1501FE Project

[4313B]

Does 4.2 cubic ft seem about right?

Greg used it in a 4.2 cubic foot volume tuned to 32 Hz and yes, WinISD does yield smaller volumes with less bandwidth.

I do have a pair of enclosures in progress that are something like 3 cubic feet tuned a bit higher for more impact. The AutoCAD drawing is on my laptop which I don't have access to at the moment. All the MDF is already in the garage stacked next to the table saw and, true to form, it's been there for months.

My plan was to build "B4" volumes with the option to tune them as "B6" volumes for response to 25 Hz. I figured that was as low as I wanted them to go.


I'm not sure what volume/tuning 1audiohack evaluated a pair in. I'm not sure what volume/tuning RobH3606 plans on evaluating the same pair in. I'm not sure what volume/tuning hlaari plans on using. Jerry Moro wanted to know how we all used them and whether or not we liked them. He mentioned that he didn't have a whole lot of experience with system design so he was interested in our feedback.

The 1500AL in the 4.6 cubic foot volume tuned to 28 Hz is a real work of art. The 1501FE won't beat it, but it should be very nice in its own right. Plus it isn't as heavy or expensive, albeit just as impossible to obtain. Rather irritating actually. To this day neither Greg nor Jerry seem to be able to fathom why it is impossible to get these transducers or their recone kits. I've read some of their internal emails and they seem totally perplexed. I suspect Harman simply doesn't want to stock anything and that means not building spares.

[speakerdave]

. . . . I suspect Harman simply doesn't want to stock anything . . .

That may be the $30M idea.

[Odd]

Greg used it in a 4.2 cubic foot volume tuned to 32 Hz and yes, WinISD does yield smaller volumes with less bandwidth.

I do have a pair of enclosures in progress that are something like 3 cubic feet tuned a bit higher for more impact. The AutoCAD drawing is on my laptop which I don't have access to at the moment. All the MDF is already in the garage stacked next to the table saw and, true to form, it's been there for months.

My plan was to build "B4" volumes with the option to tune them as "B6" volumes for response to 25 Hz. I figured that was as low as I wanted them to go.


I'm not sure what volume/tuning 1audiohack evaluated a pair in. I'm not sure what volume/tuning RobH3606 plans on evaluating the same pair in. I'm not sure what volume/tuning hlaari plans on using. Jerry Moro wanted to know how we all used them and whether or not we liked them. He mentioned that he didn't have a whole lot of experience with system design so he was interested in our feedback.

The 1500AL in the 4.6 cubic foot volume tuned to 28 Hz is a real work of art. The 1501FE won't beat it, but it should be very nice in its own right. Plus it isn't as heavy or expensive, albeit just as impossible to obtain. Rather irritating actually. To this day neither Greg nor Jerry seem to be able to fathom why it is impossible to get these transducers or their recone kits. I've read some of their internal emails and they seem totally perplexed. I suspect Harman simply doesn't want to stock anything and that means not building spares.

Lucky you with access to all new products and access to all technical information.
Having said that, I follow with interest all your projects and benefit from all your knowledge.

Thanks for sharing with us who do not have the same opportunity.

[spkrman57]

Greg used it in a 4.2 cubic foot volume tuned to 32 Hz and yes, WinISD does yield smaller volumes with less bandwidth.

I do have a pair of enclosures in progress that are something like 3 cubic feet tuned a bit higher for more impact.
My plan was to build "B4" volumes with the option to tune them as "B6" volumes for response to 25 Hz. I figured that was as low as I wanted them to go.


I'm not sure what volume/tuning 1audiohack evaluated a pair in. I'm not sure what volume/tuning RobH3606 plans on evaluating the same pair in. I'm not sure what volume/tuning hlaari plans on using. Jerry Moro wanted to know how we all used them and whether or not we liked them. He mentioned that he didn't have a whole lot of experience with system design so he was interested in our feedback.

The 1500AL in the 4.6 cubic foot volume tuned to 28 Hz is a real work of art. The 1501FE won't beat it, but it should be very nice in its own right. Plus it isn't as heavy or expensive, albeit just as impossible to obtain. Rather irritating actually. To this day neither Greg nor Jerry seem to be able to fathom why it is impossible to get these transducers or their recone kits. I've read some of their internal emails and they seem totally perplexed. I suspect Harman simply doesn't want to stock anything and that means not building spares.

