Ok, the advantage is that the dessign of the box is quite simple and the crossover should be simple as well...
Now, I need to understand "decent"...
Can the Pioneer B20 be called "decent" ?
There is a few Zilla (Godzilla?) projects using this one, but no dipole.
Or does "decent" only starts with the well known Fostex units ? More in the driver(s) but no filter at all here... Might be an option... and provides almost a "sure shot"...
Other avenues to explore !!!
Decent means something that is not terrible. No need to go to esoteric brands like Fostec. I look for pleated surrounds not roles. Otherwise the pioneer looks fine. I use a B&C, without the wizzer - I'm not fond of wizzers. In the surrounds you are looking for 200 - 2 Khz basically. It would be good if it died above about 3-4 kHz. The very high frequencies (> 4 kHz) are virtually never present at long distances or after a reflection so not having them gives the auditory impression of distance. HF loss is one of our predominate determinations of distance. Our ears are well calibrated to the HF loss that occurs in nature.
PS. What crossover? Its a full range.
PS. What crossover? Its a full range.
Following the "cheap dipole full range", I did just a bit of browsing and it seems that there are options in euraope as well (as if I doubt it 
)...
Monacor (as often) as a few units that are full range and a bargain, the SP-200MX (8') can be found for 30€ in a French web shop (not one known for good prices)...
The SP-165X (6') is only 20€
Beyma (no, I niether work for them nor have shares in the company ) as well offer the 8AGN that is on the cheap side (less then 40€).
Completing the surrounds for less than 80€ each (top) open some more "horizon" for the fronts that might be useful... And only one crossover to worry about...
It brakes my strategy of starting "little" with a configuration that would be used for surrounds and eventually for fronts, but at the same time we have a bit of budget back either for fronts... or sub
...
Are we getting "somewhere" here ?
)...Monacor (as often) as a few units that are full range and a bargain, the SP-200MX (8') can be found for 30€ in a French web shop (not one known for good prices)...
The SP-165X (6') is only 20€
Beyma (no, I niether work for them nor have shares in the company
) as well offer the 8AGN that is on the cheap side (less then 40€).Completing the surrounds for less than 80€ each (top) open some more "horizon" for the fronts that might be useful... And only one crossover to worry about...
It brakes my strategy of starting "little" with a configuration that would be used for surrounds and eventually for fronts, but at the same time we have a bit of budget back either for fronts... or sub
...Are we getting "somewhere" here ?
jm_kzo said:
I've done something very similar to this- using the Dayton Quatro 15 and the 300w BASH amp, in a 2 foot cube (60cm x 60cm x 60cm, roughly). About 200 liters, give or take, per cabinet. Vents were two 4" diameter ports per box, tuned to about 23 Hz.
Two of those enclosures were able to fill a 400 seat auditorium (theater style, about 25m x 15m x 3m ceiling) room in a hotel, with enough SPL to make your shirt literally shake with the sound, without breaking a sweat. And surprisingly, they seemed to have very low distortion, at least subjectively. Our crossover point (from them, to 12" 3-way cabinets for L, C and R) was about 60 Hz, IIRC.
I'd think the Dayton DVC would be even better... better magnetic motor, longer X-max. Should be able to remain linear up to 80 Hz, even better than the Quatro, I'd expect.
As for drivers in the mid-high cabinets... have you thought about maybe a 10" woofer? The Eminence Delta 10 might just work. Looks like with some crossover trickery (staggered/gapped lowpass/highpass, etc), that it could be just the thing. And even with just 3.5mm X-max... it's a 10" woofer. I can't see it having problems down to 80 Hz!! Since you're using horn mid-high drivers, a 1500 Hz acoustic crossover (maybe electrical crossover of about 1KHz on the woofer lowpass, and 2KHz on the horn highpass, as a start, both low-electrical-Q?) might just do it...
Regards,
Gordon.
I ahve been working in my room all week end and make quite good progress...
