SB acoustics 8" / HiVi RT2C Build thread!!!!!

[6thplanet]

You really should give the planar plan a second thought. If you've never played or heard them before they are worth giving another go. I'd be happy to help in anyway I can.

 

[Assesears]

The goals stay the same, a bookshelf with the SB woofer. Now I just need a replacement for the highs. Either a nice tweeter or I had thought about a ScanSpeak 10F and crossing around 3-400hz.

Hi

About to finish my own pair with SB23 & SS 10F, will start measuring soon hopefully, thought about crossing up higher though. Oh well will see how they turn out

Bruce

 

[mctavish]

Hi

About to finish my own pair with SB23 & SS 10F, will start measuring soon hopefully, thought about crossing up higher though. Oh well will see how they turn out

Bruce

Sounds exciting!!! Keep us posted about the progress!

What are you planning for a crossover? Passive? MiniDSP?

The tweeters I ordered should arrive this coming week....

 

[Bill poster]

At least now you can cross around 2.5khz.

 

[mctavish]

Yup, the peerless list fs at 800hz.....

So plenty of wiggle room🙂

I'll finish the boxes and mount the drivers and then its just a matter of playing with the minidsp until I find the voicing I want!

 

[silverprout]

At least now you can cross around 2.5khz.

A 8" at 2.5Khz... 1,5Khz is more realistic IMHO unless you don't care about lobing.

 

[Bill poster]

A 8" at 2.5Khz... 1,5Khz is more realistic IMHO unless you don't care about lobing.

Beaming or lobing? He's already bought the tweeters and they allegedly dont like being crossed too low despite the fs.
At least now the crossover point isn't 4khz or something..

 

[silverprout]

Beaming or lobing? He's already bought the tweeters and they allegedly dont like being crossed too low despite the fs.
At least now the crossover point isn't 4khz or something..
if it were me I'd use a waveguide.

For a 2K OX the 8" should be at -6dB at 90° and the tweeter will radiate at 180°... not very homogenous.
My seas T25 are ok at 1,4Khz (LR24 active) but i'm agree with you, they don't sound amazing at such frequencies.
But in a WG i'm sure they shoud be a lot better.

 

[zman01]

I have many very pricey good texile dome tweeters, and one pair of "cheap challenge" DIY loudspakers with a Visaton BG16 (15$ 6" fullrange) with a cheap monacor RBT95, i'm blowed by the quality of the treble each time i listen to them.

silverprout,

What is your crossover point and what crossover did you implement for the RBT-95 and BG 16?

Edit: I could not find a BG 16 on the Vsiaton website - did you mean BG 17?

 

[eriksquires]

Doh!!! !

Wait, no, get the BG!! The BG will do 2K, the TG won't!

 

[silverprout]

silverprout,

What is your crossover point and what crossover did you implement for the RBT-95 and BG 16?

Edit: I could not find a BG 16 on the Vsiaton website - did you mean BG 17?

No crossover, just a cap on the RBT (i'm not a big fan of SPL contests)


PS : yes you are right, the BG 17, the wizzler and dust cap removed and added a phase plug.

http://www.visaton.com/en/chassis_zubehoer/breitband/bg17_8.html

 

[zman01]

No crossover, just a cap on the RBT (i'm not a big fan of SPL contests)

Thanks for clarifying - what cap value are you using at the moment?

 

[silverprout]

Thanks for clarifying - what cap value are you using at the moment?

The circuit is a tad complex because it is an array.

 

[wolf_teeth]

Shame bout the HiVi's though, I was really excited to give some isodynamics a try....🙁

Those were not HiVi units. Let's be clear on that.
Later,
Wolf

 

[youknowyou]

The RT2H cannot xover that low. 2.3k is about the limit of those units. 2k they sound stressed.

OP- then you have PT2C instead of RT2C- VERY different units. The FR plot you posted is for the RT2C, and is wrong for the PT2C. The PT2C (I've used them) is only good down to 2.3k (24dB) at the lowest, and 2.1k in multiples, 3k (12dB) for better usage.
This is the FR of the PT2:
https://www.parts-express.com/pedocs/specs/275-085--dayton-audio-pt2c-8-specifications.pdf

It has a peak before lowend rolloff, and a peak before highend rolloff, and a broad dip in the middle.

Later,
Wolf

nah, the rt2h can play down to 1.5 khz.
SWANS RT2H-
"Excellent performance down to 1.5 kHz." says troel

 

[wolf_teeth]

nah, the rt2h can play down to 1.5 khz.
SWANS RT2H-
"Excellent performance down to 1.5 kHz." says troel

It can, but the HD rises below there (in his graph). It sounds better above 2k where the HD is -25dB or lower. The usable FR is down to 1.5k, but I still don't recommend it.

Later,
Wolf

 

[youknowyou]

It can, but the HD rises below there (in his graph). It sounds better above 2k where the HD is -25dB or lower. The usable FR is down to 1.5k, but I still don't recommend it.

Later,
Wolf

yeah
its a pick your poison kind of situation if op wants to use a 8 inch. depends how loud he needs to go with his speakers.

 

[mctavish]

Well, maybe so, but they had HiVi written on them and the box they came in was covered with the words "HiVi Research"........😱

 

[Bill poster]

So.. You have the tweets(on order) . Whats the next step

 

[wolf_teeth]

Well, maybe so, but they had HiVi written on them and the box they came in was covered with the words "HiVi Research"........😱

So there was a HiVi emblem on them? Or was it hand-written?

FWIW, they will fit the same recess in a cabinet, and have a lot of similar parts, but the PT2-C is not made by HiVi.

This means packaging is interchangeable.

Later,
Wolf