I'm hoping for some help. This is my first delve into the world of wide range speakers so please forgive the ignorant questions. I have a couple of diy builds under my belt and want to try something different and not involving a crossover...
I like the size and attributes that are described of the CHR-70 microtower and I think they will suit my purposes well. However, I see that the Alpair 7.3 is considered superior to the CHR-70 and as such I'm really interested in knowing if anyone has built or modelled an Alpair 7.3 microtower bipole (preferably in a castle configuration).
I have seen the Alpair 7.3 HT design by 11opas (with feedback from Dave, P-10 and Scott). These look wonderful but I am after a different aesthetic which leads me to my questions. Given it is ML-TL can you change the cross section profile if you keep the height constant. I am thinking a square such as the microtower or a curved cabinet similar to the Mirage Omni 550 with either a flat or backward sloping top.
Is there a tried and tested design out there which I have been unable to dig up that I could be pointed to?
If greater minds than me are willing to present plans or advise I will build and provide a build log for everyone's enjoyment.
I'm up for the more complex woodworking challenge of curved cabinets but want to make sure the effort will be rewarded with the best possible sound!
Any help or advice would be gratefully received.
Thank you, Andrew
I like the size and attributes that are described of the CHR-70 microtower and I think they will suit my purposes well. However, I see that the Alpair 7.3 is considered superior to the CHR-70 and as such I'm really interested in knowing if anyone has built or modelled an Alpair 7.3 microtower bipole (preferably in a castle configuration).
I have seen the Alpair 7.3 HT design by 11opas (with feedback from Dave, P-10 and Scott). These look wonderful but I am after a different aesthetic which leads me to my questions. Given it is ML-TL can you change the cross section profile if you keep the height constant. I am thinking a square such as the microtower or a curved cabinet similar to the Mirage Omni 550 with either a flat or backward sloping top.
Is there a tried and tested design out there which I have been unable to dig up that I could be pointed to?
If greater minds than me are willing to present plans or advise I will build and provide a build log for everyone's enjoyment.
I'm up for the more complex woodworking challenge of curved cabinets but want to make sure the effort will be rewarded with the best possible sound!
Any help or advice would be gratefully received.
Thank you, Andrew
IINM, Dave has modeled a variant of the microtower for A7.3 - I could very well even have a set of drawings somewhere in my e-mail archives - there must be 5 or 6 times as many designs as I've yet had time to build.
As the questions of adjusting enclosure dimensions, - with an MLTL, you can alter the aspect ratio of Wx D that make up the CSA, but not the line length, driver location and terminus location/dimensions.
Today seems to be great opportunity for me to chatter on about this design - I've built a total of 3 pairs now, and much prefer the Castle version with second driver mounted on top & up-firing.
If you're up for a curved enclosure such as the Omni, calculating the exact CSA might be easier than actually constructing them. I've tried a couple over the years, and CCM curves cost money (and time) - whether you use rubber ply and vacuum bagging, or KerfCore, etc
As the questions of adjusting enclosure dimensions, - with an MLTL, you can alter the aspect ratio of Wx D that make up the CSA, but not the line length, driver location and terminus location/dimensions.
Today seems to be great opportunity for me to chatter on about this design - I've built a total of 3 pairs now, and much prefer the Castle version with second driver mounted on top & up-firing.
If you're up for a curved enclosure such as the Omni, calculating the exact CSA might be easier than actually constructing them. I've tried a couple over the years, and CCM curves cost money (and time) - whether you use rubber ply and vacuum bagging, or KerfCore, etc
Hi Chris, thanks for the feedback. You have confirmed my thinking on CSA vs length for the ML-TL. The question that follows would be the effect on changing baffle width on performance.
For example if I recreated 11opas' design in a curved design I could maintain the baffle width, volume, length and CSA fairly easily. However if I went for the traditional micro tower design with a square CSA then the baffle width will increase. Being a dipole with an up firing driver I think this will have less impact than in a single driver cabinet but will it affect room placement and performance etc...
Thanks again
For example if I recreated 11opas' design in a curved design I could maintain the baffle width, volume, length and CSA fairly easily. However if I went for the traditional micro tower design with a square CSA then the baffle width will increase. Being a dipole with an up firing driver I think this will have less impact than in a single driver cabinet but will it affect room placement and performance etc...
Thanks again
ps I'm planning on using a translam technique for the curved cabinet build which means a fair bit of work to design but then a CNC machine will cut all the layers creating a relatively straightforward build. It is however a fairly inefficient use of material but will provide consistent results.
Thanks Dave, so just confirming if the port dimensions you quote above are used then the 7.3s can just drop in to the standard micro tower cabinets (driver cutouts excepted)? The plans you knocked up for 11opas were marginally taller, had a larger front firing port and a larger volume.
Sorry for the newbie questions
Sorry for the newbie questions
Yes. for a pair of A7.3 in microTower.
You'll have to remind what that enclosure is. Link?
dave
Member
Joined 2009
Paid Member
I can attest to the good results to be obtained from this type of enclosure. I used a different MA designed driver but the box does wonders with the bass.
http://www.diyaudio.com/forums/full-range/220047-martello-2-mini-tower-single-2-x-4-a.html
http://www.diyaudio.com/forums/full-range/220047-martello-2-mini-tower-single-2-x-4-a.html
So, I've been blocked by the love of my life from getting the A7s due to the cost... I know the futility of going down that road so I'm now back to the original plan of CHR-70's which to be honest im still super excited about.