I will probably have it damped in the nex 3 weeks (though not optimistic as I have 2 socially busy week-ends coming up)... I will then be in a position to rent so PA stuff and see (listen ?) how it sounds in the "real" situation...
As well, I have quickly "sketched up" my room... Drawing it, (thank you Seb) it is making the "surrounds coverage angle" challenge even more obvious...
The dipole option is really gaining some advantage here, specially if it does not break the budget...
I will probably have it damped in the nex 3 weeks (though not optimistic as I have 2 socially busy week-ends coming up)... I will then be in a position to rent so PA stuff and see (listen ?) how it sounds in the "real" situation...
As well, I have quickly "sketched up" my room... Drawing it, (thank you Seb) it is making the "surrounds coverage angle" challenge even more obvious...
The dipole option is really gaining some advantage here, specially if it does not break the budget...
Attachments
As well, browsing a bit, it seems these little Monacor SPH-60X are quite popular and are in quite a few kits...
Only 5' though... Maybe a bit "small"...
And another 3D pic of the room... I have drawn main speakers under the screen (so as to confuse everyone )
Only 5' though... Maybe a bit "small"...
And another 3D pic of the room... I have drawn main speakers under the screen (so as to confuse everyone
)Attachments
Some news after a long time silent...
The project is not dead... It never had as much life as now!!!
After discussions with other French DIYers and the reseller, it seems that the less risky/better quality configuration for the front speakers will be the B&C DE250 + H100 combined with the Beyma 10G40.
We were afraid the 8' would be a bit limited (or would have to be pushed) and then between the 10', it seems the 10G40 is really having an edge on the SM110/N (on paper distorsion is less, people that were able to listen both said it was better "by hear" as well).
I considered the 18Sound XT1086 horn, but I failed to find users and it does not seem easy to source in France (I could probabaly source it in Germany, but it would mean 3 different orders in 3 different shops... lazzy ?). So H100 it will be.
I am as well set on using full rangers for the rears (possibly the Beyma 8AG/N[/n], but I will sort this out later.
I think I will order the drivers for the front speakers today (if time allows) or tomorrow.
Once the front will be sorted (filtered, etc.) I will order 2 full rangers and will test monopole and dipole configuration. If monopole are right that will be fine, if dipole are required I will order 2 more full range.
That were the news for today...
More later.
The project is not dead... It never had as much life as now!!!
After discussions with other French DIYers and the reseller, it seems that the less risky/better quality configuration for the front speakers will be the B&C DE250 + H100 combined with the Beyma 10G40.
We were afraid the 8' would be a bit limited (or would have to be pushed) and then between the 10', it seems the 10G40 is really having an edge on the SM110/N (on paper distorsion is less, people that were able to listen both said it was better "by hear" as well).
I considered the 18Sound XT1086 horn, but I failed to find users and it does not seem easy to source in France (I could probabaly source it in Germany, but it would mean 3 different orders in 3 different shops... lazzy ?). So H100 it will be.
I am as well set on using full rangers for the rears (possibly the Beyma 8AG/N[/n], but I will sort this out later.
I think I will order the drivers for the front speakers today (if time allows) or tomorrow.
Once the front will be sorted (filtered, etc.) I will order 2 full rangers and will test monopole and dipole configuration. If monopole are right that will be fine, if dipole are required I will order 2 more full range.
That were the news for today...
More later.
Drivers and horns for 2 main speakers were delivered on Friday (2 x Beyma 10G40 + 2 x B&C DE250 + 2 x RCF H100).
I had to tinker quite a lot to get SpeakerWorkshop configuration that worked but I finally got there yesterday evening and I was able to do my first impedance measures.
I will build a temporary box this evening to get impedance measured in box and shall be ready to start simulating the cross-over from that point...
First impressions : those drivers are booldy impressive. The build and look are more than serious and they are as heavy as solid steel!!!
The sound they produce just from the output of the sound card (700mV) is really surprising as well. I would never have thought that they would be that load with "nothing"!!!
I will try to post some pictures tonight.
