herr Huenecke has a number of further quite interesting calculators and articles.
No problem, if at all it will help.
You probably want to consider shifting the sofa a little, maybe to 18.5ft from the front wall (not 20 or 10, avoid such even divisions as halves, quarters of thirds, though thirds are better than quarters) as starting point. I find some fine tuning is usually beneficial.
Ideally you want to couple the listening position to all room modes in such a way that the frequency response is minimally disturbed by the room modes. This can be quite tricky to achieve, but it is possible. You may also want to consider some room treatment for higher frequencies, but with room modes you cannot really do much other than by physical arrangements.
Ciao T
Hi,
For commercial studio monitors, have a look at Mackie's website, their manuals. You can find some info.
As for my own approach, design for maximum flat alignment (for free-field or near free-field use) and use different types of foam inserts in the port to damp the excessive LF output if the speaker is placed too close to walls. It does not work perfectly, but is quite effective and can be easily implemented in production.
You can read a bit about these speakers here:
Special Report: Chris Redmond on Abbingdon Music Research Part III: LS-77 Reference Class Professional Monitor Review - Equipment Reviews - Dagogo
Note among other things the problems the reviewer had when he used the speakers in his upstair room, which lacked both a solid floor and a solid ceiling (and had a listening distance of maybe 1.5m!).
Sadly he was very reluctant to mess with the resistors to adjust the lower to higher midrange balance, I think we could have adjusted the system to a reasonable flat response and his taste even in his rather subideal upstairs settings.
Having installed several systems now myself I found that the original +/-2dB adjustment I designed into the upper midrange and lower treble was not enough to cover the whole range of different domestic rooms (I found +/-4dB usually covers it well enough though), let alone to account for personal tastes. In factory trim the speakers are flat at 3m Distance with at least a meter behind and besides them.
If we include the personal tastes in this I have had to adjust the speakers by as much a difference as 12dB in the upper midrange/lower treble, which is staggering.
Ciao T
ThorstenL, interesting. Any (construction/technical) details? Regards.
For commercial studio monitors, have a look at Mackie's website, their manuals. You can find some info.
As for my own approach, design for maximum flat alignment (for free-field or near free-field use) and use different types of foam inserts in the port to damp the excessive LF output if the speaker is placed too close to walls. It does not work perfectly, but is quite effective and can be easily implemented in production.
You can read a bit about these speakers here:
Special Report: Chris Redmond on Abbingdon Music Research Part III: LS-77 Reference Class Professional Monitor Review - Equipment Reviews - Dagogo
Note among other things the problems the reviewer had when he used the speakers in his upstair room, which lacked both a solid floor and a solid ceiling (and had a listening distance of maybe 1.5m!).
Sadly he was very reluctant to mess with the resistors to adjust the lower to higher midrange balance, I think we could have adjusted the system to a reasonable flat response and his taste even in his rather subideal upstairs settings.
Having installed several systems now myself I found that the original +/-2dB adjustment I designed into the upper midrange and lower treble was not enough to cover the whole range of different domestic rooms (I found +/-4dB usually covers it well enough though), let alone to account for personal tastes. In factory trim the speakers are flat at 3m Distance with at least a meter behind and besides them.
If we include the personal tastes in this I have had to adjust the speakers by as much a difference as 12dB in the upper midrange/lower treble, which is staggering.
Ciao T
Hi Leo,
Just decided to do a quick run of the Tannoys in Mr. Hueneckes calculator.
Ignore anything above 500Hz, it would not be relevant to the speaker you are working on, with the Audax Mid and Horn Tweeter.
To get a better idea how midrange and tweeter will integrate into the room, the Triangle Celius 202 uses a similar (but less efficient) midrange and a horn loaded tweeter, so it is a good first order approximation.
Below 500Hz you can see what the room makes out of our overdamped LF response. I probably would be tempted to use a parametric EQ to pull down the spikes below 63Hz, above that the response is pretty good.
I placed the sofa at the golden ratio point in the room. The speakers placed approximately as you show.
Of course, this is only a simulator and you should take it with a pinch of salt.
Ciao T
Just decided to do a quick run of the Tannoys in Mr. Hueneckes calculator.
