Hi,
I,d like to build a horn for 8PE21 to be put between B&C DE250 attached to FaitalPro LTH102 horn and 15'' woofer in OB (FaitalPro 15FH510).
I hoped I would be able to find tons of projects or plans for such a "horn friendly" driver but I couldn't find anything for the given application. Hence the thread.
The idea is to cover 250-2000Hz band without any (or very little) EQ. Something Avantgarde midrange horns like. I thought I would modify the project from speakerplans.com website:
Speakerplans.com
Instead of two 10'' drivers I'll use one 8PE21 and downsize the horn proportionately: instead 15x21cm thorat (for one 10'' driver) I'll have 12x16,8cm (proportionate reagarding Sd of the drivers). And by the same method the mouth width would be 48cm instead of 60.
The big question is:
Is it totally insane?
I'd appreciate any valueble comments, ideas etc. I tried to use Hornresp but propably too stupid for that. I didn't buy the 8PE21 yet so they are not a must. What matters is the frequency scope and, if possible, Xover-less design.
Thanks.
Chris
I,d like to build a horn for 8PE21 to be put between B&C DE250 attached to FaitalPro LTH102 horn and 15'' woofer in OB (FaitalPro 15FH510).
I hoped I would be able to find tons of projects or plans for such a "horn friendly" driver but I couldn't find anything for the given application. Hence the thread.
The idea is to cover 250-2000Hz band without any (or very little) EQ. Something Avantgarde midrange horns like. I thought I would modify the project from speakerplans.com website:
Speakerplans.com
Instead of two 10'' drivers I'll use one 8PE21 and downsize the horn proportionately: instead 15x21cm thorat (for one 10'' driver) I'll have 12x16,8cm (proportionate reagarding Sd of the drivers). And by the same method the mouth width would be 48cm instead of 60.
The big question is:
Is it totally insane?
I'd appreciate any valueble comments, ideas etc. I tried to use Hornresp but propably too stupid for that. I didn't buy the 8PE21 yet so they are not a must. What matters is the frequency scope and, if possible, Xover-less design.
Thanks.
Chris
To be honest, there is no free lunch when trying to extend a tractrix or LeCleach horn lower. It just doesn't work.
What you should consider is that group delay is affected by the horn at low frequencies. It is possible to change this by setting the rear volume and type of rear enclosure, but it is also effective to choose a conical horn and avoid horn loading.
Of course that would be a bold project indeed. Don't be discouraged.
What you should consider is that group delay is affected by the horn at low frequencies. It is possible to change this by setting the rear volume and type of rear enclosure, but it is also effective to choose a conical horn and avoid horn loading.
Of course that would be a bold project indeed. Don't be discouraged.
1. Make sure the wavefront is intact. Use a phase plug if necessary, although some would argue that 2kHz is OK without one.
2. Consider the narrowing directivity. The room walls are not going to be helpful here. Sure, it is good that higher frequencies don't reach the walls, but it is bad that the lows will be hemmed in.
I'm open to ideas since my knowledge about horns is quite limited. I read a lot though, but no experience in designing/building.
I would love the upper around 2000 Hz but that's not a fixed value. I just am aware that midrange horn in one of Avantgarde speakers covers more less 200-2000Hz and that's why I assumed it would be possible to build similar one.
The project from speakerplans I mentioned above has 180-1500Hz coverage so my thought was that smaller/tighter horn would play a little bit higher on the both ends. But, of course, I may be wrong.
I would love the upper around 2000 Hz but that's not a fixed value. I just am aware that midrange horn in one of Avantgarde speakers covers more less 200-2000Hz and that's why I assumed it would be possible to build similar one.
The project from speakerplans I mentioned above has 180-1500Hz coverage so my thought was that smaller/tighter horn would play a little bit higher on the both ends. But, of course, I may be wrong.
Hello!
Just today I looked over the data of multiple midwoofers to find one to work 130-1100hz.
I also want something that you mentioned, OB (or sealed, I have 18FH500 now), mid horn, and the DE250 in horn. What I can tell you now, is that you want to be able to cross the DE250 lower than 2k, say at 1k. For this you need a bigger horn. I tried some horns and now have the RCF H100, and recently bought 2 Eminence H290. I will try them soon, no time yet.
The 'scene', voice intelligibility and all instruments sound better when DE250 is crossed lower, at 1kHz or 1.1kHz. Going lower is not ok for RCF H100, maybe you can find a bigger horn to try. Dr. Geddes studied and found that the brain needs all >1k content from 1 source, if I am not mistaken.