I had to tinker quite a lot to get SpeakerWorkshop configuration that worked but I finally got there yesterday evening and I was able to do my first impedance measures.
I will build a temporary box this evening to get impedance measured in box and shall be ready to start simulating the cross-over from that point...
First impressions : those drivers are booldy impressive. The build and look are more than serious and they are as heavy as solid steel!!!
The sound they produce just from the output of the sound card (700mV) is really surprising as well. I would never have thought that they would be that load with "nothing"!!!
I will try to post some pictures tonight.
Hi all, I had not updated this thread for a while, and I apologize for this.
I have been quite busy with finishing my HT room and focused on it instead of this project...
Devils is in the details as you say, and it is what suck time!
Anyway this came to a (first) conclusion around Christmas time.
It is still missingg decoration and furniture, but is it now useable.
The front looks like this:
And the back look like that:
So, when this cleared from my mind, I could focus again on my speaker project...
You might remember that the drivers I choose where the B&C DE250 compression driver for the high, loaded by a H100 horn and a Beyma 10G40 for the mid.
My target is to cover 20K to 80Hz with those and add a sub (flavour to be decided, but "financially efficient ).
So I had the driver and built a test box for them in order to start measurement (using a home made "Wallin 2" mic pream, a WM61A Pana mic, SpeakerWorkshop and associated "jig").
The box look like this :
It is 17 x 36 x 50 (centimeters internal), so the "raw" volume is 30l (minus drivers and events). This is probabaly too much as I am targeting 23l tuned at 60Hz (F3=59Hz).
I did not work on the box or alignment a lot yet... I decided to first focus on the filter...
And it is where my woes started....
[tbc]
I have been quite busy with finishing my HT room and focused on it instead of this project...
Devils is in the details as you say, and it is what suck time!
Anyway this came to a (first) conclusion around Christmas time.
It is still missingg decoration and furniture, but is it now useable.
The front looks like this:
And the back look like that:
So, when this cleared from my mind, I could focus again on my speaker project...
You might remember that the drivers I choose where the B&C DE250 compression driver for the high, loaded by a H100 horn and a Beyma 10G40 for the mid.
My target is to cover 20K to 80Hz with those and add a sub (flavour to be decided, but "financially efficient
).So I had the driver and built a test box for them in order to start measurement (using a home made "Wallin 2" mic pream, a WM61A Pana mic, SpeakerWorkshop and associated "jig").
The box look like this :
It is 17 x 36 x 50 (centimeters internal), so the "raw" volume is 30l (minus drivers and events). This is probabaly too much as I am targeting 23l tuned at 60Hz (F3=59Hz).
I did not work on the box or alignment a lot yet... I decided to first focus on the filter...
And it is where my woes started....
[tbc]
[continued]
The filter design has been long and painful... I have abeen a bit on and off on this project, it it was long and hard work nonetheless.
I was really starting from ground 0 and it took me quite some time to understand the basic concepts, but as well to get a measurement-simulation combo that worked which really was necessary to me .
I made a few false start and explored a few dead ends, came back on my steps, started again...
Though there is quite some information available on the web on XO design and speaker measurement, I found it often difficult to understand waht in the mass of information ammplies to your set up and how it applies.
Anyway, I finally got in a position where I can model a XO with Speaker Workshop, measure it and check they are quite close one from each other (1dB to 1.5dB max).
Regarding the filter itself, I tried to follow the "Le Cléach" concepts, exactly a variation of these concepts proposed by Francis Brooke, another French well known DIYer (I think Jean-Michel Le Cléach is well known here as well).
After much iterations, I have currently narrowed down my options to 2 filters.
The first one I called "v6.1" looks like this.
Key:
Measure
Simulation
10G40 target, simulation and measure (dotted line)
DE250 target, simulation and measure (dotted line)
Reverse null measure
The second one, that I call "v6.3" looks like this (same key).
I have not "voiced" any option yet and I must say that I only hear little differences between 2 versions (but as I have to mount/dismount) filters between 2 tests I cannot really do a quick A/B comparison.