Ignore anything above 500Hz, it would not be relevant to the speaker you are working on, with the Audax Mid and Horn Tweeter.
To get a better idea how midrange and tweeter will integrate into the room, the Triangle Celius 202 uses a similar (but less efficient) midrange and a horn loaded tweeter, so it is a good first order approximation.
Below 500Hz you can see what the room makes out of our overdamped LF response. I probably would be tempted to use a parametric EQ to pull down the spikes below 63Hz, above that the response is pretty good.
I placed the sofa at the golden ratio point in the room. The speakers placed approximately as you show.
Of course, this is only a simulator and you should take it with a pinch of salt.
Ciao T
Attachments
Hi,
While we are playing with simulators, for fun I have spliced the LF response of the Tannoy System 15 DMT and the MF/HF response of the triangle Celius.
This should give a ballpark idea how the overall system might do in your room, of course, there is a fair bit of a fudge factor in that, so don't think "oh, this is what I'll get".
But I think it shows we stand a fighting chance with my suggested EBS bass alignment and the rest.
Ciao T
While we are playing with simulators, for fun I have spliced the LF response of the Tannoy System 15 DMT and the MF/HF response of the triangle Celius.
This should give a ballpark idea how the overall system might do in your room, of course, there is a fair bit of a fudge factor in that, so don't think "oh, this is what I'll get".
But I think it shows we stand a fighting chance with my suggested EBS bass alignment and the rest.
Ciao T
Attachments
HI Thorsten, thanks for the links and calculations. I will take precise measurements of the room so that since everybody is doing different plots, we can do them as close as possible.
I will play a little with those myself to see if I can learn to use them.
Anything else I can measure that could help?
Also, I am sure there is some software or recordings you can get to make the sound system play different frequencies to test it but is there one in particular that you would recommend?
Thanks.
Leo
I will play a little with those myself to see if I can learn to use them.
Anything else I can measure that could help?
Also, I am sure there is some software or recordings you can get to make the sound system play different frequencies to test it but is there one in particular that you would recommend?
Thanks.
Leo
Hi,
Plenty, but you need serious measurement gear for that. You do need the room hight.
There are tons out there. The problem is they all have limitations when used in a normal room. The biggest issue with measurements of speakers of the kind hobbyists and even most pro's can take is not how to get them, but how to interpret them...
Bascally, all common measurement methodes are lying about some aspects and the key is to know which and where.
TrueRTA is a piece of fairly easy to use software and can tell you if things are really badly wrong. I would always have it at hand for a "second opinion" compared to MLS based systems.
A number of pieces of software use what is called MLS (Maximum Length Sequence) for speaker measurements. These allow you to "window" the measurement so you can reduce the influence of room effects. I like Hobbybox, but then I'm German.
I also like the old Crown TEF Measurement system, maybe you can find one for rental?
I also use some unique test signals (in and out of phase dual mono pink noise) to aid setting up speakers in room and for testing pair matching "by ear", which is often still more meaningful than sheafs of MLS measurements to me...
Ciao T
Plenty, but you need serious measurement gear for that. You do need the room hight.
There are tons out there. The problem is they all have limitations when used in a normal room. The biggest issue with measurements of speakers of the kind hobbyists and even most pro's can take is not how to get them, but how to interpret them...
Bascally, all common measurement methodes are lying about some aspects and the key is to know which and where.
TrueRTA is a piece of fairly easy to use software and can tell you if things are really badly wrong. I would always have it at hand for a "second opinion" compared to MLS based systems.
A number of pieces of software use what is called MLS (Maximum Length Sequence) for speaker measurements. These allow you to "window" the measurement so you can reduce the influence of room effects. I like Hobbybox, but then I'm German.
I also like the old Crown TEF Measurement system, maybe you can find one for rental?
I also use some unique test signals (in and out of phase dual mono pink noise) to aid setting up speakers in room and for testing pair matching "by ear", which is often still more meaningful than sheafs of MLS measurements to me...
Ciao T
Actual measurements...
Ok here are the real measurements of the room.
It is 8 feet tall by the way.
Leo
Ok here are the real measurements of the room.
It is 8 feet tall by the way.
Leo
An externally hosted image should be here but it was not working when we last tested it.