Sounds like the 1501Fe is a neat driver although hard to get. I would guess that 3 cubit ft would get good results even without a B6 tuning if they were in a smallish room. Ron sends...

[4313B]

Thanks for sharing with us who do not have the same opportunity.

It is a very hard fought opportunity fraught with stress and disappointment. If I had my way, you'd all have access to whatever you needed.

I would guess that 3 cubit ft would get good results even without a B6 tuning if they were in a smallish room.

Well, I'm just playing around. They are a known quantity in the 4.2 cubic foot volume tuned to 32 Hz.

I just opened up my AutoCAD drawing and the enclosure I had come up with is 2.85 cubic feet tuned to 34 Hz. Dropping Fb to 24 Hz and applying a bump filter yields a very usable subwoofer system.

[spkrman57]

Disclaimer: I'm not a professional, but a seasoned rookie! If the "banana-curve" response works well (at least in my feeble mind it does!) due to the decreasing response of the driver, offset by the in-room gain and the interaction of the amplifiers driving them , then would the overall response theoretically be more "real-world" response then the B6 being forced to reproduce down to lower octaves by tuning and EQ in a larger room? I guess what I am asking is if a 2226 has a LF response that rolls off around 60 hz but has usable down to the lower 30's due to room/amp scenarios, I think the 1501Fe could be used in that same room could be tuned lower but without EQ .Oh well, just my musings and hope others chime in with their own opinions. It's a shame the we can't buy JBL raw drivers anymore as I hate to look elsewhere!!! Ron sends...

[4313B]

Group delay is pretty high in the 4.2 cu ft box tuned to 32 Hz

Yes but JBL doesn't care. Case in point, the M2 has nearly double the amount due to all the EQ JBL is using down around Fb. Apparently nobody is picking up on that. There are discussions that such high group delay numbers down that low don't matter.

[pos]

If you are worried about such things you can use rePhase to compensate the phase shifts of the box tuning and/or filters, and the associated group delay will vanish

[spkrman57]

Just curious if you had time to work on the project lately.

Ron sends...

[4313B]

Just curious if you had time to work on the project lately.

Nope. A co-worker had a heart attack this past Monday so I am pulling double duty. He will be out for awhile. I'll keep you posted though.

[spkrman57]

Nope. A co-worker had a heart attack this past Monday so I am pulling double duty. He will be out for awhile. I'll keep you posted though.

Just sweating through the 90 + degree weather here in Ohio as I'm sure you are well aware of also!

Regards, Ron

[spkrman57]

Greg used it in a 4.2 cubic foot volume tuned to 32 Hz and yes, WinISD does yield smaller volumes with less bandwidth.

I do have a pair of enclosures in progress that are something like 3 cubic feet tuned a bit higher for more impact. The AutoCAD drawing is on my laptop which I don't have access to at the moment. All the MDF is already in the garage stacked next to the table saw and, true to form, it's been there for months.

My plan was to build "B4" volumes with the option to tune them as "B6" volumes for response to 25 Hz. I figured that was as low as I wanted them to go.

I have not had the time to measure with WT2 as I have to put my old pc together to use it. This laptop I got last Dec would not work the audio correctly.

As far as actually listening to this tuning I have to admit while it lacks the 2226's percussion reproduction it plays much lower and the cone hardly ever moves with the levels I'm playing them with. I'm using a Soundcraftsman PM-860 Mosfet amp 200wpc and I can only turn up the volume so far before it is unbearable to listen to.

Pipe organ music was a little tame, but I'm comparing to 2242's which is a unfair advantage.

I do like the snappiness of the bass from the 1501. I can't help being happy that these drivers will outlast me most likely as being accordian surround will not need repairs unless abused.

Final note: A larger cabinet will work better for me in the long run, especially if one of my tube amps decides they work well together!!!

Regards, ron

[spkrman57]

After using my 1501Fe in the 3 cu' cab tuned to approx 36 Hz for several months now I'm leaning toward using it more for sub duty than up to the horn. My biggest prob is too much Solid State interjection in my system and I'm a tube (snob) and I hear a difference.

1501Fe is dependent on the right amp also and tubes did not due them justice, but for sub duty with SS amp for LF duty and tubes above sounds more to my liking and want to set that up soon.

Winter time is still raging in Ohio, but hope to re-arrange the room and set up the new system.

Sorry to hijack OP's thread!

Ron