Version 6.1 seems to have a cleaner/more punchy/sharper low medium (might even be "un natural"), but high/high mids tend to be "tiring" and can sound a bit like "disorganised" (hard to translate this).
I would like to work on the enclosure now has I do not get the bass output promised by WinISD or UniBox and it is impacting listening tests.
Currently, bass starts to roll off above 300Hz and there there is hardly "anything" below 200Hz. Simulation says that F3 should be around 60Hz... Not sure where the missing bass has gone.
The filter design has been long and painful... I have abeen a bit on and off on this project, it it was long and hard work nonetheless.
I was really starting from ground 0 and it took me quite some time to understand the basic concepts, but as well to get a measurement-simulation combo that worked which really was necessary to me .
I made a few false start and explored a few dead ends, came back on my steps, started again...
Though there is quite some information available on the web on XO design and speaker measurement, I found it often difficult to understand waht in the mass of information ammplies to your set up and how it applies.
Anyway, I finally got in a position where I can model a XO with Speaker Workshop, measure it and check they are quite close one from each other (1dB to 1.5dB max).
Regarding the filter itself, I tried to follow the "Le Cléach" concepts, exactly a variation of these concepts proposed by Francis Brooke, another French well known DIYer (I think Jean-Michel Le Cléach is well known here as well).
After much iterations, I have currently narrowed down my options to 2 filters.
The first one I called "v6.1" looks like this.
Key:
Measure
Simulation
10G40 target, simulation and measure (dotted line)
DE250 target, simulation and measure (dotted line)
Reverse null measure
The second one, that I call "v6.3" looks like this (same key).
I have not "voiced" any option yet and I must say that I only hear little differences between 2 versions (but as I have to mount/dismount) filters between 2 tests I cannot really do a quick A/B comparison.
Version 6.1 seems to have a cleaner/more punchy/sharper low medium (might even be "un natural"), but high/high mids tend to be "tiring" and can sound a bit like "disorganised" (hard to translate this).
I would like to work on the enclosure now has I do not get the bass output promised by WinISD or UniBox and it is impacting listening tests.
Currently, bass starts to roll off above 300Hz and there there is hardly "anything" below 200Hz. Simulation says that F3 should be around 60Hz... Not sure where the missing bass has gone.
Hello Jean-Michel,
Well, first off I'd like to say that I like how the room came out. I would have done differently with the wood tiling and floor, but I really like the colours and build.
I also like the test box and your measurement arrangement, both very simple and clever, straight forward approaches.
This is where I'd like to ask some questions before dealing with the filter details.
Are all measurements on axis? If so, the filters seem to significantly shift the main lobe upwards, v6.1 more so than v6.3. This usually indicates either too large mounting distance and/or too strong acoustic phase shift (uncompensated diaphragm offset).
You can see it in the upper range of the 10G40 just below the crossover frequency: the bump around 1.3kHz seems to shift like 100Hz upwards. This also shows through in the reverse polarity plot, again more so in the plot of v6.1 than v6.3.
This phenomenon significantly influences the mid fequency coverage throughout the listening room, as the acoustical crossover point audibly shifts when moving left or right throug the room. This should also be measurable with the microphone off center (i.e. subsequently moving the microphone a couple of cm to either side and taking subsequent measurements).
Did you consider a digital crossover as a design aid (for prototyping purposes)? Can even be had in software while using Speaker Workshop.
I like v6.3 as the starting point for v6.4: compensating for the horn length (delay) while also measuring phase response (on axis) and polar response (off axis) as described above.
The delay can only be accomplished reasonably in the digital domain, because otherwise you would end up requiring a huge amount of passive components in order to go through iteration steps.
You are essentially describing tweeter distortion through mechanical modulation (too large diaphragm excursion, too low acoustical crossover point).
But v6.3 looks way better in that regard. It should sound a lot cleaner in the upper end while having a more laid back mid range.
