stanhoeppner
01-07-2007, 08:40 PM
First a little background to give you an idea about me and my HT listening habits and desires for performance. Please forgive me for the length of this post as it is my first to the forums...
A few years ago I build a 14 ft^3 vented coffin sized and shaped box using 3/4" MDF for the corner of my living room (no wife, obviously) and stood it vertically on end. I used an old Memphis Car Audio (Aria branded) 15" DVC driver. It's specs are a 2.5" Kapton Voice coil former, 88 Oz stacked vented magnet, FS of 17.6 Hz, Xmax 13mm, Re of 8 Ohms (VCs in parallel), PE of 280w RMS, Vas 15.2 ft^3. I tuned this enclosure to approximately 16 Hz using a 4" x 4" Dayton ABS flared port, with the woofer and the port firing into the floor. I purchased the Dayton classic 250w plate amp which would give 180w RMS into the 8 Ohm load of the driver. I was living at the time in an old house. The room was hard wood floored with plaster walls. As this was an 80 year old house with less than perfect structural integrity, the floor itself had an FS of around 20 Hz. The hovercraft sound effects in the Matrix movies literally turned the floor of the living room into an air piston and the entire house vibrated as a result. The base was very sloppy, but with that kind of output it was irrevelent due to the viceral experience of what I could only guess was an in room SPL of at least 130 db at 18-30 Hz. It is the closest to a decent car audio system I've experienced it an HT setup.
As I am the type to costantly experiment with new designs, a year ago I built an 8.4 ft^3 net vented enclosure using 3/4" MDF. For this design I selected 4 of the Dayton SD215 8" DVC drivers which yielded a 4 Ohm nominal impedence using series/parallel wiring. The driver FS is 28Hz. I tuned the enclosure to 23.5Hz using a 6" x 12" round ABS plastic sewer pipe and flaring both ends with a 3/4" roundover bit. The woofers fire into the floor with the port being firing out the front of the box. This box does extremely well down to 18Hz or so before excessive distortion sets in due to reaching the hard mechanical limits of the drivers. The box is rather sloppy below 25Hz with a WinISD group delay in the high 30s at the tuning frequency. I'm powering it (was anyway--read on) with the same Dayton 250w (measured 272w @ 4ohm) plate amp. Although not as emphatic on the very low end as the aforementioned coffin box, this box is very impressive given the 8" driver status. However, due to the low FS (by 8" standards) this is not a surprise, as with 4 units the cone area is slightly larger than a single 15" driver.
I recently purchased the new HPSA1000R (rackmount) amplifier. I've hooked it up temporarily to this box as I've not decided on the next design. It does better than the 250 at certain frequencies, but not much before I reach the mechanical limits of the drivers. I might be getting a db or 2 at frequencies at which the 250 is not able to fully drive the woofers to max excursion.
So, now to the next chapter in my quest for the ultimate HT experience. I'm growing tired of the gargantuan, although admirably performing, boxes that I've built to this point. I'd like to build a very high output smaller box, and should be able to with a single high quality high excursion 15 driver. I now have 1000 watts available to drive my next design, which should be plenty from now til eternity (especially when I am required to deal with WAF at some point in the future).
I'm on the fence between the RS15HO and the Titanic 15". I have a personal connection with the manufacturer of the Titanic and I know the quality of this driver is top notch. I am however intrigued by the RS15HO as it's "published" power handling is slightly more, even though it's xmax is 8mm smaller.
I'd like to hear from anyone who has built either or both. Will I be able to experience any difference between the two with 1000 watts available? Can the RS actually handle 1000 watts given its lack of spider platform venting?
A few years ago I build a 14 ft^3 vented coffin sized and shaped box using 3/4" MDF for the corner of my living room (no wife, obviously) and stood it vertically on end. I used an old Memphis Car Audio (Aria branded) 15" DVC driver. It's specs are a 2.5" Kapton Voice coil former, 88 Oz stacked vented magnet, FS of 17.6 Hz, Xmax 13mm, Re of 8 Ohms (VCs in parallel), PE of 280w RMS, Vas 15.2 ft^3. I tuned this enclosure to approximately 16 Hz using a 4" x 4" Dayton ABS flared port, with the woofer and the port firing into the floor. I purchased the Dayton classic 250w plate amp which would give 180w RMS into the 8 Ohm load of the driver. I was living at the time in an old house. The room was hard wood floored with plaster walls. As this was an 80 year old house with less than perfect structural integrity, the floor itself had an FS of around 20 Hz. The hovercraft sound effects in the Matrix movies literally turned the floor of the living room into an air piston and the entire house vibrated as a result. The base was very sloppy, but with that kind of output it was irrevelent due to the viceral experience of what I could only guess was an in room SPL of at least 130 db at 18-30 Hz. It is the closest to a decent car audio system I've experienced it an HT setup.
As I am the type to costantly experiment with new designs, a year ago I built an 8.4 ft^3 net vented enclosure using 3/4" MDF. For this design I selected 4 of the Dayton SD215 8" DVC drivers which yielded a 4 Ohm nominal impedence using series/parallel wiring. The driver FS is 28Hz. I tuned the enclosure to 23.5Hz using a 6" x 12" round ABS plastic sewer pipe and flaring both ends with a 3/4" roundover bit. The woofers fire into the floor with the port being firing out the front of the box. This box does extremely well down to 18Hz or so before excessive distortion sets in due to reaching the hard mechanical limits of the drivers. The box is rather sloppy below 25Hz with a WinISD group delay in the high 30s at the tuning frequency. I'm powering it (was anyway--read on) with the same Dayton 250w (measured 272w @ 4ohm) plate amp. Although not as emphatic on the very low end as the aforementioned coffin box, this box is very impressive given the 8" driver status. However, due to the low FS (by 8" standards) this is not a surprise, as with 4 units the cone area is slightly larger than a single 15" driver.
I recently purchased the new HPSA1000R (rackmount) amplifier. I've hooked it up temporarily to this box as I've not decided on the next design. It does better than the 250 at certain frequencies, but not much before I reach the mechanical limits of the drivers. I might be getting a db or 2 at frequencies at which the 250 is not able to fully drive the woofers to max excursion.
So, now to the next chapter in my quest for the ultimate HT experience. I'm growing tired of the gargantuan, although admirably performing, boxes that I've built to this point. I'd like to build a very high output smaller box, and should be able to with a single high quality high excursion 15 driver. I now have 1000 watts available to drive my next design, which should be plenty from now til eternity (especially when I am required to deal with WAF at some point in the future).
I'm on the fence between the RS15HO and the Titanic 15". I have a personal connection with the manufacturer of the Titanic and I know the quality of this driver is top notch. I am however intrigued by the RS15HO as it's "published" power handling is slightly more, even though it's xmax is 8mm smaller.
I'd like to hear from anyone who has built either or both. Will I be able to experience any difference between the two with 1000 watts available? Can the RS actually handle 1000 watts given its lack of spider platform venting?