Hi,
Looks like a typical english front room with Bay window.
For those of us who do metric, we are looking at 4.14m wide, 2.44m high and 7.6m in the longest dimension, without the window bay 7m.
So area is around 30 Squaremeter and Volume 73 cubic meter.
Very similar in fact to my old frontroom in London.
Solid floor or wood-frame with wooden floor boards? Ceiling? Walls solid?
Ciao T
Looks like a typical english front room with Bay window.
For those of us who do metric, we are looking at 4.14m wide, 2.44m high and 7.6m in the longest dimension, without the window bay 7m.
So area is around 30 Squaremeter and Volume 73 cubic meter.
Very similar in fact to my old frontroom in London.
Solid floor or wood-frame with wooden floor boards? Ceiling? Walls solid?
Ciao T
For measurements you need to buy this
http://www.amazon.com/M-Audio-MobilePre-Mobile-Preamp-Interface/dp/B0000TP57E
This
Parts-Express.com
ayton EMM-6 Electret Measurement Microphone | Dayton EMM-6 EMM6 measurement mic measurement microphone mic microphone electret mic electret microphone speaker mic test microphone test mic recording mic recording microphone Audio_Myou need a PC and Free software (HOLM is found in this forum) or ARTA.
Those are perfect for gated speaker measurements. If you do them in your room just remember that you need to have atleast 5 feet in every direction to not have early reflections (< 3ms).
People telling you you need exotic measuring tools are completely out of touch with you and your project.
If there are publishings on those disagreements I will read them ( read many links daily, Im the only one with broaden horizons, you are stuck in the 2 ch mindset). I didn't find disagreements with Toole that much most are just forum babbling so I do not accept that as proof since forums are full of too much subjective babble. I never found a reference for your opinion about not designing a flat response speaker either.
As for your "selling thier products"...Sean Olive is a PhD and published lots of things BEFORE Harman, He worked for the Canadian Research Council. Toole published many of his findings BEFORE harman.
In the end I think I will stick to following their speaker building theories instead of yours (A unknown online, not many build threads, with zero publications).
The OP can choose his path, he is kind of stuck becuase he needs someone's help and you are here.
HTguide.com or AVSforum.com would have been a better place for him but he is here and you are pushing him the way you like your speakers
Add to that:
Vance Dickason's The Loudspeaker Design Cookbook
Joseph D'Appolito's Testing Loudspeakers
You should also get a calibrated mic. The ECM8000 is a very good mic for the money, but you really should buy one that is calibrated and I bought mine HERE.
If you are planning to also measure room acoustics you should bite the bullet and get the premium or premium+.
Lastly, testing is a very complex and frustrating experience. It takes a lot of time to learn how to do it correctly. Experience is your best friend, but the only way you get that is by struggling with it. Experience teaches you what is artifact and what is real. Expect to post a lot of plots and questions before you understand what and how to do this.
The books I recommended are a good foundation to start with and they are not light light reading, but will be a very useful guide to getting what you want.
Unfortunately, this hobby is not like fishing. There is a lot to learn and it takes time. It will also take some money, as you no doubt are realizing. However, when the first project comes together and you actually see/hear what you made you will be very happy.
Vance Dickason's The Loudspeaker Design Cookbook
Joseph D'Appolito's Testing Loudspeakers
You should also get a calibrated mic. The ECM8000 is a very good mic for the money, but you really should buy one that is calibrated and I bought mine HERE.
If you are planning to also measure room acoustics you should bite the bullet and get the premium or premium+.
Lastly, testing is a very complex and frustrating experience. It takes a lot of time to learn how to do it correctly. Experience is your best friend, but the only way you get that is by struggling with it. Experience teaches you what is artifact and what is real. Expect to post a lot of plots and questions before you understand what and how to do this.
The books I recommended are a good foundation to start with and they are not light light reading, but will be a very useful guide to getting what you want.
Unfortunately, this hobby is not like fishing. There is a lot to learn and it takes time. It will also take some money, as you no doubt are realizing. However, when the first project comes together and you actually see/hear what you made you will be very happy.
I have no experience with the clone ECM8000, but that is a very good price for a mic that is calibrated and may be worth buying. I just don't know.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.