Peerless woofer 8" help

[nicholas_23]

My neighbor wants some low end to run with his 901's (not sure of the series) . I have a peerless 831709 and a 70 watt pe plate amp , wondering what you guys think of running this 8" in a sealed 2.0 cube enclosure? I get a decent 39hz F3, modeling it in WinISD. Worst case , we can port it after, and move it down to a F3 of 30hz. He has an old pioneer VSX-406 FWIW that will supply the source. Room size is roughly 24'X24'

[Wolf]

Re: Peerless woofer 8" help

That was a Peerless driver that Tymphany should not have killed. It had a supreme rep as a 8" sub, but I think it was preferred vented. Paul K could help you with a TL if you were interested I'm sure...He used it twice that way.

Later,
Wolf

[Chris Roemer]

Re: Peerless woofer 8" help

My neighbor wants some low end to run with his 901's (not sure of the series) . I have a peerless 831709 and a 70 watt pe plate amp , wondering what you guys think of running this 8" in a sealed 2.0 cube enclosure? I get a decent 39hz F3, modeling it in WinISD. Worst case , we can port it after, and move it down to a F3 of 30hz. He has an old pioneer VSX-406 FWIW that will supply the source. Room size is roughly 24'X24'

Time to learn WinISD Pro (alpha). Yes, you DO have to enter this driver into the DB to model it (and, yes, it's a bit of a PITA - but with "autocalc" on, just skip Qes and enter: Qms, Qts, Fs, Vas, Re, Le, Xmax, Pe, and use 33 sq.in. for Sd if you don't have a value for it) but you'll know so much more after you're done.

Of course, with an 8 ohm sub, your SA70 will clip at 45w. That's probably not the biggest problem though. That wimpy Xmax (5.5mm was probably pretty dang good for a sub 10 yrs ago, and isn't even bad for WOOFER use today, but for a sub it's light) will bottom out with 45w around 70 Hz or so. You'll breach Xmax at 60Hz with only 37w, 21w @ 50Hz, and only 13w @ 40Hz. Excursion-limited SPL at those freqs (60,50,40) will be 101dB, 98, and only 94dB at 40Hz. I consider a 24'x24' room to be "pretty big", and this sub will NOT suffice for HT duty, but if he keeps it turned down, and just wants to hear whatever's down there below where his 901's quit, it MIGHT do.

As Wolf stated, it really wants a vented box twice that size to go as low as it can (which is REALLY low). But, if this was all you had to work with, and didn't need to reach 30Hz for HT duty, you CAN boost it's output in a 2 cf box in that 40-60Hz range by tuning it to 32 Hz. Then it can take 20w right down to 40Hz, and will have approx. +6dB MORE output in that range.

Chris

[nicholas_23]

Re: Peerless woofer 8" help

Thanks for input Wolf and Chris , I cant go much larger than 2 cubic feet , he has a nice little cubby hole smack dab in the middle of his entertainment center that he wants to slide the enclosure in. He's currently using two old JBL towers for his low end with the 901s sitting on top. His wife wants a litle more room , so out with the JBL towers.

[Paul K.]

Re: Wolf sure has a good memory!

Actually the first time I used the 831709 was a pair in a sealed box along with an old Morel dome midrange and a Morel MDT30 (I think). My older daughter and son-in-law still have that pair of speakers as front L/R for their 5.1 HT system. Then I used a pair in a sealed isobaric enclosure in another 3-way. Then I used it twice more as a single woofer in tapered TLs. I loved that woofer and even though its Xmax might be a little limited, it certainly sounded good and played both low enough and loud enough for my tastes.
The last TL I built with one of these (TriLangles II) had a multi-fold line ~69" long, tapered at 12:1 and in a cabinet with a gross internal volume of ~1.6 cubic feet. F3 modeled at ~ 36 Hz and an F10 of ~25 Hz with a -12 db/octave rolloff below the knee in the curve.
Paul

[Wolf]

Re: Wolf sure has a good memory!

*shux*
FWIW- I liked it better in the original 'Trilangles' than with the 'Tri'-II's'. That was mainly due to the xover frequency being a half-octave higher the second time I'm sure. Yes- I recall the xover points were 1-800 and 2-1200 as well.

Also FWIW- the 831709 is about the only numeric-model # from Peerless I have been able to remember well!
Later,
Wolf

[nicholas_23]

Re: Peerless woofer 8" help

:D Im with you Wolf on the part number recall . Well guys I built the enclosure this afternoon , it was so so sealed so I ported the enclosure and it helped. Cant go nutts with the gain on the amp , she'll bottom out. Not too shabby though considering its an 8" " woofer "

[Paul K.]

Re: Wolf sure has a good memory!

Well, the TL in the 2nd version was much better than in the 1st. I used George Augspurger's Alignment Tables to design the 1st TL which means I didn't actually model them, and while there's nothing wrong with George's work, the TL, in retrospect, ended up a bit short of ideal for this woofer. For the 2nd TriLangle I used Martin's software for the first time and it ended up very, very nice.
Paul

*shux*
FWIW- I liked it better in the original 'Trilangles' than with the 'Tri'-II's'. That was mainly due to the xover frequency being a half-octave higher the second time I'm sure. Yes- I recall the xover points were 1-800 and 2-1200 as well.

Also FWIW- the 831709 is about the only numeric-model # from Peerless I have been able to remember well!
Later,
Wolf

[Paul K.]

Re: Peerless woofer 8" help

Just for kicks I'd like to model a tapered TL that would fit into your box as built and see how it would perform. What are the internal dimensions of your box and do you happen to have T/S values for the woofers as used? If you don't, I can use the ones I used several years ago which were actual measurments.
Paul

:D Im with you Wolf on the part number recall . Well guys I built the enclosure this afternoon , it was so so sealed so I ported the enclosure and it helped. Cant go nutts with the gain on the amp , she'll bottom out. Not too shabby though considering its an 8" " woofer "