So my advice is to first see how you like the DE250 crossed lower and then maybe adjust the midhorn specs.
I had a tractrix loaded with Visaton FRS8M, 25cm throat area, 2400cm mouth, 50cm deep if I remember OK, here is the response.
220tx-frs8m-horn-only-spl — imgbb.com
Good luck!
Just today I looked over the data of multiple midwoofers to find one to work 130-1100hz.
I also want something that you mentioned, OB (or sealed, I have 18FH500 now), mid horn, and the DE250 in horn. What I can tell you now, is that you want to be able to cross the DE250 lower than 2k, say at 1k. For this you need a bigger horn. I tried some horns and now have the RCF H100, and recently bought 2 Eminence H290. I will try them soon, no time yet.
The 'scene', voice intelligibility and all instruments sound better when DE250 is crossed lower, at 1kHz or 1.1kHz. Going lower is not ok for RCF H100, maybe you can find a bigger horn to try. Dr. Geddes studied and found that the brain needs all >1k content from 1 source, if I am not mistaken.
So my advice is to first see how you like the DE250 crossed lower and then maybe adjust the midhorn specs.
I had a tractrix loaded with Visaton FRS8M, 25cm throat area, 2400cm mouth, 50cm deep if I remember OK, here is the response.
An externally hosted image should be here but it was not working when we last tested it.
The sound was very good, at that time I crossed it at 2400Hz to some dome tweeters. 220tx-frs8m-horn-only-spl — imgbb.com
Good luck!
Hello arcgotic,
Thanks for the ideas. However, I tried to play DE250 down to 1200Hz and it was good unless you didn't play loud. I think my ears are very sensitive regarding drivers' distorsion and I experienced some harshness I would like to avoid. I think that 1500Hz is the lowest point for me. From the other hand these DE250 drivers are quite new, maybe they just need some brake-in...
Thanks for the ideas. However, I tried to play DE250 down to 1200Hz and it was good unless you didn't play loud. I think my ears are very sensitive regarding drivers' distorsion and I experienced some harshness I would like to avoid. I think that 1500Hz is the lowest point for me. From the other hand these DE250 drivers are quite new, maybe they just need some brake-in...
arcgotic,
I was thinking about FaitalPro HP140 to go lower but DE250 sound so good that I it would be a shame not to try to put them into some suitable system and listen to for some time...
I am happy with the open baffle low end as well. What I'm missing is the good in-between.
I tried open baffle midrange, something like Linkwitz' LX521 but it didn't sound well to my ears...
I was thinking about FaitalPro HP140 to go lower but DE250 sound so good that I it would be a shame not to try to put them into some suitable system and listen to for some time...
I am happy with the open baffle low end as well. What I'm missing is the good in-between.
I tried open baffle midrange, something like Linkwitz' LX521 but it didn't sound well to my ears...
DE250 does sound harsh at higher volume compared to radian and peerless CD’s
I keep saying that but nobody listens
Ps check this out for reference. It’s a well designed midhorn for the excellent 8pe21 driver 135 hz Mid Bass Horn - The Paper Horn by Inlow Sound
Last edited:
DE250 does sound harsh at higher volume compared to radian and peerless CD’s
I keep saying that but nobody listens
[/url]
Agreed.
Hi frangus,
Thanks for the inlowsound link, I read that some time ago. The problem is that my experience with horn designs is next to none so, for the very first build I would prefer something already designed and checked. Or at least something proposed by a experienced person. For example a horn similar in construction to E. Forker 300Hz tractrix horn but modified to work with the given driver and expected frequency band. Of course, I'm aware that giving precise values (like throat, mouth dimensions, lenght of the horn etc.) maybe by far more complicated but I still belive that some rough dimension can be quite easy calculated by a person who built a horn or two...
Once again, I'm not sticked to the 8PE21, maybe other drivers are more suitable for the given fq band.
Thanks for the inlowsound link, I read that some time ago. The problem is that my experience with horn designs is next to none so, for the very first build I would prefer something already designed and checked. Or at least something proposed by a experienced person. For example a horn similar in construction to E. Forker 300Hz tractrix horn but modified to work with the given driver and expected frequency band. Of course, I'm aware that giving precise values (like throat, mouth dimensions, lenght of the horn etc.) maybe by far more complicated but I still belive that some rough dimension can be quite easy calculated by a person who built a horn or two...
Once again, I'm not sticked to the 8PE21, maybe other drivers are more suitable for the given fq band.