Now I'm locking down some details I have a few questions
Do the CHR-70s come with mounting screws? I know the A7s do but see no info for the cheaper drivers.
I'm looking to mate the speakers to a sub for HT and potentially music use if necessary. I believe the micro towers go down to low/mid 40s so was thinking of crossing at about 80 for HT. Any advice here gratefully received. My current thinking is RSS315HF-4 with the SPA500 plate amp in a 2cubic foot sealed box (ish). This set up seems to be able to do be a good option for music use and I am even thinking of eventually getting a pair and crossing at 180/200 to take allow the full ranges a bit off relief at the bottom end which should open up the rest of the range. Please anyone if I'm off track jump in!
This will also give me a good set of subs for upgrades in the future. I'm still hankering for the A7s
I have seen a few vague post from Bob Brines (or about Bob) about his subs for his full range system being a pair and crossed at 200. Does anyone have any details on drivers, amp and set up? Bob if you feel like chiming in with specifics it would be much appreciated.
Last question regards running in the drivers. Can you run them all off one amp (say a cheap t amp) in a set up which keeps total impedance between 4 and 8 ohms at low power for the required period...? Or is there another better, more efficient way?
Thanks to all who have helped so far. The CHR drivers are I in the post and I'm super excited to get cracking (sub options still tbd - anything will be better than current cheap (and dead and not worth fixing) box I have. Currently prepping to do some quick MDF boxes as per the P10 plan to get things started and will then set to work on the more complicated curved can build... Sucker for punishment but will be worth it and besides I love the woodwork!
Andy
Now I'm locking down some details I have a few questions
Do the CHR-70s come with mounting screws? I know the A7s do but see no info for the cheaper drivers.
I'm looking to mate the speakers to a sub for HT and potentially music use if necessary. I believe the micro towers go down to low/mid 40s so was thinking of crossing at about 80 for HT. Any advice here gratefully received. My current thinking is RSS315HF-4 with the SPA500 plate amp in a 2cubic foot sealed box (ish). This set up seems to be able to do be a good option for music use and I am even thinking of eventually getting a pair and crossing at 180/200 to take allow the full ranges a bit off relief at the bottom end which should open up the rest of the range. Please anyone if I'm off track jump in!
This will also give me a good set of subs for upgrades in the future. I'm still hankering for the A7s
I have seen a few vague post from Bob Brines (or about Bob) about his subs for his full range system being a pair and crossed at 200. Does anyone have any details on drivers, amp and set up? Bob if you feel like chiming in with specifics it would be much appreciated.
Last question regards running in the drivers. Can you run them all off one amp (say a cheap t amp) in a set up which keeps total impedance between 4 and 8 ohms at low power for the required period...? Or is there another better, more efficient way?
Thanks to all who have helped so far. The CHR drivers are I in the post and I'm super excited to get cracking (sub options still tbd - anything will be better than current cheap (and dead and not worth fixing) box I have. Currently prepping to do some quick MDF boxes as per the P10 plan to get things started and will then set to work on the more complicated curved can build... Sucker for punishment but will be worth it and besides I love the woodwork!
Andy
@Crankyajc
The A7s are great! May I suggest that if you save a few weeks more you won't regret it. Maybe some fewer beers or not going out for dinner?
The A7 are one of the best drivers of it's size... but you can have a very cheap option with the new CHN-70, they are receiving very good reviews.
The FH3 or pensil would be nice builds.
Good luck!
The A7s are great! May I suggest that if you save a few weeks more you won't regret it. Maybe some fewer beers or not going out for dinner?
The A7 are one of the best drivers of it's size... but you can have a very cheap option with the new CHN-70, they are receiving very good reviews.
The FH3 or pensil would be nice builds.
Good luck!
+2 gaston re bang for buck with the CHN70s - - but the T/S parameters might require retuning of enclosures - they do drop into the FH3s nicely
I'm not sure how much time Dave / Scott or others have had to revisit their entire design catalogs - and even if they had posted on the subject, until I actually build a pair, I tend to forget
I'm not sure how much time Dave / Scott or others have had to revisit their entire design catalogs
- and even if they had posted on the subject, until I actually build a pair, I tend to forget
Andy - to answer your #13 above - sounds like a methodical enough plan - until of course you change your mind
The default THX XO of 80Hz is probably wise - although I've gone as high as 120 when using an A7 as centre in previous set-up
Yes, you can break them in as you've described
I think the drivers Bob is using for subs are a Dayton 12"?
If not too late to talk you out of it, try a decent plywood (baltic birch, etc) instead of MDF
The default THX XO of 80Hz is probably wise - although I've gone as high as 120 when using an A7 as centre in previous set-up
Yes, you can break them in as you've described
I think the drivers Bob is using for subs are a Dayton 12"?
If not too late to talk you out of it, try a decent plywood (baltic birch, etc) instead of MDF
I have stereo subs. They are designed to be standard 24" stands for whatever goes on top any given day. They are Dayton RSS315HF-4's in 2ft^3 sealed. They are powered by a Crown XLS 1500. The cross-over/DSP is a nanoDIGI. The larger the driver in the tops, the lower the XO. 200-250Hz LR4 seems to work well with the A7's and A10's.
Bob
Bob
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