The H100 can't load the DE250 down to it's lowest possible corner frequency. But the 10G40 is forgiving enough to be used that far up (in a high efficiency HT application).
This steep rollof is clearly caused by some kind of (electrical or acoustical) filtering action.
As you describe that you can't hear any low frequency output, I recommend an electrical measurement after the amplifier output (both before and after the crossover circuit) using an attenuator before the soundcard input. I suspect a configuration error...
You also mentioned that you didn't look too much into box alignment as of yet. Please post your reflex port dimensions and your T/S parameters (in case they deviate from the datasheet).
As for alignment steps, simply use sand filled up in 1l plastic bags or 1l wood/plastic/styrofoam blocks for playing with the internal volume.
Cheers,
Sebastian.
jm_kzo said:
Well, first off I'd like to say that I like how the room came out. I would have done differently with the wood tiling and floor, but I really like the colours and build.
I also like the test box and your measurement arrangement, both very simple and clever, straight forward approaches.
This is where I'd like to ask some questions before dealing with the filter details.
Are all measurements on axis? If so, the filters seem to significantly shift the main lobe upwards, v6.1 more so than v6.3. This usually indicates either too large mounting distance and/or too strong acoustic phase shift (uncompensated diaphragm offset).
You can see it in the upper range of the 10G40 just below the crossover frequency: the bump around 1.3kHz seems to shift like 100Hz upwards. This also shows through in the reverse polarity plot, again more so in the plot of v6.1 than v6.3.
This phenomenon significantly influences the mid fequency coverage throughout the listening room, as the acoustical crossover point audibly shifts when moving left or right throug the room. This should also be measurable with the microphone off center (i.e. subsequently moving the microphone a couple of cm to either side and taking subsequent measurements).
Did you consider a digital crossover as a design aid (for prototyping purposes)? Can even be had in software while using Speaker Workshop.
I like v6.3 as the starting point for v6.4: compensating for the horn length (delay) while also measuring phase response (on axis) and polar response (off axis) as described above.
The delay can only be accomplished reasonably in the digital domain, because otherwise you would end up requiring a huge amount of passive components in order to go through iteration steps.
You are essentially describing tweeter distortion through mechanical modulation (too large diaphragm excursion, too low acoustical crossover point).
But v6.3 looks way better in that regard. It should sound a lot cleaner in the upper end while having a more laid back mid range.
The H100 can't load the DE250 down to it's lowest possible corner frequency. But the 10G40 is forgiving enough to be used that far up (in a high efficiency HT application).
This steep rollof is clearly caused by some kind of (electrical or acoustical) filtering action.
As you describe that you can't hear any low frequency output, I recommend an electrical measurement after the amplifier output (both before and after the crossover circuit) using an attenuator before the soundcard input. I suspect a configuration error...
You also mentioned that you didn't look too much into box alignment as of yet. Please post your reflex port dimensions and your T/S parameters (in case they deviate from the datasheet).
As for alignment steps, simply use sand filled up in 1l plastic bags or 1l wood/plastic/styrofoam blocks for playing with the internal volume.
Cheers,
Sebastian.
Sorry about being really late to the party.
The dudes at the loudspeakerkit have several kits that would suit your purposes:
This one is below your budget:
http://www.theloudspeakerkit.com/shop/productdetails.asp?ProductID=84&ProcessType=1
But sounds like it would pretty much suit your purposes
And this one is just over your budget, and probably comes with bigger bragging rights:
http://www.theloudspeakerkit.com/shop/productdetails.asp?ProductID=85&ProcessType=1
The dudes at the loudspeakerkit have several kits that would suit your purposes:
This one is below your budget:
http://www.theloudspeakerkit.com/shop/productdetails.asp?ProductID=84&ProcessType=1
But sounds like it would pretty much suit your purposes
And this one is just over your budget, and probably comes with bigger bragging rights:
http://www.theloudspeakerkit.com/shop/productdetails.asp?ProductID=85&ProcessType=1
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.